XML 80 R65.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Fair Value - Recurring Fair Value Measures (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2013 | Dec. 31, 2012
Investments [Abstract] |  |
Cash Equivalents | $ 34.2 | $ 20.7
Liabilities [Abstract] |  |
Fair Value Activity in Level 3 | 0 | 0
Fair Value Hierarchy Transfers, All Levels | 0 | 0
Recurring Fair Value Measures [Member] |  |
Investments [Abstract] |  |
Available-for-sale Securities - Equity Securities | 7.9 | 18.0
Available-for-sale Securities - Corporate Debt Securities | 9.8 | 8.8
Cash Equivalents | 34.2 | 20.7
Total Fair Value of Assets | 51.9 | 47.5
Liabilities [Abstract] |  |
Deferred Compensation | 16.8 | 14.0
Derivatives - Interest Rate Swap | 0.6 | 0.7
Total Fair Value of Liabilities | 17.4 | 14.7
Total Net Fair Value of Assets (Liabilities) | 34.5 | 32.8
Recurring Fair Value Measures [Member] | Level 1 [Member] |  |
Investments [Abstract] |  |
Available-for-sale Securities - Equity Securities | 7.9 | 18.0
Available-for-sale Securities - Corporate Debt Securities | 0 | 0
Cash Equivalents | 34.2 | 20.7
Total Fair Value of Assets | 42.1 | 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) | 42.1 | 38.7
Recurring Fair Value Measures [Member] | Level 2 [Member] |  |
Investments [Abstract] |  |
Available-for-sale Securities - Equity Securities | 0 | 0
Available-for-sale Securities - Corporate Debt Securities | 9.8 | 8.8
Cash Equivalents | 0 | 0
Total Fair Value of Assets | 9.8 | 8.8
Liabilities [Abstract] |  |
Deferred Compensation | 16.8 | 14.0
Derivatives - Interest Rate Swap | 0.6 | 0.7
Total Fair Value of Liabilities | 17.4 | 14.7
Total Net Fair Value of Assets (Liabilities) | (7.6) | (5.9)
Recurring Fair Value Measures [Member] | Level 3 [Member] |  |
Investments [Abstract] |  |
Available-for-sale Securities - Equity Securities | 0 | 0
Available-for-sale Securities - Corporate Debt Securities | 0 | 0
Cash Equivalents | 0 | 0
Total Fair Value of Assets | 0 | 0
Liabilities [Abstract] |  |
Deferred Compensation | 0 | 0
Derivatives - Interest Rate Swap | 0 | 0
Total Fair Value of Liabilities | 0 | 0
Total Net Fair Value of Assets (Liabilities) | $ 0 | $ 0

X
- Definition This element represents the portion of the balance sheet assertion, Deferred Compensation, valued at fair value by the entity. + References No definition available. + Details
Name: | ale_DeferredCompensationFairValueDisclosure
Namespace Prefix: | ale_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair Value Activity in Level 3 + References No definition available. + Details
Name: | ale_FairValueActivityInLevel3
Namespace Prefix: | ale_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of transfers in and out of levels 1, 2 and 3 of the fair value hierarchy during the period. + References No definition available. + Details
Name: | ale_FairValueHierarchyTransfersAllLevels
Namespace Prefix: | ale_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

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. + References No definition available. + Details
Name: | ale_InvestmentsCashAndCashEquivalentsFairValueDisclosure
Namespace Prefix: | ale_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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. + References No definition available. + Details
Name: | ale_NetAssetsAndLiabilitiesFairValueDisclosure
Namespace Prefix: | ale_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of debt securities categorized neither as held-to-maturity nor trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 320 -Section 50 -Paragraph 2 -Subparagraph (b)-(g) -URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62557-112803 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of equity securities categorized neither as held-to-maturity nor as trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 320 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62557-112803 + Details
Name: | us-gaap_AvailableForSaleSecuritiesEquitySecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value as of the balance sheet date of all interest rate derivative liabilities designated as cash flow hedging instruments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624163-113959 + Details
Name: | us-gaap_InterestRateCashFlowHedgeLiabilityAtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_InvestmentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of financial and nonfinancial obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258 + Details
Name: | us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_LiabilitiesFairValueDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration