XML 45 R42.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Quarterly Financial Data (Unaudited) (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2012
Quarterly Financial Data (Unaudited) [Abstract] |
Quarterly Financial Data (Unaudited) [Table Text Block] |
Quarter Ended | Mar. 31 | Jun. 30 | Sept. 30 | Dec. 31
Millions Except Earnings Per Share |  |  |  |
2012 |  |  |  |
Operating Revenue |  | $240.0 |  |  | $216.4 |  |  | $248.8 |  |  | $256.0 |
Operating Income |  | $38.4 |  |  | $23.3 |  |  | $45.6 |  |  | $47.9 |
Net Income Attributable to ALLETE |  | $24.4 |  |  | $14.4 |  |  | $29.4 |  |  | $28.9 |
Earnings Per Share of Common Stock |  |  |  |
Basic |  | $0.66 |  |  | $0.39 |  |  | $0.78 |  |  | $0.76 |
Diluted |  | $0.66 |  |  | $0.39 |  |  | $0.78 |  |  | $0.75 |
2011 |  |  |  |
Operating Revenue |  | $242.2 |  |  | $219.9 |  |  | $226.9 |  |  | $239.2 |
Operating Income |  | $50.8 |  |  | $26.1 |  |  | $38.9 |  |  | $34.2 |
Net Income Attributable to ALLETE |  | $37.2 |  |  | $17.0 |  |  | $20.5 |  |  | $19.1 |
Earnings Per Share of Common Stock |  |  |  |
Basic |  | $1.07 |  |  | $0.49 |  |  | $0.57 |  |  | $0.53 |
Diluted |  | $1.07 |  |  | $0.48 |  |  | $0.57 |  |  | $0.53 |

X
- Details
Name: | ale_QuarterlyFinancialDataUnauditedAbstract
Namespace Prefix: | ale_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the quarterly financial data in the annual financial statements. The disclosure includes financial information for each fiscal quarter for the current and previous year, including revenues, gross profit, income (loss) before extraordinary items and cumulative effect of a change in accounting principle and earnings per share data. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 270 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a)-(j) -URI http://asc.fasb.org/extlink&oid=20225539&loc=d3e1280-108306 + Details
Name: | us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration