XML 60 R23.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Operations and Significant Accounting Policies (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2013
Operations and Significant Accounting Policies [Abstract] |
Inventories [Table Text Block] |
Inventories | March 31, 2013 |  |  | December 31, 2012 |
Millions |  |  |
Fuel |  | $22.4 |  |  |  | $28.0 |
Materials and Supplies | 41.9 |  |  | 41.8 |
Total Inventories |  | $64.3 |  |  |  | $69.8 |
Prepayments and Other Current Assets [Table Text Block] |
Prepayments and Other Current Assets | March 31, 2013 |  |  | December 31, 2012 |
Millions |  |  |
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 and Non-Current Liabilities [Table Text Block] |
Other Current Liabilities | March 31, 2013 |  |  | December 31, 2012 |
Millions |  |  |
Customer Deposits (a) |  | $28.4 |  |  |  | $28.8 |
Other | 29.4 |  |  | 33.8 |
Total Other Current Liabilities |  | $57.8 |  |  |  | $62.6 |
(a) | Customer deposits are primarily due to security deposits for capital expenditures relating to a transmission project.
Other Non-Current Liabilities | March 31, 2013 |  |  | December 31, 2012 |
Millions |  |  |
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 [Table Text Block] | Supplemental Statement of Cash Flows Information.
For the Quarter Ended March 31, | 2013 |  |  | 2012 |
Millions |  |  |
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 |  |  |
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 |

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

X
- Definition Tabular disclosure of supplemental cash flow information for the periods presented. + References No definition available. + Details
Name: | us-gaap_ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the carrying amount as of the balance sheet date of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 2 -Paragraph 6 -Subparagraph a,b,c -Article 5 + Details
Name: | us-gaap_ScheduleOfInventoryCurrentTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of other assets and other liabilities not separately disclosed on the balance sheet. + References No definition available. + Details
Name: | us-gaap_ScheduleOfOtherAssetsAndOtherLiabilitiesTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the carrying amounts of other current assets. + References No definition available. + Details
Name: | us-gaap_ScheduleOfOtherCurrentAssetsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration