XML 37 R30.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Other Income (Expense) (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2013
Other Income (Expense) [Abstract] |
Other Income (Expense) [Table Text Block] |
|  | Quarter Ended
|  | March 31,
|  | 2013 |  | 2012
Millions |  |  |  |
AFUDC – Equity |  |  | $1.1 |  |  |  | $0.8 |
Gain on Sale of Available-for-sale Securities |  | 0.8 |  |  | — |
Investments and Other Income (Expense) |  | 0.8 |  |  | (0.1 | )
Total Other Income |  |  | $2.7 |  |  |  | $0.7 |

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

X
- 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. + References No definition available. + Details
Name: | us-gaap_ScheduleOfOtherNonoperatingIncomeExpenseTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration