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Document and Entity Information Document (USD $)
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12 Months Ended | ||
|---|---|---|---|
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Dec. 31, 2012
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Feb. 01, 2013
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Jun. 30, 2012
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| Document Information [Line Items] | |||
| Entity Registrant Name | ALLETE INC | ||
| Entity Central Index Key | 0000066756 | ||
| Current Fiscal Year End Date | --12-31 | ||
| Entity Well-known Seasoned Issuer | Yes | ||
| Entity Voluntary Filers | No | ||
| Entity Current Reporting Status | Yes | ||
| Entity Filer Category | Large Accelerated Filer | ||
| Entity Public Float | $ 1,591,836,880 | ||
| Entity Common Stock, Shares Outstanding | 39,468,463 | ||
| Document Fiscal Year Focus | 2012 | ||
| Document Fiscal Period Focus | FY | ||
| Document Type | 10-K | ||
| Amendment Flag | false | ||
| Document Period End Date | Dec. 31, 2012 |
| X | ||||||||||
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- Definition
If the value is true, then the document is an amendment to previously-filed/accepted document. No definition available.
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- Definition
End date of current fiscal year in the format --MM-DD. No definition available.
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- Definition
This is focus fiscal period of the document report. For a first quarter 2006 quarterly report, which may also provide financial information from prior periods, the first fiscal quarter should be given as the fiscal period focus. Values: FY, Q1, Q2, Q3, Q4, H1, H2, M9, T1, T2, T3, M8, CY. No definition available.
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- Definition
This is focus fiscal year of the document report in CCYY format. For a 2006 annual report, which may also provide financial information from prior periods, fiscal 2006 should be given as the fiscal year focus. Example: 2006. No definition available.
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- Details
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- Definition
The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented. If there is no historical data in the report, use the filing date. The format of the date is CCYY-MM-DD. No definition available.
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- Definition
The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word "Other". No definition available.
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- Definition
A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Indicate number of shares or other units outstanding of each of registrant's classes of capital or common stock or other ownership interests, if and as stated on cover of related periodic report. Where multiple classes or units exist define each class/interest by adding class of stock items such as Common Class A [Member], Common Class B [Member] or Partnership Interest [Member] onto the Instrument [Domain] of the Entity Listings, Instrument. No definition available.
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- Definition
Indicate "Yes" or "No" whether registrants (1) have filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that registrants were required to file such reports), and (2) have been subject to such filing requirements for the past 90 days. This information should be based on the registrant's current or most recent filing containing the related disclosure. No definition available.
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- Definition
Indicate whether the registrant is one of the following: (1) Large Accelerated Filer, (2) Accelerated Filer, (3) Non-accelerated Filer, (4) Smaller Reporting Company (Non-accelerated) or (5) Smaller Reporting Accelerated Filer. Definitions of these categories are stated in Rule 12b-2 of the Exchange Act. This information should be based on the registrant's current or most recent filing containing the related disclosure. No definition available.
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- Definition
State aggregate market value of voting and non-voting common equity held by non-affiliates computed by reference to price at which the common equity was last sold, or average bid and asked price of such common equity, as of the last business day of registrant's most recently completed second fiscal quarter. The public float should be reported on the cover page of the registrants form 10K. No definition available.
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- Definition
The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Indicate "Yes" or "No" if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. No definition available.
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- Definition
Indicate "Yes" or "No" if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Is used on Form Type: 10-K, 10-Q, 8-K, 20-F, 6-K, 10-K/A, 10-Q/A, 20-F/A, 6-K/A, N-CSR, N-Q, N-1A. No definition available.
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| X | ||||||||||
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- Definition
Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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| X | ||||||||||
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- Definition
Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Represents the caption on the face of the balance sheet to indicate that the entity has entered into (1) purchase or supply arrangements that will require expending a portion of its resources to meet the terms thereof, and (2) is exposed to potential losses or, less frequently, gains, arising from (a) possible claims against a company's resources due to future performance under contract terms, and (b) possible losses or likely gains from uncertainties that will ultimately be resolved when one or more future events that are deemed likely to occur do occur or fail to occur. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of deferred tax liability attributable to taxable temporary differences, net of deferred tax asset attributable to deductible temporary differences and carryforwards net of valuation allowances expected to be realized or consumed after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Carrying value as of the balance sheet date of [accrued] interest payable on all forms of debt, including trade payables, that has been incurred and is unpaid. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Carrying amount (lower of cost or market) as of the balance sheet date of inventories less all valuation and other allowances. Excludes noncurrent inventory balances (expected to remain on hand past one year or one operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Sum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Total of all Liabilities and Stockholders' Equity items (or Partners' Capital, as applicable), including the portion of equity attributable to noncontrolling interests, if any. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Total obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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| X | ||||||||||
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- Definition
Carrying amount of long-term debt, net of unamortized discount or premium, scheduled to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Sum of the carrying values as of the balance sheet date of the portions of long-term notes payable due within one year or the operating cycle if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Aggregate carrying amount, as of the balance sheet date, of noncurrent assets not separately disclosed in the balance sheet. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Aggregate carrying amount of current liabilities (due within one year or within the normal operating cycle if longer) not separately disclosed in the balance sheet. Includes costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered and of liabilities not separately disclosed. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Aggregate carrying amount, as of the balance sheet date, of noncurrent obligations not separately disclosed in the balance sheet. Noncurrent liabilities are expected to be paid after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
This represents the noncurrent liability for underfunded plans recognized in the balance sheet that is associated with the defined benefit pension plans and other postretirement defined benefit plans. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The total of the amounts paid in advance for capitalized costs that will be expensed with the passage of time or the occurrence of a triggering event, and will be charged against earnings within one year or the normal operating cycle, if longer, and the aggregate carrying amount of current assets, as of the balance sheet date, not separately presented elsewhere in the balance sheet. Current assets are expected to be realized or consumed within one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount, net of accumulated depreciation, depletion and amortization, of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The amount for the individual regulatory noncurrent liability as itemized in a table of regulatory noncurrent liabilities as of the end of the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The cumulative amount of the reporting entity's undistributed earnings or deficit. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
Carrying value as of the balance sheet date of obligations incurred and payable for statutory income, sales, use, payroll, excise, real, property and other taxes. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Fair value of unearned shares for all classes of common stock and nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by an employee stock ownership plan (ESOP). Includes the sale of shares or the issuance treasury shares to an ESOP. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Consolidated Balance Sheet Parentheticals (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
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Dec. 31, 2011
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|---|---|---|
| Accounts Receivable [Abstract] | ||
| Accounts Receivable, Allowance | $ 1.0 | $ 0.9 |
| Common Stock [Abstract] | ||
| Common Stock, Par Value | $ 0 | $ 0 |
| Common Stock, Shares Authorized | 80.0 | 80.0 |
| Common Stock, Shares Outstanding | 39.4 | 37.5 |
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- Details
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- Definition
A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Issuance value per share of no-par value common stock; generally not indicative of the fair market value per share. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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| X | ||||||||||
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- Definition
The maximum number of common shares permitted to be issued by an entity's charter and bylaws. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Aggregate dividends declared during the period for each share of common stock outstanding. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Cost of electricity purchased as well as fuel used to generate electricity used in operations and sold during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Details
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| X | ||||||||||
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- Definition
The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The cost of borrowed funds accounted for as interest that was charged against earnings during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of Net Income (Loss) attributable to noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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| X | ||||||||||
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- Definition
The net result for the period of deducting operating expenses from operating revenues. No definition available.
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| X | ||||||||||
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- Definition
The net amount of other income and expense amounts, the components of which are not separately disclosed on the income statement, resulting from ancillary business-related activities (that is, excluding major activities considered part of the normal operations of the business) also known as other nonoperating income (expense) recognized for the period. Such amounts may include: (a) dividends, (b) interest on securities, (c) net gains or losses on securities, (d) unusual costs, (e) gains or losses on foreign exchange transactions, and (f) miscellaneous other income and expense items. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The total amount of operating revenues recognized during the period. No definition available.
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| X | ||||||||||
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- Definition
Discloses the total amount of all operating expenses for the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Discloses the amount of operating expense for the period related to depreciation and amortization. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Discloses the amount of operating expense for the period for routine plant maintenance, repairs and operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Consolidated Statement of Comprehensive Income (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
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Dec. 31, 2012
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Dec. 31, 2011
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Dec. 31, 2010
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|
| Net Income | $ 97.1 | $ 93.6 | $ 74.8 |
| Other Comprehensive Income (Loss) [Abstract] | |||
| Unrealized Gain (Loss) on Securities - Net of Income Taxes of $0.8, $(0.1) and $0.6 | 1.2 | (0.3) | 0.8 |
| Unrealized Loss on Derivatives - Net of Income Taxes of $(0.1), $(0.2) and $- | (0.2) | (0.3) | 0 |
| Defined Benefit Pension and Other Postretirement Benefit Plans - Net of Income Taxes of $3.9, $(3.6), and $- | 5.9 | (5.1) | 0 |
| Total Other Comprehensive Income (Loss) | 6.9 | (5.7) | 0.8 |
| Total Comprehensive Income | 104.0 | 87.9 | 75.6 |
| Less: Non-Controlling Interest in Subsidiaries | 0 | (0.2) | (0.5) |
| Comprehensive Income Attributable to ALLETE | $ 104.0 | $ 88.1 | $ 76.1 |
| X | ||||||||||
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- Definition
The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to noncontrolling interests. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the economic entity, including both controlling (parent) and noncontrolling interests. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, including any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Net of tax amount of other comprehensive income (loss) attributable to both parent entity and noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
Net of tax and reclassifications amount of pension and other postretirement benefit plans (gain) loss included in accumulated other comprehensive income (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Net of tax amount, before reclassification adjustments, of the change in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Also includes an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Net of tax amount of unrealized holding gain (loss) before reclassification adjustments and transfers on available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Consolidated Statement of Comprehensive Income Parentheticals (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
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Dec. 31, 2012
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Dec. 31, 2011
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Dec. 31, 2010
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| Consolidated Statement of Comprehensive Income Parentheticals [Abstract] | |||
| Unrealized Gain (Loss) on Securities, Taxes | $ 0.8 | $ (0.1) | $ 0.6 |
| Unrealized Loss on Derivatives, Taxes | (0.1) | (0.2) | 0 |
| Defined Benefit Pension and Other Postretirement Benefit Plans, Taxes | $ 3.9 | $ (3.6) | $ 0 |
| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
Tax effect, net of reclassification adjustments, of pension and other postretirement benefit plans (gain) loss included in accumulated other comprehensive income (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Tax effect of the change in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Also includes an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Tax effect of unrealized holding gain (loss) before reclassification adjustments and transfers on available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Gain On Real Estate Foreclosure No definition available.
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| X | ||||||||||
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- Definition
Amount of noncash expense included in interest expense to issue debt and obtain financing associated with the related debt instruments. Alternate captions include noncash interest expense. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The charge against earnings resulting from the aggregate write down of all assets from their carrying value to their fair value. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of increase (decrease) in cash and cash equivalents. Cash and cash equivalents are the amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The component of income tax expense for the period representing the increase (decrease) in the entity's deferred tax assets and liabilities pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The amount of plan compensation cost recognized during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The gains (losses) included in results of operations resulting from the sale or disposal of other assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
This element represents the undistributed income (or loss) of equity method investments, net of dividends or other distributions received from unconsolidated subsidiaries, certain corporate joint ventures, and certain noncontrolled corporations; such investments are accounted for under the equity method of accounting. This element excludes distributions that constitute a return of investment, which are classified as investing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The increase (decrease) during the reporting period in the amount due from customers for the credit sale of goods and services; includes accounts receivable and other types of receivables. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The increase (decrease) during the reporting period in the aggregate amount of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The increase (decrease) during the reporting period in the capitalized cost of equity (based on assumed rate of return) and / or borrowed funds (based on interest rate) used to finance construction of regulated assets, which is expected to be recovered through rate adjustments. As a result of this capitalization, net income is increased. This element pertains to certain regulated industries, such as public utilities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The increase (decrease) during the reporting period in the aggregate value of all inventory held by the reporting entity, associated with underlying transactions that are classified as operating activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
The increase (decrease) during the reporting period in other current operating liabilities not separately disclosed in the statement of cash flows. No definition available.
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| X | ||||||||||
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- Definition
The increase (decrease) during the reporting period in other noncurrent operating assets not separately disclosed in the statement of cash flows. No definition available.
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| X | ||||||||||
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- Definition
The increase (decrease) during the reporting period in other noncurrent operating liabilities not separately disclosed in the statement of cash flows. No definition available.
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| X | ||||||||||
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- Definition
The increase (decrease) during the reporting period in the amount due to fund pension and non-pension benefits to employees, retired and disabled former employees. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The increase (decrease) during the reporting period in the value of prepaid expenses and other assets not separately disclosed in the statement of cash flows, for example, deferred expenses, intangible assets, or income taxes. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The net cash inflow or outflow from financing activity for the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
The net cash inflow or outflow from investing activity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
The net cash from (used in) all of the entity's operating activities, including those of discontinued operations, of the reporting entity. Operating activities generally involve producing and delivering goods and providing services. Operating activity cash flows include transactions, adjustments, and changes in value that are not defined as investing or financing activities. While for technical reasons this element has no balance attribute, the default assumption is a debit balance consistent with its label. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
The net cash outflow or inflow from other investing activities. This element is used when there is not a more specific and appropriate element in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Cash outflow in the form of ordinary dividends to common shareholders, generally out of earnings. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The cash outflow to acquire debt and equity securities not classified as either held-to-maturity securities or trading securities which would be classified as available-for-sale securities and reported at fair value, with unrealized gains and losses excluded from earnings and reported in a separate component of shareholders' equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The cash outflow associated with the acquisition of or advances to an entity that is related to it but not strictly controlled (for example, an unconsolidated subsidiary, affiliate, and joint venture or equity method investment) or the acquisition of an additional interest in a subsidiary (controlled entity). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The amount of pension and other (such as medical, dental and life insurance) postretirement benefit costs recognized during the period for (1) defined benefit plans (periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain (loss) on assets, prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments) and for (2) defined contribution plans (to the extent that a plan's defined contributions to an individual's account are to be made for periods in which that individual renders services, the net cost for a period is the contribution called for in that period; if a plan calls for contributions for periods after an individual retires or terminates, the estimated cost is accrued during the employee's service period). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The cash inflow from the additional capital contribution to the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The net cash inflow or outflow from a long-term borrowing supported by a written promise to pay an obligation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The cash inflow from the sale of property, plant and equipment (capital expenditures), software, and other intangible assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of the current period expense charged against operations, the offset which is generally to the allowance for doubtful accounts for the purpose of reducing receivables, including notes receivable, to an amount that approximates their net realizable value (the amount expected to be collected). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the economic entity, including both controlling (parent) and noncontrolling interests. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, including any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
Equity impact of aggregate cash, stock, and paid-in-kind dividends declared for common shareholders during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of Net Income (Loss) attributable to noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
Net of tax and reclassifications amount of pension and other postretirement benefit plans (gain) loss included in accumulated other comprehensive income (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Net of tax amount, before reclassification adjustments, of the change in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Also includes an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Net of tax amount of unrealized holding gain (loss) before reclassification adjustments and transfers on available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Aggregate value of stock issued during the period as a result of employee stock ownership plan (ESOP). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Operations and Significant Accounting Policies
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Dec. 31, 2012
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| Operations and Significant Accounting Policies [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Operations and Significant Accounting Policies [Text Block] | OPERATIONS AND SIGNIFICANT ACCOUNTING POLICIES Financial Statement Preparation. References in this report to “we,” “us,” and “our” are to ALLETE and its subsidiaries, collectively. We prepare our financial statements in conformity with accounting principles generally accepted in the United States of America. These principles require management to make informed judgments, best estimates, and assumptions that affect the reported amounts of assets, liabilities, revenue, and expenses. Actual results could differ from those estimates. Subsequent Events. The Company performed an evaluation of subsequent events for potential recognition and disclosure through the time of the financial statements issuance. Principles of Consolidation. Our consolidated financial statements include the accounts of ALLETE and all of our majority-owned subsidiary companies. All material intercompany balances and transactions have been eliminated in consolidation. Business Segments. Our Regulated Operations and Investments and Other segments were determined in accordance with the guidance on segment reporting. Segmentation is based on the manner in which we operate, assess, and allocate resources to the business. We measure performance of our operations through budgeting and monitoring of contributions to consolidated net income by each business segment. Regulated Operations includes our regulated utilities, Minnesota Power and SWL&P, as well as our investment in ATC, a Wisconsin-based regulated utility that owns and maintains electric transmission assets in parts of Wisconsin, Michigan, Minnesota and Illinois. Minnesota Power provides regulated utility electric service in northeastern Minnesota to approximately 143,000 retail customers. Minnesota Power’s non-affiliated municipal customers consist of 16 municipalities in Minnesota and 1 private utility in Wisconsin. SWL&P is also a private utility in Wisconsin and a customer of Minnesota Power. SWL&P provides regulated electric, natural gas and water service in northwestern Wisconsin to approximately 15,000 electric customers, 12,000 natural gas customers and 10,000 water customers. Our regulated utility operations include retail and wholesale activities under the jurisdiction of state and federal regulatory authorities. Investments and Other is comprised primarily of BNI Coal, our coal mining operations in North Dakota, ALLETE Properties, our Florida real estate investment, and ALLETE Clean Energy, our business aimed at developing or acquiring capital projects that create energy solutions via wind, solar, biomass, hydro, natural gas/liquids, shale resources, clean coal and other clean energy innovations. This segment also includes other business development and corporate expenditures, a small amount of non-rate base generation, approximately 6,100 acres of land in Minnesota, and earnings on cash and investments. BNI Coal, a wholly-owned subsidiary, mines and sells lignite coal to two North Dakota mine-mouth generating units, one of which is Square Butte. In 2012, Square Butte supplied 50 percent (227.5 MW) of its output to Minnesota Power under a long-term contract. (See Note 11. Commitments, Guarantees and Contingencies.) Coal sales are recognized when delivered at the cost of production plus a specified profit per ton of coal delivered. ALLETE Properties represents our Florida real estate investment. Our current strategy for the assets is to complete and maintain key entitlements and infrastructure improvements without requiring significant additional investment, sell the portfolio when opportunities arise and reinvest the proceeds in our growth initiatives. ALLETE does not intend to acquire additional Florida real estate. Full profit recognition is recorded on sales upon closing, provided that cash collections are at least 20 percent of the contract price and the other requirements under the guidance for sales of real estate are met. In certain cases, where there are obligations to perform significant development activities after the date of sale, we recognize profit on a percentage-of-completion basis. From time to time, certain contracts with customers allow us to receive participation revenue from land sales to third parties if various formula-based criteria are achieved. In certain cases, we pay fees or construct improvements to mitigate offsite traffic impacts. In return, we receive traffic impact fee credits as a result of some of these expenditures. We recognize revenue from the sale of traffic impact fee credits when payment is received. NOTE 1. OPERATIONS AND SIGNIFICANT ACCOUNTING POLICIES (Continued) Land inventories are accounted for in accordance with the accounting standards for property, plant and equipment, and are included in Other Investments on our Consolidated Balance Sheet. Real estate costs include the cost of land acquired, subsequent development costs and costs of improvements, capitalized development period interest, real estate taxes and payroll costs of certain employees devoted directly to the development effort. These real estate costs incurred are capitalized to the cost of real estate parcels based upon the relative sales value of parcels within each development project in accordance with the accounting standards for real estate. The cost of real estate sold includes the actual costs incurred and the estimate of future completion costs allocated to the real estate sold based upon the relative sales value method. Whenever events or circumstances indicate that the carrying value of the real estate may not be recoverable, impairments are recorded and the related assets are adjusted to their estimated fair value. (See Note 7. Investments.) ALLETE Clean Energy, a wholly-owned subsidiary of ALLETE, operates independently of Minnesota Power to develop or acquire capital projects aimed at creating energy solutions via wind, solar, biomass, hydro, natural gas/liquids, shale resources, clean coal and other clean energy innovations. ALLETE Clean Energy intends to market to electric utilities, cooperatives, municipalities, independent power marketers and large end-users across North America through long-term contracts or other sale arrangements, and will be subject to applicable state and federal regulatory approvals. Non-Controlling Interest in Subsidiaries. In August 2011, ALLETE purchased the remaining shares of the ALLETE Properties non-controlling interest at book value for $8.8 million by issuing 0.2 million shares of ALLETE common stock. This was accounted for as an equity transaction, and no gain or loss was recognized in net income or comprehensive income. Cash and Cash Equivalents. We consider all investments purchased with original maturities of three months or less to be cash equivalents. Supplemental Statement of Cash Flow Information
Accounts Receivable. Accounts receivable are reported on the balance sheet net of an allowance for doubtful accounts. The allowance is based on our evaluation of the receivable portfolio under current conditions, overall portfolio quality, review of specific problems and such other factors that, in our judgment, deserve recognition in estimating losses.
NOTE 1. OPERATIONS AND SIGNIFICANT ACCOUNTING POLICIES (Continued) Concentration of Credit Risk. Financial instruments that subject us to concentrations of credit risk consist primarily of accounts receivable. Minnesota Power sells electricity to 9 Large Power Customers. Receivables from these customers totaled $11.6 million at December 31, 2012 ($9.3 million at December 31, 2011). Minnesota Power does not obtain collateral to support utility receivables, but monitors the credit standing of major customers. In addition, our taconite-producing Large Power Customers, which are a part of our Regulated Operations segment, are on a weekly billing cycle, which allows us to closely manage collection of amounts due. One of these customers accounted for 12.3 percent of consolidated revenue in 2012 (12.8 percent in 2011; 12.5 percent in 2010). In the third quarter of 2011, one of Minnesota Power’s Large Power Customers, NewPage Corporation (NewPage), filed for Chapter 11 bankruptcy protection. In September 2012, NewPage submitted a motion to the bankruptcy court to approve amended and restated service agreements and payment of the pre-petition amount, which was approved on October 16, 2012. The agreement was subsequently approved by the MPUC in a December 10, 2012 order, which resulted in the pre-petition receivable of $3.2 million being paid as of December 31, 2012. Throughout the bankruptcy proceedings this customer’s operations continued without interruption and we continued to provide electric and steam service to this customer. Long-Term Finance Receivables. Long-term finance receivables relating to our real estate operations are collateralized by property sold, accrue interest at market-based rates and are net of an allowance for doubtful accounts. We assess delinquent finance receivables by comparing the balance of such receivables to the estimated fair value of the collateralized property. If the fair value of the property is less than the finance receivable, we record a reserve for the difference. We estimate fair value based on recent property tax assessed values or current appraisals. (See Note 7. Investments.) Available-for-Sale Securities. Available-for-sale securities are recorded at fair value with unrealized gains and losses included in accumulated other comprehensive income (loss), net of tax. Unrealized losses that are other than temporary are recognized in earnings. We use the specific identification method as the basis for determining the cost of securities sold. Our policy is to review available-for-sale securities for other than temporary impairment on a quarterly basis by assessing such factors as the share price trends and the impact of overall market conditions. (See Note 7. Investments.) Inventories. Inventories are stated at the lower of cost or market. Amounts removed from inventory are recorded on an average cost basis.
Property, Plant and Equipment. Property, plant and equipment are recorded at original cost and are reported on the balance sheet net of accumulated depreciation. Expenditures for additions, significant replacements, improvements and major plant overhauls are capitalized; maintenance and repair costs are expensed as incurred. Gains or losses on non-rate base property, plant and equipment are recognized when they are retired or otherwise disposed. When regulated utility property, plant and equipment are retired or otherwise disposed, no gain or loss is recognized in accordance with the accounting standards for Regulated Operations. Our Regulated Operations capitalize AFUDC, which includes both an interest and equity component. AFUDC represents the cost of both debt and equity funds used to finance utility plant additions during construction periods. AFUDC amounts capitalized are included in rate base and are recovered from customers as the related property is depreciated. The MPUC has approved cost recovery for several large capital projects recently, at which time the recognition of AFUDC ceases. (See Note 3. Property, Plant and Equipment.) We believe that long-standing ratemaking practices approved by applicable state and federal regulatory commissions have allowed for the recovery of the remaining basis of retired plant assets. In January 2013 we announced the retirement of Taconite Harbor Unit 3 and conversion of Laskin Energy Center to natural gas in 2015, which is subject to MPUC approval. Accordingly, we do not expect any loss as a result of the retirement of Taconite Harbor Unit 3 or conversion of Laskin Energy Center. Impairment of Long-Lived Assets. We review our long-lived assets, which include the real estate assets of ALLETE Properties, for indicators of impairment in accordance with the accounting standards for property, plant and equipment on a quarterly basis. NOTE 1. OPERATIONS AND SIGNIFICANT ACCOUNTING POLICIES (Continued) In accordance with the accounting standards for property, plant and equipment, if indicators of impairment exist, we test our real estate assets for recoverability by comparing the carrying amount of the asset to the undiscounted future net cash flows expected to be generated by the asset. Cash flows are assessed at the lowest level of identifiable cash flows, which may be by each land parcel, combining various parcels into bulk sales, or other combinations thereof. Our consideration of possible impairment for our real estate assets requires us to make estimates of future cash flows on an undiscounted basis. The undiscounted future net cash flows are impacted by trends and factors known to us at the time they are calculated and our expectations related to: management’s best estimate of future sales prices; holding period and timing of sales; method of disposition; and future expenditures necessary to develop and maintain the operations, including community development district assessments, property taxes and normal operation and maintenance costs. These estimates and expectations are specific to each land parcel or various bulk sales, and may vary among each land parcel or bulk sale. If the excess of undiscounted cash flows over the carrying value of a property is small, there is a greater risk of future impairment in the event of such changes and any resulting impairment charges could be material. Weak market conditions for real estate in Florida have required us to review our land inventories for impairment. Our undiscounted cash flow analysis was estimated using management’s current intent for disposition of each property, which is an estimated selling period of five to ten years based on a December 2011 asset management and disposition plan (“Plan”). The Plan is reviewed annually for adjustment or modification and we have concluded that the estimates and assumptions remain appropriate in 2012. As such, we continue to utilize the Plan when evaluating our land inventory for impairment. Future selling prices have been estimated through management’s best estimate of future sales prices in collaboration and consultation with outside advisors, and based on the best use of the properties over the expected period of sale. The undiscounted cash flow analysis assumes two scenarios: retail land sales followed by project bulk sales over a five year period and retail land sales over a ten year period. Our analysis assumes the most likely case of retail land sales followed by project bulk sales over a five year period; however, under both scenarios, except as noted below, the undiscounted cash flows exceeded carrying values. If our major development projects are sold in one bulk sale or if the properties are sold differently than anticipated in the Plan, the actual results could be materially different from our undiscounted cash flow analysis. The results of the impairment analysis are particularly dependent on the estimated future sales prices, method of disposition, and holding period for each property. The estimated holding period is based on management’s current intent for the use and disposition of each property, which could be subject to change in future periods if the intentions of the Company as set by management and approved by the Board of Directors were to change. In the event that projected future undiscounted cash flows are not adequate to recover the carrying value of an asset, impairment is indicated and may require a write down to the asset’s fair value. Fair value is determined based on best available evidence including comparable sales, current appraised values, property tax assessed values, and discounted cash flow analysis. If fair value is less than cost, the carrying value of our investments is reduced and an impairment charge is recorded in the current period. In 2012, impairment analysis’ of estimated future undiscounted cash flows were conducted and indicated that the cash flows were adequate to recover the carrying basis of our land inventory. As a result, there was no impairment recorded for the year ended December 31, 2012. For the year ended December 31, 2011, a $1.7 million impairment charge was recorded. Derivatives. ALLETE is exposed to certain risks relating to its business operations that can be managed through the use of derivative instruments. ALLETE may enter into derivative instruments to manage interest rate risk related to certain variable-rate borrowings. Accounting for Stock-Based Compensation. We apply the fair value recognition guidance for share-based payments. Under this guidance, we recognize stock-based compensation expense for all share-based payments granted, net of an estimated forfeiture rate. (See Note 16. Employee Stock and Incentive Plans.)
NOTE 1. OPERATIONS AND SIGNIFICANT ACCOUNTING POLICIES (Continued)
Environmental Liabilities. We review environmental matters for disclosure on a quarterly basis. Accruals for environmental matters are recorded when it is probable that a liability has been incurred and the amount of the liability can be reasonably estimated, based on current law and existing technologies. These accruals are adjusted periodically as assessment and remediation efforts progress or as additional technical or legal information becomes available. Accruals for environmental liabilities are included in the balance sheet at undiscounted amounts and exclude claims for recoveries from insurance or other third parties. Costs related to environmental contamination treatment and cleanup are charged to operating expense unless recoverable in rates from customers. (See Note 11. Commitments, Guarantees and Contingencies.) Revenue Recognition. Regulated utility rates are under the jurisdiction of Minnesota, Wisconsin and federal regulatory authorities. Customers are billed on a cycle basis. Revenue is accrued for service provided but not billed. Regulated utility electric rates include adjustment clauses that: (1) bill or credit customers for fuel and purchased energy costs above or below the base levels in rate schedules; (2) bill retail customers for the recovery of conservation improvement program expenditures not collected in base rates; and (3) bill customers for the recovery of certain transmission and renewable energy expenditures. Fuel and purchased power expense is deferred to match the period in which the revenue for fuel and purchased power expense is collected from customers pursuant to the fuel adjustment clause. BNI recognizes revenue when coal is delivered. Minnesota Power participates in MISO. MISO transactions are accounted for on a net hourly basis in each of the day-ahead and real-time markets. Minnesota Power records net sales in Operating Revenue and net purchases in Fuel and Purchased Power Expense on our Consolidated Statement of Income. The revenues and charges from MISO related to serving retail and municipal electric customers are recorded on a net basis as Fuel and Purchased Power Expense. Unamortized Discount and Premium on Debt. Discount and premium on debt are deferred and amortized over the terms of the related debt instruments using the straight-line method which approximates the effective interest method. Income Taxes. ALLETE and its subsidiaries file a consolidated federal income tax return and combined and separate state income tax returns. We account for income taxes using the liability method in accordance with the accounting standards for income taxes. Under the liability method, deferred income tax assets and liabilities are established for all temporary differences in the book and tax basis of assets and liabilities, based upon enacted tax laws and rates applicable to the periods in which the taxes become payable. Due to the effects of regulation on Minnesota Power and SWL&P, certain adjustments made to deferred income taxes are, in turn, recorded as regulatory assets or liabilities. Federal investment tax credits have been recorded as deferred credits and are being amortized to income tax expense over the service lives of the related property. In accordance with the accounting standards for uncertainty in income taxes, we are required to recognize in our financial statements the largest tax benefit of a tax position that is “more-likely-than-not” to be sustained on audit, based solely on the technical merits of the position as of the reporting date. The term “more-likely-than-not” means more than 50 percent likely. (See Note 14. Income Tax Expense.) NOTE 1. OPERATIONS AND SIGNIFICANT ACCOUNTING POLICIES (Continued) Excise Taxes. We collect excise taxes from our customers levied by government entities. These taxes are stated separately on the billing to the customer and recorded as a liability to be remitted to the government entity. We account for the collection and payment of these taxes on a net basis. New Accounting Standards. There are no recently issued accounting standard updates applicable for our adoption in future periods. |
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The entire disclosure for the general note to the financial statements for the reporting entity which may include, descriptions of the basis of presentation, business description, significant accounting policies, consolidations, reclassifications, new pronouncements not yet adopted and changes in accounting principles. No definition available.
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Business Segments
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Dec. 31, 2012
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| Business Segments [Text Block] | BUSINESS SEGMENTS Regulated Operations includes our regulated utilities, Minnesota Power and SWL&P, as well as our investment in ATC, a Wisconsin-based regulated utility that owns and maintains electric transmission assets in parts of Wisconsin, Michigan, Minnesota and Illinois. Investments and Other is comprised primarily of BNI Coal, our coal mining operations in North Dakota, ALLETE Properties, our Florida real estate investment, and ALLETE Clean Energy, our business aimed at developing or acquiring capital projects that create energy solutions via wind, solar, biomass, hydro, natural gas/liquids, shale resources, clean coal and other clean energy innovations. This segment also includes other business development and corporate expenditures, a small amount of non-rate base generation, approximately 6,100 acres of land in Minnesota, and earnings on cash and investments. For a description of our reportable business segments, see Item 1. Business.
NOTE 2. BUSINESS SEGMENTS (Continued)
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The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Property, Plant and Equipment
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Dec. 31, 2012
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| Property, Plant and Equipment [Text Block] | PROPERTY, PLANT AND EQUIPMENT
Depreciation is computed using the straight-line method over the estimated useful lives of the various classes of assets.
Asset Retirement Obligations. We recognize, at fair value, obligations associated with the retirement of certain tangible, long-lived assets that result from the acquisition, construction or development and/or normal operation of the asset. Asset retirement obligations (ARO) relate primarily to the decommissioning of our coal-fired and wind generating facilities and land reclamation at BNI Coal, and are included in other non-current liabilities on our Consolidated Balance Sheet. The associated retirement costs are capitalized as part of the related long-lived asset and depreciated over the useful life of the asset. Removal costs associated with certain distribution and transmission assets have not been recognized, as these facilities have indeterminate useful lives. Conditional asset retirement obligations have been identified for treated wood poles and remaining polychlorinated biphenyl and asbestos-containing assets; however, removal costs have not been recognized because they are considered immaterial to our consolidated financial statements. Long-standing ratemaking practices approved by applicable state and federal regulatory commissions have allowed provisions for future plant removal costs in depreciation rates. These plant removal cost recoveries are classified either as AROs or as a regulatory liability for non-ARO obligations. To the extent annual accruals for plant removal costs differ from accruals under approved depreciation rates, a regulatory asset has been established in accordance with the guidance for AROs. (See Note 5. Regulatory Matters.)
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The entire disclosure for long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software. This disclosure may include property plant and equipment accounting policies and methodology, a schedule of property, plant and equipment gross, additions, deletions, transfers and other changes, depreciation, depletion and amortization expense, net, accumulated depreciation, depletion and amortization expense and useful lives, income statement disclosures, assets held for sale and public utility disclosures. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| Jointly-Owned Facilities [Text Block] | JOINTLY-OWNED FACILITIES Following are our investments in jointly-owned facilities and the related ownership percentages as of December 31, 2012:
We own 80 percent of the 585 MW Boswell Unit 4. While we operate the plant, certain decisions about the operations of Boswell Unit 4 are subject to the oversight of a committee on which we and WPPI Energy, the owner of the remaining 20 percent of Boswell Unit 4, have equal representation and voting rights. Each of us must provide our own financing and is obligated to pay our ownership share of operating costs. Our share of direct operating expenses of Boswell Unit 4 is included in operating expense on our Consolidated Statement of Income. We are a participant in the CapX2020 initiative to ensure reliable electric transmission and distribution in the region surrounding our rate-regulated operations in Minnesota, along with other electric cooperatives, municipals, and investor-owned utilities. We are currently participating in three CapX2020 projects with varying ownership percentages. |
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Regulatory Matters
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Dec. 31, 2012
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| Regulatory Matters [Text Block] | REGULATORY MATTERS Electric Rates. Entities within our Regulated Operations segment file for periodic rate revisions with the MPUC, the FERC or the PSCW. 2010 Minnesota Rate Case. Minnesota Power’s current retail rates are based on a 2011 MPUC retail rate order, effective June 1, 2011, that allowed for a 10.38 percent return on common equity and a 54.29 percent equity ratio. In February 2011, Minnesota Power appealed the MPUC’s interim rate decision in the Company’s 2010 rate case to the Minnesota Court of Appeals. The Company appealed the MPUC’s finding of exigent circumstances in the interim rate decision with the primary arguments being that the MPUC exceeded its statutory authority, made its decision without the support of a body of record evidence and that the decision violated public policy. The Company desires to resolve whether the MPUC’s finding of exigent circumstances was lawful for application in future rate cases. In December 2011, the Minnesota Court of Appeals concluded that the MPUC did not err in finding exigent circumstances and properly exercised its discretion in setting interim rates. On January 4, 2012, the Company filed a petition for review at the Minnesota Supreme Court (Court). On February 14, 2012, the Court granted the petition for review and oral arguments were held before the Court on October 9, 2012. A decision is expected in early 2013; however, we cannot predict the outcome at this time. FERC-Approved Wholesale Rates. Minnesota Power’s non-affiliated municipal customers consist of 16 municipalities in Minnesota and 1 private utility in Wisconsin. SWL&P, a wholly-owned subsidiary of ALLETE, is also a private utility in Wisconsin and a customer of Minnesota Power. Minnesota Power’s formula-based contract with the City of Nashwauk is effective April 1, 2013 through June 30, 2024, and the restated formula-based contracts with the remaining 15 Minnesota municipal customers and SWL&P are effective through June 30, 2019. The rates included in these contracts are calculated using a cost-based formula methodology that is set each July 1, using estimated costs and a rate of return that is equal to our authorized rate of return for Minnesota retail customers (currently 10.38 percent). The formula-based rate methodology also provides for a yearly true-up calculation for actual costs incurred. The contract terms include a termination clause requiring a three-year notice to terminate. Under the City of Nashwauk contract, no termination notice may be given prior to July 1, 2021. Under the restated contracts, no termination notices may be given prior to June 30, 2016. A two-year cancellation notice is required for the one private non-affiliated utility in Wisconsin, and on December 31, 2011, this customer submitted a cancellation notice with termination effective on December 31, 2013. The 17 MW of average monthly demand provided to this customer is expected to be used to supply energy to prospective customers beginning in 2014. 2012 Wisconsin Rate Case. During 2012, SWL&P’s retail rates were based on a 2010 PSCW retail rate order, which was effective January 1, 2011. SWL&P’s 2013 retail rates are based on a 2012 PSCW retail rate order, effective January 1, 2013, and allows for a 10.9 percent return on common equity. The new rates reflect an average overall increase of 2.4 percent for retail customers (a 13.8 percent increase in water rates, a 1.2 percent increase in electric rates, and a 2.0 percent decrease in natural gas rates). On an annualized basis, the rate increase will generate approximately $1.7 million in additional revenue. NOTE 5. REGULATORY MATTERS (Continued) Rapids Energy Center. On December 19, 2012, Minnesota Power filed with the MPUC for approval to transfer the assets of Rapids Energy Center from non-rate base generation to Minnesota Power’s Regulated Operations. Rapids Energy Center is a generation facility that is located at the UPM, Blandin Paper Mill (Blandin). Minnesota Power and Blandin entered into a new electric service agreement in September 2012 which is also subject to MPUC approval. We expect a decision from the MPUC on these filings in mid-2013. ALLETE Clean Energy. In August 2011, the Company filed with the MPUC for approval of certain affiliated interest agreements between ALLETE and ALLETE Clean Energy. These agreements relate to various relationships between the parties, including the accounting for certain shared services, as well as the transfer of transmission and wind development rights in North Dakota to ALLETE Clean Energy. These transmission and wind development rights are separate and distinct from those needed by Minnesota Power to meet Minnesota’s renewable energy standard requirements. On July 23, 2012, the MPUC issued an order approving certain administrative items related to accounting for shared services and the transfer of meteorological towers, while deferring decisions related to transmission and wind development rights pending the MPUC’s further review of Minnesota Power’s future retail electric service needs. Boswell Mercury Emissions Reduction Plan. Minnesota Power is required to implement a mercury emissions reduction project for Boswell Unit 4 under the Minnesota Mercury Emissions Reduction and the Federal MATS rule. On August 31, 2012, Minnesota Power filed its mercury emissions reduction plan for Boswell Unit 4 with the MPUC and the MPCA. The plan proposes that Minnesota Power install pollution controls by early 2016 to address both the Minnesota mercury emissions reduction requirements and the Federal MATS rule. Costs to implement the Boswell Unit 4 mercury emissions reduction plan are included in the estimated capital expenditures required for compliance with the MATS rule and are estimated to be between $350 million and $400 million. The MPCA has 180 days to comment on the mercury emissions reduction plan, which then is reviewed by the MPUC for a decision. We expect a decision by the MPUC on the plan in the third quarter of 2013. After approval by the MPUC we anticipate filing a petition to include investments and expenditures in customer billing rates. The Patient Protection and Affordable Care Act of 2010 (PPACA). In March 2010, the PPACA was signed into law. One of the provisions changed the tax treatment for retiree prescription drug expenses by eliminating the tax deduction for expenses that are reimbursed under Medicare Part D, beginning January 1, 2013. Based on this provision, we are subject to additional taxes in the future and were required to reverse previously recorded tax benefits which resulted in a non-recurring charge to net income of $4.0 million in 2010. In October 2010, we submitted a filing with the MPUC requesting deferral of the retail portion of the tax charge taken in 2010 resulting from the PPACA. In May 2011, the MPUC approved our request for deferral until the next rate case and as a result we recorded an income tax benefit of $2.9 million and a related regulatory asset of $5.0 million in the second quarter of 2011. Pension. In December 2011, the Company filed a petition with the MPUC requesting a mechanism to recover the cost of capital associated with the prepaid pension asset (or liability) created by the required contributions under the pension plan in excess of (or less than) annual pension expense. The Company further requested a mechanism to defer pension expenses in excess of (or less than) those currently being recovered in base rates. On February 14, 2013, the MPUC denied the Company's petition for recovery of the pension asset and deferral of expenses outside of a general rate case. The MPUC decision does not impact the results of operations for the year ended December 31, 2012. Regulatory Assets and Liabilities. Our regulated utility operations are subject to the accounting guidance for Regulated Operations. We capitalize incurred costs which are probable of recovery in future utility rates as regulatory assets. Regulatory liabilities represent amounts expected to be refunded or credited to customers in rates. No regulatory assets or liabilities are currently earning a return. NOTE 5. REGULATORY MATTERS (Continued)
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- Definition
The entire disclosure for public utilities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Investment in ATC
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Dec. 31, 2012
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| Investment in ATC [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Investment in ATC [Text Block] | INVESTMENT IN ATC Investment in ATC. Our wholly-owned subsidiary, Rainy River Energy, owns approximately 8 percent of ATC, a Wisconsin-based utility that owns and maintains electric transmission assets in parts of Wisconsin, Michigan, Minnesota, and Illinois. ATC rates are FERC-approved and are based on a 12.2 percent return on common equity dedicated to utility plant. We account for our investment in ATC under the equity method of accounting. As of December 31, 2012, our equity investment in ATC was $107.3 million ($98.9 million at December 31, 2011). On January 30, 2013, we invested an additional $0.4 million in ATC. In total, we expect to invest approximately $2.0 million throughout 2013.
NOTE 6. INVESTMENT IN ATC (Continued)
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- Definition
The entire disclosure for equity method investments and joint ventures. Equity method investments are investments that give the investor the ability to exercise significant influence over the operating and financial policies of an investee. Joint ventures are entities owned and operated by a small group of businesses as a separate and specific business or project for the mutual benefit of the members of the group. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Investments
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Dec. 31, 2012
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| Investments [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Investments [Text Block] | INVESTMENTS Investments. At December 31, 2012, our long-term investment portfolio included the real estate assets of ALLETE Properties, debt and equity securities consisting primarily of securities held to fund employee benefits, and other assets consisting primarily of cash equivalents and land in Minnesota.
NOTE 7. INVESTMENTS (Continued)
Land Inventory. Land inventory is accounted for as held for use and is recorded at cost, unless the carrying value is determined not to be recoverable in accordance with the accounting standards for property, plant and equipment, in which case the land inventory is written down to fair value. Land values are reviewed for impairment on a quarterly basis. In 2012, impairment analysis’ of estimated future undiscounted cash flows was conducted and indicated that the cash flows were adequate to recover the carrying basis of our land inventory. Consequently, there was no impairment recorded for the year ended December 31, 2012. For the year ended December 31, 2011, a 1.7 million impairment charge was recorded. Long-Term Finance Receivables. As of December 31, 2012, long-term finance receivables were $1.4 million net of allowance ($2.0 million net of allowance as of December 31, 2011). The decrease is primarily the result of the transfer of properties back to ALLETE Properties by deed-in-lieu of foreclosure, in satisfaction of amounts previously owed under long-term finance receivables. Long-term finance receivables are collateralized by property sold, accrue interest at market-based rates and are net of an allowance for doubtful accounts. As of December 31, 2012, we had allowance for doubtful accounts of $0.6 million ($0.6 million as of December 31, 2011). If a purchaser defaults on a sales contract, the legal remedy is usually limited to terminating the contract and retaining the purchaser’s deposit. The property is then available for resale. Contract purchasers may incur significant costs during due diligence, planning, designing and marketing the property before the contract closes, therefore they may have substantially more at risk than the deposit. Available-for-Sale Investments. We account for our available-for-sale portfolio in accordance with the guidance for certain investments in debt and equity securities. Our available-for-sale securities portfolio consisted of securities established to fund certain employee benefits and auction rate securities. Our auction rate securities of $6.7 million were redeemed at carrying value on January 5, 2011.
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The entire disclosure for investments, including all tables. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Derivatives
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Dec. 31, 2012
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| Derivatives [Abstract] | |
| Derivatives [Text Block] | DERIVATIVES During the third quarter of 2011, we entered into a variable-to-fixed interest rate swap (Swap), designated as a cash flow hedge, in order to manage the interest rate risk associated with a $75.0 million Term Loan. The Term Loan has a variable interest rate equal to the one-month LIBOR plus 1.00 percent, has a maturity of August 25, 2014, and represents approximately 8 percent of the Company’s outstanding long-term debt as of December 31, 2012. (See Note 10. Short-Term and Long-Term Debt.) The Swap agreement has a notional amount equal to the underlying debt principal and matures on August 25, 2014. The Swap agreement involves the receipt of variable rate amounts in exchange for fixed rate interest payments over the life of the agreement without an exchange of the underlying notional amount. The variable rate of the Swap is equal to the one-month LIBOR and the fixed rate is equal to 0.825 percent. Cash flows from the interest rate swap are expected to be highly effective in offsetting the variable interest expense of the debt attributable to fluctuations in the one-month LIBOR interest rate over the life of the Swap. If it is determined that a derivative is not or has ceased to be effective as a hedge, the Company prospectively discontinues hedge accounting with respect to that derivative. The shortcut method is used to assess hedge effectiveness. At inception, all shortcut method requirements were satisfied; thus changes in value of the Swap designated as the hedging instrument will be deemed 100 percent effective. As a result, there was no ineffectiveness recorded for the year ended December 31, 2012. The mark-to-market fluctuation on the cash flow hedge was recorded in accumulated other comprehensive income on the Consolidated Balance Sheet. As of December 31, 2012, the fair value of the swap was a $0.7 million liability (a $0.4 million liability as of December 31, 2011) and is included in other non-current liabilities on the Consolidated Balance Sheet. Cash flows from derivative activities are presented in the same category as the item being hedged on the Consolidated Statement of Cash Flows. Amounts recorded in other comprehensive income related to cash flow hedges will be recognized in earnings when the hedged transactions occur or when it is probable that the hedged transactions will not occur. Gains or losses on interest rate hedging transactions are reflected as a component of interest expense on the Consolidated Statement of Income. |
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The entire disclosure for the entity's entire derivative instruments and hedging activities. Describes an entity's risk management strategies, derivatives in hedging activities and non-hedging derivative instruments, the assets, obligations, liabilities, revenues and expenses arising therefrom, and the amounts of and methodologies and assumptions used in determining the amounts of such items. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Fair Value
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Dec. 31, 2012
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| Fair Value [Text Block] | FAIR VALUE Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). We utilize market data or assumptions that market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, market corroborated, or generally unobservable. We primarily apply the market approach for recurring fair value measurements and endeavor to utilize the best available information. Accordingly, we utilize valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. These inputs, which are used to measure fair value, are prioritized through the fair value hierarchy. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority to unobservable inputs (Level 3 measurement). The three levels of the fair value hierarchy are as follows: Level 1 — Quoted prices are available in active markets for identical assets or liabilities as of the reported date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis. This category includes primarily mutual fund investments held to fund employee benefits. Level 2 — Pricing inputs are other than quoted prices in active markets, but are either directly or indirectly observable as of the reported date. The types of assets and liabilities included in Level 2 are typically either comparable to actively traded securities or contracts, such as treasury securities with pricing interpolated from recent trades of similar securities, or priced with models using highly observable inputs, such as commodity options priced using observable forward prices and volatilities. This category includes deferred compensation, fixed income securities, and derivative instruments consisting of cash flow hedges. Level 3 — Significant inputs that are generally less observable from objective sources. The types of assets and liabilities included in Level 3 are those with inputs requiring significant management judgment or estimation, such as the complex and subjective models and forecasts used to determine the fair value. This category included ARS consisting of guaranteed student loans. The following tables set forth by level within the fair value hierarchy, our assets and liabilities that were accounted for at fair value on a recurring basis as of December 31, 2012 and December 31, 2011. Each asset and liability is classified based on the lowest level of input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement requires judgment, which may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels. The estimated fair value of cash and cash equivalents listed on the Consolidated Balance Sheet approximates the carrying amount and therefore are excluded from the recurring fair value measures in the tables below. NOTE 9. FAIR VALUE (Continued)
There was no activity in Level 3 during the year ended December 31, 2012.
The Company’s policy is to recognize transfers in and transfers out as of the actual date of the event or change in circumstances that caused the transfer. For the years ended December 31, 2012 and 2011, there were no transfers in or out of Levels 1, 2 or 3. NOTE 9. FAIR VALUE (Continued) Fair Value of Financial Instruments. With the exception of the items listed in the table below, the estimated fair value of all financial instruments approximates the carrying amount. The fair value for the items below were based on quoted market prices for the same or similar instruments (Level 2).
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- Definition
The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Dec. 31, 2012
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| Short-Term and Long-Term Debt [Text Block] | SHORT-TERM AND LONG-TERM DEBT Short-Term Debt. Total short-term debt outstanding as of December 31, 2012, was $84.5 million ($6.5 million at December 31, 2011) and consisted of long-term debt due within one year and notes payable. As of December 31, 2012, short-term debt increased from December 31, 2011, primarily due to $60.0 million of long-term debt maturing in April 2013. As of December 31, 2012, we had bank lines of credit aggregating $406.4 million ($256.4 million at December 31, 2011), of which $150.0 million expires in January 2014, and $250.0 million expires in June 2015. These bank lines of credit are available to provide short-term bank loans and liquidity support for ALLETE’s commercial paper program and to issue up to $50.0 million in letters of credit. We had no outstanding draws on our lines of credit as of December 31, 2012 ($1.1 million at December 31, 2011). On February 1, 2012, ALLETE entered into a $150.0 million credit agreement (Agreement) with JPMorgan Chase Bank, N.A., as administrative agent, and several other lenders that are parties thereto. The Agreement is unsecured and has a maturity date of January 31, 2014, which may be extended for one year, subject to bank approvals. Advances under the Agreement may be used for general corporate purposes, to provide liquidity support for ALLETE’s commercial paper program and to issue up to $10.0 million in letters of credit. Long-Term Debt. Total long-term debt outstanding as of December 31, 2012, was $933.6 million ($857.9 million at December 31, 2011). The aggregate amount of long-term debt maturing during 2013 is $84.5 million ($94.8 million in 2014; $17.4 million in 2015; $21.7 million in 2016; $51.2 million in 2017; and $748.5 million thereafter). Substantially all of our electric plant is subject to the lien of the mortgage collateralizing outstanding first mortgage bonds. The mortgages contain non-financial covenants customary in utility mortgages, including restrictions on our ability to incur liens, dispose of assets, and merge with other entities. On July 2, 2012, we issued $160.0 million of the Company’s First Mortgage Bonds (Bonds) in the private placement market in two series as follows:
We have the option to prepay all or a portion of the 3.20 percent Bonds at our discretion at any time prior to January 15, 2026, subject to a make-whole provision, and at any time on or after January 15, 2026, at par, including, in each case, accrued and unpaid interest. We also have the option to prepay all or a portion of the 4.08 percent Bonds at our discretion at any time prior to January 15, 2042, subject to a make-whole provision, and at any time on or after January 15, 2042, at par, including, in each case, accrued and unpaid interest. The Bonds are subject to the additional terms and conditions of our utility mortgage. In July 2012, we used a portion of the proceeds from the sale of the Bonds to redeem $6.0 million of our 6.50 percent Industrial Development Revenue Bonds and to repay $14.0 million in outstanding borrowings on our $150.0 million line of credit. The remaining proceeds were used to fund utility capital expenditures and for general corporate purposes. The Bonds were sold in reliance on an exemption from registration under Section 4(a)(2) of the Securities Act of 1933, as amended, to certain institutional accredited investors. NOTE 10. SHORT-TERM AND LONG-TERM DEBT (Continued)
Financial Covenants. Our long-term debt arrangements contain customary covenants. In addition, our lines of credit and letters of credit supporting certain long-term debt arrangements contain financial covenants. Our compliance with financial covenants is not dependent on debt ratings. The most restrictive covenant requires ALLETE to maintain a ratio of its Indebtedness to Total Capitalization (as the amounts are calculated in accordance with the respective long-term debt arrangements) of less than or equal to 0.65 to 1.00 measured quarterly. As of December 31, 2012, our ratio was approximately 0.46 to 1.00. Failure to meet this covenant would give rise to an event of default if not cured after notice from the lender, in which event ALLETE may need to pursue alternative sources of funding. Some of ALLETE’s debt arrangements contain “cross-default” provisions that would result in an event of default if there is a failure under other financing arrangements to meet payment terms or to observe other covenants that would result in an acceleration of payments due. As of December 31, 2012, ALLETE was in compliance with its financial covenants. |
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The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| Commitments, Guarantees and Contingencies [Text Block] | COMMITMENTS, GUARANTEES AND CONTINGENCIES Power Purchase Agreements. Our long-term PPAs have been evaluated under the accounting guidance for variable interest entities. We have determined that either we have no variable interest in the PPAs, or where we do have variable interests, we are not the primary beneficiary; therefore, consolidation is not required. These conclusions are based on the fact that we do not have both control over activities that are most significant to the entity and an obligation to absorb losses or receive benefits from the entity’s performance. Our financial exposure relating to these PPAs is limited to our capacity and energy payments. NOTE 11. COMMITMENTS, GUARANTEES AND CONTINGENCIES (Continued) Power Purchase Agreements (Continued) Square Butte PPA. Minnesota Power has a PPA with Square Butte that extends through 2026 (Agreement). It provides a long-term supply of energy to customers in our electric service territory and enables Minnesota Power to meet reserve requirements. Square Butte, a North Dakota cooperative corporation, owns a 455 MW coal-fired generating unit (Unit) near Center, North Dakota. The Unit is adjacent to a generating unit owned by Minnkota Power, a North Dakota cooperative corporation whose Class A members are also members of Square Butte. Minnkota Power serves as the operator of the Unit and also purchases power from Square Butte. Minnesota Power is obligated to pay its pro rata share of Square Butte’s costs based on Minnesota Power’s entitlement to Unit output. Our output entitlement under the Agreement is 50 percent for the remainder of the contract, subject to the provisions of the Minnkota Power sales agreement described below. Minnesota Power’s payment obligation will be suspended if Square Butte fails to deliver any power, whether produced or purchased, for a period of one year. Square Butte’s costs consist primarily of debt service, operating and maintenance, depreciation and fuel expenses. As of December 31, 2012, Square Butte had total debt outstanding of $416.9 million. Annual debt service for Square Butte is expected to be approximately $44 million in each of the next five years, 2013 through 2017, of which Minnesota Power’s obligation is 50 percent. Fuel expenses are recoverable through our fuel adjustment clause and include the cost of coal purchased from BNI Coal, under a long-term contract. Minnesota Power’s cost of power purchased from Square Butte during 2012 was $67.1 million ($61.2 million in 2011; $55.2 million in 2010). This reflects Minnesota Power’s pro rata share of total Square Butte costs based on the 50 percent output entitlement. Included in this amount was Minnesota Power’s pro rata share of interest expense of $11.1 million in 2012 ($11.1 million in 2011; $10.2 million in 2010). Minnesota Power’s payments to Square Butte are approved as a purchased power expense for ratemaking purposes by both the MPUC and the FERC. Minnkota Power Sales Agreement. In December 2009, Minnesota Power entered into a power sales agreement with Minnkota Power. Under the power sales agreement, Minnesota Power will sell a portion of its output from Square Butte to Minnkota Power, resulting in Minnkota Power’s net entitlement increasing and Minnesota Power’s net entitlement decreasing until Minnesota Power’s share is eliminated at the end of 2025. No power will be sold under the 2009 agreement until Minnkota Power has placed in service a new AC transmission line, which is anticipated to occur in late 2013. This new AC transmission line will allow Minnkota Power to transmit its entitlement from Square Butte directly to its customers, which in turn will enable Minnesota Power the ability to transmit additional wind generation on the existing DC transmission line. Minnkota Power PPA. On December 12, 2012, Minnesota Power entered into a long-term PPA with Minnkota Power. Under this agreement Minnesota Power will purchase 50 MW of capacity and the energy associated with that capacity over the term June 1, 2016 through May 31, 2020. The agreement includes a fixed capacity charge and energy pricing that escalates at a fixed rate annually over the term. Oliver Wind I and II PPAs. In 2006 and 2007, Minnesota Power entered into two long-term wind PPAs with an affiliate of NextEra Energy, Inc. to purchase the output from Oliver Wind I (50 MW) and Oliver Wind II (48 MW)—wind facilities located near Center, North Dakota. Each agreement is for 25 years and provides for the purchase of all output from the facilities at fixed energy prices. There are no fixed capacity charges and we only pay for energy as it is delivered to us. Manitoba Hydro PPAs. Minnesota Power has a long-term PPA with Manitoba Hydro that expires in April 2015. Under this agreement Minnesota Power is purchasing 50 MW of capacity and the energy associated with that capacity. Both the capacity price and the energy price are adjusted annually by the change in a governmental inflationary index. Minnesota Power has a separate long-term PPA with Manitoba Hydro to purchase surplus energy through April 2022. This energy-only agreement primarily consists of surplus hydro energy on Manitoba Hydro’s system that is delivered to Minnesota Power on a non-firm basis. The pricing is based on forward market prices. Under this agreement, Minnesota Power will purchase at least one million MWh of energy over the contract term. NOTE 11. COMMITMENTS, GUARANTEES AND CONTINGENCIES (Continued) Power Purchase Agreements (Continued) In May 2011, Minnesota Power and Manitoba Hydro signed an additional PPA. The PPA calls for Manitoba Hydro to sell 250 MW of capacity and energy to Minnesota Power for 15 years beginning in 2020 and is subject to construction of additional transmission capacity between Manitoba and the U.S., along with construction of new hydroelectric generating capacity in Manitoba. The capacity price is adjusted annually until 2020 by a change in a governmental inflationary index. The energy price is based on a formula that includes an annual fixed price component adjusted for a change in a governmental inflationary index and a natural gas index, as well as market prices. In February 2012, Minnesota Power and Manitoba Hydro proposed construction of the Great Northern Transmission Line, a 500 kV transmission line between Manitoba and Minnesota’s Iron Range in order to strengthen the electric grid, enhance regional reliability and promote a greater exchange of sustainable energy, which is targeted to be in service in 2020. Total project cost and cost allocations are still to be determined.The Great Northern Transmission Line is subject to various federal and state regulatory approvals. In addition, Manitoba Hydro must obtain regulatory and governmental approvals related to new transmission lines and hydroelectric generation development in Canada. North Dakota Wind Development. Minnesota Power uses the 465-mile, 250 kV DC transmission line that runs from Center, North Dakota, to Duluth, Minnesota to transport increasing amounts of wind energy from North Dakota while gradually phasing out coal-based electricity delivered to our system over this transmission line from Square Butte’s lignite coal-fired generating unit. Our Bison Wind Energy Center in North Dakota consists of 292 MW of nameplate capacity. Bison 1 is an 82 MW wind facility in North Dakota, which was completed in two phases. The first phase was completed in 2010, and the second phase was completed in January 2012. The project also included construction of a 22-mile, 230 kV transmission line. Bison 1 had a total project cost of $174.9 million through December 31, 2012, including additional costs related to land restoration and completion of remaining associated upgrades to the 250 kV DC transmission line. The 105 MW Bison 2 and 105 MW Bison 3 wind facilities in North Dakota were completed in December 2012. Total project costs for Bison 2 and Bison 3 were $148.6 million and $149.8 million, respectively, through December 31, 2012. In September 2011 and November 2011, the MPUC approved Minnesota Power’s petitions seeking cost recovery for investments and expenditures related to Bison 2 and Bison 3, respectively. Current customer billing rates were approved by the MPUC in a November 2011 order and are based on investments and expenditures associated with Bison 1. We anticipate filing a cost recovery petition with the MPUC in the first half of 2013 to update customer billing rates for Bison 1 and to include investments and expenditures associated with Bison 2 and Bison 3. Coal, Rail and Shipping Contracts. We have coal supply agreements providing for the purchase of a significant portion of our coal requirements with expiration dates through 2014. We also have coal transportation agreements in place for the delivery of a significant portion of our coal requirements with expiration dates through 2015. Our minimum annual payment obligation under these supply and transportation agreements is $51.4 million for 2013 and $0.8 million for 2014. Our minimum annual payment obligation will increase when annual nominations are made for coal deliveries in future years. The delivered costs of fuel for Minnesota Power’s generation are recoverable from Minnesota Power’s utility customers through the fuel adjustment clause. Leasing Agreements. BNI Coal is obligated to make lease payments for a dragline totaling $2.8 million annually for the lease term which expires in 2027. BNI Coal has the option at the end of the lease term to renew the lease at fair market value, to purchase the dragline at fair market value, or to surrender the dragline and pay a $3.0 million termination fee. We also lease other properties and equipment under operating lease agreements with terms expiring through 2016. The aggregate amount of minimum lease payments for all operating leases is $11.5 million in 2013, $11.7 million in 2014, $11.4 million in 2015, $9.3 million in 2016, $8.5 million in 2017 and $35.0 million thereafter. Total rent and lease expense was $11.5 million in 2012 ($9.4 million in 2011; $9.4 million in 2010). Transmission. We continue to make investments in Upper Midwest transmission opportunities that strengthen or enhance the regional transmission grid. This includes the CapX2020 initiative, investments in our own transmission assets, investments in other regional transmission assets (individually or in combination with others), and our investment in ATC. NOTE 11. COMMITMENTS, GUARANTEES AND CONTINGENCIES (Continued) Transmission (Continued) Transmission Investments. We have an approved cost recovery rider in place for certain transmission investments and expenditures and the continued use of our 2009 billing factor was approved by the MPUC in May 2011. The billing factor allows us to charge our retail customers on a current basis for the costs of constructing certain transmission facilities plus a return on the capital invested. In June 2011, we filed an updated billing factor that includes additional transmission expenditures, which we expect to be approved in the first quarter of 2013. CapX2020. Minnesota Power is a participant in the CapX2020 initiative which represents an effort to ensure electric transmission and distribution reliability in Minnesota and the surrounding region for the future. CapX2020, which consists of electric cooperatives, municipal and investor-owned utilities, including Minnesota’s largest transmission owners, has assessed the transmission system and projected growth in customer demand for electricity through 2020. Studies show that the region’s transmission system will require major upgrades and expansion to accommodate increased electricity demand as well as support renewable energy expansion through 2020. Minnesota Power is participating in three CapX2020 projects: the Fargo, North Dakota to St. Cloud, Minnesota project, the Monticello, Minnesota to St. Cloud, Minnesota project, which together total a 238-mile, 345 kV line from Fargo, North Dakota to Monticello, Minnesota, and the 70-mile, 230 kV line between Bemidji, Minnesota and Minnesota Power’s Boswell Energy Center near Grand Rapids, Minnesota. The 28-mile 345 kV line between Monticello and St. Cloud was placed into service in December 2011 and the 70-mile 230 kV line between Bemidji, Minnesota and Minnesota Power’s Boswell Energy Center near Grand Rapids, Minnesota was placed into service in September 2012. In June 2011, the MPUC approved the route permit for the Minnesota portion of the Fargo to St. Cloud project. The North Dakota permitting process was completed on August 12, 2012. The entire 238-mile, 345 kV line from Fargo to Monticello is expected to be in service by 2015. Based on projected costs of the three transmission lines and the allocation agreements among participating utilities, Minnesota Power plans to invest between $100 million and $110 million in the CapX2020 initiative through 2015. A total of $48.2 million was spent through December 31, 2012, of which $37.3 million related to the Fargo, North Dakota to Monticello, Minnesota projects and $10.9 million related to the Bemidji, Minnesota to Minnesota Power’s Boswell Energy Center project ($27.8 million as of December 31, 2011 of which $20.4 million related to the Fargo, North Dakota to Monticello, Minnesota projects and $7.4 million related to the Bemidji, Minnesota to Minnesota Power’s Boswell Energy Center project). As future CapX2020 projects are identified, Minnesota Power may elect to participate on a project-by-project basis. Environmental Matters Our businesses are subject to regulation of environmental matters by various federal, state and local authorities. Currently, a number of regulatory changes to the Clean Air Act, the Clean Water Act and various waste management requirements are under consideration by both Congress and the EPA. Minnesota Power’s fossil fuel facilities will likely be subject to regulation under these proposals. Our intention is to reduce our exposure to these requirements by reshaping our generation portfolio over time to reduce our reliance on coal. We consider our businesses to be in substantial compliance with currently applicable environmental regulations and believe all necessary permits to conduct such operations have been obtained. Due to expected future restrictive environmental requirements imposed through legislation and/or rulemaking, we anticipate that potential expenditures for environmental matters will be material and will require significant capital investments. Minnesota Power has evaluated various environmental compliance scenarios using possible ranges of future environmental regulations to project power supply trends and impacts on customers. We review environmental matters on a quarterly basis. Accruals for environmental matters are recorded when it is probable that a liability has been incurred and the amount of the liability can be reasonably estimated, based on current law and existing technologies. Accruals are adjusted as assessment and remediation efforts progress or as additional technical or legal information becomes available. Accruals for environmental liabilities are included in the Consolidated Balance Sheet at undiscounted amounts and exclude claims for recoveries from insurance or other third parties. Costs related to environmental contamination treatment and cleanup are charged to expense unless recoverable in rates from customers. Air. The electric utility industry is heavily regulated both at the federal and state level to address air emissions. Minnesota Power’s generating facilities mainly burn low-sulfur western sub-bituminous coal. All of Minnesota Power’s coal-fired generating facilities are equipped with pollution control equipment such as scrubbers, bag houses and low NOX technologies. Under currently applicable environmental regulations, these facilities are substantially compliant with applicable emission requirements. NOTE 11. COMMITMENTS, GUARANTEES AND CONTINGENCIES (Continued) Environmental Matters (Continued) New Source Review (NSR). In August 2008, Minnesota Power received a Notice of Violation (NOV) from the EPA asserting violations of the NSR requirements of the Clean Air Act at Boswell Units 1, 2, 3 and 4 and Laskin Unit 2. The NOV asserts that seven projects undertaken at these coal-fired plants between the years 1981 and 2000 should have been reviewed under the NSR requirements and that the Boswell Unit 4 Title V permit was violated. In April 2011, Minnesota Power received a NOV alleging that two projects undertaken at Rapids Energy Center in 2004 and 2005 should have been reviewed under the NSR requirements and that the Rapids Energy Center’s Title V permit was violated. Minnesota Power believes the projects specified in the NOVs were in full compliance with the Clean Air Act, NSR requirements and applicable permits. Resolution of the NOVs could result in civil penalties, which we do not believe will be material to our results of operations, and the installation of additional pollution control equipment, some of which is already planned or which has been completed to comply with other regulatory requirements. We are engaged in discussions with the EPA regarding resolution of these matters, but we are unable to estimate the expenditures, or range of expenditures that may be required upon resolution. Any costs of installing additional pollution control equipment would likely be eligible for recovery in rates over time subject to regulatory approval in a rate proceeding. Cross-State Air Pollution Rule (CSAPR). In July 2011, the EPA issued the CSAPR, which replaced the EPA’s 2005 CAIR. However, on August 21, 2012, a three judge panel of the District of Columbia Circuit Court of Appeals vacated the CSAPR, ordering that the CAIR remain in effect while a CSAPR replacement rule is promulgated. The EPA and other parties to the case have until April 24, 2013, to request that the Supreme Court review the matter. The CSAPR would have required states in the CSAPR region, including Minnesota, to significantly improve air quality by reducing power plant emissions that contribute to ozone and/or fine particle pollution in other states. The CSAPR did not directly require the installation of controls. Instead, the rule would have required facilities to have sufficient emission allowances to cover their emissions on an annual basis. These allowances would have been allocated to facilities from each state’s annual budget and would also have been able to be bought and sold. The CAIR regulations similarly require certain states to improve air quality by reducing power plant emissions that contribute to ozone and/or fine particle pollution in other states. The CAIR also created an allowance allocation and trading program rather than specifying pollution controls. Minnesota participation in the CAIR was stayed by EPA administrative action while the EPA completed a review of air quality modeling issues in conjunction with the development of a final replacement rule. While the CAIR remains in effect, Minnesota participation in the CAIR will continue to be stayed. It remains uncertain if emission restrictions similar to those contained in the CSAPR will become effective for Minnesota utilities due to the August 2012 District of Columbia Circuit Court of Appeals decision. Since 2006, we have significantly reduced emissions at our Laskin, Taconite Harbor and Boswell generating units. Based on our expected generation, these emission reductions would have satisfied Minnesota Power’s SO2 and NOX emission compliance obligations with respect to the EPA-allocated CSAPR allowances for 2012. Minnesota Power will continue to track the EPA activity related to promulgation of a CSAPR replacement rule. We are unable to predict any additional compliance costs we might incur if the CSAPR is reinstated or if a CSAPR replacement rule is promulgated. Regional Haze. The federal Regional Haze Rule requires states to submit SIPs to the EPA to address regional haze visibility impairment in 156 federally-protected parks and wilderness areas. Under the first phase of the Regional Haze Rule, certain large stationary sources, put in place between 1962 and 1977, with emissions contributing to visibility impairment, are required to install emission controls, known as Best Available Retrofit Technology (BART). We have two steam units, Boswell Unit 3 and Taconite Harbor Unit 3, that are subject to BART requirements. The MPCA requested that companies with BART-eligible units complete and submit a BART emissions control retrofit study, which was completed for Taconite Harbor Unit 3 in November 2008. The retrofit work completed in 2009 at Boswell Unit 3 meets the BART requirements for that unit. In December 2009, the MPCA approved the Minnesota SIP for submittal to the EPA for its review and approval. The Minnesota SIP incorporates information from the BART emissions control retrofit studies that were completed as requested by the MPCA. NOTE 11. COMMITMENTS, GUARANTEES AND CONTINGENCIES (Continued) Environmental Matters (Continued) In December 2011, the EPA published in the Federal Register a proposal to approve the trading program in the CSAPR as an alternative to determining BART. However, as a result of the August 2012 District of Columbia Circuit Court of Appeals decision to vacate the CSAPR (See CSAPR), Minnesota Power is now evaluating whether significant additional expenditures at Taconite Harbor Unit 3 will be required to comply with BART requirements under the Regional Haze Rule. If additional regional haze related controls are ultimately required, Minnesota Power will have up to five years from the final rule promulgation to bring Taconite Harbor Unit 3 into compliance with the Regional Haze Rule requirements. It is uncertain what controls would ultimately be required at Taconite Harbor Unit 3 under this scenario. On January 30, 2013, Minnesota Power announced “EnergyForward”, a strategic plan for assuring reliability, protecting affordability and further improving environmental performance. The plan includes retiring Taconite Harbor Unit 3 in 2015, subject to MPUC approval. Mercury and Air Toxics Standards (MATS) Rule (formerly known as the Electric Generating Unit Maximum Achievable Control Technology (MACT) Rule). Under Section 112 of the Clean Air Act, the EPA is required to set emission standards for hazardous air pollutants (HAPs) for certain source categories. The EPA published the final MATS rule in the Federal Register on February 16, 2012, addressing such emissions from coal-fired utility units greater than 25 MW. There are currently 187 listed HAPs that the EPA is required to evaluate for establishment of MACT standards. In the final MATS rule, the EPA established categories of HAPs, including mercury, trace metals other than mercury, acid gases, dioxin/furans, and organics other than dioxin/furans. The EPA also established emission limits for the first three categories of HAPs, and work practice standards for the remaining categories. Affected sources must be in compliance with the rule by April 2015. States have the authority to grant sources a one-year extension. Minnesota Power was notified by the MPCA that they have approved Minnesota Power’s request of an additional year extending the date of compliance for the Boswell Unit 4 retrofit to April 1, 2016. Compliance at our Boswell Unit 4 to address the final MATS rule is expected to result in capital expenditures totaling between $350 million and $400 million through 2016. Our “EnergyForward” plan also includes the conversion of Laskin Units 1 and 2 to natural gas addressing the MATS requirements. EPA National Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial, Commercial and Institutional Boilers and Process Heaters. In March 2011, a final rule was published in the Federal Register for industrial boiler maximum achievable control technology (Industrial Boiler MACT). The rule was stayed by the EPA in May 2011, to allow the EPA time to consider additional comments received. The EPA re-proposed the rule in December 2011. On January 9, 2012, the United States District Court for the District of Columbia ruled that the EPA stay of the Industrial Boiler MACT was unlawful, effectively reinstating the March 2011 rule and associated compliance deadlines. A final rule based on the December 2011 proposal, which supersedes the March 2011 rule, was released on December 21, 2012. Major sources have three years to achieve compliance with the final rule. Minnesota Power is in the process of assessing the impact of this rule on our affected units including the Hibbard Renewable Energy Center and Rapids Energy Center. Costs for complying with the final rule cannot be estimated at this time. Minnesota Mercury Emissions Reduction Act. Under the 2006 Minnesota Mercury Emissions Reduction Act, Minnesota Power is required to implement a mercury emissions reduction project for Boswell Unit 4 by December 31, 2018. On August 31, 2012, Minnesota Power filed its mercury emissions reduction plan for Boswell Unit 4 with the MPUC and the MPCA. The plan proposes that Minnesota Power install pollution controls to address both the Minnesota mercury emissions reduction requirements and the MATS rule, which also regulates mercury emissions. Minnesota Power's request of an additional year extending the date of compliance for the Boswell Unit 4 retrofit to April 1, 2016, was approved by the MPCA. Costs to implement the Boswell Unit 4 mercury emissions reduction plan are included in the estimated capital expenditures required for compliance with the MATS rule discussed above. Proposed and Finalized National Ambient Air Quality Standards (NAAQS). The EPA is required to review the NAAQS every five years. If the EPA determines that a state’s air quality is not in compliance with a NAAQS, the state is required to adopt plans describing how it will reduce emissions to attain the NAAQS. These state plans often include more stringent air emission limitations on sources of air pollutants than the NAAQS. Four NAAQS have either recently been revised or are currently proposed for revision, as described below. Ozone NAAQS. The EPA has proposed to more stringently control emissions that result in ground level ozone. In January 2010, the EPA proposed to revise the 2008 eight-hour ozone standard and to adopt a secondary standard for the protection of sensitive vegetation from ozone-related damage. The EPA was scheduled to decide upon the 2008 eight-hour ozone standard in July 2011, but has since announced that it is deferring revision of this standard until 2013. NOTE 11. COMMITMENTS, GUARANTEES AND CONTINGENCIES (Continued) Environmental Matters (Continued) Particulate Matter NAAQS. The EPA finalized the NAAQS Particulate Matter standards in September 2006. Since then, the EPA has established a more stringent 24-hour average fine particulate matter (PM2.5) standard; the annual PM2.5 standard and the 24-hour coarse particulate matter standard have remained unchanged. The United States Court of Appeals for the District of Columbia Circuit remanded the annual PM2.5 standard to the EPA, requiring consideration of lower annual standard values. The EPA proposed new PM2.5 standards on June 14, 2012. On December 14, 2012, the EPA confirmed in a final rule that the current annual PM2.5 standard, which has been in place since 1997, will be lowered, while retaining the current 24-hour PM2.5 standard. To implement the new lower annual PM2.5 standard, the EPA is also revising aspects of relevant monitoring, designations and permitting requirements. New projects and permits must comply with the new lower standard, and compliance with the NAAQS at the facility level is generally demonstrated by modeling. To bridge the transition to the lower standard, the EPA is finalizing a grandfathering provision to ensure that projects and pending permits already underway are not unduly delayed. Under the final rule, states will be responsible for additional PM2.5 monitoring, which will likely be accomplished by relocation or repurposing of existing monitors. States are expected to propose attainment designations by December 2013, based on already available monitoring data. The EPA believes that most U.S. counties currently already meet the new standard and plans to finalize designations of attainment by December 2014. For those counties that the EPA does not designate as having already met the requirements of the new standard, specific dates for required attainment will depend on technology availability, state permitting goals, potential legal challenges and other factors. SO2 and NO2 NAAQS. During 2010, the EPA finalized new one-hour NAAQS for SO2 and NO2. Ambient monitoring data indicates that Minnesota will likely be in compliance with these new standards; however, the one-hour SO2 NAAQS also require the EPA to evaluate modeling data to determine attainment. The EPA has notified states that their SIPs for attainment of the standard will be required to be submitted to the EPA for approval by June 2013 but will not be required to include the evaluation of modeling data until 2017. In late 2011, the MPCA initiated modeling activities that included approximately 65 sources within Minnesota that emit greater than 100 tons of SO2 per year. However, on April 12, 2012, the MPCA notified Minnesota Power that such modeling had been suspended as a result of the EPA’s announcement that the June 2013 SIP submittals would no longer require modeling demonstrations for states, such as Minnesota, where ambient monitors indicate compliance with the new standard. The MPCA is awaiting updated EPA guidance and will communicate with affected sources once the MPCA has more information on how the state will meet the EPA’s SIP requirements. Currently, compliance with these new NAAQS is expected to be required as early as 2017. The costs for complying with the final standards cannot be estimated at this time. Climate Change. The scientific community generally accepts that emissions of GHGs are linked to global climate change. Climate change creates physical and financial risk. Physical risks could include, but are not limited to: increased or decreased precipitation and water levels in lakes and rivers; increased temperatures; and the intensity and frequency of extreme weather events. These all have the potential to affect the Company’s business and operations. We are addressing climate change by taking the following steps that also ensure reliable and environmentally compliant generation resources to meet our customers’ requirements:
EPA Regulation of GHG Emissions. In May 2010, the EPA issued the final Prevention of Significant Deterioration (PSD) and Title V Greenhouse Gas Tailoring Rule (Tailoring Rule). The Tailoring Rule establishes permitting thresholds required to address GHG emissions for new facilities, at existing facilities that undergo major modifications and at other facilities characterized as major sources under the Clean Air Act’s Title V program. For our existing facilities, the rule does not require amending our existing Title V operating permits to include GHG requirements. However, GHG requirements are likely to be added to our existing Title V operating permits by the MPCA as these permits are renewed or amended. NOTE 11. COMMITMENTS, GUARANTEES AND CONTINGENCIES (Continued) Environmental Matters (Continued) In late 2010, the EPA issued guidance to permitting authorities and affected sources to facilitate incorporation of the Tailoring Rule permitting requirements into the Title V and PSD permitting programs. The guidance stated that the project-specific, top-down BACT determination process used for other pollutants will also be used to determine BACT for GHG emissions. Through sector-specific white papers, the EPA also provided examples and technical summaries of GHG emission control technologies and techniques the EPA considers available or likely to be available to sources. It is possible that these control technologies could be determined to be BACT on a project-by-project basis. On March 28, 2012, the EPA announced its proposed rule to apply CO2 emission New Source Performance Standards (NSPS) to new fossil fuel-fired electric generating units. The proposed NSPS apply only to new or re-powered units and were open for public comment through June 25, 2012. It is anticipated that the EPA will issue NSPS for existing fossil fuel-fired generating units in the future. We cannot predict what CO2 control measures, if any, may be required by such NSPS. Legal challenges have been filed with respect to the EPA’s regulation of GHG emissions, including the Tailoring Rule. On June 26, 2012, the United States District Court for the District of Columbia upheld most of the EPA’s proposed regulations, including the Tailoring Rule criteria, finding that the Clean Air Act compels the EPA to regulate in the manner the EPA proposed. Comments to the permitting guidance were submitted by Minnesota Power and others and may be addressed by the EPA in the form of revised guidance documents. We are unable to predict the GHG emission compliance costs we might incur; however, the costs could be material. We would seek recovery of any additional costs through cost recovery riders or in a general rate case. Water. The Clean Water Act requires NPDES permits be obtained from the EPA (or, when delegated, from individual state pollution control agencies) for any wastewater discharged into navigable waters. We have obtained all necessary NPDES permits, including NPDES storm water permits for applicable facilities, to conduct our operations. Clean Water Act - Aquatic Organisms. In April 2011, the EPA published in the Federal Register proposed regulations under Section 316(b) of the Clean Water Act that set standards applicable to cooling water intake structures for the protection of aquatic organisms. The proposed regulations would require existing large power plants and manufacturing facilities that withdraw greater than 25 percent of water from adjacent water bodies for cooling purposes and have a design intake flow of greater than 2 million gallons per day to limit the number of aquatic organisms that are killed when they are pinned against the facility’s intake structure or that are drawn into the facility’s cooling system. The Section 316(b) standards would be implemented through NPDES permits issued to the covered facilities. The Section 316(b) proposed rule comment period ended in August 2011 and the EPA is obligated to finalize the rule by June 27, 2013. We are unable to predict the compliance costs we might incur under the final rule; however, the costs could be material. We would seek recovery of any additional costs through cost recovery riders or in a general rate case. Steam Electric Power Generating Effluent Guidelines. In late 2009, the EPA announced that it will be reviewing and reissuing the federal effluent guidelines for steam electric stations. These are the underlying federal water discharge rules that apply to all steam electric stations. It is expected that the EPA will publish the proposed new rule in April 2013 and a final rule in 2014. As part of the review phase for this new rule, the EPA issued an Information Collection Request (ICR) in June 2010, to most thermal electric generating stations in the country, including all five of Minnesota Power’s generating stations. The ICR was completed and submitted to the EPA in September 2010, for Boswell, Laskin, Taconite Harbor, Hibbard and Rapids Energy Center. The ICR was designed to gather extensive information on the nature and extent of all water discharge and related wastewater handling at power plants. The information gathered through the ICR will form a basis for development of the eventual new rule, which could include more restrictive requirements on wastewater discharge, flue gas desulfurization, and wet ash handling operations. We are unable to predict the costs we might incur to comply with potential future water discharge regulations at this time. Solid and Hazardous Waste. The Resource Conservation and Recovery Act of 1976 regulates the management and disposal of solid and hazardous wastes. We are required to notify the EPA of hazardous waste activity and, consequently, routinely submit the necessary reports to the EPA. NOTE 11. COMMITMENTS, GUARANTEES AND CONTINGENCIES (Continued) Environmental Matters (Continued) Coal Ash Management Facilities. Minnesota Power generates coal ash at all five of its coal-fired electric generating facilities. Two facilities store ash in onsite impoundments (ash ponds) with engineered liners and containment dikes. Another facility stores dry ash in a landfill with an engineered liner and leachate collection system. Two facilities generate a combined wood and coal ash that is either land applied as an approved beneficial use or trucked to state permitted landfills. In June 2010, the EPA proposed regulations for coal combustion residuals generated by the electric utility sector. The proposal sought comments on three general regulatory schemes for coal ash. Comments on the proposed rule were due in November 2010. It is estimated that the final rule will be published in 2013. We are unable to predict the compliance costs we might incur; however, the costs could be material. We would seek recovery of any additional costs through cost recovery riders or in a general rate case. Other Matters BNI Coal. As of December 31, 2012, BNI Coal had surety bonds outstanding of $29.8 million related to the reclamation liability for closing costs associated with its mine and mine facilities. Although the coal supply agreements obligate the customers to provide for the closing costs, additional assurance is required by federal and state regulations. In addition to the surety bonds, BNI Coal has secured a letter of credit with CoBANK ACB for an additional $2.6 million to provide for BNI Coal’s total reclamation liability, which is currently estimated at $32.4 million. BNI Coal does not believe it is likely that any of these outstanding surety bonds or the letter of credit will be drawn upon. ALLETE Properties. As of December 31, 2012, ALLETE Properties, through its subsidiaries, had surety bonds outstanding and letters of credit to governmental entities totaling $10.2 million primarily related to development and maintenance obligations for various projects. The estimated cost of the remaining development work is approximately $7.4 million, of which $0.6 million is the contractual obligation of land purchasers. ALLETE Properties does not believe it is likely that any of these outstanding surety bonds or letters of credit will be drawn upon. Community Development District Obligations. In March 2005, the Town Center District issued $26.4 million of tax-exempt, 6 percent capital improvement revenue bonds and in May 2006, the Palm Coast Park District issued $31.8 million of tax-exempt, 5.7 percent special assessment bonds. The capital improvement revenue bonds and the special assessment bonds are payable over 31 years (by May 1, 2036 and 2037, respectively) and secured by special assessments on the benefited land. The bond proceeds were used to pay for the construction of a portion of the major infrastructure improvements in each district and to mitigate traffic and environmental impacts. The assessments were billed to the landowners beginning in November 2006 for Town Center and November 2007 for Palm Coast Park. To the extent that we still own land at the time of the assessment, we will incur the cost of our portion of these assessments, based upon our ownership of benefited property. At December 31, 2012, we owned 73 percent of the assessable land in the Town Center District (73 percent at December 31, 2011) and 93 percent of the assessable land in the Palm Coast Park District (93 percent at December 31, 2011). At these ownership levels, our annual assessments are approximately $1.4 million for Town Center and $2.1 million for Palm Coast Park. As we sell property, the obligation to pay special assessments will pass to the new landowners. In accordance with accounting guidance, these bonds are not reflected as debt on our Consolidated Balance Sheet. Legal Proceedings. In January 2011, the Company was named as a defendant in a lawsuit in the Sixth Judicial District for the State of Minnesota by one of our customer’s (United Taconite, LLC) property and business interruption insurers. In October 2006, United Taconite experienced a fire as a result of the failure of certain electrical protective equipment. The equipment at issue in the incident was not owned, designed, or installed by Minnesota Power, but Minnesota Power had provided testing and calibration services related to the equipment. The lawsuit alleges approximately $20.0 million in damages related to the fire. The Company believes that it has strong defenses to the lawsuit and intends to vigorously assert such defenses. An accrual related to any damages that may result from the lawsuit has not been recorded as of December 31, 2012, because a potential loss is not currently probable or reasonably estimable; however, the Company believes it has adequate insurance coverage for any potential loss. Other. We are involved in litigation arising in the normal course of business. Also in the normal course of business, we are involved in tax, regulatory and other governmental audits, inspections, investigations and other proceedings that involve state and federal taxes, safety, and compliance with regulations, rate base and cost of service issues, among other things. While the resolution of such matters could have a material effect on earnings and cash flows in the year of resolution, none of these matters are expected to materially change our present liquidity position, or have a material adverse effect on our financial condition. |
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| Common Stock and Earnings Per Share [Text Block] | COMMON STOCK AND EARNINGS PER SHARE
Equity Issuance Program. We entered into a distribution agreement with KCCI, Inc., in February 2008, as amended most recently on August 3, 2012, with respect to the issuance and sale of up to an aggregate of 9.6 million shares of our common stock, without par value, of which 4.5 million remain available for issuance. For the year ended December 31, 2012, 1.3 million shares of common stock were issued under this agreement resulting in net proceeds of $53.1 million. During 2011, 0.4 million shares of common stock were issued for net proceeds of $16.0 million. The shares issued in 2012 and 2011 were, and the remaining shares may be, offered for sale, from time to time, in accordance with the terms of the amended distribution agreement pursuant to Registration Statement No. 333-170289. Earnings Per Share. The difference between basic and diluted earnings per share, if any, arises from outstanding stock options, non-vested restricted stock, and performance share awards granted under our Executive and Director Long-Term Incentive Compensation Plans. In 2012, in accordance with accounting standards for earnings per share, 0.2 million options to purchase shares of common stock were excluded from the computation of diluted earnings per share because the option exercise prices were greater than the average market prices; therefore, their effect would have been anti-dilutive (0.3 million shares were excluded in 2011 and 0.5 million in 2010). Purchase of Non-Controlling Interest. In 2011, the remaining shares of the ALLETE Properties non-controlling interest were purchased at book value for $8.8 million by issuing 0.2 million unregistered shares of ALLETE common stock. This was accounted for as an equity transaction, and no gain or loss is recognized in net income or comprehensive income. Contributions to Pension. In 2011, ALLETE contributed approximately 0.5 million shares of ALLETE common stock to its pension plan. These shares of ALLETE common stock were contributed in reliance upon an exemption available pursuant to Section 4(a)(2) of the Securities Act of 1933 and had an aggregate value of $20.0 million when contributed. NOTE 12. COMMON STOCK AND EARNINGS PER SHARE (Continued)
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The entire disclosure for earnings per share. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| Other Income (Expense) [Text Block] | OTHER INCOME (EXPENSE)
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The entire disclosure for other income or other expense items (both operating and nonoperating). Sources of nonoperating income or nonoperating expense that may be disclosed, include amounts earned from dividends, interest on securities, profits (losses) on securities, net and miscellaneous other income or income deductions. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| Income Tax Expense [Text Block] | INCOME TAX EXPENSE
NOTE 14. INCOME TAX EXPENSE (Continued) The effective tax rate on income was 28.1 percent for 2012 (27.6 percent for 2011; 37.2 percent for 2010). The 2012 effective rate was primarily impacted by renewable tax credits and by the deduction for AFUDC-Equity (included in Regulatory Differences for Utility Plant, above). The 2011 effective tax rate was primarily impacted by the deduction for AFUDC-Equity, the reversal of a deferred tax liability related to a revenue receivable that Minnesota Power agreed to forgo as part of a stipulation and settlement agreement in its 2010 rate case, renewable tax credits, and the MPUC’s approval of our request to defer the retail portion of the tax charge taken in 2010 as a result of the PPACA. The 2010 effective tax rate was primarily impacted by the PPACA eliminating the tax deduction for expenses that are reimbursed under Medicare Part D, the deduction for AFUDC-Equity, and renewable tax credits.
NOTE 14. INCOME TAX EXPENSE (Continued) In 2012, we generated federal and various state NOLs and tax credit carryforwards primarily due to the bonus depreciation provisions of the Tax Relief, Unemployment Insurance Reauthorization, and Job Creation Act of 2010. The 2012 federal NOL will be utilized by carrying it forward to offset future years’ income. The federal NOL and tax credit carryforward periods expire between 2019 and 2032; included in the federal NOL carryforward are charitable contribution carryforwards which expire between 2014 and 2016. We expect to fully utilize the federal NOL, charitable contributions, and federal tax credit carryforwards; therefore no valuation allowance has been recognized as of December 31, 2012. The state NOLs and tax credits will be carried forward to future tax years. We have established a valuation allowance against certain state NOL and tax credits that we do not expect to utilize before their expiration. The state NOL and tax credit carryforward periods expire between 2024 and 2032; included in the state NOL carryforwards are charitable contribution carryforwards which expire between 2014 and 2016.
Unrecognized tax benefits are the differences between a tax position taken or expected to be taken in a tax return and the benefit recognized and measured pursuant to the “more-likely-than-not” criteria. The unrecognized tax benefit balance includes permanent tax positions, which if recognized would affect the annual effective tax rate. In addition, the unrecognized tax benefit balance includes temporary tax positions for which the ultimate deductibility is highly certain but for which there is uncertainty about the timing of such deductibility. A change in the period of deductibility would not affect the effective tax rate but would accelerate the payment of cash to the taxing authority to an earlier period. The gross unrecognized tax benefits as of December 31, 2012, includes $0.5 million of net unrecognized tax benefits that, if recognized, would affect the annual effective income tax rate. The decrease in the unrecognized tax benefit balance of $8.7 million in 2012 was due to the removal of our uncertain tax position for our tax accounting method change for deductible repairs. During 2012, the IRS issued a directive from its Large Business and International Division to its local examination teams that led to the removal of the repairs uncertain tax position in 2012. As of December 31, 2012, we had $0.5 million ($1.1 million for 2011 and $0.7 million for 2010) of accrued interest related to unrecognized tax benefits included in our Consolidated Balance Sheet. We classify interest related to unrecognized tax benefits as interest expense and tax-related penalties in operating expenses in our Consolidated Statement of Income. In 2012, we recognized a $0.6 million decrease in interest expense (interest expense of $0.4 million for 2011 and a reduction of interest expense of $0.2 million for 2010). There were no penalties recognized in 2012, 2011 or 2010. ALLETE and its subsidiaries file a consolidated federal income tax return as well as combined and separate state income tax returns in various jurisdictions. ALLETE is currently under examination by the IRS for the tax years 2005 through 2009. ALLETE is no longer subject to federal or state examination for years before 2005. During the next 12 months it is reasonably possible the amount of unrecognized tax benefits could be reduced by $2.5 million due to statute expirations and anticipated audit settlements. This amount is primarily due to temporary tax positions. |
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The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| Pension and Other Postretirement Benefit Plans [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Pension and Other Postretirement Benefit Plans [Text Block] | PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS We have noncontributory union and non-union defined benefit pension plans covering eligible employees. The plans provide defined benefits based on years of service and final average pay. In 2012, we made total contributions of $7.3 million ($33.8 million in 2011, of which $20.0 million was contributed in shares of ALLETE common stock). We also have a defined contribution pension plan covering substantially all employees. The 2012 plan year employer contributions, which are made through the employee stock ownership plan portion of the RSOP, totaled $7.7 million ($7.3 million for the 2011 plan year.) (See Note 12. Common Stock and Earnings Per Share and Note 16. Employee Stock and Incentive Plans). In 2006, the non-union defined benefit pension plan was amended to suspend further crediting of service to the plan and to close the plan to new participants. In conjunction with those amendments, contributions were increased to the RSOP. In 2010, the Minnesota Power union defined benefit pension plan was amended to close the plan to new participants beginning February 1, 2011. We have postretirement health care and life insurance plans covering eligible employees. In 2010, our postretirement health plan was amended to close the plan to employees hired after January 31, 2011. The full eligibility requirement was also amended in 2010, to age 55 with 10 years of participation in the plan. The postretirement health plans are contributory with participant contributions adjusted annually. Postretirement health and life benefits are funded through a combination of Voluntary Employee Benefit Association trusts (VEBAs), established under section 501(c)(9) of the Internal Revenue Code, and an irrevocable grantor trust. In 2012, $1.5 million was contributed to the VEBAs. In 2011, we contributed $10.9 million to the VEBAs. There were no contributions made to the grantor trust in 2012 and 2011. Management considers various factors when making funding decisions such as regulatory requirements, actuarially determined minimum contribution requirements, and contributions required to avoid benefit restrictions for the pension plans. Contributions are based on estimates and assumptions which are subject to change. We do not expect to make any contributions to the defined benefit pension plan in 2013. In January 2013, we contributed $4.8 million to the defined benefit postretirement health and life plan, of which $2.0 million was contributed to an irrevocable grantor trust and $2.8 million was contributed to the VEBAs. We do not expect to make any additional contributions to the defined benefit postretirement health and life plan in 2013. Accounting for defined benefit pension and postretirement benefit plans requires that employers recognize on a prospective basis the funded status of their defined benefit pension and other postretirement plans on their Consolidated Balance Sheet and recognize as a component of other comprehensive income, net of tax, the gains or losses and prior service costs or credits that arise during the period but are not recognized as components of net periodic benefit cost. The defined benefit pension and postretirement health and life benefit costs recognized annually by our regulated companies are expected to be recovered through rates filed with our regulatory jurisdictions. As a result, these amounts that are required to otherwise be recognized in accumulated other comprehensive income have been recognized as a long-term regulatory asset on our Consolidated Balance Sheet, in accordance with the accounting standards for Regulated Operations. The defined benefit pension and postretirement health and life benefit costs associated with our other non-rate base operations are recognized in accumulated other comprehensive income. NOTE 15. PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Continued)
The pension costs that are reported as a component within our Consolidated Balance Sheet, reflected in long-term regulatory assets and accumulated other comprehensive income, consist of the following:
NOTE 15. PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Continued)
According to the accounting standards for retirement benefits, only assets in the VEBAs are treated as plan assets in the above table for the purpose of determining funded status. In addition to the postretirement health and life assets reported in the previous table, we had $22.1 million in irrevocable grantor trusts included in Other Investments on our Consolidated Balance Sheet at December 31, 2012 ($20.3 million at December 31, 2011). NOTE 15. PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Continued) The postretirement health and life costs that are reported as a component within our Consolidated Balance Sheet, reflected in regulatory long-term assets and accumulated other comprehensive income, consist of the following:
NOTE 15. PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Continued) The pension and postretirement health and life costs recorded in regulatory long-term assets and accumulated other comprehensive income expected to be recognized as a component of net pension and postretirement benefit costs for the year ending December 31, 2013, are as follows:
In establishing the expected long-term rate of return on plan assets, we determine the long-term historical performance of each asset class, adjust these for current economic conditions, and utilizing the target allocation of our plan assets, forecast the expected long-term rate of return. The discount rate is computed using a yield curve adjusted for ALLETE’s projected cash flows to match our plan characteristics. The yield curve is determined using high-quality long-term corporate bond rates at the valuation date. We believe the adjusted discount curve used in this comparison does not materially differ in duration and cash flows from our pension obligation.
NOTE 15. PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Continued)
There were no shares of ALLETE common stock included in pension plan equity securities at December 31, 2012 ($20.0 million, approximately 0.5 million shares, in 2011). To achieve strong returns within managed risk, we diversify our asset portfolio to approximate the target allocations in the table below. Equity securities are diversified among domestic companies with large, mid and small market capitalizations, as well as investments in international companies. The majority of debt securities are made up of investment grade bonds.
Fair Value Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). We utilize market data or assumptions that market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, market corroborated, or generally unobservable. We primarily apply the market approach for recurring fair value measurements and endeavor to utilize the best available information. Accordingly, we utilize valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. These inputs, which are used to measure fair value, are prioritized through the fair value hierarchy. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority to unobservable inputs (Level 3 measurement). The three levels of the fair value hierarchy are as follows: Level 1 — Quoted prices are available in active markets for identical assets or liabilities as of the reported date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis. This category includes various U.S. equity securities, public mutual funds, and futures. These instruments are valued using the closing price from the applicable exchange or whose value is quoted and readily traded daily. Level 2 — Pricing inputs are other than quoted prices in active markets, but are either directly or indirectly observable as of the reported date. The types of assets and liabilities included in Level 2 are typically either comparable to actively traded securities or contracts, such as treasury securities with pricing interpolated from recent trades of similar securities, or priced with models using highly observable inputs. This category includes various bonds and non-public funds whose underlying investments may be level 1 or level 2 securities. NOTE 15. PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Continued) Fair Value (Continued) Level 3 — Significant inputs that are generally less observable from objective sources. The types of assets and liabilities included in Level 3 are those with inputs requiring significant management judgment or estimation, such as the complex and subjective models and forecasts used to determine the fair value. This category includes private equity funds and real estate valued through external appraisal processes. Valuation methodologies incorporate pricing models, discounted cash flow models, and similar techniques which utilize capitalization rates, discount rates, cash flows and other factors. Pension Fair Value
NOTE 15. PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Continued) Fair Value (Continued)
NOTE 15. PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Continued) Fair Value (Continued) Postretirement Health and Life Fair Value
NOTE 15. PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Continued) Fair Value (Continued)
Accounting and disclosure requirements for the Medicare Prescription Drug, Improvement and Modernization Act of 2003 (Act) provide guidance for employers that sponsor postretirement health care plans that provide prescription drug benefits. We provide a fully insured postretirement health benefit, including a prescription drug benefit, which qualifies us for a federal subsidy under the Act. The federal subsidy is reflected in the premiums charged to us by the insurance company. |
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The entire disclosure for pension and other postretirement benefits. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Employee Stock and Incentive Plans
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| Employee Stock and Incentive Plans [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Employee Stock and Incentive Plans [Text Block] | EMPLOYEE STOCK AND INCENTIVE PLANS Employee Stock Ownership Plan. We sponsor a leveraged ESOP within the RSOP. Eligible employees may contribute to the RSOP plan as of their date of hire. In 1990, the ESOP issued a $75.0 million note (term not to exceed 25 years at 10.25 percent) to use as consideration for 2.8 million shares (1.9 million shares adjusted for stock splits) of our newly issued common stock. The note was refinanced in 2006 at 6 percent. We make annual contributions to the ESOP equal to the ESOP’s debt service less available dividends received by the ESOP. The majority of dividends received by the ESOP are used to pay debt service, with the balance distributed to participants. The ESOP shares were initially pledged as collateral for the debt. As the debt is repaid, shares are released from collateral and allocated to participants based on the proportion of debt service paid in the year. As shares are released from collateral, we report compensation expense equal to the current market price of the shares less dividends on allocated shares. Dividends on allocated ESOP shares are recorded as a reduction of retained earnings; available dividends on unallocated ESOP shares are recorded as a reduction of debt and accrued interest. ESOP compensation expense was $7.7 million in 2012 ($7.4 million in 2011; $7.1 million in 2010). According to the accounting standards for stock compensation, unallocated shares of ALLETE common stock currently held and purchased by the ESOP will be treated as unearned ESOP shares and not considered outstanding for earnings per share computations. ESOP shares are included in earnings per share computations after they are allocated to participants.
Stock-Based Compensation. Stock Incentive Plan. Under our Executive Long-Term Incentive Compensation Plan (Executive Plan), share-based awards may be issued to key employees through a broad range of methods, including non-qualified and incentive stock options, performance shares, performance units, restricted stock, stock appreciation rights and other awards. There are 1.2 million shares of common stock reserved for issuance under the Executive Plan, with 0.6 million of these shares available for issuance as of December 31, 2012. We had a Director Long-Term Stock Incentive Plan (Director Plan) which expired on January 1, 2006. No grants have been made since 2003 under the Director Plan. The 1,293 remaining options outstanding at December 31, 2011, were exercised during 2012. There were no options outstanding under the Director Plan at December 31, 2012. NOTE 16. EMPLOYEE STOCK AND INCENTIVE PLANS (Continued) We currently have the following types of share-based awards outstanding: Non-Qualified Stock Options. These options allow for the purchase of shares of common stock at a price equal to the market value of our common stock at the date of grant. Options become exercisable beginning one year after the grant date, with one-third vesting each year over three years. Options may be exercised up to ten years following the date of grant. In the case of qualified retirement, death or disability, options vest immediately and the period over which the options can be exercised is three years. Employees have up to three months to exercise vested options upon voluntary termination or involuntary termination without cause. All options are canceled upon termination for cause. All options vest immediately upon retirement, death, disability or a change of control, as defined in the award agreement. We determine the fair value of options using the Black-Scholes option-pricing model. The estimated fair value of options, including the effect of estimated forfeitures, is recognized as expense on the straight-line basis over the options’ vesting periods, or the accelerated vesting period if the employee is retirement eligible. Stock options have not been granted under our Executive Plan since 2008. The risk-free interest rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the grant date. Expected volatility is estimated based on the historic volatility of our stock and the stock of our peer group companies. We utilize historical option exercise and employee pre-vesting termination data to estimate the option life. The dividend growth rate is based upon historical growth rates in our dividends. Performance Shares. Under the performance share awards plan, the number of shares earned is contingent upon attaining specific market goals over a three-year performance period. Market goals are measured by total shareholder return relative to a group of peer companies. In the case of qualified retirement, death or disability during a performance period, a pro rata portion of the award will be earned at the conclusion of the performance period based on the market goals achieved. In the case of termination of employment for any reason other than qualified retirement, death or disability, no award will be earned. If there is a change in control, a pro rata portion of the award will be paid based on the greater of actual performance up to the date of the change in control or target performance. The fair value of these awards is determined by the probability of meeting the total shareholder return goals. Compensation cost is recognized over the three-year performance period based on our estimate of the number of shares which will be earned by the award recipients. Restricted Stock Units. Under the restricted stock units plan, shares for retirement eligible participants vest monthly over a three-year period. For non-retirement eligible participants, shares vest at the end of the three-year period. In the case of qualified retirement, death or disability, a pro rata portion of the award will be earned. In the case of termination of employment for any reason other than qualified retirement, death or disability, no award will be earned. If there is a change in control, a pro rata portion of the award will be earned. The fair value of these awards is equal to the grant date fair value. Compensation cost is recognized over the three-year vesting period based on our estimate of the number of shares which will be earned by the award recipients. Employee Stock Purchase Plan (ESPP). Under our ESPP, eligible employees may purchase ALLETE common stock at a 5 percent discount from the market price. Because the discount is not greater than 5 percent, we are not required to apply fair value accounting to these awards. RSOP. The RSOP is a contributory defined contribution plan subject to the provisions of the Employee Retirement Income Security Act of 1974, as amended, and qualifies as an employee stock ownership plan and profit sharing plan. The RSOP provides eligible employees an opportunity to save for retirement. The following share-based compensation expense amounts were recognized in our Consolidated Statement of Income for the periods presented.
NOTE 16. EMPLOYEE STOCK AND INCENTIVE PLANS (Continued) There were no capitalized stock-based compensation costs at December 31, 2012, 2011, or 2010. As of December 31, 2012, the total unrecognized compensation cost for the performance share awards and restricted stock units not yet recognized in our Consolidated Statements of Income was $1.3 million and $0.6 million, respectively. These amounts are expected to be recognized over a weighted-average period of 1.7 years for performance share awards and 1.7 years for restricted stock units. Non-Qualified Stock Options. The following table presents information regarding our outstanding stock options as of December 31, 2012.
Cash received from non-qualified stock options exercised was less than $0.1 million in 2012. The intrinsic value of a stock award is the amount by which the fair value of the underlying stock exceeds the exercise price of the award. The total intrinsic value of options exercised was $0.3 million during 2012 ($0.5 million in 2011; $0.3 million in 2010).
Performance Shares. The following table presents information regarding our non-vested performance shares as of December 31, 2012.
(a) Shares granted includes accrued dividends. NOTE 16. EMPLOYEE STOCK AND INCENTIVE PLANS (Continued) There were 33,525 and 41,332 performance shares granted in January 2012 and 2013, for the three-year performance periods ending in 2014 and 2015, respectively. The ultimate issuance is contingent upon the attainment of certain future market goals of ALLETE during the performance periods. The grant date fair value of the performance shares granted was $1.5 million and $2.2 million, respectively. There were 41,009 and 18,605 performance shares awarded in February 2012 and 2013, for the three-year performance periods ending in 2011 and 2012, respectively. The grant date fair value of the shares awarded was $1.4 million and $0.7 million, respectively. Restricted Stock Units. The following table presents information regarding our available restricted stock units as of December 31, 2012.
(a) Shares granted includes accrued dividends. There were 16,355 and 19,193 restricted stock units granted in January 2012 and 2013, for the vesting periods ending in 2014 and 2015, respectively. The grant date fair value of the restricted stock units granted was $0.7 million and $0.8 million, respectively. There were 24,707 restricted stock units awarded in 2012. The grant date fair value of the shares awarded was $0.7 million. There were 20,939 restricted stock units awarded in February 2013. The grant date fair value of the shares awarded was $0.7 million. |
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| Quarterly Financial Data (Unaudited) [Text Block] | QUARTERLY FINANCIAL DATA (UNAUDITED) Information for any one quarterly period is not necessarily indicative of the results which may be expected for the year.
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The entire disclosure for the quarterly financial data in the annual financial statements. The disclosure may include a tabular presentation of financial information for each fiscal quarter for the current and previous year, including revenues, gross profit, income or loss before extraordinary items and earnings per share data. It also includes an indication if the information in the note is unaudited, comments on the aggregate effect of year-end adjustments, and an explanation of matters or transactions that affect comparability or are pertinent to an understanding of the information furnished. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| Valuation and Qualifying Accounts and Reserves [Text Block] | Schedule II ALLETE Valuation and Qualifying Accounts and Reserves
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The entire disclosure for any allowance and reserve accounts (their beginning and ending balances, as well as a reconciliation by type of activity during the period). Alternatively, disclosure of the required information may be within the footnotes to the financial statements or a supplemental schedule to the financial statements. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Operations and Significant Accounting Policies (Policies)
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| Operations and Significant Accounting Policies [Abstract] | |
| Financial Statement Preparation [Policy Text Block] | Financial Statement Preparation. References in this report to “we,” “us,” and “our” are to ALLETE and its subsidiaries, collectively. We prepare our financial statements in conformity with accounting principles generally accepted in the United States of America. These principles require management to make informed judgments, best estimates, and assumptions that affect the reported amounts of assets, liabilities, revenue, and expenses. Actual results could differ from those estimates. |
| Subsequent Events [Policy Text Block] | Subsequent Events. The Company performed an evaluation of subsequent events for potential recognition and disclosure through the time of the financial statements issuance. |
| Principles of Consolidation [Policy Text Block] | Principles of Consolidation. Our consolidated financial statements include the accounts of ALLETE and all of our majority-owned subsidiary companies. All material intercompany balances and transactions have been eliminated in consolidation. |
| Business Segments [Policy Text Block] | Business Segments. Our Regulated Operations and Investments and Other segments were determined in accordance with the guidance on segment reporting. Segmentation is based on the manner in which we operate, assess, and allocate resources to the business. We measure performance of our operations through budgeting and monitoring of contributions to consolidated net income by each business segment. |
| Land Inventory [Policy Text Block] | Land inventories are accounted for in accordance with the accounting standards for property, plant and equipment, and are included in Other Investments on our Consolidated Balance Sheet. Real estate costs include the cost of land acquired, subsequent development costs and costs of improvements, capitalized development period interest, real estate taxes and payroll costs of certain employees devoted directly to the development effort. These real estate costs incurred are capitalized to the cost of real estate parcels based upon the relative sales value of parcels within each development project in accordance with the accounting standards for real estate. The cost of real estate sold includes the actual costs incurred and the estimate of future completion costs allocated to the real estate sold based upon the relative sales value method. Whenever events or circumstances indicate that the carrying value of the real estate may not be recoverable, impairments are recorded and the related assets are adjusted to their estimated fair value. |
| Cash and Cash Equivalents [Policy Text Block] | Cash and Cash Equivalents. We consider all investments purchased with original maturities of three months or less to be cash equivalents. |
| Accounts Receivable [Policy Text Block] | Accounts Receivable. Accounts receivable are reported on the balance sheet net of an allowance for doubtful accounts. The allowance is based on our evaluation of the receivable portfolio under current conditions, overall portfolio quality, review of specific problems and such other factors that, in our judgment, deserve recognition in estimating losses. |
| Long-Term Finance Receivables [Policy Text Block] | Long-Term Finance Receivables. Long-term finance receivables relating to our real estate operations are collateralized by property sold, accrue interest at market-based rates and are net of an allowance for doubtful accounts. We assess delinquent finance receivables by comparing the balance of such receivables to the estimated fair value of the collateralized property. If the fair value of the property is less than the finance receivable, we record a reserve for the difference. We estimate fair value based on recent property tax assessed values or current appraisals. |
| Available-for-Sale Securities [Policy Text Block] | Available-for-Sale Securities. Available-for-sale securities are recorded at fair value with unrealized gains and losses included in accumulated other comprehensive income (loss), net of tax. Unrealized losses that are other than temporary are recognized in earnings. We use the specific identification method as the basis for determining the cost of securities sold. Our policy is to review available-for-sale securities for other than temporary impairment on a quarterly basis by assessing such factors as the share price trends and the impact of overall market conditions. |
| Inventories [Policy Text Block] | Inventories. Inventories are stated at the lower of cost or market. Amounts removed from inventory are recorded on an average cost basis. |
| Property, Plant and Equipment [Policy Text Block] | Property, Plant and Equipment. Property, plant and equipment are recorded at original cost and are reported on the balance sheet net of accumulated depreciation. Expenditures for additions, significant replacements, improvements and major plant overhauls are capitalized; maintenance and repair costs are expensed as incurred. Gains or losses on non-rate base property, plant and equipment are recognized when they are retired or otherwise disposed. When regulated utility property, plant and equipment are retired or otherwise disposed, no gain or loss is recognized in accordance with the accounting standards for Regulated Operations. Our Regulated Operations capitalize AFUDC, which includes both an interest and equity component. AFUDC represents the cost of both debt and equity funds used to finance utility plant additions during construction periods. AFUDC amounts capitalized are included in rate base and are recovered from customers as the related property is depreciated. The MPUC has approved cost recovery for several large capital projects recently, at which time the recognition of AFUDC ceases. Depreciation is computed using the straight-line method over the estimated useful lives of the various classes of assets. |
| Impairment of Long-Lived Assets [Policy Text Block] | Impairment of Long-Lived Assets. We review our long-lived assets, which include the real estate assets of ALLETE Properties, for indicators of impairment in accordance with the accounting standards for property, plant and equipment on a quarterly basis. In the event that projected future undiscounted cash flows are not adequate to recover the carrying value of an asset, impairment is indicated and may require a write down to the asset’s fair value. Fair value is determined based on best available evidence including comparable sales, current appraised values, property tax assessed values, and discounted cash flow analysis. If fair value is less than cost, the carrying value of our investments is reduced and an impairment charge is recorded in the current period. In accordance with the accounting standards for property, plant and equipment, if indicators of impairment exist, we test our real estate assets for recoverability by comparing the carrying amount of the asset to the undiscounted future net cash flows expected to be generated by the asset. Cash flows are assessed at the lowest level of identifiable cash flows, which may be by each land parcel, combining various parcels into bulk sales, or other combinations thereof. Our consideration of possible impairment for our real estate assets requires us to make estimates of future cash flows on an undiscounted basis. The undiscounted future net cash flows are impacted by trends and factors known to us at the time they are calculated and our expectations related to: management’s best estimate of future sales prices; holding period and timing of sales; method of disposition; and future expenditures necessary to develop and maintain the operations, including community development district assessments, property taxes and normal operation and maintenance costs. These estimates and expectations are specific to each land parcel or various bulk sales, and may vary among each land parcel or bulk sale. If the excess of undiscounted cash flows over the carrying value of a property is small, there is a greater risk of future impairment in the event of such changes and any resulting impairment charges could be material. |
| Derivatives [Policy Text Block] | Derivatives. ALLETE is exposed to certain risks relating to its business operations that can be managed through the use of derivative instruments. ALLETE may enter into derivative instruments to manage interest rate risk related to certain variable-rate borrowings. Cash flows from derivative activities are presented in the same category as the item being hedged on the Consolidated Statement of Cash Flows. Amounts recorded in other comprehensive income related to cash flow hedges will be recognized in earnings when the hedged transactions occur or when it is probable that the hedged transactions will not occur. Gains or losses on interest rate hedging transactions are reflected as a component of interest expense on the Consolidated Statement of Income. |
| Accounting for Stock-Based Compensation [Policy Text Block] | Accounting for Stock-Based Compensation. We apply the fair value recognition guidance for share-based payments. Under this guidance, we recognize stock-based compensation expense for all share-based payments granted, net of an estimated forfeiture rate. |
| Environmental Liabilities [Policy Text Block] | Environmental Liabilities. We review environmental matters for disclosure on a quarterly basis. Accruals for environmental matters are recorded when it is probable that a liability has been incurred and the amount of the liability can be reasonably estimated, based on current law and existing technologies. These accruals are adjusted periodically as assessment and remediation efforts progress or as additional technical or legal information becomes available. Accruals for environmental liabilities are included in the balance sheet at undiscounted amounts and exclude claims for recoveries from insurance or other third parties. Costs related to environmental contamination treatment and cleanup are charged to operating expense unless recoverable in rates from customers. |
| Revenue Recognition [Policy Text Block] | Revenue Recognition. Regulated utility rates are under the jurisdiction of Minnesota, Wisconsin and federal regulatory authorities. Customers are billed on a cycle basis. Revenue is accrued for service provided but not billed. Regulated utility electric rates include adjustment clauses that: (1) bill or credit customers for fuel and purchased energy costs above or below the base levels in rate schedules; (2) bill retail customers for the recovery of conservation improvement program expenditures not collected in base rates; and (3) bill customers for the recovery of certain transmission and renewable energy expenditures. Fuel and purchased power expense is deferred to match the period in which the revenue for fuel and purchased power expense is collected from customers pursuant to the fuel adjustment clause. BNI recognizes revenue when coal is delivered. Minnesota Power participates in MISO. MISO transactions are accounted for on a net hourly basis in each of the day-ahead and real-time markets. Minnesota Power records net sales in Operating Revenue and net purchases in Fuel and Purchased Power Expense on our Consolidated Statement of Income. The revenues and charges from MISO related to serving retail and municipal electric customers are recorded on a net basis as Fuel and Purchased Power Expense. Full profit recognition is recorded on sales upon closing, provided that cash collections are at least 20 percent of the contract price and the other requirements under the guidance for sales of real estate are met. In certain cases, where there are obligations to perform significant development activities after the date of sale, we recognize profit on a percentage-of-completion basis. From time to time, certain contracts with customers allow us to receive participation revenue from land sales to third parties if various formula-based criteria are achieved. In certain cases, we pay fees or construct improvements to mitigate offsite traffic impacts. In return, we receive traffic impact fee credits as a result of some of these expenditures. We recognize revenue from the sale of traffic impact fee credits when payment is received. |
| Unamortized Discount and Premium on Debt [Policy Text Block] | Unamortized Discount and Premium on Debt. Discount and premium on debt are deferred and amortized over the terms of the related debt instruments using the straight-line method which approximates the effective interest method. |
| Income Taxes [Policy Text Block] | Income Taxes. ALLETE and its subsidiaries file a consolidated federal income tax return and combined and separate state income tax returns. We account for income taxes using the liability method in accordance with the accounting standards for income taxes. Under the liability method, deferred income tax assets and liabilities are established for all temporary differences in the book and tax basis of assets and liabilities, based upon enacted tax laws and rates applicable to the periods in which the taxes become payable. Due to the effects of regulation on Minnesota Power and SWL&P, certain adjustments made to deferred income taxes are, in turn, recorded as regulatory assets or liabilities. Federal investment tax credits have been recorded as deferred credits and are being amortized to income tax expense over the service lives of the related property. In accordance with the accounting standards for uncertainty in income taxes, we are required to recognize in our financial statements the largest tax benefit of a tax position that is “more-likely-than-not” to be sustained on audit, based solely on the technical merits of the position as of the reporting date. The term “more-likely-than-not” means more than 50 percent likely. |
| Excise Taxes [Policy Text Block] | Excise Taxes. We collect excise taxes from our customers levied by government entities. These taxes are stated separately on the billing to the customer and recorded as a liability to be remitted to the government entity. We account for the collection and payment of these taxes on a net basis. |
| Asset Retirement Obligations [Policy Text Block] | Asset Retirement Obligations. We recognize, at fair value, obligations associated with the retirement of certain tangible, long-lived assets that result from the acquisition, construction or development and/or normal operation of the asset. |
| Regulatory Assets and Liabilities [Policy Text Block] | Regulatory Assets and Liabilities. Our regulated utility operations are subject to the accounting guidance for Regulated Operations. We capitalize incurred costs which are probable of recovery in future utility rates as regulatory assets. Regulatory liabilities represent amounts expected to be refunded or credited to customers in rates. No regulatory assets or liabilities are currently earning a return. |
| Fair Value Transfers [Policy Text Block] | The Company’s policy is to recognize transfers in and transfers out as of the actual date of the event or change in circumstances that caused the transfer. |
| Pension and Other Postretirement Benefit Plans [Policy Text Block] | Accounting for defined benefit pension and postretirement benefit plans requires that employers recognize on a prospective basis the funded status of their defined benefit pension and other postretirement plans on their Consolidated Balance Sheet and recognize as a component of other comprehensive income, net of tax, the gains or losses and prior service costs or credits that arise during the period but are not recognized as components of net periodic benefit cost. The defined benefit pension and postretirement health and life benefit costs recognized annually by our regulated companies are expected to be recovered through rates filed with our regulatory jurisdictions. As a result, these amounts that are required to otherwise be recognized in accumulated other comprehensive income have been recognized as a long-term regulatory asset on our Consolidated Balance Sheet, in accordance with the accounting standards for Regulated Operations. The defined benefit pension and postretirement health and life benefit costs associated with our other non-rate base operations are recognized in accumulated other comprehensive income. |
| Employee Stock Ownership Plan (ESOP) [Policy Text Block] | We make annual contributions to the ESOP equal to the ESOP’s debt service less available dividends received by the ESOP. The majority of dividends received by the ESOP are used to pay debt service, with the balance distributed to participants. The ESOP shares were initially pledged as collateral for the debt. As the debt is repaid, shares are released from collateral and allocated to participants based on the proportion of debt service paid in the year. As shares are released from collateral, we report compensation expense equal to the current market price of the shares less dividends on allocated shares. Dividends on allocated ESOP shares are recorded as a reduction of retained earnings; available dividends on unallocated ESOP shares are recorded as a reduction of debt and accrued interest. According to the accounting standards for stock compensation, unallocated shares of ALLETE common stock currently held and purchased by the ESOP will be treated as unearned ESOP shares and not considered outstanding for earnings per share computations. ESOP shares are included in earnings per share computations after they are allocated to participants. |
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Disclosure of accounting policy for determining amounts to accrue and charge against earnings so as to satisfy legal obligations associated with the retirement (through sale, abandonment, recycling, or disposal in some other manner) of a tangible long-lived asset that result from the acquisition, construction, or development and (or) the normal operation of a long-lived asset. This accounting policy disclosure excludes obligations arising 1) in connection with leased property, whether imposed by a lease agreement or by a party other than the lessor, that meet the definition of either minimum lease payments or contingent rentals; 2) solely from a plan to sell or otherwise dispose of a long-lived asset and 3) from certain environmental remediation liabilities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Disclosure of accounting policy for basis of accounting, or basis of presentation, used to prepare the financial statements (for example, US Generally Accepted Accounting Principles, Other Comprehensive Basis of Accounting, IFRS). No definition available.
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Disclosure of accounting policy for cash and cash equivalents, including the policy for determining which items are treated as cash equivalents. Other information that may be disclosed includes (1) the nature of any restrictions on the entity's use of its cash and cash equivalents, (2) whether the entity's cash and cash equivalents are insured or expose the entity to credit risk, (3) the classification of any negative balance accounts (overdrafts), and (4) the carrying basis of cash equivalents (for example, at cost) and whether the carrying amount of cash equivalents approximates fair value. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Disclosure of accounting policy regarding (1) the principles it follows in consolidating or combining the separate financial statements, including the principles followed in determining the inclusion or exclusion of subsidiaries or other entities in the consolidated or combined financial statements and (2) its treatment of interests (for example, common stock, a partnership interest or other means of exerting influence) in other entities, for example consolidation or use of the equity or cost methods of accounting. The accounting policy may also address the accounting treatment for intercompany accounts and transactions, noncontrolling interest, and the income statement treatment in consolidation for issuances of stock by a subsidiary. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Disclosure of accounting policy for costs incurred to obtain or issue debt, the effects of refinancings, method of amortizing deferred financing costs and original issue discount, and classifications of debt on the balance sheet. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Disclosure of accounting policy for ESOP transactions, including the method of measuring compensation, the classification of dividends on ESOP shares, and the treatment of ESOP shares for EPS computations. If the employer has both old ESOP shares for which it does not adopt new guidance and new ESOP shares for which new guidance is required, these disclosures are required for both blocks of shares. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Disclosure of accounting policy for obligations that resulted from improper or other-than normal operation of a long-lived asset in the past. This accounting policy may address (1) whether the related remediation costs are expensed or capitalized, (2) whether the obligation is measured on a discounted basis, (3) the event, situation, or set of circumstances that generally triggers recognition of loss contingencies arising from the entity's environmental remediation-related obligations, and (4) the timing of recognition of any recoveries. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Disclosure of accounting policy for those finance, loan and lease receivables classified as held for investment. This disclosure may include (1) the basis at which such receivables are carried in the entity's statements of financial position (2) how the level of the allowance for loan and lease losses is determined (3) when impairments, charge-offs or recoveries are recognized for such receivables (4) the treatment of commitment and other fees and loan origination costs (including, if applicable, how the entity accounts for fees and costs associated with credit cards that are either purchased or originated) (5) the treatment of any premiums or discounts or unearned income (6) the entity's income recognition policies for such receivables, including those that are impaired, past due or placed on nonaccrual status (for impaired loans, the policy for recognizing interest income on such loans, including how cash receipts are recorded) and (7) the treatment of foreclosures or repossessions. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Disclosure of accounting policy for recognizing and measuring the impairment of long-lived assets. An entity also may disclose its accounting policy for long-lived assets to be sold. This policy excludes goodwill and intangible assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Disclosure of accounting policy for major classes of inventories, bases of stating inventories (for example, lower of cost or market), methods by which amounts are added and removed from inventory classes (for example, FIFO, LIFO, or average cost), loss recognition on impairment of inventories, and situations in which inventories are stated above cost. If inventory is carried at cost, this disclosure includes the nature of the cost elements included in inventory. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Disclosure of accounting policy for investments in debt and equity securities that are classified as available-for-sale. This policy also may describe the entity's accounting treatment for transfers between investment categories, how the entity determines whether impairments of available-for-sale securities are other than temporary, and how the fair values of such securities are determined. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Disclosure of accounting policy for pension and other postretirement benefit plans. This accounting policy may address (1) the types of plans sponsored by the entity, and the benefits provided by each plan (2) groups that participate in (or are covered by) each plan (3) how plan assets, liabilities and expenses are measured, including the use of any actuaries and (4) significant assumptions used by the entity to value plan assets and liabilities and how such assumptions are derived. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Disclosure of accounting policy for property, plant and equipment which may include the basis of such assets, depreciation methods used and estimated useful lives, the entity's capitalization policy, including its accounting treatment for costs incurred for repairs and maintenance activities, whether such asset balances include capitalized interest and the method by which such is calculated, how disposals of such assets are accounted for and how impairment of such assets is assessed and recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Disclosure of accounting policy for public utilities. Examples include a discussion about the scope criteria and appropriateness for and extent of the application of generally accepted accounting principles related to accounting for the effects of certain types of regulation (may include identification of specific business units). Other examples of the disclosures may include: descriptions of the form and economic effects of regulation (for example, but not limited to, recording of regulatory assets and liabilities to the rate setting process); statement about periodic assessments of periodic assessments of generally accepted accounting principles related to accounting for the effects of certain types of regulation; information regarding amortization of and return on regulatory assets and liabilities, including the remaining amounts and recovery or settlement periods; accounting for changes to recovery estimates; AFUDC, plant abandonment's and plant disallowances. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Disclosure of accounting policy for real estate held for development or sale. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Disclosure of accounting policy for revenue recognition. If the entity has different policies for different types of revenue transactions, the policy for each material type of transaction is generally disclosed. If a sales transaction has multiple element arrangements (for example, delivery of multiple products, services or the rights to use assets) the disclosure may indicate the accounting policy for each unit of accounting as well as how units of accounting are determined and valued. The disclosure may encompass important judgment as to appropriateness of principles related to recognition of revenue. The disclosure also may indicate the entity's treatment of any unearned or deferred revenue that arises from the transaction. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Disclosure of accounting policy for segment reporting. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Disclosure of accounting policy for stock option and stock incentive plans. This disclosure may include (1) the types of stock option or incentive plans sponsored by the entity (2) the groups that participate in (or are covered by) each plan (3) significant plan provisions and (4) how stock compensation is measured, and the methodologies and significant assumptions used to determine that measurement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Disclosure of accounting policy for reporting subsequent events. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Disclosure of accounting policy for trade and other accounts receivables. This disclosure may include the basis at which such receivables are carried in the entity's statements of financial position (for example, net realizable value), how the entity determines the level of its allowance for doubtful accounts, when impairments, charge-offs or recoveries are recognized, and the entity's income recognition policies for such receivables, including its treatment of related fees and costs, its treatment of premiums, discounts or unearned income, when accrual of interest is discontinued, how the entity records payments received on nonaccrual receivables and its policy for resuming accrual of interest on such receivables. If the enterprise holds a large number of similar loans, disclosure may include the accounting policy for the anticipation of prepayments and significant assumptions underlying prepayment estimates for amortization of premiums, discounts, and nonrefundable fees and costs. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Operations and Significant Accounting Policies (Tables)
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Dec. 31, 2012
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| Operations and Significant Accounting Policies [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Supplemental Statement of Cash Flow Information [Table Text Block] | Supplemental Statement of Cash Flow Information
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| Accounts Receivable [Table Text Block] |
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| Inventories [Table Text Block] |
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| Prepayments and Other Current Assets [Table Text Block] |
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| Other Liabilities [Table Text Block] |
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- Definition
Schedule of Other Liabilities [Table Text Block] including Current and Non-Current No definition available.
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- Definition
Tabular disclosure of the various types of trade accounts and notes receivable and for each the gross carrying value, allowance, and net carrying value as of the balance sheet date. Presentation is categorized by current, noncurrent and unclassified receivables. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Tabular disclosure of supplemental cash flow information for the periods presented. No definition available.
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- Definition
Tabular disclosure of the carrying amount as of the balance sheet date of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Tabular disclosure of the carrying amounts of other current assets. No definition available.
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Business Segments (Tables)
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Dec. 31, 2012
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| Business Segments [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Business Segments [Table Text Block] |
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- Definition
Tabular disclosure of the profit or loss and total assets for each reportable segment. An entity discloses certain information on each reportable segment if the amounts (a) are included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) are otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Property, Plant and Equipment (Tables)
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Dec. 31, 2012
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| Property, Plant and Equipment [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Property, Plant, and Equipment [Table Text Block] |
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| Estimated Useful Lives of Property, Plant and Equipment [Table Text Block] |
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| Asset Retirement Obligation [Table Text Block] |
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- Details
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- Definition
Tabular disclosure of the useful life and salvage value of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Tabular disclosure of the changes in carrying amount of a liability for asset retirement obligations, for changes such as new obligations, changes in estimates of existing obligations, spending on existing obligations, property dispositions, and foreign currency translation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Tabular disclosure of public utility property plant and equipment. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Jointly-Owned Facilities (Tables)
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Dec. 31, 2012
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| Jointly-Owned Facilities [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Jointly-Owned Facilities [Table Text Block] | Following are our investments in jointly-owned facilities and the related ownership percentages as of December 31, 2012:
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- Definition
Tabular disclosure of proportionate interests in jointly owned utility plants. Includes the amount of plants in service, the accumulated provision for depreciation (if available), the amount of plants under construction, and the proportionate share. The amounts presented may be further subdivided to show amounts applicable to plant subcategories (for example, production, transmission, distribution). Includes statements that the amounts represent the utility's share in each joint plant and that it must provide its own financing. Information concerning two or more generating plants on the same site may be combined. States that the utility's share of direct expenses of the joint plants is included in the corresponding operating expenses on its income statement (for example, fuel, maintenance of plant, other operating expense). If the share of direct expenses is charged to purchased power, then disclose the amount so charged and the proportionate amounts charged to specific operating expenses on the records maintained for the joint plants. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Regulatory Matters (Tables)
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Dec. 31, 2012
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| Regulatory Matters [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Regulatory Assets and Liabilities [Table Text Block] |
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- Definition
Schedule of Regulatory Assets and Liabilities [Table Text Block] No definition available.
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Investment in ATC (Tables)
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Dec. 31, 2012
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| Investment in ATC [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| ALLETE's Interest in ATC [Table Text Block] |
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| ATC Summarized Financial Data [Table Text Block] |
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- Definition
Tabular disclosure of summarized financial data reported by an equity method investment of the entity. No definition available.
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- Definition
Tabular disclosure of equity method investments in common stock. The disclosure may include: (a) the name of each investee or group of investments for which combined disclosure is appropriate, (2) the percentage ownership of common stock, (3) the difference, if any, between the carrying amount of an investment and the value of the underlying equity in the net assets and the accounting treatment of difference, if any, and (4) the aggregate value of each identified investment based on its quoted market price, if available. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Investments (Tables)
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Dec. 31, 2012
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| Investments [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Investments and ALLETE Properties [Table Text Block] |
NOTE 7. INVESTMENTS (Continued)
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| Available-for-sale Securities [Table Text Block] |
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| Available-for-sale Securities [Table Text Block] |
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- Definition
A table of investments, shown as a text block. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Tabular disclosure of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Tabular disclosure of the reconciliation of available-for-sale securities from cost basis to fair value. No definition available.
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Fair Value (Tables)
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Dec. 31, 2012
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| Fair Value [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Recurring Fair Value Measures [Table Text Block] |
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| Recurring Fair Value Measures - Activity in Level 3 [Table Text Block] |
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| Financial Instruments [Table Text Block] |
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- Definition
Tabular disclosure of the fair value measurement of assets using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes during the period attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets) and gains or losses recognized in other comprehensive income (loss), and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issues, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs), by class of asset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Tabular disclosure of the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments, assets, and liabilities. Such certain disclosures about the financial instruments, assets, and liabilities include: (1) the fair value of the required items together with their carrying amounts (as appropriate) and (2) the methodology and assumptions used in developing such estimates of fair value. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Tabular disclosure of assets and liabilities, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, that are measured at fair value on a recurring basis. The disclosures contemplated herein include the fair value measurements at the reporting date by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Short-Term and Long-Term Debt (Tables)
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Dec. 31, 2012
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| Short-Term and Long-Term Debt [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Long-term Debt [Table Text Block] |
On July 2, 2012, we issued $160.0 million of the Company’s First Mortgage Bonds (Bonds) in the private placement market in two series as follows:
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- Definition
Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Common Stock and Earnings Per Share (Tables)
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Dec. 31, 2012
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| Common Stock and Earnings Per Share [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Summary of Common Stock [Table Text Block] |
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| Reconciliation of Basic and Diluted Earnings Per Share [Table Text Block] |
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Tabular disclosure of the change in common stock outstanding. No definition available.
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- Definition
Tabular disclosure of an entity's basic and diluted earnings per share calculations. No definition available.
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Other Income (Expense) (Tables)
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Dec. 31, 2012
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| Other Income (Expense) [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Other Income (Expense) [Table Text Block] |
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- Definition
Tabular disclosure of the components of non-operating income or non-operating expense that may include amounts earned from dividends, interest on securities, gains (losses) on securities sold, equity earnings of unconsolidated affiliates, net gain (loss) on sales of business, interest expense and other miscellaneous income or expense items. No definition available.
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Income Tax Expense (Tables)
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Dec. 31, 2012
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| Income Tax Expense [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Income Tax Expense [Table Text Block] |
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| Reconciliation of Taxes from Federal Statutory Rate to Total Income Tax Expense [Table Text Block] |
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| Deferred Tax Assets and Liabilities [Table Text Block] |
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| NOL and Tax Credit Carryforwards [Table Text Block] |
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| Gross Unrecognized Income Tax Benefits [Table Text Block] |
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Summary of Operating Loss and Tax Credit Carryforwards [Table Text Block] [Table Text Block] No definition available.
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- Definition
Tabular disclosure of the components of income tax expense attributable to continuing operations for each year presented including, but not limited to: current tax expense (benefit), deferred tax expense (benefit), investment tax credits, government grants, the benefits of operating loss carryforwards, tax expense that results from allocating certain tax benefits either directly to contributed capital or to reduce goodwill or other noncurrent intangible assets of an acquired entity, adjustments of a deferred tax liability or asset for enacted changes in tax laws or rates or a change in the tax status of the entity, and adjustments of the beginning-of-the-year balances of a valuation allowance because of a change in circumstances that causes a change in judgment about the realizability of the related deferred tax asset in future years. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Tabular disclosure of the components of net deferred tax asset or liability recognized in an entity's statement of financial position, including the following: the total of all deferred tax liabilities, the total of all deferred tax assets, the total valuation allowance recognized for deferred tax assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Tabular disclosure of the reconciliation using percentage or dollar amounts of the reported amount of income tax expense attributable to continuing operations for the year to the amount of income tax expense that would result from applying domestic federal statutory tax rates to pretax income from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Tabular disclosure of tax positions taken in the tax returns filed or to be filed for which it is more likely than not that the tax position will not be sustained upon examination by taxing authorities (i.e., uncertain tax positions) and other types of income tax contingencies, including: (1) the policy on classification of interest and penalties; (2) a tabular reconciliation of the total amounts of unrecognized tax benefits at the beginning and end of the period; the total amount(s) of: (3) unrecognized tax benefits that, if recognized, would affect the effective tax rate, and (4) interest and penalties recognized in each of the income statement and balance sheet; (5) for positions for which it is reasonably possible that the total amounts unrecognized will significantly change within 12 months of the reporting date the: (i) nature of the uncertainty, (ii) nature of the event that could occur that would cause the change, and (iii) an estimate of the range of the reasonably possible change or a statement that an estimate of the range cannot be made; and (6) a description of tax years that remain subject to examination by major tax jurisdictions. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Pension and Other Postretirement Benefit Plans (Tables)
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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Dec. 31, 2012
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| Defined Benefit Plan Disclosure [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Estimated Future Benefit Payments [Table Text Block] |
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| Defined Benefit Costs Recorded in Regulatory Long-Term Assets and Accumulated Other Comprehensive Income Expected to be Recognized over Next Fiscal Year [Table Text Block] | The pension and postretirement health and life costs recorded in regulatory long-term assets and accumulated other comprehensive income expected to be recognized as a component of net pension and postretirement benefit costs for the year ending December 31, 2013, are as follows:
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| Weighted-Average Assumptions Used to Determine Benefit Obligation and Net Periodic Benefit Costs [Table Text Block] |
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| Plan Asset Allocations, Actual and Target [Table Text Block] |
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| Recurring Fair Value Measures [Table Text Block] |
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| Recurring Fair Value Measures - Activity in Level 3 [Table Text Block] |
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Pension [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Obligation and Funded Status [Table Text Block] |
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| Unrecognized Benefit Costs [Table Text Block] | The pension costs that are reported as a component within our Consolidated Balance Sheet, reflected in long-term regulatory assets and accumulated other comprehensive income, consist of the following:
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| Components of Net Periodic Expense [Table Text Block] |
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| Other Changes in Defined Benefit Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income and Regulatory Assets [Table Text Block] |
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| Information for Pension Plans with an Accumulated Benefit Obligation in Excess of Plan Assets [Table Text Block] |
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| Recurring Fair Value Measures [Table Text Block] |
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| Recurring Fair Value Measures - Activity in Level 3 [Table Text Block] |
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Postretirement Health and Life [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Obligation and Funded Status [Table Text Block] |
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| Unrecognized Benefit Costs [Table Text Block] | The postretirement health and life costs that are reported as a component within our Consolidated Balance Sheet, reflected in regulatory long-term assets and accumulated other comprehensive income, consist of the following:
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| Components of Net Periodic Expense [Table Text Block] |
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| Other Changes in Defined Benefit Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income and Regulatory Assets [Table Text Block] |
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| Sensitivity of a One-Percentage-Point Change in Health Care Trend Rates [Table Text Block] |
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| Recurring Fair Value Measures [Table Text Block] |
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| Recurring Fair Value Measures - Activity in Level 3 [Table Text Block] |
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
Tabular disclosure of the fair value measurement of assets using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes during the period attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets) and gains or losses recognized in other comprehensive income (loss), and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issues, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs), by class of asset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Tabular disclosure of accumulated benefit obligations and fair values of plan assets of pension plans and/or other employee benefit plans where the accumulated benefit obligation exceeds the fair value of plan assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Tabular disclosure of the major categories of plan assets of pension plans and/or other employee benefit plans. This information may include, but is not limited to, the target allocation of plan assets, the fair value of each major category of plan assets, and the level within the fair value hierarchy in which the fair value measurements fall. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Tabular disclosure of the amounts related to pension plans and/or other employee benefit plans in accumulated other comprehensive income (loss) expected to be recognized as components of net periodic benefit cost over the next fiscal year, including the net gain (loss), net prior service cost or credit, and net transition asset or obligation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Tabular disclosure of the assumptions used to determine for pension plans and/or other employee benefit plans the benefit obligation and net benefit cost, including assumed discount rates, rate increase in compensation increase, and expected long-term rates of return on plan assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Tabular disclosure of the changes in plan assets and benefit obligations recognized in other comprehensive income (loss) during the period. No definition available.
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| X | ||||||||||
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- Definition
Tabular disclosure of the effect of a one-percentage-point increase and the effect of a one-percentage-point decrease in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs and the accumulated postretirement benefit obligation for health care benefits. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Tabular disclosure of benefits expected to be paid by pension plans and/or other employee benefit plans in each of the next five fiscal years and in the aggregate for the five fiscal years thereafter. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Tabular disclosure of assets and liabilities, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, that are measured at fair value on a recurring basis. The disclosures contemplated herein include the fair value measurements at the reporting date by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Tabular disclosure of net funded status of pension plans and/or other employee benefit plans. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Tabular disclosure of the amounts related to pension plans and/or other employee benefit plans in accumulated other comprehensive income or loss that have not yet been recognized as components of net periodic benefit cost, such as the net gain (loss), net prior service cost or credit, and net transition asset or obligation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Employee Stock and Incentive Plans (Tables)
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12 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Dec. 31, 2012
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| Employee Stock and Incentive Plans [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Employee Stock Ownership Plan [Table Text Block] |
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| Share-Based Compensation Expense [Table Text Block] | The following share-based compensation expense amounts were recognized in our Consolidated Statement of Income for the periods presented.
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| Non-Qualified Stock Options [Table Text Block] | Non-Qualified Stock Options. The following table presents information regarding our outstanding stock options as of December 31, 2012.
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| Stock Options, by Exercise Price Range [Table Text Block] |
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| Performance Shares [Table Text Block] | Performance Shares. The following table presents information regarding our non-vested performance shares as of December 31, 2012.
(a) Shares granted includes accrued dividends. |
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| Restricted Stock Units [Table Text Block] | Restricted Stock Units. The following table presents information regarding our available restricted stock units as of December 31, 2012.
(a) Shares granted includes accrued dividends. |
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- Details
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| X | ||||||||||
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- Definition
Tabular disclosure of the amount of total share-based compensation cost, including the amounts attributable to each share-based compensation plan and any related tax benefits. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Tabular disclosure of the description of the plan, the basis for determining contributions, including the employee groups covered, and the nature and effect of significant matters affecting comparability of information for all periods presented. For leveraged ESOPs and pension reversion ESOPs, the disclosure may include the basis for releasing shares and how dividends on allocated and unallocated shares are used. Disclosure may also include a description of the accounting policies followed for ESOP transactions, including the method of measuring compensation, the classification of dividends on ESOP shares, and the treatment of ESOP shares for EPS computations. If the employer has both old ESOP shares for which it does not adopt the latest guidance and new ESOP shares for which the new guidance is required, the accounting policies for both blocks of shares may be described. Disclosure may also include he amount of compensation cost recognized during the period, the number of allocated shares, committed-to-be-released shares, and suspense shares held by the ESOP at the balance-sheet date, the fair value of unearned ESOP shares at the balance-sheet date for shares accounted for under the latest guidance, the existence and nature of any repurchase obligation, including disclosure of the fair value of the shares allocated as of the balance sheet date, which are subject to a repurchase obligation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Tabular disclosure of the changes in outstanding nonvested performance-based units. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Disclosure of the number and weighted-average grant date fair value for restricted stock and restricted stock units that were outstanding at the beginning and end of the year, and the number of restricted stock and restricted stock units that were granted, vested, or forfeited during the year. No definition available.
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| X | ||||||||||
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- Definition
Tabular disclosure of option exercise prices, by grouped ranges, including the upper and lower limits of the price range, the number of shares under option, weighted average exercise price and remaining contractual option terms. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Tabular disclosure of the number and weighted-average exercise prices (or conversion ratios) for share options (or share units) that were outstanding at the beginning and end of the year, vested and expected to vest, exercisable or convertible at the end of the year, and the number of share options or share units that were granted, exercised or converted, forfeited, and expired during the year. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Quarterly Financial Data (Unaudited) (Tables)
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12 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Dec. 31, 2012
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| Quarterly Financial Data (Unaudited) [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Quarterly Financial Data (Unaudited) [Table Text Block] |
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
Tabular disclosure of the quarterly financial data in the annual financial statements. The disclosure includes financial information for each fiscal quarter for the current and previous year, including revenues, gross profit, income (loss) before extraordinary items and cumulative effect of a change in accounting principle and earnings per share data. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Current accounts receivable net of the allowance for doubtful accounts and net of income taxes receivable. No definition available.
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
The percentage guideline to determine more-likely-than-not status No definition available.
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| X | ||||||||||
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- Definition
Number of Customers No definition available.
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| X | ||||||||||
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- Definition
Number of shares of stock issued during the period to purchase non-controlling interest. No definition available.
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
Amounts due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer) for goods or services (including trade receivables) that have been delivered or sold in the normal course of business. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The current portion of money or property received from customers which is either to be returned upon satisfactory contract completion or applied to customer receivables in accordance with the terms of the contract or the understandings. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Carrying amount as of the balance sheet date of capitalized fuel costs of a regulated entity that are expected to be recoverable through rate adjustments within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Carrying amount as of the balance sheet date of coal, which is a combustible rock or minerals which are extracted from the ground and used as fuel. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
Carrying amount due within one year of the balance sheet date (or one operating cycle, if longer) from tax authorities as of the balance sheet date representing refunds of overpayments or recoveries based on agreed-upon resolutions of disputes. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
Carrying amount (lower of cost or market) as of the balance sheet date of inventories less all valuation and other allowances. Excludes noncurrent inventory balances (expected to remain on hand past one year or one operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Aggregated amount of unprocessed materials to be used in manufacturing or production process and supplies that will be consumed. This amount is net of valuation reserves and adjustments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Decrease in noncontrolling interest (for example, but not limited to, redeeming or purchasing the interests of noncontrolling shareholders, issuance of shares (interests) by the non-wholly owned subsidiary to the parent entity for other than cash, and a buyback of shares (interest) by the non-wholly owned subsidiary from the noncontrolling interests). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
Carrying value as of the balance sheet date of obligations incurred through that date and payable arising from transactions not otherwise specified in the taxonomy. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The noncurrent portion (due beyond one year or one operating cycle) of other accrued expenses (expenses incurred at the end of the reporting period but not yet paid) not otherwise defined in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Aggregate carrying amount, as of the balance sheet date, of current assets not separately disclosed in the balance sheet. Current assets are expected to be realized or consumed within one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Aggregate carrying amount of current liabilities (due within one year or within the normal operating cycle if longer) not separately disclosed in the balance sheet. Includes costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered and of liabilities not separately disclosed. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
Aggregate carrying amount, as of the balance sheet date, of noncurrent obligations not separately disclosed in the balance sheet. Noncurrent liabilities are expected to be paid after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
The total of the amounts paid in advance for capitalized costs that will be expensed with the passage of time or the occurrence of a triggering event, and will be charged against earnings within one year or the normal operating cycle, if longer, and the aggregate carrying amount of current assets, as of the balance sheet date, not separately presented elsewhere in the balance sheet. Current assets are expected to be realized or consumed within one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
The amount due for services rendered or products shipped, but not yet billed, recognized in conformity with revenue recognition criteria. This element is distinct from unbilled contracts receivables because this is based on noncontract transactions. No definition available.
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Operations and Significant Accounting Policies - Minnesota Land Acres (Details) (Investments and Other [Member])
|
Dec. 31, 2012
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|---|---|
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Investments and Other [Member]
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| Business Segments [Line Items] | |
| Number of acres of land in Minnesota (in acres) | 6,100 |
| X | ||||||||||
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- Definition
Number of acres of land available-for-sale. No definition available.
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| X | ||||||||||
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- Details
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Operations and Significant Accounting Policies - Supplemental Statement of Cash Flow Information (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | |||||||
|---|---|---|---|---|---|---|---|---|
|
Dec. 31, 2012
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Dec. 31, 2011
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Dec. 31, 2010
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| Supplemental Cash Flow Information [Abstract] | ||||||||
| Cash Paid During the Period for Interest - Net of Amounts Capitalized | $ 42.7 | $ 43.2 | $ 35.7 | |||||
| Cash Received During the Period for Income Taxes | 0 | [1] | (11.4) | [1] | (54.2) | [1] | ||
| Noncash Investing and Financing Activities [Abstract] | ||||||||
| Increase in Accounts Payable for Capital Additions to Property, Plant and Equipment | 20.2 | 5.9 | 7.5 | |||||
| Capitalized Asset Retirement Costs | 17.1 | 0.3 | 2.8 | |||||
| AFUDC - Equity | 5.1 | 2.5 | 4.2 | |||||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||||||||
| ALLETE Common Stock Contributed to Pension Plan | 0 | (20.0) | 0 | |||||
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Pension [Member]
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| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||||||||
| ALLETE Common Stock Contributed to Pension Plan | $ 20.0 | |||||||
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| X | ||||||||||
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- Definition
Amount of asset retirement obligations incurred during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Future cash outflow to pay for purchases of fixed assets that have occurred. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of taxes. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
|
- Definition
The increase (decrease) during the reporting period in the capitalized cost of equity (based on assumed rate of return) and / or borrowed funds (based on interest rate) used to finance construction of regulated assets, which is expected to be recovered through rate adjustments. As a result of this capitalization, net income is increased. This element pertains to certain regulated industries, such as public utilities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The amount of cash paid for interest during the period net of cash paid for interest that is capitalized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Value of shares issued during the period to an employee benefit plan, such as a defined contribution or defined benefit plan. No definition available.
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| X | ||||||||||
|
- Details
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|
Operations and Significant Accounting Policies - Investments and Other (Details)
|
12 Months Ended |
|---|---|
|
Dec. 31, 2012
|
|
| Long-term Contract for Purchase of Electric Power [Line Items] | |
| Real Estate Sales Revenue Recognition, Minimum Contract Price Cash Collections Requirement | 20.00% |
|
Square Butte PPA [Member]
|
|
| Long-term Contract for Purchase of Electric Power [Line Items] | |
| Output Purchased (Percent) | 50.00% |
| Output Purchased (MW) | 227.5 |
| X | ||||||||||
|
- Definition
Long-Term Contract for Purchase of Electric Power, Share of Plant Output Purchased No definition available.
|
| X | ||||||||||
|
- Definition
The minimum amount of cash collected on the contract price in order to fully recognize profit on the sale of real estate upon closing (company policy). No definition available.
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
Share of plant output being purchased under a long-term contract to purchase electricity from a production plant constructed and financed by a public utility district, cooperative, or other organization. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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|
Operations and Significant Accounting Policies - Concentraion of Credit Risk (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Customer Information [Line Items] | |||
| Major Customer, Percent of Total Revenue | 12.30% | 12.80% | 12.50% |
| NewPage Bankruptcy Pre-Petition Receivable | $ 3.2 | ||
|
Large Power Customer [Member]
|
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| Customer Information [Line Items] | |||
| Number of Customers | 9 | ||
| Large Power Customers, Accounts Receivable | $ 11.6 | $ 9.3 | |
| X | ||||||||||
|
- Details
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| X | ||||||||||
|
- Definition
Number of Customers No definition available.
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| X | ||||||||||
|
- Definition
For unclassified balance sheet, amounts due from customers or clients for goods or services that have been delivered or sold in the normal course of business. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of bankruptcy claim settled. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Percentage of revenue generated from a single external customer that accounts for 10 percent or more of an entity's revenues. No definition available.
|
|
Business Segments (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
Dec. 31, 2012
|
Sep. 30, 2012
|
Jun. 30, 2012
|
Mar. 31, 2012
|
Dec. 31, 2011
|
Sep. 30, 2011
|
Jun. 30, 2011
|
Mar. 31, 2011
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Business Segments [Line Items] | |||||||||||
| Operating Revenue | $ 256.0 | $ 248.8 | $ 216.4 | $ 240.0 | $ 239.2 | $ 226.9 | $ 219.9 | $ 242.2 | $ 961.2 | $ 928.2 | $ 907.0 |
| Fuel and Purchased Power Expense | 308.7 | 306.6 | 325.1 | ||||||||
| Operating and Maintenance Expense | 397.1 | 381.2 | 365.6 | ||||||||
| Depreciation Expense | 100.2 | 90.4 | 80.5 | ||||||||
| Operating Income (Loss) | 47.9 | 45.6 | 23.3 | 38.4 | 34.2 | 38.9 | 26.1 | 50.8 | 155.2 | 150.0 | 135.8 |
| Interest Expense | (45.5) | (43.6) | (39.2) | ||||||||
| Equity Earnings in ATC | 19.4 | 18.4 | 17.9 | ||||||||
| Other Income | 6.0 | 4.4 | 4.6 | ||||||||
| Income (Loss) Before Non-Controlling Interest and Income Taxes | 135.1 | 129.2 | 119.1 | ||||||||
| Income Tax Expense (Benefit) | 38.0 | 35.6 | 44.3 | ||||||||
| Net Income (Loss) | 97.1 | 93.6 | 74.8 | ||||||||
| Less: Non-Controlling Interest in Subsidiaries | 0 | (0.2) | (0.5) | ||||||||
| Net Income (Loss) Attributable to ALLETE | 28.9 | 29.4 | 14.4 | 24.4 | 19.1 | 20.5 | 17.0 | 37.2 | 97.1 | 93.8 | 75.3 |
| Total Assets | 3,253.4 | 2,876.0 | 3,253.4 | 2,876.0 | 2,609.1 | ||||||
| Capital Additions | 432.2 | 246.8 | 260.0 | ||||||||
|
Regulated Operations [Member]
|
|||||||||||
| Business Segments [Line Items] | |||||||||||
| Operating Revenue | 874.4 | 851.9 | 835.5 | ||||||||
| Fuel and Purchased Power Expense | 308.7 | 306.6 | 325.1 | ||||||||
| Operating and Maintenance Expense | 310.0 | 301.5 | 292.3 | ||||||||
| Depreciation Expense | 93.9 | 85.4 | 76.1 | ||||||||
| Operating Income (Loss) | 161.8 | 158.4 | 142.0 | ||||||||
| Interest Expense | (39.8) | (35.8) | (32.3) | ||||||||
| Equity Earnings in ATC | 19.4 | 18.4 | 17.9 | ||||||||
| Other Income | 5.1 | 2.6 | 3.8 | ||||||||
| Income (Loss) Before Non-Controlling Interest and Income Taxes | 146.5 | 143.6 | 131.4 | ||||||||
| Income Tax Expense (Benefit) | 50.4 | 43.2 | 51.6 | ||||||||
| Net Income (Loss) | 96.1 | 100.4 | 79.8 | ||||||||
| Less: Non-Controlling Interest in Subsidiaries | 0 | 0 | 0 | ||||||||
| Net Income (Loss) Attributable to ALLETE | 96.1 | 100.4 | 79.8 | ||||||||
| Total Assets | 2,962.4 | 2,579.8 | 2,962.4 | 2,579.8 | 2,375.4 | ||||||
| Capital Additions | 418.2 | 228.0 | 256.4 | ||||||||
|
Investments and Other [Member]
|
|||||||||||
| Business Segments [Line Items] | |||||||||||
| Number of acres of land in Minnesota (in acres) | 6,100 | 6,100 | |||||||||
| Operating Revenue | 86.8 | 76.3 | 71.5 | ||||||||
| Fuel and Purchased Power Expense | 0 | 0 | 0 | ||||||||
| Operating and Maintenance Expense | 87.1 | 79.7 | 73.3 | ||||||||
| Depreciation Expense | 6.3 | 5.0 | 4.4 | ||||||||
| Operating Income (Loss) | (6.6) | (8.4) | (6.2) | ||||||||
| Interest Expense | (5.7) | (7.8) | (6.9) | ||||||||
| Equity Earnings in ATC | 0 | 0 | 0 | ||||||||
| Other Income | 0.9 | 1.8 | 0.8 | ||||||||
| Income (Loss) Before Non-Controlling Interest and Income Taxes | (11.4) | (14.4) | (12.3) | ||||||||
| Income Tax Expense (Benefit) | (12.4) | (7.6) | (7.3) | ||||||||
| Net Income (Loss) | 1.0 | (6.8) | (5.0) | ||||||||
| Less: Non-Controlling Interest in Subsidiaries | 0 | (0.2) | (0.5) | ||||||||
| Net Income (Loss) Attributable to ALLETE | 1.0 | (6.6) | (4.5) | ||||||||
| Total Assets | 291.0 | 296.2 | 291.0 | 296.2 | 233.7 | ||||||
| Capital Additions | $ 14.0 | $ 18.8 | $ 3.6 | ||||||||
| X | ||||||||||
|
- Definition
Number of acres of land available-for-sale. No definition available.
|
| X | ||||||||||
|
- Definition
Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Cost of electricity purchased as well as fuel used to generate electricity used in operations and sold during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The cost of borrowed funds accounted for as interest that was charged against earnings during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of Net Income (Loss) attributable to noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The net result for the period of deducting operating expenses from operating revenues. No definition available.
|
| X | ||||||||||
|
- Definition
The net amount of other income and expense amounts, the components of which are not separately disclosed on the income statement, resulting from ancillary business-related activities (that is, excluding major activities considered part of the normal operations of the business) also known as other nonoperating income (expense) recognized for the period. Such amounts may include: (a) dividends, (b) interest on securities, (c) net gains or losses on securities, (d) unusual costs, (e) gains or losses on foreign exchange transactions, and (f) miscellaneous other income and expense items. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Acquisition of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. No definition available.
|
| X | ||||||||||
|
- Definition
The total amount of operating revenues recognized during the period. No definition available.
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Discloses the amount of operating expense for the period related to depreciation and amortization. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Discloses the amount of operating expense for the period for routine plant maintenance, repairs and operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Property, Plant and Equipment (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Property, Plant and Equipment [Line Items] | |||
| Total Property, Plant and Equipment - Net | $ 2,347.6 | $ 1,982.7 | |
| Asset Retirement Obligation [Roll Forward] | |||
| Beginning Obligation | 57.0 | 50.3 | |
| Accretion Expense | 3.8 | 6.4 | |
| Additional Liabilities Incurred | 17.1 | 0.3 | 2.8 |
| Ending Obligation | 77.9 | 57.0 | 50.3 |
|
Regulated Utiity [Member]
|
|||
| Property, Plant and Equipment [Line Items] | |||
| Property, Plant and Equipment | 3,232.9 | 2,794.8 | |
| Construction Work in Progress | 151.8 | 155.0 | |
| Accumulated Depreciation | (1,102.8) | (1,024.6) | |
| Property, Plant and Equipment - Net | 2,281.9 | 1,925.2 | |
| Estimated Useful Life - Generation | 3 to 35 years | ||
| Estimated Useful Life - Transmission | 42 to 61 years | ||
| Estimated Useful Life - Distribution | 14 to 65 years | ||
|
Non-Rate Base Energy Operations and Other Plant [Member]
|
|||
| Property, Plant and Equipment [Line Items] | |||
| Property, Plant and Equipment | 118.0 | 106.4 | |
| Construction Work in Progress | 4.2 | 2.3 | |
| Accumulated Depreciation | (56.7) | (51.4) | |
| Property, Plant and Equipment - Net | 65.5 | 57.3 | |
| Other Plant - Net | $ 0.2 | $ 0.2 | |
| Estimated Useful Life - Non-Rate Base Operations | 3 to 61 years | ||
| Estimated Useful Life - Other Plant | 5 to 25 years | ||
| X | ||||||||||
|
- Definition
The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of asset retirement obligations incurred during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Amount, net of accumulated depreciation, depletion and amortization, of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Period end book value of accumulated depreciation on property, plant and equipment (PPE) that is owned by the regulated operations of the public utility. No definition available.
|
| X | ||||||||||
|
- Definition
Estimated useful life of property, plant and equipment (PPE) related to assets common to business units owned by public utility. No definition available.
|
| X | ||||||||||
|
- Definition
Period end amount of construction work in progress in public utility. No definition available.
|
| X | ||||||||||
|
- Definition
Estimated useful life of property, plant and equipment (PPE) related to utility distribution owned by public utility. No definition available.
|
| X | ||||||||||
|
- Definition
Estimated useful life of property, plant and equipment (PPE) related to utility generation owned by the public utility. No definition available.
|
| X | ||||||||||
|
- Definition
Period end amount of total net PPE. No definition available.
|
| X | ||||||||||
|
- Definition
Period end book value of other property, plant and equipment (PPE) owned (but not classified elsewhere) by the public utility. No definition available.
|
| X | ||||||||||
|
- Definition
Estimated useful life of other property, plant and equipment (PPE) owned (but not classified elsewhere) by the public utility. No definition available.
|
| X | ||||||||||
|
- Definition
Period end amount of total gross PPE. No definition available.
|
| X | ||||||||||
|
- Definition
Estimated useful life of property, plant and equipment (PPE) related to utility transmission. No definition available.
|
|
Jointly-Owned Facilities (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
|
|---|---|
| Jointly-Owned Facilities [Line Items] | |
| Plant in Service | $ 435.9 |
| Accumulated Depreciation | 188.5 |
| Construction Work in Progress | 50.4 |
|
Boswell Unit 4 [Member]
|
|
| Jointly-Owned Facilities [Line Items] | |
| Plant in Service | 413.1 |
| Accumulated Depreciation | 188.1 |
| Construction Work in Progress | 25.0 |
| % Ownership | 80.00% |
| Generating Unit Capacity (MW) | 585 |
| % Not Owned | 20.00% |
|
CapX2020 [Member]
|
|
| Jointly-Owned Facilities [Line Items] | |
| Plant in Service | 22.8 |
| Accumulated Depreciation | 0.4 |
| Construction Work in Progress | $ 25.4 |
| Number of Projects | 3 |
|
CapX2020 [Member] | Minimum [Member]
|
|
| Jointly-Owned Facilities [Line Items] | |
| % Ownership | 9.30% |
|
CapX2020 [Member] | Maximum [Member]
|
|
| Jointly-Owned Facilities [Line Items] | |
| % Ownership | 14.70% |
| X | ||||||||||
|
- Definition
Capacity of each generating unit/individual project in megawatts. No definition available.
|
| X | ||||||||||
|
- Definition
Jointly-Owned Electric Facility Percentage Not Owned No definition available.
|
| X | ||||||||||
|
- Definition
Number of projects. No definition available.
|
| X | ||||||||||
|
- Definition
The period end amount owned by the reporting utility of a jointly owned utility plant in service. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The period end amount of construction work in progress at a jointly owned electricity generation plant. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The period end amount of accumulated depreciation in a jointly owned electricity generation plant. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The proportionate share of interest (percent) in a jointly owned utility plant. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Regulatory Matters - Electric Rates (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
Municipal Customers [Member]
Customers
|
Dec. 31, 2012
Non-Affiliated Private Utility [Member]
Customers
|
Jun. 01, 2011
MPUC 2010 MN Rate Case [Member]
Electric Rates [Member]
Retail Customers [Member]
|
Dec. 31, 2012
FERC-Approved Wholesale Rates [Member]
Electric Rates [Member]
Municipal Customers [Member]
Years
Customers
|
Dec. 31, 2012
FERC-Approved Wholesale Rates [Member]
Electric Rates [Member]
Non-Affiliated Private Utility [Member]
Years
MW
Customers
|
Dec. 31, 2012
PSCW 2012 Wisconsin Rate Case [Member]
Retail Customers [Member]
|
Dec. 31, 2012
PSCW 2012 Wisconsin Rate Case [Member]
Natural Gas Rates [Member]
Retail Customers [Member]
|
Dec. 31, 2012
PSCW 2012 Wisconsin Rate Case [Member]
Electric Rates [Member]
Retail Customers [Member]
|
Dec. 31, 2012
PSCW 2012 Wisconsin Rate Case [Member]
Water Rates [Member]
Retail Customers [Member]
|
|---|---|---|---|---|---|---|---|---|---|
| Rate Regulation [Line Items] | |||||||||
| Approved Rate of Return on Common Equity | 10.38% | 10.90% | |||||||
| Approved Percentage of Capital Structure Related to Equity | 54.29% | ||||||||
| Number of Customers | 16 | 1 | 16 | 1 | |||||
| Length of Notice Required to Terminate (Years) | 3 | 2 | |||||||
| Average Monthly Demand (in MWs) | 17 | ||||||||
| Approved Rate Increase or Decrease | 2.40% | (2.00%) | 1.20% | 13.80% | |||||
| Amount Of Estimated Additional Revenue | $ 1.7 |
| X | ||||||||||
|
- Definition
The amount of estimated additional revenue generated on an annualized basis as a result of a rate increase. No definition available.
|
| X | ||||||||||
|
- Definition
Percentage of capital structure related to equity approved by the regulatory commission through a rate case proceeding. No definition available.
|
| X | ||||||||||
|
- Definition
The rate increase or decrease approved by appropriate regulatory body No definition available.
|
| X | ||||||||||
|
- Definition
Rate of return on common equity approved by the regulatory commission through a rate case proceeding. No definition available.
|
| X | ||||||||||
|
- Definition
The Average Monthly Demand (in MWs) No definition available.
|
| X | ||||||||||
|
- Definition
The length of notice required to terminate a contract (in years). No definition available.
|
| X | ||||||||||
|
- Definition
Number of Customers No definition available.
|
| X | ||||||||||
|
- Details
|
|
Regulatory Matters - Boswell Mercury Emission Reduction Plan (Details) (Boswell Unit 4 [Member], USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
|
|---|---|
|
Boswell Unit 4 [Member]
|
|
| Schedule of Utility Generating Facilities [Line Items] | |
| Estimated Environmental Compliance Costs - Minimum | $ 350 |
| Estimated Environmental Compliance Costs - Maximum | $ 400 |
| X | ||||||||||
|
- Definition
The maximum amount expected to be invested related to compliance with a certain environmental regualtion/mandate. No definition available.
|
| X | ||||||||||
|
- Definition
The minimum amount expected to be invested related to compliance with a certain environmental regualtion/mandate. No definition available.
|
| X | ||||||||||
|
- Details
|
|
Regulatory Matters - The Patient Protection and Affordable Care Act of 2010 (PPACA) (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
|
Jun. 30, 2011
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Unusual or Infrequent Item [Line Items] | ||||
| Deferred Income Tax Expense (Benefit) | $ 37.5 | $ 35.8 | $ 66.0 | |
| Non-Current Regulatory Asset | 340.3 | 345.9 | ||
|
PPACA Elimination of Medicare Part D [Member]
|
||||
| Unusual or Infrequent Item [Line Items] | ||||
| Reversal of Previously Recorded Tax Benefit | 0 | 0 | 4.0 | |
| Deferred Income Tax Expense (Benefit) | 2.9 | 0 | (2.9) | 0 |
| Non-Current Regulatory Asset | $ 5.0 | |||
| X | ||||||||||
|
- Definition
The component of income tax expense for the period representing the increase (decrease) in the entity's deferred tax assets and liabilities pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Reflects the effects of adjustments of previously recorded tax expense, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, IRS tax settlement and unusual repatriation of foreign earnings. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
|
Regulatory Matters - Regulatory Assets and Liabilities (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
|
Dec. 31, 2011
|
||||||
|---|---|---|---|---|---|---|---|---|
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Current Regulatory Asset | $ 22.5 | $ 17.5 | ||||||
| Non-Current Regulatory Asset | 340.3 | 345.9 | ||||||
| Total Regulatory Assets | 362.8 | 363.4 | ||||||
| Non-Current Regulatory Liability | 60.1 | 43.5 | ||||||
|
Income Taxes [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Liability | 19.5 | 21.9 | ||||||
|
Plant Removal Obligations [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Liability | 18.1 | 15.0 | ||||||
|
Wholesale and Retail Contra AFUDC [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Liability | 15.5 | 1.5 | ||||||
|
Other [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Liability | 7.0 | 5.1 | ||||||
|
Deferred Fuel [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Current Regulatory Asset | 22.5 | [1] | 17.5 | [1] | ||||
|
Future Benefit Obligations Under Defined Benefit Pension and Other Postretirement Benefit Plans [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Asset | 260.7 | 292.8 | ||||||
|
Income Taxes [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Asset | 36.0 | 28.6 | ||||||
|
Asset Retirement Obligation [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Asset | 12.1 | 9.8 | ||||||
|
Cost Recovery Riders [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Asset | 18.5 | [2] | 0.7 | [2] | ||||
|
PPACA Income Tax Deferral [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Asset | 5.0 | 5.0 | ||||||
|
Conservation Improvement Program [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Asset | 4.3 | 4.6 | ||||||
|
Other [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Asset | $ 3.7 | $ 4.4 | ||||||
|
||||||||
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are expected to be recovered through revenue sources within one year or the normal operating cycle, if longer. Such costs are capitalized if they meet both of the following criteria: a. It is probable that future revenue in an amount at least equal to the capitalized cost will result from inclusion of that cost in allowable costs for rate-making purposes. b. Based on available evidence, the future revenue will be provided to permit recovery of the previously incurred cost rather than to provide for expected levels of similar future costs. If the revenue will be provided through an automatic rate-adjustment clause, this criterion requires that the regulator's intent clearly be to permit recovery of the previously incurred cost. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The amount for the individual regulatory noncurrent liability as itemized in a table of regulatory noncurrent liabilities as of the end of the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Investment in ATC (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
|
Mar. 31, 2013
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Balance Sheet Data [Abstract] | ||||
| Current Assets | $ 63.1 | $ 58.7 | ||
| Non-Current Assets | 3,274.7 | 3,053.7 | ||
| Total Assets | 3,337.8 | 3,112.4 | ||
| Current Liabilities | 251.5 | 298.5 | ||
| Long-Term Debt | 1,550.0 | 1,400.0 | ||
| Other Non-Current Liabilities | 95.8 | 82.6 | ||
| Members' Equity | 1,440.5 | 1,331.3 | ||
| Total Liabilities and Members' Equity | 3,337.8 | 3,112.4 | ||
| Income Statement Data [Abstract] | ||||
| Revenue | 603.2 | 567.2 | 556.7 | |
| Operating Expense | 281.0 | 261.6 | 251.1 | |
| Other Expense | 84.8 | 81.7 | 85.9 | |
| Net Income | 237.4 | 223.9 | 219.7 | |
| ALLETE's Equity in Net Income | 19.4 | 18.4 | 17.9 | |
| Investment in ATC [Abstract] | ||||
| Equity Method Investment, Ownership Percentage | 8.00% | |||
| Equity Method Investment, Approved Return on Common Equity | 12.20% | |||
| Equity Method Investment, Expected Future Investment | 2.0 | |||
| ALLETE's Investment in ATC [Roll Forward] | ||||
| Equity Investment Beginning Balance | 107.3 | 98.9 | 93.3 | |
| Cash Investments | 0.4 | 4.7 | 2.0 | |
| Equity Earnings in ATC | 19.4 | 18.4 | 17.9 | |
| Distributed ATC Earnings | (15.7) | (14.8) | ||
| Equity Investment Ending Balance | $ 107.3 | $ 98.9 | $ 93.3 | |
| X | ||||||||||
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- Details
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| X | ||||||||||
|
- Definition
The approved percentage return on common equity dedicated to the utility plant in the investee accounted for under the equity method of accounting. No definition available.
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| X | ||||||||||
|
- Definition
Equity Method Investment, Expected Future Investment No definition available.
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Equity Method Investment, Summarized Financial Information, Long-Term Debt No definition available.
|
| X | ||||||||||
|
- Definition
The amount of the operating expense reported by an equity method investment of the entity. No definition available.
|
| X | ||||||||||
|
- Definition
The amount of other expense reported by an equity method investment of the entity. No definition available.
|
| X | ||||||||||
|
- Definition
Equity Method Investment, Summarized Financial Information, Other Non-Current Liabilities No definition available.
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| X | ||||||||||
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- Details
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| X | ||||||||||
|
- Definition
This item represents disclosure of the amount of dividends or other distributions received from unconsolidated subsidiaries, certain corporate joint ventures, and certain noncontrolled corporation; these investments are accounted for under the equity method of accounting. This element excludes distributions that constitute a return of investment, which are classified as investing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
|
- Definition
The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
|
- Definition
This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
|
- Definition
The amount of assets reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
|
- Definition
The amount of current assets reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
|
- Definition
The amount of current liabilities reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of equity, including noncontrolling interest, reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Details
|
| X | ||||||||||
|
- Definition
The amount of liabilities and equity reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The amount of net income (loss) reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
|
- Definition
The amount of noncurrent assets reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
|
- Definition
The amount of revenue from sale of goods and services reduced by sales returns, allowances, and discounts reported by an equity method investment of the entity. No definition available.
|
| X | ||||||||||
|
- Definition
This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
|
- Definition
The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Investments (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | |||
|---|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
Jan. 05, 2011
|
|
| Available-for-sale Securities [Abstract] | ||||
| Cost | $ 27.4 | $ 27.3 | $ 27.4 | |
| Gross Unrealized Gain | 0.5 | 0.1 | 0.2 | |
| Gross Unrealized (Loss) | (1.1) | (2.7) | (2.4) | |
| Fair Value | 26.8 | 24.7 | 25.2 | |
| Net Proceeds | 1.5 | 7.8 | 0.6 | |
| Gross Realized Gain | 0 | 0 | 0 | |
| Gross Realized (Loss) | 0 | 0 | 0 | |
| Net Unrealized Gain (Loss) in Other Comprehensive Income | 1.2 | (0.3) | 0.8 | |
| Available for sale securities, Issued by States of the United States (ARS) | 6.7 | |||
| Investments [Abstract] | ||||
| ALLETE Properties | 91.1 | 91.3 | ||
| Available-for-sale Securities | 26.8 | 24.7 | ||
| Other | 25.6 | 16.3 | ||
| Total Investments | 143.5 | 132.3 | ||
| Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward] | ||||
| Land Inventory Beginning Balance | 86.0 | 86.0 | ||
| Deeds to Collateralized Property | 0.5 | 1.8 | ||
| Land Impairment | 0 | (1.7) | ||
| Cost of Sales | (0.2) | (0.3) | ||
| Capitalized Improvements and Other | 0.2 | 0.2 | ||
| Land Inventory Ending Balance | 86.5 | 86.0 | 86.0 | |
| Long-Term Finance Receivables (net of allowances of $0.6 and $0.6) | 1.4 | 2.0 | ||
| Other | 3.2 | 3.3 | ||
| Total Real Estate Assets | 91.1 | 91.3 | ||
| Long-Term Finance Receivables, Allowance | $ 0.6 | $ 0.6 | ||
| X | ||||||||||
|
- Definition
Total of debt securities issued by states of the United States categorized as neither held-to-maturity nor trading. No definition available.
|
| X | ||||||||||
|
- Definition
A valuation allowance relating to a written agreement to receive money (at a specified future date(s) more than one year from the reporting date, consisting of principal as well as any accrued interest) for the portion that is expected to be uncollectible. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
|
- Definition
This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
|
- Definition
The total amount of proceeds received for the sale of securities, categorized neither as held-to-maturity nor trading securities, during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
This item represents the gross unrealized losses for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities. No definition available.
|
| X | ||||||||||
|
- Definition
Investments in debt and equity securities which are categorized neither as held-to-maturity nor trading and which are intended to be sold or mature more than one year from the balance sheet date or operating cycle, if longer. Such securities are reported at fair value; unrealized gains (losses) related to Available-for-sale Securities are excluded from earnings and reported in a separate component of shareholders' equity (other comprehensive income), unless the Available-for-sale security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding gain (loss) of an Available-for-sale security that is designated as being hedged in a fair value hedge is recognized in earnings during the period of the hedge, as are other than temporary declines in fair value below the cost basis for investments in equity securities and debt securities that an entity intends to sell or it is more likely than not that it will be required to sell before the recovery of its amortized cost basis. Other than temporary declines in fair value below the cost basis for debt securities categorized as Available-for-sale that an entity does not intend to sell and for which it is not more likely than not that the entity will be required to sell before the recovery of its amortized cost basis are bifurcated into credit losses and losses related to all other factors. Other than temporary declines in fair value below cost basis related to credit losses are recognized in earnings, and losses related to all other factors are recognized in other comprehensive income. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The charge against earnings in the period to reduce the carrying amount of real property to fair value. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Carrying value of land held for sale. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
An amount representing an agreement for an unconditional promise by the maker to pay the Entity (holder) a definite sum of money at a future date more than one year from the balance sheet date, net of any write-downs taken for collection uncertainty on the part of the holder. Such amount may include accrued interest receivable in accordance with the terms of the debt. The debt also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. This amount does not include amounts related to receivables held-for-sale. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Before tax and reclassification adjustments amount of unrealized holding gain (loss) and transfers on available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
|
- Definition
Other investments not otherwise specified in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Other long-term investments not otherwise specified in the taxonomy, not including investments in marketable securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Carrying amount of other real estate not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. This does not include real estate assets taken in settlement of troubled loans through surrender or foreclosure. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of real estate investments acquired through foreclosure during the period. Title through foreclosure occurs in a legal proceeding in which a secured creditor obtains title typically by bidding the amount of debt owed to it after the borrower has defaulted on the debt instrument. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
|
- Definition
The carrying amount of real estate sold during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Gross amount of real estate as of the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of improvements made to real estate investments during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
|
Investments Parenthetical (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
|
Dec. 31, 2011
|
|---|---|---|
| Investments Parenthetical [Abstract] | ||
| Long-Term Finance Receivables, Allowance | $ 0.6 | $ 0.6 |
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
A valuation allowance relating to a written agreement to receive money (at a specified future date(s) more than one year from the reporting date, consisting of principal as well as any accrued interest) for the portion that is expected to be uncollectible. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Derivatives - Hedged Items (Details) (Term Loan [Member], USD $)
In Millions, unless otherwise specified |
12 Months Ended | |
|---|---|---|
|
Dec. 31, 2012
|
Sep. 30, 2011
|
|
|
Term Loan [Member]
|
||
| Debt Instrument [Line Items] | ||
| Term Loan Principal Amount | $ 75.0 | |
| Term Loan Variable Rate Basis | one-month LIBOR | |
| Term Loan Basis Spread on Variable Rate | 1.00% |
| X | ||||||||||
|
- Definition
The percentage points added to the reference rate to compute the variable rate on the debt instrument. No definition available.
|
| X | ||||||||||
|
- Definition
The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR. No definition available.
|
| X | ||||||||||
|
- Definition
The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
|
Derivatives (Details) (Interest Rate Swap [Member], USD $)
In Millions, unless otherwise specified |
12 Months Ended | |
|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
|
|
Interest Rate Swap [Member]
|
||
| Derivative [Line Items] | ||
| Percentage of Debt Hedged by Interest Rate Swap | 8.00% | |
| Interest Rate Swap Variable Rate Basis | one-month LIBOR | |
| Interest Rate Swap Fixed Interest Rate | 0.825% | |
| Discussion of Interest Rate Cash Flow Hedge Effectiveness Assessment and Measurement | The shortcut method is used to assess hedge effectiveness. At inception, all shortcut method requirements were satisfied; thus changes in value of the Swap designated as the hedging instrument will be deemed 100 percent effective. As a result, there was no ineffectiveness recorded for the year ended December 31, 2012. | |
| Interest Rate Swap Liability | $ (0.7) | $ (0.4) |
| X | ||||||||||
|
- Definition
The reference rate for the variable rate of the interest rate derivative, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR. No definition available.
|
| X | ||||||||||
|
- Definition
Fixed interest rate related to the interest rate derivative. No definition available.
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Discussion of how the entity assesses hedge effectiveness and measures hedge ineffectiveness in interest rate derivatives designated as cash flow hedges. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Fair value as of the balance sheet date of all interest rate derivative liabilities designated as cash flow hedging instruments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Percentage of an entity's outstanding debt that is designated as a hedged item in cash flow, fair value, or net investment hedge. No definition available.
|
|
Fair Value - Recurring Fair Value Measures (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | |
|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
|
| Liabilities [Abstract] | ||
| Fair Value Activity in Level 3 | $ 0 | |
| Fair Value Hierarchy Transfers, All Levels | 0 | 0 |
|
Recurring Fair Value Measures [Member]
|
||
| Investments [Abstract] | ||
| Available-for-sale Securities - Equity Securities | 18.0 | 17.6 |
| Available-for-sale Securities - Corporate Debt Securities | 8.8 | 8.2 |
| Cash Equivalents | 20.7 | 11.4 |
| Total Fair Value of Assets | 47.5 | 37.2 |
| Liabilities [Abstract] | ||
| Deferred Compensation | 14.0 | 12.8 |
| Derivatives - Interest Rate Swap | 0.7 | 0.4 |
| Total Fair Value of Liabilities | 14.7 | 13.2 |
| Total Net Fair Value of Assets (Liabilities) | 32.8 | 24.0 |
|
Recurring Fair Value Measures [Member] | Level 1 [Member]
|
||
| Investments [Abstract] | ||
| Available-for-sale Securities - Equity Securities | 18.0 | 17.6 |
| Available-for-sale Securities - Corporate Debt Securities | 0 | 0 |
| Cash Equivalents | 20.7 | 11.4 |
| Total Fair Value of Assets | 38.7 | 29.0 |
| Liabilities [Abstract] | ||
| Deferred Compensation | 0 | 0 |
| Derivatives - Interest Rate Swap | 0 | 0 |
| Total Fair Value of Liabilities | 0 | 0 |
| Total Net Fair Value of Assets (Liabilities) | 38.7 | 29.0 |
|
Recurring Fair Value Measures [Member] | Level 2 [Member]
|
||
| Investments [Abstract] | ||
| Available-for-sale Securities - Equity Securities | 0 | 0 |
| Available-for-sale Securities - Corporate Debt Securities | 8.8 | 8.2 |
| Cash Equivalents | 0 | 0 |
| Total Fair Value of Assets | 8.8 | 8.2 |
| Liabilities [Abstract] | ||
| Deferred Compensation | 14.0 | 12.8 |
| Derivatives - Interest Rate Swap | 0.7 | 0.4 |
| Total Fair Value of Liabilities | 14.7 | 13.2 |
| Total Net Fair Value of Assets (Liabilities) | (5.9) | (5.0) |
|
Recurring Fair Value Measures [Member] | Level 3 [Member]
|
||
| Investments [Abstract] | ||
| Available-for-sale Securities - Equity Securities | 0 | 0 |
| Available-for-sale Securities - Corporate Debt Securities | 0 | 0 |
| Cash Equivalents | 0 | 0 |
| Total Fair Value of Assets | 0 | 0 |
| Liabilities [Abstract] | ||
| Deferred Compensation | 0 | 0 |
| Derivatives - Interest Rate Swap | 0 | 0 |
| Total Fair Value of Liabilities | 0 | 0 |
| Total Net Fair Value of Assets (Liabilities) | $ 0 | $ 0 |
| X | ||||||||||
|
- Definition
This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. No definition available.
|
| X | ||||||||||
|
- Definition
This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represeent Available-for-sale Securities which consist of all investments in certain equity securities neither classified as trading or held-to-maturity securities. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options and put options, but do not include convertible debt. No definition available.
|
| X | ||||||||||
|
- Definition
This element represents the portion of the balance sheet assertion, Deferred Compensation, valued at fair value by the entity. No definition available.
|
| X | ||||||||||
|
- Definition
Fair Value Activity in Level 3 No definition available.
|
| X | ||||||||||
|
- Definition
The amount of transfers in and out of levels 1, 2 and 3 of the fair value hierarchy during the period. No definition available.
|
| X | ||||||||||
|
- Definition
This element represents the portion of the balance sheet Investments line item's cash and cash equivalents, valued at fair value by the entity. No definition available.
|
| X | ||||||||||
|
- Definition
This element represents the aggregate of the assets and liabilities reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. No definition available.
|
| X | ||||||||||
|
- Definition
This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Derivative instrument obligations meeting the definition of a liability which the Company is a party to as of the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
This element represents the aggregate of the liabilities reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
|
Fair Value - Recurring Fair Value Measures, Activity in Level 3 (Details) (Debt Securities Issued by States of the United States (ARS) [Member], USD $)
In Millions, unless otherwise specified |
12 Months Ended | |||
|---|---|---|---|---|
|
Dec. 31, 2011
|
||||
|
Debt Securities Issued by States of the United States (ARS) [Member]
|
||||
| Recurring Fair Value Measures, Activity in Level 3 [Line Items] | ||||
| Beginning Balance | $ 6.7 | |||
| Redeemed During the Period | (6.7) | [1] | ||
| Ending Balance | $ 0 | |||
|
||||
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Sales that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Fair Value - Financial Instruments (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
|
Dec. 31, 2011
|
|---|---|---|
| Financial Instruments [Abstract] | ||
| Long-Term Debt, Including Current Portion - Carrying Amount | $ 1,018.1 | $ 863.3 |
| Long-Term Debt, Including Current Portion - Fair Value | $ 1,143.7 | $ 966.4 |
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. No definition available.
|
|
Short-Term and Long-Term Debt (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | 12 Months Ended | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2012
Lines of Credit [Member]
|
Dec. 31, 2011
Lines of Credit [Member]
|
Dec. 31, 2012
ALLETE LOC January 2014 [Member]
|
Jun. 30, 2012
ALLETE LOC January 2014 [Member]
|
Feb. 01, 2012
ALLETE LOC January 2014 [Member]
|
Dec. 31, 2012
ALLETE LOC June 2015 [Member]
|
Dec. 31, 2012
ALLETE Bonds 4.86% Due 2013 [Member]
|
Dec. 31, 2012
ALLETE Bonds 3.20% Due July 2026 [Member]
|
Dec. 31, 2012
ALLETE Bonds 4.08% Due July2042 [Member]
|
Dec. 31, 2012
Industrial Development Revenue Bonds 6.5% Due 2025 [Member]
|
|
| Financial Covenants [Abstract] | ||||||||||||
| Required Indebtedness to Total Capital Ratio | 0.65 | |||||||||||
| Actual Indebtedness to Total Capital Ratio | 0.46 | |||||||||||
| Maturities of Long-term Debt [Abstract] | ||||||||||||
| Long-Term Debt | $ 933.6 | $ 857.9 | ||||||||||
| Long-Term Debt Due Within One Year | 84.5 | 5.4 | 60.0 | |||||||||
| Long-Term Debt, 2014 Maturities | 94.8 | |||||||||||
| Long-Term Debt, 2015 Maturities | 17.4 | |||||||||||
| Long-Term Debt, 2016 Maturities | 21.7 | |||||||||||
| Long-Term Debt, 2017 Maturities | 51.2 | |||||||||||
| Long-Term Debt, Thereafter Maturities | 748.5 | |||||||||||
| Debt Instrument [Line Items] | ||||||||||||
| Short-Term Debt | 84.5 | 6.5 | ||||||||||
| Line of Credit Facility, Maximum Borrowing Capacity | 406.4 | 256.4 | 150.0 | 150.0 | 250.0 | |||||||
| Letter of Credit Maximum Issuances | 50.0 | 10.0 | ||||||||||
| Lines of Credit, Current | 0 | 1.1 | ||||||||||
| Proceeds from Issuance of First Mortgage Bond | 160.0 | 75.0 | 85.0 | |||||||||
| First Mortgage Bonds, Interest Rate | 3.20% | 4.08% | 6.50% | |||||||||
| Redemption of Bond | 6.0 | |||||||||||
| Line of Credit Facility, Amount Outstanding | $ 14.0 | |||||||||||
| X | ||||||||||
|
- Definition
Actual indebtedness to total capital ratio required to be maintained by most restrictive financial covenant. No definition available.
|
| X | ||||||||||
|
- Definition
Indebtedness to total capital ratio required to be maintained by most restrictive financial covenant. No definition available.
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
This represents the allowed amount of letters of credit issuances under another credit agreement. No definition available.
|
| X | ||||||||||
|
- Definition
Carrying value as of the balance sheet date of the sum of short-term debt and current maturities of long-term debt and capital lease obligations, which are due within one year (or one business cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Decrease for amounts repaid on the debt instrument for the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Interest rate stated in the contractual debt agreement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Amount borrowed under the credit facility as of the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The carrying value as of the balance sheet date of the current portion of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Carrying amount of long-term debt, net of unamortized discount or premium, scheduled to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the fifth fiscal year following the latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the fourth fiscal year following the latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the third fiscal year following the latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the second fiscal year following the latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The cash inflow from amounts received from a long-term debt instrument secured by a first mortgage deed of trust, containing a pledge of real property. The lender has the highest claim on the property in case of default. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Short-term and Long-term Debt - Schedule of Long-Term Debt (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
|
Dec. 31, 2011
|
|---|---|---|
| Debt Instrument [Line Items] | ||
| Long-term Debt | $ 1,018.1 | $ 863.3 |
| Less: Due Within One Year | 84.5 | 5.4 |
| Net Long-Term Debt | 933.6 | 857.9 |
|
4.86% Series Due 2013 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 60.0 | 60.0 |
| Less: Due Within One Year | 60.0 | |
|
6.94% Series Due 2014 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 18.0 | 18.0 |
|
7.70% Series Due 2016 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 20.0 | 20.0 |
|
8.17% Series Due 2019 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 42.0 | 42.0 |
|
5.28% Series Due 2020 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 35.0 | 35.0 |
|
4.85% Series Due 2021 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 15.0 | 15.0 |
|
4.95% Pollution Control Series F Due 2022 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 111.0 | 111.0 |
|
6.02% Series Due 2023 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 75.0 | 75.0 |
|
4.90% Series Due 2025 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 30.0 | 30.0 |
|
5.10% Series Due 2025 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 30.0 | 30.0 |
|
3.20% Series Due 2026 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 75.0 | 0 |
|
5.99% Series Due 2027 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 60.0 | 60.0 |
|
5.69% Series Due 2036 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 50.0 | 50.0 |
|
6.00% Series Due 2040 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 35.0 | 35.0 |
|
5.82% Series Due 2040 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 45.0 | 45.0 |
|
4.08% Series Due 2042 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 85.0 | 0 |
|
SWL&P First Mortgage Bonds 7.25% Series Due 2013 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 10.0 | 10.0 |
|
Senior Unsecured Notes 5.99% Due 2017 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 50.0 | 50.0 |
|
Variable Demand Revenue Refunding Bonds Series 1997 A, B, and C Due 2013-2020 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 27.5 | 28.2 |
|
Industrial Development Revenue Bonds 6.5% Due 2025 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 0 | 6.0 |
|
Industrial Development Variable Rate Demand Refunding Revenue Bonds Series 2006 Due 2025 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 27.8 | 27.8 |
|
Unsecured Term Loan Variable Rate Due 2014 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 75.0 | 75.0 |
|
Other Long-Term Debt, 1.0%-8.0% Due 2013-2037 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term Debt | $ 41.8 | $ 40.3 |
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Carrying amount of long-term debt, net of unamortized discount or premium, scheduled to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Commitments, Guarantees and Contingencies - Power Purchase Agreements (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2012
MW
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
|
Square Butte PPA [Member]
|
|||
| Power Purchase Agreements [Line Items] | |||
| Generating Unit Capacity (MW) | 455 | ||
| Output Entitlement | 50.00% | ||
| PPA Counterparty Debt Outstanding | $ 416.9 | ||
| Annual Debt Service | 44 | ||
| Power Purchased under Long-term Contracts | 67.1 | 61.2 | 55.2 |
| Interest Expense | 11.1 | 11.1 | 10.2 |
|
Minnkota PPA [Member]
|
|||
| Power Purchase Agreements [Line Items] | |||
| Output Being Purchased (MW) | 50 | ||
|
Oliver Wind I PPA [Member]
|
|||
| Power Purchase Agreements [Line Items] | |||
| Output Being Purchased (MW) | 50 | ||
| Term of Contract (Years) | 25 | ||
| Fixed Capacity Charges | 0 | ||
|
Oliver Wind II PPA [Member]
|
|||
| Power Purchase Agreements [Line Items] | |||
| Output Being Purchased (MW) | 48 | ||
| Term of Contract (Years) | 25 | ||
| Fixed Capacity Charges | $ 0 | ||
|
Manitoba Hydro PPA (expires April 2015) [Member]
|
|||
| Power Purchase Agreements [Line Items] | |||
| Output Being Purchased (MW) | 50 | ||
|
Manitoba Hydro PPA (expires April 2022) [Member]
|
|||
| Power Purchase Agreements [Line Items] | |||
| Output Being Purchased (MWh) | 1,000,000 | ||
|
Manitoba Hydro PPA (expires 2035) [Member]
|
|||
| Power Purchase Agreements [Line Items] | |||
| Output Being Purchased (MW) | 250 | ||
| Term of Contract (Years) | 15 | ||
| Transmission Line Capacity (kV) | 500 | ||
| X | ||||||||||
|
- Definition
Long-Term Contract for Purchase of Electric Power, Fixed Capacity Carges No definition available.
|
| X | ||||||||||
|
- Definition
The generating capacity of a production plant constructed and financed by a public utility district, cooperative, or other organization with whom exists a long-term contract to purchase electric power. No definition available.
|
| X | ||||||||||
|
- Definition
Share of plant output being purchased in megawatts under a long-term contract to purchase electricity from a production plant constructed and financed by a public utility district, cooperative, or other organization. No definition available.
|
| X | ||||||||||
|
- Definition
Share of plant output being purchased in megawatthours under a long-term contract to purchase electricity from a production plant constructed and financed by a public utility district, cooperative, or other organization. No definition available.
|
| X | ||||||||||
|
- Definition
Term in years of long-term contract to purchase electricity from a production plant constructed and financed by a public utility district, cooperative, or other organization. No definition available.
|
| X | ||||||||||
|
- Definition
Capacity of a transmission line in kilovolts. No definition available.
|
| X | ||||||||||
|
- Definition
Under long-term contracts with public utility districts, cooperatives or other organizations, a utility company receives a portion of the output of a production plant constructed and financed by the district or cooperative. The utility has only a nominal or no investment at all in the plant but pays a proportionate part of the plant's costs, including debt service. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Under long-term contracts with public utility districts, cooperatives or other organizations, a utility company receives a portion of the output of a production plant constructed and financed by the district or cooperative. The utility has only a nominal or no investment at all in the plant but pays a proportionate part of the plant's costs, including debt service. If the utility is obligated to pay certain minimum amounts which cover debt service requirements whether or not the plant is operating, the amount can be disclosed here. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The allocable portion of interest included in charges under a long-term contract to purchase electric power. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Share of plant output being purchased under a long-term contract to purchase electricity from a production plant constructed and financed by a public utility district, cooperative, or other organization. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The amount of purchased power procured under arrangements extending beyond one year or the normal operating cycle, if longer, which was charged against earnings for the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Commitments, Guarantees and Contingencies - North Dakota Wind Development (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
Miles
kV
|
|---|---|
|
DC Transmission Line from Square Butte [Member]
|
|
| North Dakota Wind Development [Line Items] | |
| Transmission Line Length (Miles) | 465 |
| Transmission Line Capacity (kV) | 250 |
|
Bison Wind Energy Center [Member]
|
|
| North Dakota Wind Development [Line Items] | |
| Generating Unit Capacity (MW) | 292 |
|
Bison 1 [Member]
|
|
| North Dakota Wind Development [Line Items] | |
| Transmission Line Length (Miles) | 22 |
| Transmission Line Capacity (kV) | 230 |
| Generating Unit Capacity (MW) | 82 |
| Capital Cost Spent to Date | $ 174.9 |
|
Bison 2 [Member]
|
|
| North Dakota Wind Development [Line Items] | |
| Generating Unit Capacity (MW) | 105 |
| Capital Cost Spent to Date | 148.6 |
|
Bison 3 [Member]
|
|
| North Dakota Wind Development [Line Items] | |
| Generating Unit Capacity (MW) | 105 |
| Capital Cost Spent to Date | $ 149.8 |
| X | ||||||||||
|
- Definition
Capital cost spent to date for project. No definition available.
|
| X | ||||||||||
|
- Definition
Capacity of each generating unit/individual project in megawatts. No definition available.
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Capacity of a transmission line in kilovolts. No definition available.
|
| X | ||||||||||
|
- Definition
Length of a transmission line in miles. No definition available.
|
|
Commitments, Guarantees and Contingencies - Coal Rail and Shipping Contracts (Details) (Coal and Transportation [Member], USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
|
|---|---|
|
Coal and Transportation [Member]
|
|
| Coal Rail and Shipping Contracts [Line Items] | |
| Coal Supply and Transportation Agreements, Minimum Annual Payment Obligation in 2013 | $ 51.4 |
| Coal Supply and Transportation Agreements, Minimum Annual Payment Obligation in 2014 | $ 0.8 |
| X | ||||||||||
|
- Definition
Amount of the recorded unconditional purchase obligation maturing in the second fiscal year following the latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of the recorded unconditional purchase obligation maturing in the next fiscal year following the latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
|
Commitments, Guarantees and Contingencies - Leasing Agreements (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Leasing Agreements [Line Items] | |||
| Operating Leases, Future Minimum Payments, Current | $ 11.5 | ||
| Operating Leases, Future Minimum Payments, Due in Two Years | 11.7 | ||
| Operating Leases, Future Minimum Payments, Due in Three Years | 11.4 | ||
| Operating Leases, Future Minimum Payments, Due in Four Years | 9.3 | ||
| Operating Leases, Future Minimum Payments, Due in Five Years | 8.5 | ||
| Operating Leases, Future Minimum Payments, Due Thereafter | 35.0 | ||
| Operating Leases, Rent Expense | 11.5 | 9.4 | 9.4 |
|
BNI Dragline [Member]
|
|||
| Leasing Agreements [Line Items] | |||
| Termination Fee | 3.0 | ||
| Operating Leases, Future Minimum Payments, Current | $ 2.8 | ||
| X | ||||||||||
|
- Definition
A lump sum payment in conjunction with a lease termination. No definition available.
|
| X | ||||||||||
|
- Definition
Rental expense incurred for leased assets including furniture and equipment which has not been recognized in costs and expenses applicable to sales and revenues; for example, cost of goods sold or other operating costs and expenses. No definition available.
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Amount of required minimum rental payments maturing in the next fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of required minimum rental payments maturing in the fifth fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of required minimum rental payments maturing in the forth fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of required minimum rental payments maturing in the third fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of required minimum rental payments maturing in the second fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of required minimum rental payments maturing after the fifth fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Commitments, Guarantees and Contingencies - Transmission (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
|
Dec. 31, 2011
|
|---|---|---|
|
CapX2020 [Member]
|
||
| Transmission [Line Items] | ||
| Number of Projects | 3 | |
| Minimum Amount Expected to be Invested in Transmission Projects | $ 100 | |
| Maximum Amount Expected to be Invested in Transmission Projects | 110 | |
| Capital Cost Spent to Date | 48.2 | 27.8 |
|
CapX2020 Fargo to Monticello Project [Member]
|
||
| Transmission [Line Items] | ||
| Transmission Line Length (Miles) | 238 | |
| Transmission Line Capacity (kV) | 345 | |
| Capital Cost Spent to Date | 37.3 | 20.4 |
|
CapX2020 Monticello to St. Cloud Project [Member]
|
||
| Transmission [Line Items] | ||
| Transmission Line Length (Miles) | 28 | |
| Transmission Line Capacity (kV) | 345 | |
|
CapX2020 Bemidji to Grand Rapids Project [Member]
|
||
| Transmission [Line Items] | ||
| Transmission Line Length (Miles) | 70 | |
| Transmission Line Capacity (kV) | 230 | |
| Capital Cost Spent to Date | $ 10.9 | $ 7.4 |
| X | ||||||||||
|
- Definition
Capital cost spent to date for project. No definition available.
|
| X | ||||||||||
|
- Definition
The maximum amount expected to be invested in transmission line projects. No definition available.
|
| X | ||||||||||
|
- Definition
The minimum amount expected to be invested in transmission line projects. No definition available.
|
| X | ||||||||||
|
- Definition
Number of projects. No definition available.
|
| X | ||||||||||
|
- Definition
Capacity of a transmission line in kilovolts. No definition available.
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Length of a transmission line in miles. No definition available.
|
|
Commitments, Guarantees and Contingencies - Environmental Matters (Details) (Boswell Unit 4 [Member], USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
|
|---|---|
|
Boswell Unit 4 [Member]
|
|
| Schedule of Utility Generating Facilities [Line Items] | |
| Estimated Environmental Compliance Costs - Minimum | $ 350 |
| Estimated Environmental Compliance Costs - Maximum | $ 400 |
| X | ||||||||||
|
- Definition
The maximum amount expected to be invested related to compliance with a certain environmental regualtion/mandate. No definition available.
|
| X | ||||||||||
|
- Definition
The minimum amount expected to be invested related to compliance with a certain environmental regualtion/mandate. No definition available.
|
| X | ||||||||||
|
- Details
|
|
Commitments, Guarantees and Contingencies - Other Matters (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | |
|---|---|---|
|
Dec. 31, 2012
Years
|
Dec. 31, 2011
|
|
|
BNI Coal Reclamation Liability [Member]
|
||
| Guarantor Obligations [Line Items] | ||
| Surety Bond | $ 29.8 | |
| Letters of Credit | 2.6 | |
| Estimated Reclamation Liability | 32.4 | |
|
ALLETE Properties Performance and Maintenance Obligations [Member]
|
||
| Guarantor Obligations [Line Items] | ||
| Surety Bond | 10.2 | |
| Performance and Maintenance Obligations | 7.4 | |
| Performance and Maintenance Obligations, Land Purchaser Contractual Obligation | 0.6 | |
|
Town Center Community Development District Obligation [Member]
|
||
| Guarantor Obligations [Line Items] | ||
| Community Development District Obligation, Bond | 26.4 | |
| Community Development Distrcit Obligation, Bond Interest Rate | 6.00% | |
| Community Development District Obligation, Bond Term (in Years) | 31 | |
| Community Development District Obligation, Ownership Percentage of Benefited Property | 73.00% | 73.00% |
| Community Development District Obligation, Annual Assessment | 1.4 | |
|
Palm Coast Park Community Development District Obligation [Member]
|
||
| Guarantor Obligations [Line Items] | ||
| Community Development District Obligation, Bond | 31.8 | |
| Community Development Distrcit Obligation, Bond Interest Rate | 5.70% | |
| Community Development District Obligation, Bond Term (in Years) | 31 | |
| Community Development District Obligation, Ownership Percentage of Benefited Property | 93.00% | 93.00% |
| Community Development District Obligation, Annual Assessment | $ 2.1 |
| X | ||||||||||
|
- Definition
Amount of annual assessments based on ownership percentage of benefited property related to real estate development projects funded by municipal capital improvement revenue and special assessment bonds. No definition available.
|
| X | ||||||||||
|
- Definition
Interest rate of capital improvement revenue and special assessment bonds used to fund real estate development projects. No definition available.
|
| X | ||||||||||
|
- Definition
Term (in years) of capital improvement revenue and special assessment bonds used to fund real estate development projects. No definition available.
|
| X | ||||||||||
|
- Definition
Ownership percentage of property benefitied by a real estate development project funded by municipal capital improvement revenue and special assessment bonds. No definition available.
|
| X | ||||||||||
|
- Definition
Amount of letters of credit that are available for the future payment of environmental commitments and/or contingencies. No definition available.
|
| X | ||||||||||
|
- Definition
Amount of surety bonds that are available for future payment obligations related to environmental commitments and/or contingencies. No definition available.
|
| X | ||||||||||
|
- Definition
Estimated costs remaining on performance and maintenance obligations. No definition available.
|
| X | ||||||||||
|
- Definition
Performance and Maintenance Obligations, Portion that is the Land Purchaser's Contractual Obligation No definition available.
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Amount of a reclamation and mine closing liability that is associated with a legal obligation for the closure and reclamation of a mine including the removal of buildings, equipment, machinery and other physical remnants of mining, closure of tailings impoundments, leach pads and other mine features, and contouring, covering and revegetation of waste rock piles and other disturbed areas. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Including the current and noncurrent portions, carrying value as of the balance sheet date of a type of municipal bond typically used to fund a development project. Also called special assessment limited liability bond, special district bond, special purpose bond, special tax bond and community development obligation. Interest owed to lenders is paid by taxes levied on the community benefiting from the particular bond-funded project. For example, if a bond of this sort was issued to pay for sidewalks to be repaved in a certain community, an additional tax would be levied on homeowners in the area benefiting from this project. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Commitments, Guarantees and Contingencies - Legal Proceedings (Details) (Pending Litigation [Member], USD $)
In Millions, unless otherwise specified |
12 Months Ended |
|---|---|
|
Dec. 31, 2012
|
|
|
Pending Litigation [Member]
|
|
| Loss Contingencies [Line Items] | |
| Loss Contingency, Damages Sought, Value | $ 20.0 |
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The value (monetary amount) of the award the plaintiff seeks in the legal matter. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Common Stock and Earnings Per Share - Summary of Common Stock (Details) (USD $)
In Millions, except Share data, unless otherwise specified |
3 Months Ended | 12 Months Ended | ||||||
|---|---|---|---|---|---|---|---|---|
|
Sep. 30, 2011
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
Dec. 31, 2012
Common Stock [Member]
|
Dec. 31, 2011
Common Stock [Member]
|
Dec. 31, 2010
Common Stock [Member]
|
Dec. 31, 2009
Common Stock [Member]
|
|
| Class of Stock [Line Items] | ||||||||
| Common Stock Outstanding, Shares | 39,400,000 | 37,500,000 | 39,377,000 | 37,513,000 | 35,817,000 | 35,221,000 | ||
| Common Stock Outstanding, Value | $ 784.7 | $ 705.6 | $ 636.1 | $ 613.4 | ||||
| Employee Stock Purchase Program, Shares | 20,000 | 20,000 | 19,000 | |||||
| Employee Stock Purchase Program, Value | 0.8 | 0.8 | 0.6 | |||||
| Invest Direct, Shares | 474,000 | 437,000 | 346,000 | |||||
| Invest Direct, Value | 19.2 | 17.2 | 11.7 | |||||
| Options and Stock Awards, Shares | 95,000 | 109,000 | 51,000 | |||||
| Options and Stock Awards, Value | 6.0 | 6.7 | 4.4 | |||||
| Equity Issuance Program, Shares | 1,275,000 | 400,000 | 180,000 | |||||
| Equity Issuance Program, Value | 53.1 | 16.0 | 6.0 | |||||
| Purchase of Non-Controlling Interest, Shares | 200,000 | 222,000 | ||||||
| Purchase of Non-Controlling Interest, Value | 8.8 | |||||||
| Contributions to Pension, Shares | 508,000 | |||||||
| Contributions to Pension, Value | $ 0 | $ (20.0) | $ 0 | $ 20.0 | ||||
| Antidilutive Options to Purchase Shares of Common Stock Excluded from the Computation of Earnings Per Share | 200,000 | 300,000 | 500,000 | |||||
| Equity Issuance Program Shares Authorized | 9,600,000 | |||||||
| Equity Issuance Program Shares Available for Issuance | 4,500,000 | |||||||
| X | ||||||||||
|
- Definition
Aggregate number of shares, without par value, authorized to be issued under the distribution agreement with KCCI (equity issuance program/PIE). No definition available.
|
| X | ||||||||||
|
- Definition
The number of shares of common stock that remain available for issuance under the equity issuance program (KCCI distribution agreement). No definition available.
|
| X | ||||||||||
|
- Definition
Number of shares of stock issued during the period to purchase non-controlling interest. No definition available.
|
| X | ||||||||||
|
- Definition
Gross number of shares (or other type of equity) issued during the period as a result of any equity-based compensation plan, including employee stock ownership plans (ESOP). Shares issued could result from the issuance of restricted stock units, the exercise of stock options, stock issued under the ESOP, and/or other employee benefit plans. No definition available.
|
| X | ||||||||||
|
- Definition
Stock Issued During Period, Value, Purchase of Non-Controlling Interest No definition available.
|
| X | ||||||||||
|
- Definition
Gross value of stock (or other type of equity) issued during the period as a result of any equity-based compensation plan, including employee stock ownership plans (ESOP). Stock issued could result from the issuance of retricted stock units, the exercise of stock options, stock issued under an ESOP and/or other employee benefit plans. No definition available.
|
| X | ||||||||||
|
- Definition
Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Value of all classes of common stock held by shareholders. May be all or portion of the number of common shares authorized. These shares exclude common shares repurchased by the entity and held as treasury shares. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Number of shares issued during the period from a dividend reinvestment plan (DRIP). A dividend reinvestment plan allows the shareholders to reinvest dividends paid to them by the entity on new issues of stock by the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Number of shares issued during the period to an employee benefit plan, such as a defined contribution or defined benefit plan. No definition available.
|
| X | ||||||||||
|
- Definition
Number of shares issued during the period as a result of an employee stock purchase plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Number of shares of stock issued during the period that is attributable to transactions involving issuance of stock not separately disclosed. No definition available.
|
| X | ||||||||||
|
- Definition
Value of stock issued during the period from a dividend reinvestment plan (DRIP). A dividend reinvestment plan allows the holder of the stock to reinvest dividends paid to them by the entity on new issues of stock by the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Value of shares issued during the period to an employee benefit plan, such as a defined contribution or defined benefit plan. No definition available.
|
| X | ||||||||||
|
- Definition
Aggregate change in value for stock issued during the period as a result of employee stock purchase plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Value of shares of stock issued during the period that is attributable to transactions involving issuance of stock not separately disclosed. No definition available.
|
|
Common Stock and Earnings Per Share - Reconciliation of Basic and Diluted Earnings Per Share (Details) (USD $)
In Millions, except Per Share data, unless otherwise specified |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
Dec. 31, 2012
|
Sep. 30, 2012
|
Jun. 30, 2012
|
Mar. 31, 2012
|
Dec. 31, 2011
|
Sep. 30, 2011
|
Jun. 30, 2011
|
Mar. 31, 2011
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Earnings Per Share - Basic [Abstract] | |||||||||||
| Net Income Attributable to ALLETE | $ 28.9 | $ 29.4 | $ 14.4 | $ 24.4 | $ 19.1 | $ 20.5 | $ 17.0 | $ 37.2 | $ 97.1 | $ 93.8 | $ 75.3 |
| Average Common Shares | 37.6 | 35.3 | 34.2 | ||||||||
| Earnings Per Share | $ 0.76 | $ 0.78 | $ 0.39 | $ 0.66 | $ 0.53 | $ 0.57 | $ 0.49 | $ 1.07 | $ 2.59 | $ 2.66 | $ 2.20 |
| Earnings Per Share - Diluted [Abstract] | |||||||||||
| Net Income Attributable to ALLETE | $ 97.1 | $ 93.8 | $ 75.3 | ||||||||
| Average Common Shares | 37.6 | 35.4 | 34.3 | ||||||||
| Earnings Per Share | $ 0.75 | $ 0.78 | $ 0.39 | $ 0.66 | $ 0.53 | $ 0.57 | $ 0.48 | $ 1.07 | $ 2.58 | $ 2.65 | $ 2.19 |
| Dilutive Securities (Shares) | 0 | 0.1 | 0.1 | ||||||||
| X | ||||||||||
|
- Definition
The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The portion of profit or loss for the period, net of income taxes, which is attributable to the parent, and includes adjustments resulting from the assumption that dilutive convertible securities were converted, options or warrants were exercised, or that other shares were issued upon the satisfaction of certain conditions. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Other Income (Expense) (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Other Income (Expense) [Abstract] | |||
| AFUDC - Equity | $ 5.1 | $ 2.5 | $ 4.2 |
| Investment and Other Income | 0.9 | 1.9 | 0.4 |
| Total Other Income | $ 6.0 | $ 4.4 | $ 4.6 |
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The increase (decrease) during the reporting period in the capitalized cost of equity (based on assumed rate of return) and / or borrowed funds (based on interest rate) used to finance construction of regulated assets, which is expected to be recovered through rate adjustments. As a result of this capitalization, net income is increased. This element pertains to certain regulated industries, such as public utilities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Reflects the sum of all other revenue and income recognized by the entity in the period not otherwise specified in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The net amount of other income and expense amounts, the components of which are not separately disclosed on the income statement, resulting from ancillary business-related activities (that is, excluding major activities considered part of the normal operations of the business) also known as other nonoperating income (expense) recognized for the period. Such amounts may include: (a) dividends, (b) interest on securities, (c) net gains or losses on securities, (d) unusual costs, (e) gains or losses on foreign exchange transactions, and (f) miscellaneous other income and expense items. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Income Tax Expense (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 12 Months Ended | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Jun. 30, 2011
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
||||||||||
| Income Tax Expense [Abstract] | |||||||||||||
| Current Federal Tax Expense (Benefit) | $ 0 | [1] | $ 1.4 | [1] | $ (23.0) | [1] | |||||||
| Current State Tax Expense (Benefit) | 0.5 | [1] | (1.6) | [1] | 1.3 | [1] | |||||||
| Total Current Tax Expense (Benefit) | 0.5 | (0.2) | (21.7) | ||||||||||
| Deferred Federal Tax Expense | 38.1 | [2] | 27.3 | [2] | 61.4 | [2] | |||||||
| Deferred State Tax Expense (Benefit) | (1.7) | [2] | 9.5 | [2] | 5.3 | [2] | |||||||
| Change in Valuation Allowance | 2.0 | [3] | (0.1) | [3] | 0.2 | [3] | |||||||
| Investment Tax Credit Amortization | (0.9) | (0.9) | (0.9) | ||||||||||
| Total Deferred Tax Expense | 37.5 | 35.8 | 66.0 | ||||||||||
| Total Income Tax Expense | 38.0 | 35.6 | 44.3 | ||||||||||
|
2010 Rate Case Stipulation Agreement, Revenue Receivable Foregone [Member]
|
|||||||||||||
| Income Tax Expense [Abstract] | |||||||||||||
| Total Deferred Tax Expense | 0 | (6.2) | 0 | ||||||||||
|
PPACA Elimination of Medicare Part D [Member]
|
|||||||||||||
| Income Tax Expense [Abstract] | |||||||||||||
| Total Deferred Tax Expense | 2.9 | 0 | (2.9) | 0 | |||||||||
| Unusual or Infrequent Item [Line Items] | |||||||||||||
| Tax Adjustments, Settlements, and Unusual Provisions | $ 0 | $ 0 | $ 4.0 | ||||||||||
|
|||||||||||||
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The component of income tax expense for the period representing amounts paid or payable (or refundable) as determined by applying the provisions of enacted federal tax law to the domestic taxable Income or Loss from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The component of income tax expense for the period representing amounts of income taxes paid or payable (or refundable) for the period for all income tax obligations as determined by applying the provisions of relevant enacted tax laws to relevant amounts of taxable Income or Loss from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The component of income tax expense for the period representing amounts paid or payable (or refundable) as determined by applying the provisions of enacted state and local tax law to relevant amounts of taxable Income or Loss from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The component of total income tax expense for the period comprised of the increase (decrease) during the period in the entity's domestic deferred tax assets and liabilities attributable to continuing operations as determined by applying the provisions of the federally enacted tax law. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The component of income tax expense for the period representing the increase (decrease) in the entity's deferred tax assets and liabilities pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The change during the period in the entity's deferred tax assets and liabilities attributable to continuing operations as determined by applying enacted tax laws other than federal, domestic, foreign, state or local. Items affecting deferred income taxes and required to be disclosed, but not included elsewhere, would also be designated as "Other"; for example, adjustments of a deferred tax liability or asset for enacted changes in tax laws or rates or a change in the tax status of the entity and adjustments to be beginning-of-year balance of a valuation allowance because of a change in circumstance that causes a change in judgment about the realizability of the related deferred tax asset in future periods. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The component of total income tax expense for the period comprised of the increase (decrease) in the entity's state and local deferred tax assets and liabilities attributable to continuing operations as determined by applying the provisions of the applicable enacted tax laws. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Reflects the effects of adjustments of previously recorded tax expense, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, IRS tax settlement and unusual repatriation of foreign earnings. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The amount of the change in the period in the valuation allowance for a specified deferred tax asset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Income Tax Expense - Reconciliation of Taxes from Federal Statutory Rate to Total Income Tax Expense (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
|
Jun. 30, 2011
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Income Tax Expense [Abstract] | ||||
| Income Before Non-Controlling Interest and Income Taxes | $ 135.1 | $ 129.2 | $ 119.1 | |
| Statutory Federal Income Tax Rate | 35.00% | 35.00% | 35.00% | |
| Income Taxes Computed at 35 Percent Statutory Federal Rate | 47.3 | 45.2 | 41.7 | |
| Increase (Decrease) in Tax [Abstract] | ||||
| State Income Taxes - Net of Federal Income Tax Benefit | 1.2 | 6.0 | 4.5 | |
| Unusual or Infrequent Item [Line Items] | ||||
| Deferred Income Tax Expense (Benefit) | 37.5 | 35.8 | 66.0 | |
| Regulatory Differences for Utility Plant | (2.2) | (1.2) | (2.0) | |
| Production Tax Credits | 7.6 | 4.3 | 1.6 | |
| Other | (0.7) | (1.0) | (2.3) | |
| Income Tax Expense | 38.0 | 35.6 | 44.3 | |
| Effective Income Tax Rate | 28.10% | 27.60% | 37.20% | |
|
PPACA Elimination of Medicare Part D [Member]
|
||||
| Unusual or Infrequent Item [Line Items] | ||||
| Tax Adjustments, Settlements, and Unusual Provisions | 0 | 0 | 4.0 | |
| Deferred Income Tax Expense (Benefit) | 2.9 | 0 | (2.9) | 0 |
|
2010 Rate Case Stipulation Agreement [Member]
|
||||
| Unusual or Infrequent Item [Line Items] | ||||
| Deferred Income Tax Expense (Benefit) | $ 0 | $ (6.2) | $ 0 | |
| X | ||||||||||
|
- Definition
Regulatory Differences contributing to difference in effective tax rate to federal statutory rate. No definition available.
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The component of income tax expense for the period representing the increase (decrease) in the entity's deferred tax assets and liabilities pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
A ratio calculated by dividing the reported amount of income tax expense attributable to continuing operations for the period by GAAP-basis pretax income from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The domestic federal statutory tax rate applicable under enacted tax laws to the Company's pretax income from continuing operations for the period. The "statutory" tax rate is the regular tax rate if there are alternative tax systems. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The portion of the difference, between total income tax expense or benefit as reported in the Income Statement for the year/accounting period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations, that is attributable to all other items not otherwise listed in the existing taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The portion of the difference, between total income tax expense or benefit as reported in the Income Statement for the period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations, that is attributable to state and local income tax expense or benefit. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The sum of the differences between total income tax expense or benefit as reported in the Income Statement for the period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to tax credits. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Reflects the effects of adjustments of previously recorded tax expense, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, IRS tax settlement and unusual repatriation of foreign earnings. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
|
Income Tax Expense - Deferred Tax Assets and Liabilities (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
|
Dec. 31, 2011
|
||||
|---|---|---|---|---|---|---|
| Deferred Tax Assets [Abstract] | ||||||
| Employee Benefits and Compensation | $ 120.2 | $ 132.7 | ||||
| Property Related | 59.8 | 56.4 | ||||
| NOL Carryforwards | 90.8 | 61.7 | ||||
| Tax Credit Carryforwards | 28.3 | 12.2 | ||||
| Other | 24.6 | 20.4 | ||||
| Gross Deferred Tax Assets | 323.7 | 283.4 | ||||
| Deferred Tax Asset Valuation Allowance | (2.4) | (0.4) | ||||
| Total Deferred Tax Assets | 321.3 | 283.0 | ||||
| Deferred Tax Liabilities [Abstract] | ||||||
| Property Related | 577.1 | 482.7 | ||||
| Regulatory Asset for Benefit Obligations | 104.3 | 117.9 | ||||
| Unamortized Investment Tax Credits | 11.9 | 12.8 | ||||
| Partnership Basis Differences | 28.6 | 24.4 | ||||
| Other | 30.1 | 24.0 | ||||
| Total Deferred Tax Liabilities | 752.0 | 661.8 | ||||
| Net Deferred Income Taxes | 430.7 | 378.8 | ||||
| Net Current Deferred Tax Liabilities | 6.9 | [1] | 5.2 | [1] | ||
| Net Long-Term Deferred Tax Liabilities | $ 423.8 | $ 373.6 | ||||
|
||||||
| X | ||||||||||
|
- Definition
Deferred Tax Liabilty, Partnership Basis Differences No definition available.
|
| X | ||||||||||
|
- Definition
The noncurrent portion of the reserve for accumulated deferred investment tax credits as of the balance sheet date. This is the remaining investment credit, which will reduce the cost of services collected from ratepayers by a ratable portion over the investment's regulatory life. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards, net of deferred tax liability attributable to taxable temporary differences. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences not separately disclosed. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from property, plant, and equipment. No definition available.
|
| X | ||||||||||
|
- Definition
The tax effect as of the balance sheet date of the amount of future tax deductions arising from all unused tax credit carryforwards which have been reduced by a valuation allowance. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from employee compensation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of deferred tax liability attributable to taxable temporary differences net of deferred tax asset attributable to deductible temporary differences and carryforwards after valuation allowances. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Amount of deferred tax liability attributable to taxable temporary differences, net of deferred tax asset attributable to deductible temporary differences and carryforwards net of valuation allowances expected to be realized or consumed within one year or operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of deferred tax liability attributable to taxable temporary differences, net of deferred tax asset attributable to deductible temporary differences and carryforwards net of valuation allowances expected to be realized or consumed after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of deferred tax liability attributable to taxable temporary differences not separately disclosed. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of deferred tax liability attributable to taxable temporary differences from regulatory assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Income Tax Expense - NOL and Tax Credit Carryforwards (Details) (USD $)
|
Dec. 31, 2012
|
Dec. 31, 2011
|
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
Federal [Member]
|
||||||||||
| NOL and Tax Credit Carryforwards [Line Items] | ||||||||||
| NOL Carryforward | $ 244,100,000 | [1] | $ 162,000,000 | [1] | ||||||
| Tax Credit Carryforwards | 16,000,000 | 8,400,000 | ||||||||
| NOL and Tax Credit Carryforwards, Valuation Allowance | 0 | |||||||||
|
State [Member]
|
||||||||||
| NOL and Tax Credit Carryforwards [Line Items] | ||||||||||
| NOL Carryforward | 90,600,000 | [1],[2] | 73,100,000 | [1],[2] | ||||||
| Tax Credit Carryforwards | 10,300,000 | [3] | 3,800,000 | [3] | ||||||
| NOL Carryforwards, Valuation Allowance | 400,000 | |||||||||
| Tax Credit Carryforwards, Valuation Allowance | $ 2,000,000 | |||||||||
|
||||||||||
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Operating Loss and Tax Credit Carryforwards, Valuation Allowance No definition available.
|
| X | ||||||||||
|
- Definition
The sum of domestic, foreign and state and local operating loss carryforwards, before tax effects, available to reduce future taxable income under enacted tax laws. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The portion of the valuation allowance pertaining to the deferred tax asset representing potential future taxable deductions from net operating loss carryforwards for which it is more likely than not that a tax benefit will not be realized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The portion of the deferred tax asset arising from a tax credit carryforward for which it is more likely than not that a tax benefit will not be realized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Income Tax Expense - Gross Unrecognized Income Tax Benefits (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Reconciliation of Gross Unrecognized Income Tax Benefits [Roll Forward] | |||
| Balance at January 1 | $ 11.4 | $ 12.3 | $ 9.5 |
| Reductions for Tax Positions Related to the Current Year | 0 | 0 | (0.2) |
| Additions for Tax Positions Related to Prior Years | 0 | 0 | 4.4 |
| Reduction for Tax Positions Related to Prior Years | (8.7) | (0.9) | 0 |
| Reductions for Settlements | 0 | 0 | (0.3) |
| Reductions for Expired Statute of Limitations | 0 | 0 | (1.1) |
| Balance as of December 31 | 2.7 | 11.4 | 12.3 |
| Unrecognized Tax Benefits that Would Impact Effective Tax Rate | 0.5 | ||
| Unrecognized Tax Benefits, Accrued Interest | 0.5 | 1.1 | 0.7 |
| Unrecognized Tax Benefits, Penalties | 0 | 0 | 0 |
| Unrecognized Tax Benefits, Interest Expense (Reduction) | (0.6) | 0.4 | (0.2) |
| Reasonably Possible Change in Unrecognized Tax Benefits in Next 12 Months | $ 2.5 | ||
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The amount of the unrecognized tax benefit of a position taken for which it is reasonably possible that the total amount thereof will significantly increase or decrease within twelve months of the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The gross amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns as of the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The gross amount of decreases in unrecognized tax benefits resulting from tax positions that have been or will be taken in the tax return for the current period, excluding amounts pertaining to examined tax returns. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The gross amount of decreases in unrecognized tax benefits resulting from tax positions taken in prior period tax returns, excluding amounts pertaining to examined tax returns. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The gross amount of decreases in unrecognized tax benefits resulting from settlements with taxing authorities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
This element represents the recognized expense for the amount of statutory penalties in the period in which the entity claims or expects to claim a tax position, in its tax return, that does not meet the minimum statutory threshold to avoid payment of penalties or, if not recognizing the expense in the period in which the tax return was initially filed, the expense is generally recognized in the period in which the enterprise's judgment about meeting the minimum statutory threshold changes. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The gross amount of increases in unrecognized tax benefits resulting from tax positions taken in prior period tax returns, excluding amounts pertaining to examined tax returns. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
This element represents the amount of interest expense accrued as of the date of the statement of financial position for an underpayment of income taxes computed by applying the applicable statutory rate of interest to the difference between a tax position recognized for financial reporting purposes and the amount previously taken or expected to be taken in a tax return of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
This element represents interest expense recognized for an underpayment of income taxes computed by applying the applicable statutory rate of interest to the difference between a tax position recognized for financial reporting purposes and the amount previously taken or expected to be taken in a tax return of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The gross amount of decreases in unrecognized tax benefits resulting from lapses of the applicable statutes of limitations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Pension and Other Postretirement Benefit Plans - Contributions (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | 3 Months Ended | 3 Months Ended | 12 Months Ended | 3 Months Ended | 12 Months Ended | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
Dec. 31, 2012
Pension [Member]
|
Dec. 31, 2011
Pension [Member]
|
Mar. 31, 2013
Postretirement Health and Life [Member]
|
Feb. 15, 2013
Postretirement Health and Life [Member]
|
Mar. 31, 2013
VEBA [Member]
|
Dec. 31, 2012
VEBA [Member]
|
Dec. 31, 2011
VEBA [Member]
|
Mar. 31, 2013
Grantor Trust [Member]
|
Dec. 31, 2012
Grantor Trust [Member]
|
Dec. 31, 2011
Grantor Trust [Member]
|
|
| Pension and Other Postretirement Benefit Plans [Abstract] | |||||||||||||
| Defined Contribution Plan, Employer Matching Contribution, Amount | $ 7.7 | $ 7.3 | |||||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||||||
| Defined Benefit Plans, Employer Contributions | 7.3 | 33.8 | 4.8 | 2.8 | 1.5 | 10.9 | 2.0 | 0 | 0 | ||||
| ALLETE Common Stock Contributed to Pension Plan | 0 | (20.0) | 0 | 20.0 | |||||||||
| Defined Benefit Plans, Estimated Employer Contributions | $ 0 | $ 0 | |||||||||||
| X | ||||||||||
|
- Definition
Amount employer contributed during the period, to match employee contributions, to a defined contribution plan. Includes, but not limited to, contributions made through Employee Stock Ownership Plans (ESOP). No definition available.
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The employer's best estimate, as soon as it can be reasonably determined, of contributions expected to be paid to the plan during the next fiscal year beginning after the date of the latest statement of financial position. Estimated contributions may be presented in the aggregate combining (1) contributions required by funding regulations or laws, (2) discretionary contributions, and (3) noncash contributions. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The amount of cash or cash equivalents contributed during the reporting period by the entity to fund its pension plans and its non-pension postretirement benefit plans. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Value of shares issued during the period to an employee benefit plan, such as a defined contribution or defined benefit plan. No definition available.
|
|
Pension and Other Postretirement Benefit Plans - Obligation and Funded Status (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Change in Plan Assets [Roll Forward] | |||
| Non-Current Liabilities | $ 228.2 | $ 253.5 | |
| Other Investments, Grantor Trust | 143.5 | 132.3 | |
|
Pension [Member]
|
|||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Accumulated Benefit Obligation | 598.7 | 550.6 | |
| Change in Benefit Obligation [Roll Forward] | |||
| Obligation, Beginning of Year | 597.5 | 525.6 | |
| Service Cost | 9.1 | 7.6 | 6.2 |
| Interest Cost | 26.4 | 27.4 | 26.2 |
| Actuarial Loss (Gain) | 38.5 | 54.6 | |
| Benefits Paid | (30.9) | (28.6) | |
| Participant Contributions | 11.5 | 10.9 | |
| Obligation, End of Year | 652.1 | 597.5 | 525.6 |
| Change in Plan Assets [Roll Forward] | |||
| Fair Value, Beginning of Year | 432.4 | 382.0 | |
| Actual Return on Plan Assets | 38.7 | 33.2 | |
| Employer Contribution | 19.9 | 45.8 | |
| Participant Contributions | 11.5 | 10.9 | |
| Benefits Paid | (30.9) | (28.6) | |
| Fair Value, End of Year | 460.1 | 432.4 | 382.0 |
| Funded Status, End of Year | (192.0) | (165.1) | |
| Current Liabilities | (1.1) | (1.1) | |
| Non-Current Liabilities | (190.9) | (164.0) | |
|
Postretirement Health and Life [Member]
|
|||
| Change in Benefit Obligation [Roll Forward] | |||
| Obligation, Beginning of Year | 210.6 | 204.1 | |
| Service Cost | 4.2 | 3.8 | 4.8 |
| Interest Cost | 9.4 | 10.8 | 10.9 |
| Actuarial Loss (Gain) | (43.2) | (2.9) | |
| Benefits Paid | (9.5) | (7.7) | |
| Participant Contributions | 2.6 | 2.5 | |
| Plan Amendments | (5.3) | 0 | |
| Obligation, End of Year | 168.8 | 210.6 | 204.1 |
| Change in Plan Assets [Roll Forward] | |||
| Fair Value, Beginning of Year | 121.0 | 114.7 | |
| Actual Return on Plan Assets | 14.3 | 0 | |
| Employer Contribution | 2.3 | 11.4 | |
| Participant Contributions | 2.6 | 2.5 | |
| Participant Contributions, Excluding Key Employees | 2.5 | 2.5 | |
| Benefits Paid | (9.5) | (7.7) | |
| Benefits Paid, Excluding Key Employees | (9.1) | (7.6) | |
| Fair Value, End of Year | 131.0 | 121.0 | 114.7 |
| Funded Status, End of Year | (37.8) | (89.6) | |
| Current Liabilities | (0.8) | (0.9) | |
| Non-Current Liabilities | (37.0) | (88.7) | |
|
Grantor Trust [Member]
|
|||
| Change in Plan Assets [Roll Forward] | |||
| Other Investments, Grantor Trust | $ 22.1 | $ 20.3 | |
| X | ||||||||||
|
- Definition
Defined Benefit Plan, Benefits Paid, Excluding Key Employees No definition available.
|
| X | ||||||||||
|
- Definition
Defined Benefit Plan Contributions by Plan Participants, Excluding Key Employees No definition available.
