XML 130 R82.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Common Stock and Earnings Per Share - Forward Contracts (Details) (Forward Contracts [Member], USD $) In Millions, except Per Share data, unless otherwise specified | 0 Months Ended | 12 Months Ended | 0 Months Ended |
--- | --- | --- | --- | ---
Sep. 05, 2014 | Mar. 04, 2014 | Feb. 26, 2014 | Dec. 31, 2014 | Feb. 04, 2015 | Feb. 04, 2014
Forward Contract Indexed to Issuer's Equity [Line Items] |  |  |  |  |  |
Forward Contract Indexed to Issuer's Equity, Indexed Shares |  |  | 2.8 us-gaap_ForwardContractIndexedToIssuersEquityIndexedShares |  |  |
Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share |  |  | $ 48.01 us-gaap_ForwardContractIndexedToIssuersEquityForwardRate |  |  |
Common Stock, Shares, Issued | 1.4 us-gaap_CommonStockSharesIssued |  |  |  |  | 0.4 us-gaap_CommonStockSharesIssued
Proceeds from Issuance or Sale of Equity | $ 65.0 us-gaap_ProceedsFromIssuanceOrSaleOfEquity | $ 20.2 us-gaap_ProceedsFromIssuanceOrSaleOfEquity |  |  |  |
Forward Contract Indexed to Issuer's Equity, Dilutive effect |  |  |  | 0 ale_ForwardContractIndexedtoIssuersEquityDilutiveeffect |  |
Subsequent Event [Member] |  |  |  |  |  |
Forward Contract Indexed to Issuer's Equity [Line Items] |  |  |  |  |  |
Common Stock, Shares, Issued |  |  |  |  | 1.4 us-gaap_CommonStockSharesIssued / us-gaap_ForwardContractIndexedToIssuersEquityTypeAxis = us-gaap_ForwardContractsMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember |
Proceeds from Issuance or Sale of Equity |  |  |  |  | $ 65.4 us-gaap_ProceedsFromIssuanceOrSaleOfEquity / us-gaap_ForwardContractIndexedToIssuersEquityTypeAxis = us-gaap_ForwardContractsMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember |

X
- Definition Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of equity forward arrangements using the treasury stock method. + References No definition available. + Details
Name: | ale_ForwardContractIndexedtoIssuersEquityDilutiveeffect
Namespace Prefix: | ale_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 30 -Article 5 + Details
Name: | us-gaap_CommonStockSharesIssued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The per share price of the Company's stock at which the contract holder of the freestanding contract has the right to purchase or sell the Company's stock at a future date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 40 -Section 50 -Paragraph 5 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6445032&loc=d3e90205-114008 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(1) -URI http://asc.fasb.org/extlink&oid=6940734&loc=d3e22047-110879 + Details
Name: | us-gaap_ForwardContractIndexedToIssuersEquityForwardRate
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of issuer's shares to which the forward contract is indexed. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 40 -Section 50 -Paragraph 5 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=6445032&loc=d3e90205-114008 + Details
Name: | us-gaap_ForwardContractIndexedToIssuersEquityIndexedShares
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition The cash inflow from the issuance of common stock, preferred stock, treasury stock, stock options, and other types of equity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOrSaleOfEquity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |