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Document and Entity Information Document (USD $)
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3 Months Ended | |
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Mar. 31, 2013
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Jun. 30, 2012
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| Document and Entity Information [Abstract] | ||
| 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 | 39,921,805 | |
| Document Fiscal Year Focus | 2013 | |
| Document Fiscal Period Focus | Q1 | |
| Document Type | 10-Q | |
| Amendment Flag | false | |
| Document Period End Date | Mar. 31, 2013 |
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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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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
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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- 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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- 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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- 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
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- Definition
This represents the noncurrent liability recognized in the balance sheet that is associated with the defined benefit pension plans and other postretirement and postemployment 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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- 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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- 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
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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- 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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- 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, except Per Share data, unless otherwise specified |
Mar. 31, 2013
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Dec. 31, 2012
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| Accounts Receivable, Net [Abstract] | ||
| Accounts Receivable, Allowance | $ 1.0 | $ 1.0 |
| Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract] | ||
| Common Stock, Par Value | $ 0.00 | $ 0.00 |
| Common Stock, Shares Authorized | 80.0 | 80.0 |
| Common Stock, Shares Outstanding | 39.9 | 39.4 |
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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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- 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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Consolidated Statement of Income (USD $)
In Millions, except Per Share data, unless otherwise specified |
3 Months Ended | |
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Mar. 31, 2013
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Mar. 31, 2012
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| Operating Revenue | $ 263.8 | $ 240.0 |
| Operating Expenses [Abstract] | ||
| Fuel and Purchased Power | 86.5 | 77.1 |
| Operating and Maintenance | 104.7 | 99.9 |
| Depreciation | 28.2 | 24.6 |
| Total Operating Expenses | 219.4 | 201.6 |
| Operating Income | 44.4 | 38.4 |
| Other Income (Expense) [Abstract] | ||
| Interest Expense | (12.3) | (11.0) |
| Equity Earnings in ATC | 5.2 | 4.6 |
| Other | 2.7 | 0.7 |
| Total Other Expense | (4.4) | (5.7) |
| Income Before Income Taxes | 40.0 | 32.7 |
| Income Tax Expense | 7.5 | 8.3 |
| Net Income | $ 32.5 | $ 24.4 |
| Average Shares of Common Stock [Abstract] | ||
| Basic | 38.9 | 36.8 |
| Diluted | 39.0 | 36.9 |
| Basic Earnings Per Share of Common Stock | $ 0.83 | $ 0.66 |
| Diluted Earnings Per Share of Common Stock | $ 0.83 | $ 0.66 |
| Dividends Per Share of Common Stock | $ 0.475 | $ 0.46 |
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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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- Definition
The net result for the period of deducting operating expenses from operating revenues. No definition available.
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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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- 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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- Definition
The total amount of operating revenues recognized during the period. No definition available.
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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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- 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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- 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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- 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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- 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 |
3 Months Ended | ||||
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Mar. 31, 2013
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Mar. 31, 2012
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| Comprehensive Income (Loss) [Abstract] | |||||
| Net Income | $ 32.5 | $ 24.4 | |||
| Other Comprehensive Income (Loss) [Abstract] | |||||
| Unrealized Gain on Securities, Net of Income Taxes of $- and $0.7 | 0 | [1] | 1.0 | ||
| Unrealized Gain (Loss) on Derivatives, Net of Income Taxes of $- and $(0.1) | 0.1 | [1] | (0.1) | ||
| Defined Benefit Pension and Other Postretirement Benefit Plans, Net of Income Taxes of $0.2 and $0.3 | 0.3 | [1] | 0.5 | ||
| Total Other Comprehensive Income | 0.4 | [1] | 1.4 | ||
| Comprehensive Income | $ 32.9 | $ 25.8 | |||
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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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- Details
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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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- 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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- 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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- 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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- 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 |
3 Months Ended | |
|---|---|---|
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Mar. 31, 2013
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Mar. 31, 2012
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| Consolidated Statement of Comprehensive Income Parentheticals [Abstract] | ||
| Unrealized Gain on Securities, Tax | $ 0 | $ 0.7 |
| Unrealized Gain (Loss) on Derivatives, Tax | 0 | (0.1) |
| Defined Benefit Pension and Other Postretirement Benefit Plans, Tax | $ 0.2 | $ 0.3 |
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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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- 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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- 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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Consolidated Statement of Cash Flows (USD $)
In Millions, unless otherwise specified |
3 Months Ended | |
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Mar. 31, 2013
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Mar. 31, 2012
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| Operating Activities [Abstract] | ||
| Net Income | $ 32.5 | $ 24.4 |
| Allowance for Funds Used During Construction - Equity | (1.1) | (0.8) |
| Income from Equity Investments, Net of Dividends | (1.3) | (0.7) |
| Gain on Sale of Assets | (0.2) | 0 |
| Gain on Sale of Investments | (0.8) | 0 |
| Depreciation Expense | 28.2 | 24.6 |
| Amortization of Debt Issuance Costs | 0.3 | 0.2 |
| Deferred Income Tax Expense | 7.3 | 8.3 |
| Share-Based Compensation Expense | 0.6 | 0.7 |
| ESOP Compensation Expense | 2.0 | 1.8 |
| Defined Benefit Pension and Postretirement Benefit Expense | 5.6 | 6.9 |
| Bad Debt Expense | 0.1 | 0.3 |
| Changes in Operating Assets and Liabilities [Abstract] | ||
| Accounts Receivable | 2.7 | 2.7 |
| Inventories | 5.5 | (3.1) |
| Prepayments and Other | 5.5 | 4.2 |
| Accounts Payable | (11.0) | (7.9) |
| Other Current Liabilities | (0.7) | (0.9) |
| Cash Contributions to Defined Benefit Pension and Other Postretirement Benefit Plans | (10.8) | 0 |
| Changes in Regulatory and Other Non-Current Assets | (1.9) | 2.1 |
| Changes in Regulatory and Other Non-Current Liabilities | (4.3) | 5.7 |
| Cash from Operating Activities | 58.2 | 68.5 |
| Investing Activities [Abstract] | ||
| Proceeds from Sale of Available-for-sale Securities | 7.9 | 0.5 |
| Payments for Purchase of Available-for-sale Securities | (1.2) | (0.8) |
| Investment in ATC | (0.4) | (0.8) |
| Changes to Other Investments | (1.0) | (1.5) |
| Additions to Property, Plant and Equipment | (69.8) | (53.9) |
| Proceeds from Sale of Assets | 0.6 | 0 |
| Cash for Investing Activities | (63.9) | (56.5) |
| Financing Activities [Abstract] | ||
| Proceeds from Issuance of Common Stock | 23.4 | 23.7 |
| Proceeds from Notes Payable | 0 | 0.5 |
| Payments for Long-Term Debt | (1.7) | (1.4) |
| Dividends on Common Stock | (19.5) | (17.7) |
| Cash from Financing Activities | 2.2 | 5.1 |
| Change in Cash and Cash Equivalents | (3.5) | 17.1 |
| Cash and Cash Equivalents at Beginning of Period | 80.8 | 101.1 |
| Cash and Cash Equivalents at End of Period | $ 77.3 | $ 118.2 |
| 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
This item represents the difference between the gross realized gains and losses 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 | ||||||||||
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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 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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- 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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- 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
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 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
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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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- 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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Operations and Significant Accounting Policies
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Mar. 31, 2013
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| Operations and Significant Accounting Policies [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Operations and Significant Accounting Policies [Text Block] | OPERATIONS AND SIGNIFICANT ACCOUNTING POLICIES Inventories. Inventories are stated at the lower of cost or market. Amounts removed from inventory are recorded on an average cost basis.
NOTE 1. OPERATIONS AND SIGNIFICANT ACCOUNTING POLICIES (Continued) Supplemental Statement of Cash Flows Information.
Subsequent Events. The Company performed an evaluation of subsequent events for potential recognition and disclosure through the time of the financial statements issuance. New Accounting Standards. Amounts Reclassified Out of Accumulated Other Comprehensive Income. In February 2013, the FASB issued an accounting standard update on disclosure of amounts reclassified out of accumulated other comprehensive income. This update requires entities to provide information about amounts reclassified out of accumulated other comprehensive income by component. In addition, entities are required to present, either on the face of the statement where net income is presented or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income but only if the amount reclassified is required under GAAP to be reclassified to net income in its entirety in the same reporting period. For other amounts that are not required under GAAP to be reclassified in their entirety to net income, entities are required to cross-reference to other disclosures required under GAAP that provide additional detail on these amounts. This guidance was adopted for the quarter ended March 31, 2013, and required additional disclosures but did not have an impact on our consolidated financial position, results of operations, or cash flows. (See Note 11. Reclassifications Out of Accumulated Other Comprehensive Income.) |
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- Details
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- Definition
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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Mar. 31, 2013
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| Business Segments [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 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, midstream gas and oil infrastructure, among other energy related projects. This segment also includes other business development and corporate expenditures, a small amount of non-rate base generation, approximately 6,000 acres of land in Minnesota, and earnings on cash and investments.
NOTE 2. BUSINESS SEGMENTS (Continued)
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- Details
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| X | ||||||||||
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- Definition
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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Investments
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Mar. 31, 2013
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| Investments [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Investments [Text Block] | INVESTMENTS Investments. Our long-term investment portfolio includes the real estate assets of ALLETE Properties, debt and equity securities consisting primarily of securities held in other postretirement plans to fund employee benefits, the cash equivalents within these plans, and other assets consisting primarily of land in Minnesota.
NOTE 3. 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 and no impairments were recorded for the quarter ended March 31, 2013 (none for the year ended December 31, 2012). Long-Term Finance Receivables. As of March 31, 2013, long-term finance receivables were $1.4 million net of allowance ($1.4 million net of allowance as of December 31, 2012). 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 March 31, 2013, we had an allowance for doubtful accounts of $0.6 million ($0.6 million as of December 31, 2012). |
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- Definition
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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Mar. 31, 2013
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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 March 31, 2013. (See Note 8. 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 the value of the Swap are deemed 100 percent effective. As a result, there was no ineffectiveness recorded for the quarter ended March 31, 2013. The mark-to-market fluctuation on the cash flow hedge was recorded in accumulated other comprehensive income on the Consolidated Balance Sheet. As of March 31, 2013, the fair value of the Swap was a $0.6 million liability (a $0.7 million liability as of December 31, 2012) 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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- Definition
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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Mar. 31, 2013
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| Fair Value [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 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). Descriptions of the three levels of the fair value hierarchy are discussed in Note 9. Fair Value to the consolidated financial statements in our 2012 Form 10-K. NOTE 5. FAIR VALUE (Continued) 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 March 31, 2013 and December 31, 2012. 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 and may affect the valuation of these 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.
There was no activity in Level 3 during the quarters ended March 31, 2013 and 2012. The Company’s policy is to recognize transfers in and transfers out as of the actual date of the event or of the change in circumstances that caused the transfer. For the quarters ended March 31, 2013 and 2012, there were no transfers in or out of Levels 1, 2 or 3. NOTE 5. FAIR VALUE (Continued) Fair Value of Financial Instruments. With the exception of the item listed in the table below, the estimated fair value of all financial instruments approximates the carrying amount. The fair value for the item listed below was 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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Regulatory Matters
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Mar. 31, 2013
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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 allows 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. In January 2012, the Company filed a petition for review at the Minnesota Supreme Court (Court). In February 2012, the Court granted the petition for review and oral arguments were held before the Court in October 2012. A decision is expected in the second quarter of 2013. 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 set each July 1 based on a cost-based formula methodology, 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 cost-based formula 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 power provided to this customer is expected to be used to supply power for prospective additional retail and municipal load. 2012 Wisconsin Rate Case. SWL&P’s 2013 retail rates are based on a 2012 PSCW retail rate order, effective January 1, 2013, that 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 0.2 percent decrease in natural gas rates). On an annualized basis, the rate increase will generate approximately $1.7 million in additional revenue. Transmission Cost Recovery Riders. Minnesota Power has an approved cost recovery rider in place for certain transmission investments and expenditures. The continued use of the 2009 billing factor was approved by the MPUC in May 2011, which allows Minnesota Power to charge retail customers on a current basis for the costs of constructing certain transmission facilities plus a return on the capital invested. In June 2011, Minnesota Power filed an updated billing factor that includes additional transmission expenditures, which is expected to be approved in mid-2013. NOTE 6. REGULATORY MATTERS (Continued) Renewable Cost Recovery Riders. The Bison Wind Energy Center in North Dakota consists of 292 MW of nameplate capacity and was completed in various phases through 2012. Customer billing rates for Bison were approved by the MPUC in a November 2011 order and are based on investments and expenditures through that period. Minnesota Power anticipates filing a cost recovery petition with the MPUC in the second quarter of 2013 to update customer billing rates for subsequent investments and expenditures since 2011. Rapids Energy Center. In December 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 late 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 with ALLETE, 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. In July 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. Integrated Resource Plan. In May 2011, the MPUC issued its final order approving our 2010 Integrated Resource Plan. As a condition of the final order, a required baseload diversification study evaluating the impact of additional environmental regulations over the next two decades was filed in February 2012. Minnesota Power’s 2013 Integrated Resource Plan, filed on March 1, 2013, details our “EnergyForward” strategic plan and includes an analysis of a variety of existing and future energy resource alternatives and a projection of customer cost impact by class. A decision by the MPUC on this plan is expected in late 2013. 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 Act and the Federal MATS rule. In August 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 issued its report on March 1, 2013 in support of the Boswell Unit 4 mercury emissions reduction plan stating that the plan is appropriate for accomplishing the objectives of reducing emissions of mercury and other pollutants under the Minnesota Statutes and recommended that the MPUC accept the report’s findings. We expect a decision by the MPUC on the plan in the third quarter of 2013. Upon 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. 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 6. REGULATORY MATTERS (Continued)
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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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Mar. 31, 2013
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| Investment in ATC [Text Block] | 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 March 31, 2013, our equity investment in ATC was $109.0 million ($107.3 million at December 31, 2012). In the first quarter of 2013, we invested $0.4 million in ATC, and on April 29, 2013, we invested an additional $1.2 million. We expect to make additional investments of approximately $1.5 million in 2013.
NOTE 7. INVESTMENT IN ATC (Continued) ATC’s summarized financial data for the quarters ended March 31, 2013 and 2012, is as follows:
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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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Short-Term and Long-Term Debt
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Mar. 31, 2013
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| Short-Term and Long-Term Debt [Text Block] | SHORT-TERM AND LONG-TERM DEBT Short-Term Debt. As of March 31, 2013, total short-term debt outstanding was $41.2 million ($84.5 million as of December 31, 2012) and consisted of long-term debt due within one year. Short-term debt as of December 31, 2012 included $60.0 million of long-term debt that matured in April 2013. At March 31, 2013, this debt was classified as long-term debt consistent with the accounting guidance for short-term debt expected to be refinanced. Long-Term Debt. As of March 31, 2013, total long-term debt outstanding was $975.1 million ($933.6 million as of December 31, 2012). On April 2, 2013, we issued $150.0 million of the Company’s First Mortgage Bonds (Bonds) in the private placement market in three series as follows:
We have the option to prepay all or a portion of the 1.83 percent Bonds at our discretion at any time, subject to a make-whole provision. We have the option to prepay all or a portion of the 3.30 percent Bonds at our discretion at any time prior to April 15, 2028, subject to a make-whole provision, and at any time on or after April 15, 2028, at par, including, in each case, accrued and unpaid interest. We also have the option to prepay all or a portion of the 4.21 percent Bonds at our discretion at any time prior to April 15, 2043, subject to a make-whole provision, and at any time on or after April 15, 2043, at par, including, in each case, accrued and unpaid interest. The Bonds are subject to additional terms and conditions of our utility mortgage. Proceeds from the sale of the Bonds will be used to fund utility capital investments, repay debt, and/or 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 in a private placement. 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 financial covenant requires ALLETE to maintain a ratio of 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 March 31, 2013, our ratio was approximately 0.45 to 1.00. Failure to meet this covenant would give rise to an event of default if not cured after notice from a 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 March 31, 2013, 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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Other Income (Expense)
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Mar. 31, 2013
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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
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Mar. 31, 2013
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| Income Tax Expense [Text Block] | INCOME TAX EXPENSE
For the quarter ended March 31, 2013, the effective tax rate was 18.8 percent (25.4 percent for the quarter ended March 31, 2012). The decrease from the effective tax rate for the quarter ended March 31, 2012, was primarily due to increased federal production tax credits. The effective tax rate deviated from the statutory rate of approximately 41 percent primarily due to deductions for AFUDC ‑ Equity, investment tax credits, federal production tax credits, state income tax credits and depletion. Uncertain Tax Positions. As of March 31, 2013, we had gross unrecognized tax benefits of $2.6 million ($2.7 million as of December 31, 2012). Of the total gross unrecognized tax benefits, $0.7 million represents the amount of unrecognized tax benefits included in the Consolidated Balance Sheet, that, if recognized, would favorably impact the effective income tax rate. ALLETE’s IRS exam for tax years 2005 through 2009 is currently under review at the IRS appeals office. We expect the IRS appeals process to be completed during the next twelve months, resulting in the reversal of substantially all of the unrecognized tax benefits as of March 31, 2013. The unrecognized tax benefits are primarily due to tax positions which are timing in nature and therefore would have an immaterial impact on our effective tax rate if recognized. |
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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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Reclassifications out of Accumulated Other Comprehensive Income (Loss)
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Mar. 31, 2013
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| Reclassifications Out of Accumulated Other Comprhensive Income (Loss) [Text Block] | RECLASSIFICATIONS OUT OF ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) Changes in Accumulated Other Comprehensive Loss by Component
Reclassifications Out of Accumulated Other Comprehensive Loss
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The entire disclosure for any adjustments made during the period to avoid double counting in comprehensive income items displayed as part of net income that also had been displayed as part of other comprehensive income in that period or earlier periods. These adjustments include reclassifications to net income of items in accumulated comprehensive income, such as deferred gains or losses on qualifying hedges when hedged item reported in net income, holding gains or losses on available-for-sale securities transferred into trading category, unrealized holding gains or losses on debt securities transferred from held-to-maturity category into available-for-sale category and accumulated translation adjustment attributable to foreign subsidiary or investment in foreign entity upon sale or liquidation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Earnings Per Share and Common Stock
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Mar. 31, 2013
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| Earnings Per Share and Common Stock [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Earnings Per Share and Common Stock [Text Block] | EARNINGS PER SHARE AND COMMON STOCK 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 Long-Term Incentive Compensation Plan. For the quarters ended March 31, 2013 and 2012, 0.1 million and 0.2 million options to purchase shares of common stock, respectively, 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.
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The entire disclosure for earnings per share. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Mar. 31, 2013
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| Pension and Other Postretirement Benefit Plans [Text Block] | PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS
Employer Contributions. For the quarter ended March 31, 2013, no contributions were made to our defined benefit pension plan (none for the quarter ended March 31, 2012). For the quarter ended March 31, 2013, we contributed $10.8 million to our other postretirement benefit plan (none for the quarter ended March 31, 2012). We do not expect to contribute to our defined benefit pension plan in 2013, and we do not expect to make any additional contributions to our other postretirement benefit plan in 2013. |
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Commitments, Guarantees and Contingencies
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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. 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. NOTE 14. COMMITMENTS, GUARANTEES AND CONTINGENCIES (Continued) Power Purchase Agreements (Continued) 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 March 31, 2013, Square Butte had total debt outstanding of $406.0 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 the quarter ended March 31, 2013 was $16.3 million ($15.9 million for the quarter ended March 31, 2012). 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 $2.6 million during the quarter ended March 31, 2013 ($2.7 million for the quarter ended March 31, 2012). 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 by the end of 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. In December 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. In May 2011, Minnesota Power and Manitoba Hydro signed an additional long-term 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 Minnesota’s Iron Range, 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 changes in a governmental inflationary index, a natural gas index, and market prices. NOTE 14. COMMITMENTS, GUARANTEES AND CONTINGENCIES (Continued) Power Purchase Agreements (Continued) 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. 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 $36.8 million for the remainder of 2013 and $1.3 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. 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. 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 in August 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 $53.5 million was spent through March 31, 2013, of which $42.6 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 ($48.2 million as of 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). As future CapX2020 projects are identified, Minnesota Power may elect to participate on a project-by-project basis. NOTE 14. COMMITMENTS, GUARANTEES AND CONTINGENCIES (Continued) 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. 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, in August 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. On March 29, 2013, the EPA petitioned the Supreme Court to review the District of Columbia Circuit Court of Appeals ruling. The Supreme Court has not yet decided whether it will grant review. If reinstated after Supreme Court review, the CSAPR would require 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 would not directly require the installation of controls. Instead, the rule would require facilities to have sufficient emission allowances to cover their emissions on an annual basis. These allowances would be allocated to facilities from each state’s annual budget and could 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. NOTE 14. COMMITMENTS, GUARANTEES AND CONTINGENCIES (Continued) Environmental Matters (Continued) 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 2013. 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, 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. 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 date 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 in February 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 in 2015, 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. In January 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 in December 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 Hibbard and Rapids Energy Center. Costs for complying with the final rule cannot be estimated at this time. NOTE 14. COMMITMENTS, GUARANTEES AND CONTINGENCIES (Continued) Environmental Matters (Continued) 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. In August 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 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 the second half of 2013. 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 in June 2012. In December 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, in April 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. NOTE 14. COMMITMENTS, GUARANTEES AND CONTINGENCIES (Continued) Environmental Matters (Continued) Climate Change. The scientific community generally accepts that emissions of GHGs are linked to global climate change. Climate change creates physical and financial risks. Physical risks could include, but are not limited to: increased or decreased precipitation and water levels in lakes and rivers; increased temperatures; and changes in 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, existing facilities that undergo major modifications and 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. 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. In March 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 electric 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 on 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. NOTE 14. COMMITMENTS, GUARANTEES AND CONTINGENCIES (Continued) Environmental Matters (Continued) Steam Electric Power Generating Effluent Guidelines. In late 2009, the EPA announced that it would be reviewing and reissuing the federal effluent guidelines for steam electric power generating stations under the Clean Water Act. On April 19, 2013, the EPA announced proposed revisions to those federal effluent guidelines. Instead of proposing a single rule, the EPA has proposed eight “options,” of which four are “preferred”. The proposed revisions would set limits on the level of toxic materials in wastewater discharged from seven waste streams: flue gas desulfurization wastewater, fly ash transport water, bottom ash transport water, combustion residual leachate, non-chemical metal cleaning wastes, coal gasification wastewater, and wastewater from flue gas mercury control systems. As part of this proposed rulemaking, the EPA is considering imposing rules to address “legacy” wastewater currently residing in ponds as well as rules to impose stringent best management practices for discharges from active coal combustion residual surface impoundments. The EPA’s proposed rulemaking would base effluent limitations on what can be achieved by available technologies. Compliance with the final rule would be required no later than July 1, 2022. We are reviewing the proposed rule and evaluating its potential impacts on our operations. It is expected that the EPA will issue a final rule in 2014. We are unable to predict the compliance costs we might incur related to these or other potential future water discharge regulations; however, the costs could be material, including costs associated with retrofits for bottom ash handling, pond dewatering, pond closure, and wastewater treatment and/or reuse. We would seek recovery of any additional costs through cost recovery riders or in a general rate case. 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. 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 late 2013 or early 2014. 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 March 31, 2013, BNI Coal had surety bonds outstanding of $29.7 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 $32.3 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 March 31, 2013, 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. NOTE 14. COMMITMENTS, GUARANTEES AND CONTINGENCIES (Continued) Other Matters (Continued) 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 are 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 March 31, 2013, we owned 73 percent of the assessable land in the Town Center District (73 percent at December 31, 2012) and 93 percent of the assessable land in the Palm Coast Park District (93 percent at December 31, 2012). 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 March 31, 2013, because a potential loss is not currently probable or reasonably estimable; however, the Company believes it has adequate insurance limits for any potential loss. Our insurance carrier is providing a defense subject to a reservation of rights as to certain claims. 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 our results of operations 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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| Inventories [Policy Text Block] | Inventories are stated at the lower of cost or market. Amounts removed from inventory are recorded on an average cost basis. |
| Subsequent Events [Policy Text Block] | The Company performed an evaluation of subsequent events for potential recognition and disclosure through the time of the financial statements issuance. |
| Land Inventory [Policy Text Block] | 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. |
| Long-Term Finance Receivables [Policy Text Block] | Long-term finance receivables are collateralized by property sold, accrue interest at market-based rates and are net of an allowance for doubtful accounts. |
| Derivatives [Policy Text Block] | 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. |
| 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 of the change in circumstances that caused the transfer. |
| Regulatory Assets and Liabilities [Policy Text Block] | 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. |
| Equity Method Investments [Policy Text Block] | We account for our investment in ATC under the equity method of accounting. |
| Environmental Costs [Policy Text Block] | 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. |
| New Accounting Standards [Policy Text Block] | Amounts Reclassified Out of Accumulated Other Comprehensive Income. In February 2013, the FASB issued an accounting standard update on disclosure of amounts reclassified out of accumulated other comprehensive income. This update requires entities to provide information about amounts reclassified out of accumulated other comprehensive income by component. In addition, entities are required to present, either on the face of the statement where net income is presented or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income but only if the amount reclassified is required under GAAP to be reclassified to net income in its entirety in the same reporting period. For other amounts that are not required under GAAP to be reclassified in their entirety to net income, entities are required to cross-reference to other disclosures required under GAAP that provide additional detail on these amounts. This guidance was adopted for the quarter ended March 31, 2013, and required additional disclosures but did not have an impact on our consolidated financial position, results of operations, or cash flows. (See Note 11. Reclassifications Out of Accumulated Other Comprehensive Income.) |
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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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Disclosure of accounting policy for the equity method of accounting for investments in common stock or other interests including unconsolidated subsidiaries, corporate joint ventures, noncontrolling interests in real estate ventures, limited partnerships, and limited liability companies. The accounting policy may include information such as: (1) initially recording an investment in the stock of an investee at cost; (2) adjusting the carrying amount of the investment to recognize the investor's share of the earnings or losses of the investee after the date of acquisition; and (3) adjustments to reflect the investor's share of changes in the investee's capital (dividends). This disclosure may also include a detailed description of the policy for determining the amount of equity method losses recognized after an investment has been reduced to zero as a result of previous losses, reasons for not using the equity method when the investor company owns 20 percent or more of the voting stock of the investee's company (including identification of the significant investee), reasons for using the equity method when the ownership percentage is less than 20 percent, and discussion of recognition of equity method losses when an investor's total investment in an investee includes, in addition to an investment in common stock, other investments such as preferred stock and loans to the investee. An entity also may describe how such investments are assessed for impairment. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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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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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Disclosure of accounting policy for investments in financial assets, including marketable securities (debt and equity securities with readily determinable fair values), investments accounted for under the equity method and cost method, securities borrowed and loaned, and repurchase and resale agreements. For marketable securities, the disclosure may include the entity's accounting treatment for transfers between investment categories and how the fair values for such securities are determined. Also, for all investments, an entity may describe its policy for assessing, recognizing and measuring impairment of the investment. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Disclosure of the adoption of new accounting pronouncements that may impact the entity's financial reporting. No definition available.
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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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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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Mar. 31, 2013
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| Business Segments [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Business Segments [Table Text Block] |
NOTE 2. BUSINESS SEGMENTS (Continued)
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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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Investments (Tables)
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Mar. 31, 2013
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| Investments [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Other Investments and ALLETE Properties [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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- Details
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Fair Value (Tables)
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Mar. 31, 2013
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| Fair Value [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Recurring Fair Value Measures [Table Text Block] |
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| Financial Instruments [Table Text Block] |
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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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Regulatory Matters (Tables)
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Mar. 31, 2013
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| Regulatory Matters [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Regulatory Assets and Liabilities [Table Text Block] |
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- Definition
The entire disclosure for detailed information about regulatory assets and liabilities, including current and noncurrent assets created when regulatory agencies permit the deferral of costs to the balance sheet that would otherwise be required to appear on the company's income statement and would be charged against current expenses or revenues, as well as current and noncurrent liabilities created when regulatory agencies permit. No definition available.
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Investment in ATC (Tables)
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Mar. 31, 2013
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| Investment in ATC [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| ALLETE's Investment in ATC [Table Text Block] |
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| ATC Summarized Financial Data [Table Text Block] | ATC’s summarized financial data for the quarters ended March 31, 2013 and 2012, is as follows:
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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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Short-Term and Long-Term Debt (Tables)
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Mar. 31, 2013
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| Short-Term and Long-Term Debt [Abstract] | |||||||||||||||||||
| First Mortgage Bonds Issuance [Table Text Block] | On April 2, 2013, we issued $150.0 million of the Company’s First Mortgage Bonds (Bonds) in the private placement market in three 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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Other Income (Expense) (Tables)
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Mar. 31, 2013
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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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Mar. 31, 2013
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| Income Tax Expense [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Income Tax Expense [Table Text Block] |
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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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Reclassificiations out of Accumulated Other Comprehensive Income (Loss) (Tables)
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Mar. 31, 2013
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| Reclassifications Out of Accumualted Other Comprehensive Income (Loss) [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Changes in Accumulated Other Comprehensive Income (Loss) by Component [Table Text Block] | Changes in Accumulated Other Comprehensive Loss by Component
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| Reclassifications Out of Accumulated Other Comprehensive Income (Loss) [Table Text Block] | Reclassifications Out of Accumulated Other Comprehensive Loss
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- Definition
Table Text Block for the roll-forward of Accumulated Other Comprehensive Income (AOCI) by Component, showing beginning AOCI, OCI before reclassifcations, reclassifications out of AOCI through OCI, Net OCI, and ending AOCI. No definition available.
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Table Text Block for table showing reclassifications out of AOCI through OCI by income statement line item. No definition available.
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Earnings Per Share and Common Stock (Tables)
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Mar. 31, 2013
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| Reconciliation of Basic and Diluted Earnings Per Share [Table Text Block] |
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- Definition
Tabular disclosure of the reconciliation of basic net earnings per share (or unit) to diluted earnings per share (or unit). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Pension and Other Postretirement Benefit Plans (Tables)
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Mar. 31, 2013
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| Pension and Other Postretirement Benefit Plans [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Components of Net Periodic Benefit Expense [Table Text Block] |
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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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Operations and Significant Accounting Policies (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | ||||||
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Mar. 31, 2013
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Mar. 31, 2012
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Dec. 31, 2012
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| Inventories [Abstract] | |||||||
| Fuel | $ 22.4 | $ 28.0 | |||||
| Materials and Supplies | 41.9 | 41.8 | |||||
| Total Inventories | 64.3 | 69.8 | |||||
| Prepayments and Other Current Assets [Abstract] | |||||||
| Deferred Fuel Adjustment Clause | 18.5 | 22.5 | |||||
| Other | 9.6 | 11.1 | |||||
| Total Prepayments and Other Current Assets | 28.1 | 33.6 | |||||
| Other Current Liabilites [Abstract] | |||||||
| Customer Deposits | 28.4 | [1] | 28.8 | [1] | |||
| Other | 29.4 | 33.8 | |||||
| Total Other Current Liabilities | 57.8 | 62.6 | |||||
| Other Non-Current Liabilities [Abstract] | |||||||
| Asset Retirement Obligation | 80.6 | 77.9 | |||||
| Other | 46.1 | 45.4 | |||||
| Total Other Non-Current Liabilities | 126.7 | 123.3 | |||||
| Supplemental Statement of Cash Flows Information [Abstract] | |||||||
| Cash Paid During the Period for Interest - Net of Amounts Capitalized | 12.0 | 12.3 | |||||
| Cash Paid During the Period for Income Taxes | 0.5 | 0.2 | |||||
| Noncash Investing and Financing Activities [Abstract] | |||||||
| Decrease in Accounts Payable for Capital Additions to Property, Plant and Equipment | (26.2) | (12.3) | |||||
| Capitalized Asset Retirement Costs | 1.9 | 2.4 | |||||
| AFUDC - Equity | $ 1.1 | $ 0.8 | |||||
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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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- Definition
Noncurrent portion of 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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- 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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- 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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- 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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- Definition
Carrying amount as of the balance sheet date of merchandise, goods, commodities, or supplies relating to a source of usable power held for future sale or future use in manufacturing or production process. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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Business Segments (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | ||
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Mar. 31, 2013
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Mar. 31, 2012
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Dec. 31, 2012
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| Business Segments [Line Items] | |||
| Operating Revenue | $ 263.8 | $ 240.0 | |
| Fuel and Purchased Power Expense | 86.5 | 77.1 | |
| Operating and Maintenance Expense | 104.7 | 99.9 | |
| Depreciation Expense | 28.2 | 24.6 | |
| Operating Income (Loss) | 44.4 | 38.4 | |
| Interest Expense | (12.3) | (11.0) | |
| Equity Earnings in ATC | 5.2 | 4.6 | |
| Other Income (Expense) | 2.7 | 0.7 | |
| Income (Loss) Before Income Taxes | 40.0 | 32.7 | |
| Income Tax Expense (Benefit) | 7.5 | 8.3 | |
| Net Income | 32.5 | 24.4 | |
| Total Assets | 3,251.3 | 2,906.6 | 3,253.4 |
| Property, Plant and Equipment - Net | 2,366.7 | 2,002.8 | 2,347.6 |
| Accumulated Depreciation | 1,179.8 | 1,099.0 | |
| Capital Additions | 43.1 | 39.7 | |
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Regulated Operations [Member]
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| Business Segments [Line Items] | |||
| Operating Revenue | 241.4 | 218.6 | |
| Fuel and Purchased Power Expense | 86.5 | 77.1 | |
| Operating and Maintenance Expense | 82.2 | 78.1 | |
| Depreciation Expense | 26.8 | 23.2 | |
| Operating Income (Loss) | 45.9 | 40.2 | |
| Interest Expense | (10.7) | (9.6) | |
| Equity Earnings in ATC | 5.2 | 4.6 | |
| Other Income (Expense) | 1.1 | 0.8 | |
| Income (Loss) Before Income Taxes | 41.5 | 36.0 | |
| Income Tax Expense (Benefit) | 9.4 | 11.6 | |
| Net Income | 32.1 | 24.4 | |
| Total Assets | 2,967.9 | 2,586.4 | |
| Property, Plant and Equipment - Net | 2,300.8 | 1,945.6 | |
| Accumulated Depreciation | 1,121.8 | 1,045.9 | |
| Capital Additions | 42.6 | 38.7 | |
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Investments and Other [Member]
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| Business Segments [Line Items] | |||
| Land in Minnesota (in acres) | 6,000 | ||
| Operating Revenue | 22.4 | 21.4 | |
| Fuel and Purchased Power Expense | 0 | 0 | |
| Operating and Maintenance Expense | 22.5 | 21.8 | |
| Depreciation Expense | 1.4 | 1.4 | |
| Operating Income (Loss) | (1.5) | (1.8) | |
| Interest Expense | (1.6) | (1.4) | |
| Equity Earnings in ATC | 0 | 0 | |
| Other Income (Expense) | 1.6 | (0.1) | |
| Income (Loss) Before Income Taxes | (1.5) | (3.3) | |
| Income Tax Expense (Benefit) | (1.9) | (3.3) | |
| Net Income | 0.4 | 0 | |
| Total Assets | 283.4 | 320.2 | |
| Property, Plant and Equipment - Net | 65.9 | 57.2 | |
| Accumulated Depreciation | 58.0 | 53.1 | |
| Capital Additions | $ 0.5 | $ 1.0 | |
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- Definition
Number of acres of land available-for-sale. No definition available.
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- Definition
The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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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- 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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- 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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- 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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- 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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- 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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- Definition
The net result for the period of deducting operating expenses from operating revenues. No definition available.
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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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- 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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- 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.
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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
The total amount of operating revenues recognized during the period. No definition available.
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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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- 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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Investments (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 12 Months Ended |
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Mar. 31, 2013
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Dec. 31, 2012
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| Investments [Abstract] | ||
| ALLETE Properties | $ 91.1 | $ 91.1 |
| Available-for-sale Securities | 20.1 | 26.8 |
| Cash Equivalents | 22.7 | 20.7 |
| Other | 4.7 | 4.9 |
| Total Other Investments | 138.6 | 143.5 |
| ALLETE Properties [Rollforward] | ||
| Land Inventory Beginning Balance | 86.5 | 86.0 |
| Deeds to Collateralized Property | 0 | 0.5 |
| Cost of Sales | 0 | (0.2) |
| Capitalized Improvements and Other | 0.1 | 0.2 |
| Land Inventory Ending Balance | 86.6 | 86.5 |
| Long-Term Finance Reveivables (net of allowances of $0.6 and $0.6) | 1.4 | 1.4 |
| Other | 3.1 | 3.2 |
| Total Real Estate Assets | 91.1 | 91.1 |
| Impairment of Real Estate | 0 | 0 |
| Long-Term Finance Receivables, Allowance | $ 0.6 | $ 0.6 |
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- 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.
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- 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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- 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
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- 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
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- Details
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- Definition
Carrying value of land held for sale. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- 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
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- Definition
Other investments not otherwise specified in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- 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
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- 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
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- 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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- Definition
The carrying amount of real estate sold during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Gross amount of real estate as of the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of improvements made to real estate investments during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Investments - Parentheticals (Details) (USD $)
In Millions, unless otherwise specified |
Mar. 31, 2013
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Dec. 31, 2012
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| Investments Parentheticals [Abstract] | ||
| Long-Term Finance Receivables, Allowance | $ 0.6 | $ 0.6 |
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| X | ||||||||||
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- 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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|
Derivatives - Hedged Item (Details) (Term Loan [Member], USD $)
In Millions, unless otherwise specified |
3 Months Ended |
|---|---|
|
Mar. 31, 2013
|
|
|
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% |
| Percentage of Debt Hedged by Interest Rate Derivatives | 8.00% |
| 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
|
| 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.
|
|
Derivatives - Derivative (Details) (Interest Rate Swap [Member], USD $)
In Millions, unless otherwise specified |
3 Months Ended | |
|---|---|---|
|
Mar. 31, 2013
|
Dec. 31, 2012
|
|
|
Interest Rate Swap [Member]
|
||
| Derivative [Line Items] | ||
| Interest Rate Swap Variable Rate Basis | one-month LIBOR | |
| Interest Rate Swap Fixed Interest Rate | 0.825% | |
| 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 the value of the Swap are deemed 100 percent effective. As a result, there was no ineffectiveness recorded for the quarter ended March 31, 2013. | |
| Interest Rate Swap Liability | $ 0.6 | $ 0.7 |
| 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
|
|
Fair Value - Recurring Fair Value Measures (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | ||
|---|---|---|---|
|
Mar. 31, 2013
|
Mar. 31, 2012
|
Dec. 31, 2012
|
|
| Investments [Abstract] | |||
| Cash Equivalents | $ 22.7 | $ 20.7 | |
| Fair Value [Abstract] | |||
| Fair Value Activity in Level 3 | 0 | 0 | |
| Fair Value Hierarchy Transfers, All Levels | 0 | 0 | |
|
Recurring Fair Value Measurements [Member]
|
|||
| Investments [Abstract] | |||
| Available-for-sale - Equity Securities | 11.4 | 18.0 | |
| Available-for-sale - Corporate Debt Securities | 8.7 | 8.8 | |
| Cash Equivalents | 22.7 | 20.7 | |
| Total Fair Value of Assets | 42.8 | 47.5 | |
| Liabilities [Abstract] | |||
| Deferred Compensation | 14.4 | 14.0 | |
| Derivatives - Interest Rate Swap | 0.6 | 0.7 | |
| Total Fair Value of Liabilities | 15.0 | 14.7 | |
| Total Net Fair Value of Assets (Liabilities) | 27.8 | 32.8 | |
|
Recurring Fair Value Measurements [Member] | Level 1 [Member]
|
|||
| Investments [Abstract] | |||
| Available-for-sale - Equity Securities | 11.4 | 18.0 | |
| Available-for-sale - Corporate Debt Securities | 0 | 0 | |
| Cash Equivalents | 22.7 | 20.7 | |
| Total Fair Value of Assets | 34.1 | 38.7 | |
| 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) | 34.1 | 38.7 | |
|
Recurring Fair Value Measurements [Member] | Level 2 [Member]
|
|||
| Investments [Abstract] | |||
| Available-for-sale - Equity Securities | 0 | 0 | |
| Available-for-sale - Corporate Debt Securities | 8.7 | 8.8 | |
| Cash Equivalents | 0 | 0 | |
| Total Fair Value of Assets | 8.7 | 8.8 | |
| Liabilities [Abstract] | |||
| Deferred Compensation | 14.4 | 14.0 | |
| Derivatives - Interest Rate Swap | 0.6 | 0.7 | |
| Total Fair Value of Liabilities | 15.0 | 14.7 | |
| Total Net Fair Value of Assets (Liabilities) | (6.3) | (5.9) | |
|
Recurring Fair Value Measurements [Member] | Level 3 [Member]
|
|||
| Investments [Abstract] | |||
| Available-for-sale - Equity Securities | 0 | 0 | |
| Available-for-sale - 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 | ||||||||||
|
- 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 - Financial Instruments (Details) (USD $)
In Millions, unless otherwise specified |
Mar. 31, 2013
|
Dec. 31, 2012
|
|---|---|---|
| Financial Instruments [Abstract] | ||
| Long-Term Debt, Including Current Portion - Carrying Amount | $ 1,016.3 | $ 1,018.1 |
| Long-term Debt, Including Current Portion - Fair Value | $ 1,073.3 | $ 1,143.7 |
| 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.
|
|
Regulatory Matters - Electric Rates (Details) (USD $)
In Millions, unless otherwise specified |
Mar. 31, 2013
Bison Wind Energy Center [Member]
MW
|
Jun. 01, 2011
MPUC 2010 Minnesota Rate Case [Member]
Electric Rates [Member]
Retail Customers [Member]
|
Mar. 31, 2013
FERC-Approved Wholesale Rates [Member]
Electric Rates [Member]
Municipal Customers [Member]
Years
Customers
|
Mar. 31, 2013
FERC-Approved Wholesale Rates [Member]
Electric Rates [Member]
Non-Affiliated Private Utility [Member]
Years
Customers
|
Mar. 31, 2013
PSCW 2012 Wisconsin Rate Case [Member]
Retail Customers [Member]
|
Dec. 31, 2012
PSCW 2012 Wisconsin Rate Case [Member]
Retail Customers [Member]
|
Mar. 31, 2013
PSCW 2012 Wisconsin Rate Case [Member]
Electric Rates [Member]
Retail Customers [Member]
|
Mar. 31, 2013
PSCW 2012 Wisconsin Rate Case [Member]
Natural Gas Rates [Member]
Retail Customers [Member]
|
Mar. 31, 2013
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 | |||||||
| Length of Notice Required to Terminate (in Years) | 3 | 2 | |||||||
| Approved Rate Increase or Decrease | 2.40% | 1.20% | (0.20%) | 13.80% | |||||
| Amount Of Estimated Additional Revenue | $ 1.7 | ||||||||
| Generating Capacity (MW) | 292 |
| 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
Capacity of each generating unit/individual project in megawatts. 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 Emissions Reduction Plan (Details) (Boswell Unit 4 [Member], USD $)
In Millions, unless otherwise specified |
Mar. 31, 2013
|
|---|---|
|
Minimum [Member]
|
|
| Schedule of Utility Generating Facilities [Line Items] | |
| Estimated Capital Expenditures | $ 350 |
|
Maximum [Member]
|
|
| Schedule of Utility Generating Facilities [Line Items] | |
| Estimated Capital Expenditures | $ 400 |
| X | ||||||||||
|
- Definition
The estimated amount of certain future capital expenditures related to environmental compliance, regulatory matters, or other committments and/or contingencies. 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 | 3 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|---|
|
Mar. 31, 2013
|
Mar. 31, 2012
|
Dec. 31, 2012
|
Jun. 30, 2011
Elimination of Medicare Part D [Member]
|
Dec. 31, 2010
Elimination of Medicare Part D [Member]
|
|
| Unusual or Infrequent Item [Line Items] | |||||
| Reversal of Previously Recorded Tax Benefit | $ 4.0 | ||||
| Deferred Income Tax Benefit | 7.3 | 8.3 | (2.9) | ||
| Non-Current Regulatory Assets | $ 336.6 | $ 340.3 | $ 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 |
Mar. 31, 2013
|
Dec. 31, 2012
|
||||||
|---|---|---|---|---|---|---|---|---|
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Current Regulatory Assets | $ 18.5 | $ 22.5 | ||||||
| Non-Current Regulatory Assets | 336.6 | 340.3 | ||||||
| Total Regulatory Assets | 355.1 | 362.8 | ||||||
| Non-Current Regulatory Liabilities | 59.2 | 60.1 | ||||||
|
Income Taxes [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Liabilities | 18.3 | 19.5 | ||||||
|
Plant Removal Obligations [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Liabilities | 18.6 | 18.1 | ||||||
|
Wholesale and Retail Contra AFUDC [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Liabilities | 16.0 | 15.5 | ||||||
|
Other [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Liabilities | 6.3 | 7.0 | ||||||
|
Deferred Fuel [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Current Regulatory Assets | 18.5 | [1] | 22.5 | [1] | ||||
|
Future Benefit Obligations Under Defined Benefit Pension and Other Postretirement Benefit Plans [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Assets | 256.1 | 260.7 | ||||||
|
Income Taxes [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Assets | 34.5 | 36.0 | ||||||
|
Asset Retirement Obligation [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Assets | 12.8 | 12.1 | ||||||
|
Cost Recovery Riders [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Assets | 24.1 | [2] | 18.5 | [2] | ||||
|
PPACA Income Tax Deferral [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Assets | 5.0 | 5.0 | ||||||
|
Conservation Improvement Program [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Assets | 0.4 | 4.3 | ||||||
|
Other [Member]
|
||||||||
| Regulatory Assets and Liabilities [Line Items] | ||||||||
| Non-Current Regulatory Assets | $ 3.7 | $ 3.7 | ||||||
|
||||||||
| 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 |
1 Months Ended | 3 Months Ended | |
|---|---|---|---|
|
Apr. 29, 2013
|
Mar. 31, 2013
|
Mar. 31, 2012
|
|
| Investment in ATC [Abstract] | |||
| Ownership Percentage | 8.00% | ||
| Approved Return on Common Equity | 12.20% | ||
| Expected Additional Investment | $ 1.5 | ||
| ALLETE's Investment in ATC [Roll Forward] | |||
| Equity Investment Beginning Balance as of December 31, 2012 | 109.0 | 107.3 | |
| Cash Investments | 1.2 | 0.4 | |
| Equity Earnings in ATC | 5.2 | 4.6 | |
| Distributed ATC Earnings | (3.9) | ||
| Equity Investment Balance as of March 31, 2013 | 109.0 | ||
| ATC Summarized Financial Data [Abstract] | |||
| Revenue | 151.8 | 147.7 | |
| Operating Expense | 69.8 | 69.6 | |
| Other Expense | 21.5 | 20.0 | |
| Net Income | 60.5 | 58.1 | |
| ALLETE's Equity in Net Income | $ 5.2 | $ 4.6 | |
| X | ||||||||||
|
- Details
|
| 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.
|
| X | ||||||||||
|
- Definition
Equity Method Investment, Expected Future Investment 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 | ||||||||||
|
- Details
|
| 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
|
| 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
|
| 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
|
| X | ||||||||||
|
- Details
|
| 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
|
| 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
|
| 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
|
|
Short-Term and Long-Term Debt (Details) (USD $)
In Millions, unless otherwise specified |
0 Months Ended | 3 Months Ended | |
|---|---|---|---|
|
Apr. 02, 2013
|
Mar. 31, 2013
|
Dec. 31, 2012
|
|
| Financial Covenants [Abstract] | |||
| Required Indebtedness to Total Capital Ratio | 0.65 | ||
| Actual Indebtedness to Total Capital Ratio | 0.45 | ||
| Debt Instrument [Line Items] | |||
| Short-Term Debt Outstanding | $ 41.2 | $ 84.5 | |
| Long-Term Debt Outstanding | 975.1 | 933.6 | |
| Proceeds from Issuance of First Mortgage Bonds | 150.0 | ||
|
ALLETE Bonds 4.86% Series Due 2013 [Member]
|
|||
| Debt Instrument [Line Items] | |||
| Long-Term Debt Outstanding | 60.0 | ||
|
ALLETE Bonds 1.83% Due April 2018 [Member]
|
|||
| Debt Instrument [Line Items] | |||
| Proceeds from Issuance of First Mortgage Bonds | 50.0 | ||
| First Mortgage Bonds, Interest Rate | 1.83% | ||
|
ALLETE Bonds 3.30% Due October 2028 [Member]
|
|||
| Debt Instrument [Line Items] | |||
| Proceeds from Issuance of First Mortgage Bonds | 40.0 | ||
| First Mortgage Bonds, Interest Rate | 3.30% | ||
|
ALLETE Bonds 4.21% Due October 2043 [Member]
|
|||
| Debt Instrument [Line Items] | |||
| Proceeds from Issuance of First Mortgage Bonds | $ 60.0 | ||
| First Mortgage Bonds, Interest Rate | 4.21% |
| 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
Interest rate stated in the contractual debt agreement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| 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
|
| 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
|
|
Other Income (Expense) (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | |
|---|---|---|
|
Mar. 31, 2013
|
Mar. 31, 2012
|
|
| Other Income (Expense) [Abstract] | ||
| AFUDC - Equity | $ 1.1 | $ 0.8 |
| Gain on Sale of Available-for-sale Securities | 0.8 | 0 |
| Investments and Other Income (Expense) | 0.8 | (0.1) |
| Total Other Income | $ 2.7 | $ 0.7 |
| X | ||||||||||
|
- Details
|
| 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
|
| 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 | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
Mar. 31, 2013
|
Mar. 31, 2012
|
Dec. 31, 2012
|
|||||||||
| Current Tax Expense [Abstract] | |||||||||||
| Federal | $ 0.2 | [1] | $ 0 | [1] | |||||||
| State | 0 | [1] | 0 | [1] | |||||||
| Total Current Tax Expense | 0.2 | 0 | |||||||||
| Deferred Tax Expense (Benefit) [Abstract] | |||||||||||
| Federal | 5.8 | 8.7 | |||||||||
| State | (0.5) | [2] | (0.8) | [2] | |||||||
| Change in Valuation Allowance | 2.2 | [3] | 0.6 | [3] | |||||||
| Investment Tax Credit Amortization | (0.2) | (0.2) | |||||||||
| Total Deferred Tax Expense | 7.3 | 8.3 | |||||||||
| Total Income Tax Expense | 7.5 | 8.3 | |||||||||
| Effective Income Tax Rate | 18.80% | 25.40% | |||||||||
| Federal Statutory Income Tax Rate | 41.00% | ||||||||||
| Uncertain Tax Positions [Abstract] | |||||||||||
| Gross Unrecognized Tax Benefits | 2.6 | 2.7 | |||||||||
| Unrecognized Tax Benefits that Would Favorably Impact Effective Tax Rate | $ 0.7 | ||||||||||
|
|||||||||||
| 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 | ||||||||||
|
- 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 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 | ||||||||||
|
- Details
|
| 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
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
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 | ||||||||||
|
- Details
|
| 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 total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| 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
|
|
Reclassifications out of Accumulated Other Comprehensive Income (Loss) - Changes in Accumulated Other Comprehensive Income (Loss) by Component (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
Mar. 31, 2013
|
Mar. 31, 2012
|
||||||||||
| Accumulated Other Comprehensive Loss [Roll Forward] | |||||||||||
| Beginning Accumulated Other Comprehensive Loss, Unrealized Gains and Losses on Available-for-sale Securities | $ (0.1) | [1] | |||||||||
| Beginning Accumulated Other Comprehensive Loss, Defined Benefit Pension and Other Postretirement Items | (21.5) | [1] | |||||||||
| Beginning Accumulated Other Comprehensive Loss, Gains and Losses on Cash Flow Hedge | (0.4) | [1] | |||||||||
| Beginning Accumulated Other Comprehensive Loss, Total | (22.0) | [1] | |||||||||
| Other Comprehensive Income (Loss) before Reclassifications [Abstract] | |||||||||||
| Other Comprehensive Income (Loss) Before Reclassifications, Unrealized Gains and Losses on Available-for-sale Securities | 0.5 | [1] | |||||||||
| Other Comprehensive Income (Loss) Before Reclassifications, Defined Benefit Pension and Other Postretirement Items | (2.9) | [1] | |||||||||
| Other Comprehensive Income (Loss) Before Reclassifications, Gains and Losses on Cash Flow Hedge | 0.1 | [1] | |||||||||
| Other Comprehensive Income (Loss) Before Recalssifications, Total | (2.3) | [1] | |||||||||
| Available-for-sale Securities [Abstract] | |||||||||||
| Amounts Reclassified From Accumulated Other Comprehensive Loss, Unrealized Gains and Losses on Available-for-sale Securities | 0.5 | [1] | |||||||||
| Pension and Other Postretirement Benefit Plans [Abstract] | |||||||||||
| Amounts Reclassified From Accumulated Other Comprehensive Loss, Defined Benefit Pension and Other Postretirement Items | (3.2) | [1],[2] | |||||||||
| Amounts Reclassified From Accumulated Other Comprehensive Loss, Defined Benefit Pension and Other Postretirement Items, Before Tax | (5.2) | [2] | |||||||||
| Amounts Reclassified From Accumulated Other Comprehensive Loss, Amortization of Defined Benefit Pension and Other Postretirement Items, Prior Service Costs, Before Tax | 0.5 | [3] | |||||||||
| Amounts Reclassified From Accumulated Other Comprehensive Loss, Amortization of Defined Benefit Pension and Other Postretirement Items, Actuarial Gains and Losses, Before Tax | (5.7) | [2],[3] | |||||||||
| Amounts Reclassified From Accumulated Other Comprehensive Loss, Gains and Losses on Cash Flow Hedge | 0 | [1],[4] | |||||||||
| Amounts Reclassified From Accumulated Other Comprehensive Loss, Total Reclassifications | (2.7) | [1],[2] | |||||||||
| Net Other Comprehensive Income (Loss) [Abstract] | |||||||||||
| Net Other Comprehensive Income, Unrealized Gains and Losses on Available-for-sale Securities | 0 | [1] | 1.0 | ||||||||
| Net Other Comprehensive Income, Defined Benefit Pension and Other Postretirement Items | 0.3 | [1] | 0.5 | ||||||||
| Net Other Comprehensive Income, Gains and Losses on Cash Flow Hedge | 0.1 | [1] | (0.1) | ||||||||
| Net Other Comprehensive Income, Total | 0.4 | [1] | 1.4 | ||||||||
| Ending Accumulated Other Comprehensive Loss, Unrealized Gains and Losses on Available-for-sale Securities | (0.1) | [1] | |||||||||
| Ending Accumulated Other Comprehensive Loss, Defined Benefit Pension and Other Postretirement Items | (21.2) | [1] | |||||||||
| Ending Accumulated Other Comprehensive Loss, Gains and Losses on Cash Flow Hedge | (0.3) | [1] | |||||||||
| Ending Accumulated Other Comprehensive Loss, Total | (21.6) | [1] | |||||||||
|
Other Income [Member]
|
|||||||||||
| Available-for-sale Securities [Abstract] | |||||||||||
| Amounts Reclassified From Accumulated Other Comprehensive Loss, Unrealized Gains and Losses on Available-for-sale Securities, Before Tax | 0.8 | ||||||||||
|
Income Tax Expense (Benefit) [Member]
|
|||||||||||
| Available-for-sale Securities [Abstract] | |||||||||||
| Amounts Reclassified From Accumulated Other Comprehensive Loss, Unrealized Gains and Losses on Available-for-sale Securities, Tax | (0.3) | [2] | |||||||||
| Pension and Other Postretirement Benefit Plans [Abstract] | |||||||||||
| Amounts Reclassified From Accumulated Other Comprehensive Loss, Defined Benefit Pension and Other Postretirement Items, Tax | $ 2.0 | ||||||||||
|
|||||||||||
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Other Comprehensive Income (Loss), Amortization Adjustments, Defined Benefit Pension and Other Postretirement Items, before tax: amount of the income statement impact of the reclassification adjustment from AOCI for amorization of all defined benefit and other postretirement items recognized as a component of net periodic benefit cost. No definition available.
|
| X | ||||||||||
|
- Definition
Tax effect of the income statement impact of the relcassification adjustments for pension and other postretirement items recognized as a component of net periodic pension cost. No definition available.
|
| X | ||||||||||
|
- Definition
Net of tax amount, before reclassification adjustments, of the change in accumulated other comprehensive income (loss). No definition available.
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Net of tax amount of total reclassification adjustments from accumulated other comprehensive income (loss) related to pension and other postretirement benefit plan amortization items. No definition available.
|
| X | ||||||||||
|
- Definition
Net of tax amount of all reclassification adjustments from accumulated other comprehensive income (loss). No definition available.
|
| X | ||||||||||
|
- Definition
Net of tax amount, before reclassification adjustments, of the change in accumulated other comprehensive income (loss) related to cash flow hedge derivatives. No definition available.
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Accumulated appreciation or loss, net of tax, in value of the total of available-for-sale securities at the end of an accounting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Accumulated change, net of tax, in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| 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
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
|
| X | ||||||||||
|
- Details
|
| 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
Net of tax amount of unrealized holding gain (loss) before reclassification adjustments on available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- 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
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
Net of tax amount, before reclassification adjustments, of the change in accumulated other comprehensive income (loss) related to pension and other postretirement benefit plans. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- 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
|
| X | ||||||||||
|
- Definition
Before tax amount of the income statement impact of the reclassification adjustment for unrealized gain (loss) realized upon the sale of available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Net of tax amount of the income statement impact of the reclassification adjustment for unrealized gain (loss) realized upon the sale of available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Tax effect of the income statement impact of the reclassification adjustment for unrealized gain (loss) realized upon the sale of available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Net of tax amount of the income statement impact of the reclassification adjustment of accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges realized in net income. Also includes reclassification adjustments of an entity's share of an equity investee's deferred hedging gain (loss) realized in net income. 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
|
| X | ||||||||||
|
- 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
|
| X | ||||||||||
|
- 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
|
|
Earnings Per Share and Common Stock (Details) (USD $)
In Millions, except Per Share data, unless otherwise specified |
3 Months Ended | |
|---|---|---|
|
Mar. 31, 2013
|
Mar. 31, 2012
|
|
| Earnings Per Share and Common Stock [Abstract] | ||
| Antidilutive Shares Excluded from EPS Computation | 0.1 | 0.2 |
| Earnings Per Share - Basic [Abstract] | ||
| Net Income | $ 32.5 | $ 24.4 |
| Average Common Shares | 38.9 | 36.8 |
| Earnings Per Share | $ 0.83 | $ 0.66 |
| Earnings Per Share - Diluted [Abstract] | ||
| Net Income | $ 32.5 | $ 24.4 |
| Average Common Shares | 39.0 | 36.9 |
| Earnings Per Share | $ 0.83 | $ 0.66 |
| Dilutive Securities (Shares) | 0.1 | 0.1 |
| X | ||||||||||
|
- Details
|
| 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 | ||||||||||
|
- 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
Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Net Income or Loss Available to Common Stockholders plus 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
|
|
Pension and Other Postretirement Benefit Plans (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | |
|---|---|---|
|
Mar. 31, 2013
|
Mar. 31, 2012
|
|
|
Pension [Member]
|
||
| Components of Net Periodic Benefit Expense [Abstract] | ||
| Service Cost | $ 2.5 | $ 2.3 |
| Interest Cost | 6.5 | 6.6 |
| Expected Return on Plan Assets | (8.8) | (8.8) |
| Amortization of Prior Service Costs | 0.1 | 0.1 |
| Amortization of Net Loss | 5.3 | 4.3 |
| Net Periodic Benefit Expense | 5.6 | 4.5 |
| Contributions | 0 | 0 |
| Estimated Future Contributions | 0 | |
|
Other Postretirement [Member]
|
||
| Components of Net Periodic Benefit Expense [Abstract] | ||
| Service Cost | 1.0 | 1.0 |
| Interest Cost | 1.7 | 2.4 |
| Expected Return on Plan Assets | (2.5) | (2.5) |
| Amortization of Prior Service Costs | (0.6) | (0.4) |
| Amortization of Net Loss | 0.4 | 1.9 |
| Net Periodic Benefit Expense | 0 | 2.4 |
| Contributions | 10.8 | 0 |
| Estimated Future Contributions | $ 0 | |
| 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 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 employer's best estimate, as soon as it can be reasonably determined, of contributions expected to be paid to the plan in the current remaining fiscal period. Estimated contributions may be presented in the aggregate combining (1) contributions required by funding regulations or laws, (2) discretionary contributions, and (3) noncash contributions. No definition available.
|
| 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
|
|
Commitments, Guarantees and Contingencies - Power Purchase Agreements (Details) (USD $)
|
3 Months Ended | |
|---|---|---|
|
Mar. 31, 2013
|
Mar. 31, 2012
|
|
|
Great Northern Transmission Line [Member]
|
||
| Power Purchase Agreements [Line Items] | ||
| Transmission Line Capacity (kV) | 500 | |
|
Square Butte PPA [Member]
|
||
| Power Purchase Agreements [Line Items] | ||
| PPA Counterparty Debt Outstanding | $ 406,000,000 | |
| Annual Debt Service | 44,000,000 | |
| Power Purchased under Long-term Contracts | 16,300,000 | 15,900,000 |
| Interest Expense | 2,600,000 | 2,700,000 |
|
Square Butte PPA [Member] | Square Butte Coal-fired Unit [Member]
|
||
| Power Purchase Agreements [Line Items] | ||
| Generating Capacity (MW) | 455 | |
| Output Entitlement | 50.00% | |
|
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 Carges | 0 | |
|
Oliver Wind II PPA [Member]
|
||
| Power Purchase Agreements [Line Items] | ||
| Output Being Purchased (MW) | 48 | |
| Term of Contract (Years) | 25 | |
| Fixed Capacity Carges | $ 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]
|
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| Power Purchase Agreements [Line Items] | ||
| Output Being Purchased (MWh) | 1,000,000 | |
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Manitoba Hydro PPA (expires 2035) [Member]
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| Power Purchase Agreements [Line Items] | ||
| Output Being Purchased (MW) | 250 | |
| Term of Contract (Years) | 15 | |
| X | ||||||||||
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- Definition
Capacity of each generating unit/individual project in megawatts. No definition available.
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- Definition
Long-Term Contract for Purchase of Electric Power, Fixed Capacity Carges No definition available.
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- 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.
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- 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.
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- 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.
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- Definition
Capacity of a transmission line in kilovolts. No definition available.
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- 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
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| X | ||||||||||
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- 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
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- 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
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- Details
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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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- 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
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Commitments, Guarantees and Contingencies - Coal, Rail and Shipping Contracts (Details) (Coal and Transportation [Member], USD $)
In Millions, unless otherwise specified |
Mar. 31, 2013
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Coal and Transportation [Member]
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| Coal, Rail and Shipping Contracts [Line Items] | |
| Minimum Annual Payment Obligation, Current Year | $ 36.8 |
| Minimum Annual Payment Obligation, Year Two | $ 1.3 |
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- 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
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- 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
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- Details
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Commitments, Guarantees and Contingencies - Leasing Agreements (Details) (USD $)
In Millions, unless otherwise specified |
Mar. 31, 2013
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| Leasing Agreements [Line Items] | |
| Operating Leases, Future Minimum Payments Due, Next Twelve Months | $ 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 |
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BNI Coal Dragline Lease [Member]
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| Leasing Agreements [Line Items] | |
| Termination Fee | 3.0 |
| Operating Leases, Future Minimum Payments Due, Next Twelve Months | $ 2.8 |
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- Definition
A lump sum payment in conjunction with a lease termination. No definition available.
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- Details
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- 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
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- 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
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- 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
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| X | ||||||||||
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- 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
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| X | ||||||||||
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- 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
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| X | ||||||||||
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- 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
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Commitments, Guarantees and Contingencies - Transmission (Details) (USD $)
In Millions, unless otherwise specified |
Mar. 31, 2013
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Dec. 31, 2012
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|---|---|---|
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CapX2020 [Member]
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| Transmission [Line Items] | ||
| Number of CapX2020 Projects | 3 | |
| Capital Cost Spent to Date | $ 53.5 | $ 48.2 |
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CapX2020 [Member] | Minimum [Member]
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| Transmission [Line Items] | ||
| Estimated Capital Expenditures | 100 | |
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CapX2020 [Member] | Maximum [Member]
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| Transmission [Line Items] | ||
| Estimated Capital Expenditures | 110 | |
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CapX2020 Fargo to Monticello Projects [Member]
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| Transmission [Line Items] | ||
| Transmission Line Length (Miles) | 238 | |
| Transmission Line Capacity (kV) | 345 | |
| Capital Cost Spent to Date | 42.6 | 37.3 |
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CapX2020 Monticello to St. Cloud Project [Member]
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| Transmission [Line Items] | ||
| Transmission Line Length (Miles) | 28 | |
| Transmission Line Capacity (kV) | 345 | |
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CapX2020 Bemidji to Grand Rapids Project [Member]
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| Transmission [Line Items] | ||
| Transmission Line Length (Miles) | 70 | |
| Transmission Line Capacity (kV) | 230 | |
| Capital Cost Spent to Date | $ 10.9 | $ 10.9 |
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- Definition
Capital cost spent to date for project. No definition available.
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- Definition
The estimated amount of certain future capital expenditures related to environmental compliance, regulatory matters, or other committments and/or contingencies. No definition available.
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| X | ||||||||||
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- Definition
Number of projects. No definition available.
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| X | ||||||||||
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- Definition
Capacity of a transmission line in kilovolts. No definition available.
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
Length of a transmission line in miles. No definition available.
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Commitments, Guarantees and Contingencies - Environmental Matters (Details) (Boswell Unit 4 [Member], USD $)
In Millions, unless otherwise specified |
Mar. 31, 2013
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Minimum [Member]
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| Schedule of Utility Generating Facilities [Line Items] | |
| Estimated Capital Expenditures | $ 350 |
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Maximum [Member]
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| Schedule of Utility Generating Facilities [Line Items] | |
| Estimated Capital Expenditures | $ 400 |
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- Definition
The estimated amount of certain future capital expenditures related to environmental compliance, regulatory matters, or other committments and/or contingencies. No definition available.
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| X | ||||||||||
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- Details
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Commitments, Guarantees and Contingencies - Other Matters (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | |
|---|---|---|
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Mar. 31, 2013
Years
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Dec. 31, 2012
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BNI Coal Reclamation Liability [Member]
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| Guarantor Obligations [Line Items] | ||
| Surety Bond Amount | $ 29.7 | |
| Reclamation Letter of Credit | 2.6 | |
| Total Current Estimated Reclamation Liability | 32.3 | |
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ALLETE Properties Performance and Maintenance Obligations [Member]
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| Guarantor Obligations [Line Items] | ||
| Surety Bond Amount | 10.2 | |
| Performance and Maintenance Obligations | 7.4 | |
| Performance and Maintenance Obligations, Land Purchaser Contractual Obligation | 0.6 | |
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Town Center Community Development District [Member]
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| Guarantor Obligations [Line Items] | ||
| Bond Amount | 26.4 | |
| Bond Interest Rate | 6.00% | |
| Bond Term (Years) | 31 | |
| Ownership of Property Benefited | 73.00% | 73.00% |
| Annual Assessment | 1.4 | |
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Palm Coast Park Community Development District [Member]
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| Guarantor Obligations [Line Items] | ||
| Bond Amount | 31.8 | |
| Bond Interest Rate | 5.70% | |
| Bond Term (Years) | 31 | |
| Ownership of Property Benefited | 93.00% | 93.00% |
| Annual Assessment | $ 2.1 |
| X | ||||||||||
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- 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.
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| X | ||||||||||
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- Definition
Interest rate of capital improvement revenue and special assessment bonds used to fund real estate development projects. No definition available.
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| X | ||||||||||
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- Definition
Term (in years) of capital improvement revenue and special assessment bonds used to fund real estate development projects. No definition available.
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| X | ||||||||||
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- 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.
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| X | ||||||||||
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- Definition
Amount of letters of credit that are available for the future payment of environmental commitments and/or contingencies. No definition available.
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| X | ||||||||||
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- Definition
Amount of surety bonds that are available for future payment obligations related to environmental commitments and/or contingencies. No definition available.
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| X | ||||||||||
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- Definition
Estimated costs remaining on performance and maintenance obligations. No definition available.
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| X | ||||||||||
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- Definition
Performance and Maintenance Obligations, Portion that is the Land Purchaser's Contractual Obligation No definition available.
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- 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
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| X | ||||||||||
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- 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
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Commitments, Guarantees and Contingencies - Legal Proceedings (Details) (Pending Litigation [Member], USD $)
In Millions, unless otherwise specified |
3 Months Ended |
|---|---|
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Mar. 31, 2013
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Pending Litigation [Member]
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| Legal Proceedings [Line Items] | |
| Damages Sought | $ 20.0 |
| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
The value (monetary amount) of the award the plaintiff seeks in the legal matter. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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