|
| X | ||||||||||
|
- Definition
For defined benefit pension plans, the actuarial present value of benefits (whether vested or nonvested) attributed by the pension benefit formula to employee service rendered before a specified date and based on employee service and compensation (if applicable) before that date. The accumulated benefit obligation differs from the projected benefit obligation in that it includes no assumption about future compensation levels. For plans with flat-benefit or nonpay-related pension benefit formulas, the accumulated benefit obligation and the projected benefit obligation are the same. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The difference between fair value of plan assets at the end of the period and the fair value at the beginning of the period, adjusted for contributions and payments of benefits during the period, and after adjusting for taxes and other expenses, as applicable. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of gain (loss) from a decision to temporarily deviate from the substantive plan, or from a change in benefit obligation or plan asset value from changes in actuarial assumptions, for example, but not limited to, interest, mortality, employee turnover or salary scale. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
1) For defined benefit pension plans, the benefit obligation is the projected benefit obligation, which is the actuarial present value as of a date of all benefits attributed by the pension benefit formula to employee service rendered prior to that date. 2) For other postretirement defined benefit plans, the benefit obligation is the accumulated postretirement benefit obligation, which is the actuarial present value of benefits attributed to employee service rendered to a particular date. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The amount of payments made for which participants are entitled under a pension plan, including pension benefits, death benefits, and benefits due on termination of employment. Also includes payments made under a postretirement benefit plan, including prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. This item represents a periodic decrease to the plan obligations and a decrease to plan assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The increase in the fair value of plan assets from contributions made by the employer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The amount of contributions made by plan participants. This item represents a periodic increase to the plan obligation and an increase to plan assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The funded status is measured as the difference between the fair value of plan assets and the benefit obligation. Will normally be the same as the net Defined Benefit Plan, Amounts Recognized in Balance Sheet, Total. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The amount of increase or decrease due to a change in the terms of an existing plan or the initiation of a new plan. A plan amendment may increase or decrease benefits, including those attributed to years of service already rendered. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
For a classified balance sheet, the amount recognized in balance sheet as a current liability associated with an underfunded defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
This represents the noncurrent liability for underfunded plans recognized in the balance sheet that is associated with the defined benefit pension plans and other postretirement defined benefit plans. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Pension and Other Postretirement Benefit Plans - Unrecognized Costs (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
|
Dec. 31, 2011
|
|---|---|---|
|
Pension [Member]
|
||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||
| Net Loss | $ 286.8 | $ 269.0 |
| Prior Service Cost (Credit) | 0.7 | 1.1 |
| Total Unrecognized Costs | 287.5 | 270.1 |
|
Postretirement Health and Life [Member]
|
||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||
| Net Loss | 23.5 | 78.5 |
| Prior Service Cost (Credit) | (13.1) | (9.5) |
| Transition Obligation | 0 | 0.1 |
| Total Unrecognized Costs | $ 10.4 | $ 69.1 |
| X | ||||||||||
|
- Definition
The total of net gain (loss), prior service cost (credit), and transition assets (obligations), as well as minimum pension liability if still remaining, included in accumulated other comprehensive income associated with a defined benefit pension or other postretirement plan(s) because they have yet to be recognized as components of net periodic benefit cost. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The pretax net amount of gains and losses that are not yet recognized as a component of net periodic benefit cost, and that are recognized as increases or decreases in other comprehensive income as they arise. Gains and losses are due to changes in the value of either the benefit obligation or the plan assets resulting from experience different from that assumed or from a change in an actuarial assumption, or the consequence of a decision to temporarily deviate from the substantive plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount related to the pretax cost of benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation, which has not yet been recognized as components of net periodic benefit cost. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Before tax amount of net transition assets (obligations) which has yet to be recognized as a component of net periodic benefit cost. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
|
Pension and Other Postretirement Benefit Plans - Components of Net Periodic Benefit Expense (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
|
Pension [Member]
|
|||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | |||
| Service Cost | $ 9.1 | $ 7.6 | $ 6.2 |
| Interest Cost | 26.4 | 27.4 | 26.2 |
| Expected Return on Plan Assets | (35.4) | (34.6) | (33.7) |
| Amortization of Loss | 17.5 | 12.1 | 6.6 |
| Amortization of Prior Service Cost (Credit) | 0.3 | 0.3 | 0.5 |
| Net Expense | 17.9 | 12.8 | 5.8 |
|
Postretirement Health and Life [Member]
|
|||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | |||
| Service Cost | 4.2 | 3.8 | 4.8 |
| Interest Cost | 9.4 | 10.8 | 10.9 |
| Expected Return on Plan Assets | (9.9) | (9.7) | (9.5) |
| Amortization of Loss | 7.5 | 8.5 | 4.8 |
| Amortization of Prior Service Cost (Credit) | (1.7) | (1.7) | (0.1) |
| Amortization of Transition Obligation | 0.1 | 0.1 | 2.5 |
| Net Expense | $ 9.6 | $ 11.8 | $ 13.4 |
| X | ||||||||||
|
- Definition
The amount of gains or losses recognized in net periodic benefit cost. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The amount of the prior service cost or credit recognized in net periodic benefit cost relating to benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The amount of the transition obligation or asset recognized in net periodic benefit cost. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
An amount calculated as a basis for determining the extent of delayed recognition of the effects of changes in the fair value of assets. The expected return on plan assets is determined based on the expected long-term rate of return on plan assets and the market-related value of plan assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The total amount of net periodic benefit cost for defined benefit plans for the period. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Pension and Other Postretirement Benefit Plans - Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income and Regulatory Assets (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | |
|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
|
|
Pension [Member]
|
||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||
| Net (Gain) Loss | $ 35.2 | $ 56.1 |
| Amortization of Prior Service (Cost) Credit | (0.3) | (0.3) |
| Amortization of Loss | (17.5) | (12.2) |
| Total Recognized in Other Comprehensive Income and Regulatory Assets | 17.4 | 43.6 |
|
Postretirement Health and Life [Member]
|
||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||
| Net (Gain) Loss | (47.5) | 6.9 |
| Prior Service Credit Arising During the Period | (5.3) | 0 |
| Amortization of Prior Service (Cost) Credit | 1.7 | 1.7 |
| Amortization of Transition Obligation | (0.1) | (0.1) |
| Amortization of Loss | (7.5) | (8.5) |
| Total Recognized in Other Comprehensive Income and Regulatory Assets | $ (58.7) | $ 0 |
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Before tax amount of the benefit improvement costs resulting from a plan amendment that occurred that has not been recognized in net periodic benefit cost. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Before tax amount of the income statement impact of the reclassification adjustment for prior service costs recognized as a component of net period benefit cost. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Before tax amount, net of reclassifications, of pension and other postretirement benefit plans (gain) loss included in accumulated other comprehensive income. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Before tax amount of the (increase) decrease in the value of the projected benefit obligation and the increase (decrease) in the value of the plan assets resulting from experience different from that assumed or from a change in an actuarial assumption that has not been recognized in net periodic benefit cost. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Before tax amount of the income statement impact of the reclassification adjustment for the net transition asset (obligation) recognized as a component of net periodic benefit cost. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Before tax amount of the income statement impact of the reclassification adjustment for actuarial gain (loss) recognized as a component of net periodic benefit cost. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Pension and Other Postretirement Benefit Plans - Information for Pension Plans with an Accumulated Benefit Obligation in Excess of Plan Assets (Details) (Pension [Member], USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
|
Dec. 31, 2011
|
|---|---|---|
|
Pension [Member]
|
||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||
| Projected Benefit Obligation | $ 652.1 | $ 597.5 |
| Accumulated Benefit Obligation | 598.7 | 550.6 |
| Fair Value of Plan Assets | $ 460.1 | $ 432.4 |
| X | ||||||||||
|
- Definition
If aggregate disclosures are presented, the aggregate pension accumulated benefit obligation for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
If aggregate disclosures are presented, the aggregate fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
If aggregate disclosures are presented, the aggregate projected benefit obligation for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
|
Pension and Other Postretirement Benefit Plans - Estimated Future Benefit Payments (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
|
|---|---|
|
Pension [Member]
|
|
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | |
| 2013 | $ 31.2 |
| 2014 | 32.1 |
| 2015 | 33.2 |
| 2016 | 34.4 |
| 2017 | 35.5 |
| Years 2018 - 2022 | 189.4 |
|
Postretirement Health and Life [Member]
|
|
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | |
| 2013 | 7.6 |
| 2014 | 8.2 |
| 2015 | 8.9 |
| 2016 | 9.4 |
| 2017 | 9.7 |
| Years 2018 - 2022 | $ 52.0 |
| X | ||||||||||
|
- Definition
Amount of benefits expected to be paid in the five fiscal years after the fifth fiscal year following the latest fiscal year from a defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of benefits expected to be paid in the next fiscal year following the latest fiscal year from a defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of benefits expected to be paid in the fifth fiscal year following the latest fiscal year from a defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of benefits expected to be paid in the fourth fiscal year following the latest fiscal year from a defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of benefits expected to be paid in the third fiscal year following the latest fiscal year from a defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of benefits expected to be paid in the second fiscal year following the latest fiscal year from a defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
|
Pension and Other Postretirement Benefit Plans - Costs Recorded in Other Long-Term Assets and AOCI Expected to be Recognized as a Component of Net Pension and Postretirement Benefit Costs in the Next Fiscal Year (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended |
|---|---|
|
Dec. 31, 2013
|
|
|
Pension [Member]
|
|
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | |
| Net Loss | $ 21.4 |
| Prior Service Cost (Credit) | 0.3 |
| Total Pension and Postretirement Health and Life Cost (Credit) | 21.7 |
|
Postretirement Health and Life [Member]
|
|
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | |
| Net Loss | 1.6 |
| Prior Service Cost (Credit) | (2.5) |
| Total Pension and Postretirement Health and Life Cost (Credit) | $ (0.9) |
| X | ||||||||||
|
- Definition
The amounts in accumulated other comprehensive income related to gains and losses that are not recognized immediately and are expected to be recognized as components of net periodic benefit cost over the next fiscal year that follows the most recent annual statement of financial position presented. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The amounts in accumulated other comprehensive income related to prior service cost or credit expected to be recognized as components of net periodic benefit cost over the next fiscal year that follows the most recent annual statement of financial position presented. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The aggregate amount in accumulated other comprehensive income expected to be recognized as a component of net periodic benefit cost over the fiscal year that follows the most recent annual statement of financial position presented, including the net gain (loss), net prior service cost or credit, and net transition asset or obligation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
|
Pension and Other Postretirement Benefit Plans - Weighted-Average Assumptions Used to Determine Benefit Obligation and Net Periodic Benefit Costs (Details)
|
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
|
Pension [Member]
|
|||
| Weighted-Average Assumptions Used to Determine Benefit Obligation [Abstract] | |||
| Discount Rate | 4.10% | 4.54% | |
| Weighted-Average Assumptions Used to Determine Net Periodic Benefit Costs [Abstract] | |||
| Discount Rate | 4.54% | 5.36% | 5.81% |
| Expected Long-term Return on Plan Assets | 8.25% | 8.50% | 8.50% |
|
Pension [Member] | Minimum [Member]
|
|||
| Weighted-Average Assumptions Used to Determine Benefit Obligation [Abstract] | |||
| Rate of Compensation Increase | 4.30% | 4.30% | |
| Weighted-Average Assumptions Used to Determine Net Periodic Benefit Costs [Abstract] | |||
| Rate of Compensation Increase | 4.30% | 4.30% | 4.30% |
|
Pension [Member] | Maximum [Member]
|
|||
| Weighted-Average Assumptions Used to Determine Benefit Obligation [Abstract] | |||
| Rate of Compensation Increase | 4.60% | 4.60% | |
| Weighted-Average Assumptions Used to Determine Net Periodic Benefit Costs [Abstract] | |||
| Rate of Compensation Increase | 4.60% | 4.60% | 4.60% |
|
Postretirement Health and Life [Member]
|
|||
| Weighted-Average Assumptions Used to Determine Benefit Obligation [Abstract] | |||
| Discount Rate | 4.13% | 4.56% | |
| Trend Rate | 9.25% | 10.00% | |
| Ultimate Trend Rate | 5.00% | 5.00% | |
| Year Ultimate Trend Rate Effective | 2019 | 2018 | |
| Weighted-Average Assumptions Used to Determine Net Periodic Benefit Costs [Abstract] | |||
| Discount Rate | 4.56% | 5.40% | 5.81% |
|
Postretirement Health and Life [Member] | Minimum [Member]
|
|||
| Weighted-Average Assumptions Used to Determine Net Periodic Benefit Costs [Abstract] | |||
| Expected Long-term Return on Plan Assets | 6.60% | 6.80% | 6.80% |
|
Postretirement Health and Life [Member] | Maximum [Member]
|
|||
| Weighted-Average Assumptions Used to Determine Net Periodic Benefit Costs [Abstract] | |||
| Expected Long-term Return on Plan Assets | 8.25% | 8.50% | 8.50% |
| X | ||||||||||
|
- Definition
The interest rate used to adjust for the time value of money for the plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Expected rate of compensation increases (for pay-related plans). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The interest rate used to adjust for the time value of money. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Expected rate of compensation increases (for pay-related plans). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The assumed health care cost trend rate for the next year used to measure the expected cost of benefits covered by the plan (gross eligible charges). This is based upon the annual rate of change in the cost of health care benefits currently provided by the postretirement benefit plan, due to factors other than changes in the composition of the plan population by age and dependency status. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The ultimate trend rate for health care costs. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Year the ultimate health care cost trend rate is expected to be reached, in CCYY format. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Pension and Other Postretirement Benefit Plans - Sensitivity of a One-Percentage-Point Change in Health Care Trend Rates (Details) (Postretirement Health and Life [Member], USD $)
In Millions, unless otherwise specified |
12 Months Ended |
|---|---|
|
Dec. 31, 2012
|
|
|
Postretirement Health and Life [Member]
|
|
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | |
| Effect of One Percent Increase on Total of Postretirement Health and Life Service and Interest Cost | $ 2.0 |
| Effect of One Percent Decrease on Total of Postretirement Health and Life Service and Interest Cost | (1.6) |
| Effect of One Percent Increase on Postretirement Health and Life Obligation | 18.2 |
| Effect of One Percent Decrease on Postretirement Health and Life Obligation | $ (15.1) |
| X | ||||||||||
|
- Definition
Amount of effect of a one-percentage-point decrease in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of effect of a one-percentage-point decrease in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The effect of a one-percentage-point increase in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The effect of a one-percentage-point increase in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
|
Pension and Other Postretirement Benefit Plans - Plan Asset Allocations (Details)
|
12 Months Ended | |||||
|---|---|---|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
|||||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||||||
| Defined Benefit Plans, Company Stock Contributed (in Shares) | 500,000 | |||||
|
Pension [Member]
|
||||||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||||||
| Actual Plan Asset Allocation | 100.00% | 100.00% | ||||
| Defined Benefit Plans, Company Stock Contributed (in Shares) | 0 | |||||
| Target Plan Asset Allocation | 100.00% | |||||
|
Pension [Member] | Equity Securities [Member]
|
||||||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||||||
| Actual Plan Asset Allocation | 54.00% | 52.00% | ||||
| Target Plan Asset Allocation | 52.00% | |||||
|
Pension [Member] | Debt Securities [Member]
|
||||||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||||||
| Actual Plan Asset Allocation | 28.00% | 27.00% | ||||
| Target Plan Asset Allocation | 30.00% | |||||
|
Pension [Member] | Real Estate [Member]
|
||||||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||||||
| Actual Plan Asset Allocation | 5.00% | 5.00% | ||||
| Target Plan Asset Allocation | 9.00% | |||||
|
Pension [Member] | Private Equity [Member]
|
||||||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||||||
| Actual Plan Asset Allocation | 13.00% | 16.00% | ||||
| Target Plan Asset Allocation | 9.00% | |||||
|
Postretirement Health and Life [Member]
|
||||||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||||||
| Actual Plan Asset Allocation | 100.00% | [1] | 100.00% | [1] | ||
| Target Plan Asset Allocation | 100.00% | [1] | ||||
|
Postretirement Health and Life [Member] | Equity Securities [Member]
|
||||||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||||||
| Actual Plan Asset Allocation | 56.00% | [1] | 51.00% | [1] | ||
| Target Plan Asset Allocation | 48.00% | [1] | ||||
|
Postretirement Health and Life [Member] | Debt Securities [Member]
|
||||||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||||||
| Actual Plan Asset Allocation | 35.00% | [1] | 39.00% | [1] | ||
| Target Plan Asset Allocation | 34.00% | [1] | ||||
|
Postretirement Health and Life [Member] | Real Estate [Member]
|
||||||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||||||
| Actual Plan Asset Allocation | 0.00% | [1] | 0.00% | [1] | ||
| Target Plan Asset Allocation | 9.00% | [1] | ||||
|
Postretirement Health and Life [Member] | Private Equity [Member]
|
||||||
| Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] | ||||||
| Actual Plan Asset Allocation | 9.00% | [1] | 10.00% | [1] | ||
| Target Plan Asset Allocation | 9.00% | [1] | ||||
|
||||||
| X | ||||||||||
|
- Definition
The number of employer shares or related party shares included in plan assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Target allocation of investments of this type to total plan assets presented on a weighted average basis. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Pension and Other Postretirement Benefit Plans - Recurring Fair Value Measures (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
||||||
|---|---|---|---|---|---|---|---|---|---|
|
Pension [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | $ 460.1 | $ 432.4 | $ 382.0 | ||||||
|
Pension [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 213.0 | 152.8 | |||||||
|
Pension [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 163.3 | 188.9 | |||||||
|
Pension [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 83.8 | 90.7 | |||||||
|
Pension [Member] | U.S. Large-Cap [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 79.0 | [1] | 69.4 | [1] | |||||
|
Pension [Member] | U.S. Large-Cap [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 43.0 | [1] | 32.1 | [1] | |||||
|
Pension [Member] | U.S. Large-Cap [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 36.0 | [1] | 37.3 | [1] | |||||
|
Pension [Member] | U.S. Large-Cap [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | [1] | 0 | [1] | |||||
|
Pension [Member] | U.S. Mid-Cap Growth [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 33.6 | [1] | 29.3 | [1] | |||||
|
Pension [Member] | U.S. Mid-Cap Growth [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 18.3 | [1] | 13.5 | [1] | |||||
|
Pension [Member] | U.S. Mid-Cap Growth [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 15.3 | [1] | 15.8 | [1] | |||||
|
Pension [Member] | U.S. Mid-Cap Growth [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | [1] | 0 | [1] | |||||
|
Pension [Member] | U.S. Small Cap [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 33.6 | [1] | 28.3 | [1] | |||||
|
Pension [Member] | U.S. Small Cap [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 18.3 | [1] | 13.1 | [1] | |||||
|
Pension [Member] | U.S. Small Cap [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 15.3 | [1] | 15.2 | [1] | |||||
|
Pension [Member] | U.S. Small Cap [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | [1] | 0 | [1] | |||||
|
Pension [Member] | International [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 96.4 | 75.1 | |||||||
|
Pension [Member] | International [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 50.5 | 0 | |||||||
|
Pension [Member] | International [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 45.9 | 75.1 | |||||||
|
Pension [Member] | International [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Pension [Member] | ALLETE [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 21.3 | ||||||||
|
Pension [Member] | ALLETE [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 21.3 | ||||||||
|
Pension [Member] | ALLETE [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | ||||||||
|
Pension [Member] | ALLETE [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | ||||||||
|
Pension [Member] | Mutual Funds [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 72.5 | 72.8 | |||||||
|
Pension [Member] | Mutual Funds [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 72.5 | 72.8 | |||||||
|
Pension [Member] | Mutual Funds [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Pension [Member] | Mutual Funds [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Pension [Member] | Fixed Income [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 61.2 | 45.5 | |||||||
|
Pension [Member] | Fixed Income [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 10.4 | 0 | |||||||
|
Pension [Member] | Fixed Income [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 50.8 | 45.5 | |||||||
|
Pension [Member] | Fixed Income [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Pension [Member] | Private Equity Funds [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 58.9 | 69.0 | |||||||
|
Pension [Member] | Private Equity Funds [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Pension [Member] | Private Equity Funds [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Pension [Member] | Private Equity Funds [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 58.9 | 69.0 | |||||||
|
Pension [Member] | Real Estate [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 24.9 | 21.7 | |||||||
|
Pension [Member] | Real Estate [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Pension [Member] | Real Estate [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Pension [Member] | Real Estate [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 24.9 | 21.7 | |||||||
|
Postretirement Health and Life [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 131.0 | 121.0 | 114.7 | ||||||
|
Postretirement Health and Life [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 99.2 | 88.1 | |||||||
|
Postretirement Health and Life [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 18.3 | 18.9 | |||||||
|
Postretirement Health and Life [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 13.5 | 14.0 | |||||||
|
Postretirement Health and Life [Member] | U.S. Large-Cap [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 16.7 | 15.9 | |||||||
|
Postretirement Health and Life [Member] | U.S. Large-Cap [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 16.7 | [2] | 15.9 | [2] | |||||
|
Postretirement Health and Life [Member] | U.S. Large-Cap [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Postretirement Health and Life [Member] | U.S. Large-Cap [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Postretirement Health and Life [Member] | U.S. Mid-Cap Growth [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 13.2 | 11.5 | |||||||
|
Postretirement Health and Life [Member] | U.S. Mid-Cap Growth [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 13.2 | [2] | 11.5 | [2] | |||||
|
Postretirement Health and Life [Member] | U.S. Mid-Cap Growth [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Postretirement Health and Life [Member] | U.S. Mid-Cap Growth [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Postretirement Health and Life [Member] | U.S. Small Cap [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 13.3 | 11.2 | |||||||
|
Postretirement Health and Life [Member] | U.S. Small Cap [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 13.3 | [2] | 11.2 | [2] | |||||
|
Postretirement Health and Life [Member] | U.S. Small Cap [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Postretirement Health and Life [Member] | U.S. Small Cap [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Postretirement Health and Life [Member] | International [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 30.3 | 25.1 | |||||||
|
Postretirement Health and Life [Member] | International [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 30.3 | 25.1 | |||||||
|
Postretirement Health and Life [Member] | International [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Postretirement Health and Life [Member] | International [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Postretirement Health and Life [Member] | Mutual Funds [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 25.5 | 24.1 | |||||||
|
Postretirement Health and Life [Member] | Mutual Funds [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 25.5 | 24.1 | |||||||
|
Postretirement Health and Life [Member] | Mutual Funds [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Postretirement Health and Life [Member] | Mutual Funds [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Postretirement Health and Life [Member] | Fixed Income [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 18.5 | 19.2 | |||||||
|
Postretirement Health and Life [Member] | Fixed Income [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0.2 | 0.3 | |||||||
|
Postretirement Health and Life [Member] | Fixed Income [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 18.3 | 18.9 | |||||||
|
Postretirement Health and Life [Member] | Fixed Income [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Postretirement Health and Life [Member] | Private Equity Funds [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 13.5 | 14.0 | |||||||
|
Postretirement Health and Life [Member] | Private Equity Funds [Member] | Level 1 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Postretirement Health and Life [Member] | Private Equity Funds [Member] | Level 2 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | 0 | 0 | |||||||
|
Postretirement Health and Life [Member] | Private Equity Funds [Member] | Level 3 [Member]
|
|||||||||
| Recurring Fair Value Measures [Line Items] | |||||||||
| Fair Value of Plan Assets | $ 13.5 | $ 14.0 | |||||||
|
|||||||||
| X | ||||||||||
|
- Definition
Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
|
Pension and Other Postretirement Benefit Plans - Recurring Fair Value Measures, Activity in Level 3 (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | |
|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
|
|
Pension [Member] | Equity Securities (ARS) [Member]
|
||
| Activity in Level 3 [Roll Forward] | ||
| Beginning Balance | $ 6.7 | |
| Actual Return on Plan Assets | 0 | |
| Purchases, sales and settlements, net | (6.7) | |
| Ending Balance | 0 | |
|
Pension [Member] | Private Equity Funds [Member]
|
||
| Activity in Level 3 [Roll Forward] | ||
| Beginning Balance | 69.0 | 50.7 |
| Actual Return on Plan Assets | (9.7) | 30.9 |
| Purchases, sales and settlements, net | (0.4) | (12.6) |
| Ending Balance | 58.9 | 69.0 |
|
Pension [Member] | Real Estate [Member]
|
||
| Activity in Level 3 [Roll Forward] | ||
| Beginning Balance | 21.7 | 20.1 |
| Actual Return on Plan Assets | 3.4 | 3.5 |
| Purchases, sales and settlements, net | (0.2) | (1.9) |
| Ending Balance | 24.9 | 21.7 |
|
Postretirement Health and Life [Member] | Private Equity Funds [Member]
|
||
| Activity in Level 3 [Roll Forward] | ||
| Beginning Balance | 14.0 | 12.4 |
| Actual Return on Plan Assets | 0.2 | 1.1 |
| Purchases, sales and settlements, net | (0.7) | 0.5 |
| Ending Balance | $ 13.5 | $ 14.0 |
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Amount of gain (loss) recognized in earnings, arising from assets measured at fair value on a recurring basis using unobservable inputs (level 3). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of purchases, sales, issues, and settlements (net) which have taken place in relation to assets measured at fair value on a recurring basis using unobservable inputs (level 3). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Employee Stock and Incentive Plans - Employee Stock Ownership Plan (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Employee Stock and Incentive Plans [Abstract] | |||
| ESOP Employer Loan, Description | In 1990, the ESOP issued a $75.0 million note (term not to exceed 25 years at 10.25 percent) to use as consideration for 2.8 million shares (1.9 million shares adjusted for stock splits) of our newly issued common stock. The note was refinanced in 2006 at 6 percent. | ||
| ESOP Compensation Expense | $ 7.7 | $ 7.4 | $ 7.1 |
| ESOP Shares, Allocated | 2.2 | 2.2 | 2.2 |
| ESOP Shares, Unallocated | 0.7 | 1.0 | 1.3 |
| ESOP Shares, Total | 2.9 | 3.2 | 3.5 |
| Fair Value of Unallocated ESOP Shares | $ 28.7 | $ 42.0 | $ 48.4 |
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The amount of plan compensation cost recognized during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Sets forth the terms of the arrangement, including interest rate and repayment requirements, in which the employer lends funds to the ESOP. The loan amount is not required to be externally reported. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The fair value of shares held by the ESOP as of the balance sheet date in which no ESOP participant has a vested interest and no lender has a claim. The fair value of an ESOP share is the amount the seller could reasonably expect to receive for it in a current sale between a willing buyer and a willing seller, that is, other than in a forced or liquidation sale, which would be the market price of the stock if it is publicly traded. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The shares or units in an ESOP trust that have been assigned to individual participant accounts based on a known formula. IRS rules require allocations to be nondiscriminatory generally based on compensation, length of service, or a combination of both. For any particular participant such shares or units may be vested, unvested, or partially vested. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Shares contributed to the ESOP that have not yet been released, committed to be released, or allocated to participant accounts. Suspense shares generally collateralize ESOP debt. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Sum of the allocated, committed-to-be-released and suspense shares of the entity held by the plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Employee Stock and Incentive Plans - Stock-Based Compensation (Details)
|
12 Months Ended | ||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
Dec. 31, 2009
|
||||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||||
| Grants | 0 | [1] | 0 | [1] | 0 | [1] | |||
| Exercised | 49,075 | 80,798 | 40,769 | ||||||
| Options Outstanding | 395,678 | 460,234 | 560,887 | 646,235 | |||||
|
Performance Shares [Member]
|
|||||||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||||
| Vesting Period | 3 years | ||||||||
|
Restricted Stock Units [Member]
|
|||||||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||||
| Vesting Period | 3 years | ||||||||
|
Employee Stock Purchase Plan (ESPP) [Member]
|
|||||||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||||
| ESPP Discount | 5.00% | ||||||||
|
Executive Plan [Member]
|
|||||||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||||
| Common Stock Reserved | 1,200,000 | ||||||||
| Shares Available for Issuance | 600,000 | ||||||||
|
Director Plan [Member]
|
|||||||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||||
| Grants | 0 | ||||||||
| Exercised | 1,293 | ||||||||
| Options Outstanding | 0 | ||||||||
|
|||||||||
| X | ||||||||||
|
- Definition
Aggregate number of common shares reserved for future issuance. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The discount rate from market value on purchase date that participants pay for shares. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Net number of share options (or share units) granted during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Number of share options (or share units) exercised during the current period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Employee Stock and Incentive Plans - Share-Based Compensation Expense (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Share-Based Compensation Expense | $ 2.1 | $ 1.6 | $ 2.2 |
| Income Tax Benefit | 0.9 | 0.7 | 0.9 |
| Capitalized Stock-Based Compensation Expense | 0 | 0 | 0 |
|
Stock Options [Member]
|
|||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Share-Based Compensation Expense | 0 | 0 | 0.1 |
|
Performance Shares [Member]
|
|||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Share-Based Compensation Expense | 1.4 | 1.1 | 1.5 |
| Unrecognized Compensation Cost | 1.3 | ||
| Weighted Average Period for Recognition | 1 year 8 months 12 days | ||
|
Restricted Stock Units [Member]
|
|||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Share-Based Compensation Expense | 0.7 | 0.5 | 0.6 |
| Unrecognized Compensation Cost | $ 0.6 | ||
| Weighted Average Period for Recognition | 1 year 8 months 12 days | ||
| X | ||||||||||
|
- Definition
Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Represents the compensation cost capitalized during the period arising from equity-based compensation arrangements (for example, shares of stock, units, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
As of the balance sheet date, the aggregate unrecognized cost of equity-based awards made to employees under equity-based compensation awards that have yet to vest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
|
Employee Stock and Incentive Plans - Non-Qualified Stock Options (Details) (USD $)
In Millions, except Share data, unless otherwise specified |
12 Months Ended | ||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
Dec. 31, 2008
|
||||||
| Number of Options [Abstract] | |||||||||
| Outstanding as of January 1, | 460,234 | 560,887 | 646,235 | ||||||
| Granted | 0 | [1] | 0 | [1] | 0 | [1] | |||
| Exercised | 49,075 | 80,798 | 40,769 | ||||||
| Forfeited | 15,481 | 19,855 | 44,579 | ||||||
| Outstanding as of December 31, | 395,678 | 460,234 | 560,887 | ||||||
| Exercisable as of December 31, | 395,678 | 460,234 | 523,491 | ||||||
| Weighted Average Exercise Price [Abstract] | |||||||||
| Outstanding as of January 1, | $ 41.68 | $ 40.69 | $ 40.05 | ||||||
| Granted | $ 0 | [1] | $ 0 | [1] | $ 0 | [1] | |||
| Exercised | $ 35.84 | $ 34.25 | $ 27.76 | ||||||
| Forfeited | $ 44.86 | $ 43.96 | $ 43.16 | ||||||
| Outstanding as of December 31, | $ 42.28 | $ 41.68 | $ 40.69 | ||||||
| Exercisable as of December 31, | $ 41.71 | $ 41.59 | $ 39.76 | ||||||
| Proceeds from Stock Options Exercised | $ 0.1 | ||||||||
| Weighted Average Grant Date Intrinsic Value of Options Granted | $ 6.18 | ||||||||
| Total Intrinsic Value of Options Exercised | $ 0.3 | $ 0.5 | $ 0.3 | ||||||
|
|||||||||
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The cash inflow associated with the amount received from holders exercising their stock options. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The total accumulated difference between fair values of underlying shares on dates of exercise and exercise price on options which were exercised (or share units converted) into shares during the reporting period under the plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Net number of share options (or share units) granted during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The grant-date intrinsic value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Weighted average price at which option holders acquired shares when converting their stock options into shares. No definition available.
|
| X | ||||||||||
|
- Definition
Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated. No definition available.
|
| X | ||||||||||
|
- Definition
Weighted average price at which grantees can acquire the shares reserved for issuance on stock options awarded. No definition available.
|
| X | ||||||||||
|
- Definition
Number of share options (or share units) exercised during the current period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Employee Stock and Incentive Plans - Stock Options, Range of Exercise Price (Details) (USD $)
|
12 Months Ended |
|---|---|
|
Dec. 31, 2012
|
|
|
$23.79 to $26.91 [Member]
|
|
| Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | |
| Exercise Price Range, Lower Range Limit | $ 23.79 |
| Exercise Price Range, Upper Range Limit | $ 26.91 |
| Number Outstanding | 1,340 |
| Weighted Average Remaining Contractual Term (in Years) | 1 month 6 days |
| Weighted Average Exercise Price | $ 23.79 |
| Number Exercisable | 1,340 |
| Weighted Average Remaining Contractual Term (in Years) | 1 month 6 days |
| Weighted Average Exercise Price | $ 23.79 |
|
$37.76 to $41.35 [Member]
|
|
| Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | |
| Exercise Price Range, Lower Range Limit | $ 37.76 |
| Exercise Price Range, Upper Range Limit | $ 41.35 |
| Number Outstanding | 236,052 |
| Weighted Average Remaining Contractual Term (in Years) | 3 years 6 months |
| Weighted Average Exercise Price | $ 39.64 |
| Number Exercisable | 236,052 |
| Weighted Average Remaining Contractual Term (in Years) | 3 years 6 months |
| Weighted Average Exercise Price | $ 39.64 |
|
$44.15 to $48.65 [Member]
|
|
| Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | |
| Exercise Price Range, Lower Range Limit | $ 44.15 |
| Exercise Price Range, Upper Range Limit | $ 48.65 |
| Number Outstanding | 158,286 |
| Weighted Average Remaining Contractual Term (in Years) | 3 years 7 months 6 days |
| Weighted Average Exercise Price | $ 46.38 |
| Number Exercisable | 158,286 |
| Weighted Average Remaining Contractual Term (in Years) | 3 years 7 months 6 days |
| Weighted Average Exercise Price | $ 46.38 |
| X | ||||||||||
|
- Definition
Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Weighted average remaining contractual term of exercisable stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Employee Stock and Incentive Plans - Performance Shares and Restricted Stock Units (Details) (USD $)
In Millions, except Share data, unless otherwise specified |
3 Months Ended | 12 Months Ended | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
Mar. 31, 2013
|
Mar. 31, 2012
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
||||||
|
Performance Shares [Member]
|
||||||||||
| Number of Shares [Abstract] | ||||||||||
| As of January 1, | 107,899 | 128,333 | 128,333 | 122,489 | 121,825 | |||||
| Granted | 41,332 | 33,525 | 38,764 | [1] | 39,312 | [1] | 49,302 | [1] | ||
| Awarded | 18,605 | (41,009) | (32,368) | 0 | ||||||
| Unearned Grant Award | (17,575) | 0 | (22,909) | |||||||
| Forfeited | (614) | (1,100) | (25,729) | |||||||
| As of December 31, | 107,899 | 128,333 | 122,489 | |||||||
| Weighted Average Grant Date Fair Value [Abstract] | ||||||||||
| As of January 1, | $ 40.73 | $ 36.54 | $ 36.54 | $ 38.15 | $ 41.96 | |||||
| Granted | $ 44.70 | [1] | $ 41.00 | [1] | $ 35.44 | [1] | ||||
| Awarded | $ 34.25 | $ 48.10 | $ 0.00 | |||||||
| Unearned Grant Award | $ 34.25 | $ 0.00 | $ 54.50 | |||||||
| Forfeited | $ 34.49 | $ 34.35 | $ 36.45 | |||||||
| As of December 31, | $ 40.73 | $ 36.54 | $ 38.15 | |||||||
| Performance Period | 3 years | |||||||||
| Grants, Grant Date Fair Value | $ 2.2 | $ 1.5 | ||||||||
| Awards, Grant Date Fair Value | 0.7 | 1.4 | ||||||||
|
Restricted Stock Units [Member]
|
||||||||||
| Number of Shares [Abstract] | ||||||||||
| As of January 1, | 56,415 | 63,464 | 63,464 | 43,803 | 28,983 | |||||
| Granted | 19,193 | 16,355 | 18,162 | [1] | 20,136 | [1] | 26,589 | [1] | ||
| Awarded | 20,939 | (24,707) | (215) | (3,091) | ||||||
| Forfeited | (504) | (260) | (8,678) | |||||||
| As of December 31, | 56,415 | 63,464 | 43,803 | |||||||
| Weighted Average Grant Date Fair Value [Abstract] | ||||||||||
| As of January 1, | $ 36.61 | $ 32.57 | $ 32.57 | $ 30.61 | $ 29.41 | |||||
| Granted | $ 40.83 | [1] | $ 36.74 | [1] | $ 31.83 | [1] | ||||
| Awarded | $ 29.43 | $ 30.30 | $ 29.75 | |||||||
| Forfeited | $ 31.80 | $ 29.41 | $ 30.62 | |||||||
| As of December 31, | $ 36.61 | $ 32.57 | $ 30.61 | |||||||
| Performance Period | 3 years | |||||||||
| Grants, Grant Date Fair Value | 0.8 | 0.7 | ||||||||
| Awards, Grant Date Fair Value | $ 0.7 | $ 0.7 | ||||||||
|
||||||||||
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The total grant date fair value of equity-based awards other than options, granted during the period. No definition available.
|
| X | ||||||||||
|
- Definition
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Shares of original grant unearned (not paid out), a reduction to non-vested shares balance, similar to a forfeiture. No definition available.
|
| X | ||||||||||
|
- Definition
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Unearned Grant Award, Weighted Average Grant Date Fair Value (Per Share) No definition available.
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The total fair value of equity-based awards for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
|
Quarterly Financial Data (Unaudited) (Details) (USD $)
In Millions, except Per Share data, unless otherwise specified |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
Dec. 31, 2012
|
Sep. 30, 2012
|
Jun. 30, 2012
|
Mar. 31, 2012
|
Dec. 31, 2011
|
Sep. 30, 2011
|
Jun. 30, 2011
|
Mar. 31, 2011
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Quarterly Financial Data (Unaudited) [Abstract] | |||||||||||
| Operating Revenue | $ 256.0 | $ 248.8 | $ 216.4 | $ 240.0 | $ 239.2 | $ 226.9 | $ 219.9 | $ 242.2 | $ 961.2 | $ 928.2 | $ 907.0 |
| Operating Income | 47.9 | 45.6 | 23.3 | 38.4 | 34.2 | 38.9 | 26.1 | 50.8 | 155.2 | 150.0 | 135.8 |
| Net Income Attributable to ALLETE | $ 28.9 | $ 29.4 | $ 14.4 | $ 24.4 | $ 19.1 | $ 20.5 | $ 17.0 | $ 37.2 | $ 97.1 | $ 93.8 | $ 75.3 |
| Basic Earnings Per Share of Common Stock | $ 0.76 | $ 0.78 | $ 0.39 | $ 0.66 | $ 0.53 | $ 0.57 | $ 0.49 | $ 1.07 | $ 2.59 | $ 2.66 | $ 2.20 |
| Diluted Earnings Per Share of Common Stock | $ 0.75 | $ 0.78 | $ 0.39 | $ 0.66 | $ 0.53 | $ 0.57 | $ 0.48 | $ 1.07 | $ 2.58 | $ 2.65 | $ 2.19 |
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The net result for the period of deducting operating expenses from operating revenues. No definition available.
|
| X | ||||||||||
|
- Definition
The total amount of operating revenues recognized during the period. No definition available.
|
|
Schedule II (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | |||||||
|---|---|---|---|---|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
||||||
|
Trade Accounts Receivable [Member]
|
||||||||
| Valuation and Qualifying Accounts and Reserves [Line Items] | ||||||||
| Balance at Beginning of Period | $ 0.9 | $ 0.9 | $ 0.9 | |||||
| Additions, Charged to Income | 1.0 | 1.3 | 1.1 | |||||
| Additions, Other Charges | 0 | 0 | 0 | |||||
| Deductions from Reserves | 0.9 | [1] | 1.3 | [1] | 1.1 | [1] | ||
| Balance at End of Period | 1.0 | 0.9 | 0.9 | |||||
|
Finance Receivables - Long-Term [Member]
|
||||||||
| Valuation and Qualifying Accounts and Reserves [Line Items] | ||||||||
| Balance at Beginning of Period | 0.6 | 0.8 | 0.4 | |||||
| Additions, Charged to Income | 0 | 0.1 | 0.8 | |||||
| Additions, Other Charges | 0 | 0 | 0 | |||||
| Deductions from Reserves | 0 | [1] | 0.3 | [1] | 0.4 | [1] | ||
| Balance at End of Period | 0.6 | 0.6 | 0.8 | |||||
|
Deferred Tax Assets [Member]
|
||||||||
| Valuation and Qualifying Accounts and Reserves [Line Items] | ||||||||
| Balance at Beginning of Period | 0.4 | 0.5 | 0.3 | |||||
| Additions, Charged to Income | 2.0 | (0.1) | 0.2 | |||||
| Additions, Other Charges | 0 | 0 | 0 | |||||
| Deductions from Reserves | 0 | [1] | 0 | [1] | 0 | [1] | ||
| Balance at End of Period | $ 2.4 | $ 0.4 | $ 0.5 | |||||
|
||||||||
| X | ||||||||||
|
- Definition
Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, charged to costs and expenses. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, charged to accounts other than costs and expenses in a given period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Total of the deductions in a given period to allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, representing receivables written off as uncollectible and portions of the reserves utilized, respectively. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|