XML 45 R53.htm IDEA: XBRL DOCUMENT v2.4.0.8

Short-Term and Long-Term Debt (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended			0 Months Ended				0 Months Ended		0 Months Ended		0 Months Ended		0 Months Ended
	Sep. 30, 2014	Jan. 30, 2014	Dec. 31, 2013	Mar. 04, 2014 ALLETE Bonds 3.69% Due March 2024 [Member]	Mar. 04, 2014 ALLETE Bonds 4.95% Due March 2044 [Member]	Jun. 26, 2014 ALLETE Bonds 3.40% Due July 2022 [Member]	Jun. 26, 2014 ALLETE Bonds 3.40% Due July 2022 [Member]	Jun. 26, 2014 ALLETE Bonds 5.05% Due July 2044 [Member]	Jun. 26, 2014 ALLETE Bonds 5.05% Due July 2044 [Member]	Sep. 16, 2014 ALLETE Bonds 3.02% Due September 2021 [Member]	Sep. 16, 2014 ALLETE Bonds 3.02% Due September 2021 [Member]	Sep. 16, 2014 ALLETE Bonds 3.74% Due September 2029 [Member]	Sep. 16, 2014 ALLETE Bonds 3.74% Due September 2029 [Member]	Sep. 16, 2014 ALLETE Bonds 4.39% Due September 2044 [Member]	Sep. 16, 2014 ALLETE Bonds 4.39% Due September 2044 [Member]
Debt Instrument [Line Items]
Short-Term Debt Outstanding	$ 88.0		$ 27.2
Long-Term Debt Outstanding	1,289.2		1,083.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Long-term Debt Including Long-term Debt Due Within One Year		23.3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Long-term Debt Due Within One Year		2.2
Proceeds from Issuance of First Mortgage Bonds	$ 375.0			$ 60.0	$ 40.0	$ 75.0		$ 40.0		$ 60.0		$ 50.0		$ 50.0
Interest Rate				3.69%	4.95%		3.40%		5.05%		3.02%		3.74%		4.39%

X

- Definition

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Long-term Debt, Including current portion

+ References

No definition available.

+ Details

Name:	ale_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedLongtermDebt
Namespace Prefix:	ale_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Amount of long-term debt due within one year or within the normal operating cycle, if longer, assumed at the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472

+ Details

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesLongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Amount of short-term debt and current maturity of long-term debt and capital lease obligations due within one year or the normal operating cycle, if longer.

+ 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 210.5-02.19,20)

-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 19

-Article 5

+ Details

Name:	us-gaap_DebtCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ 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 210.5-02.22)

-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 22

-Article 5

+ Details

Name:	us-gaap_LongTermDebtNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

The cash inflow from amounts received from a long-term debt instrument secured by a first mortgage deed of trust, containing a pledge of real property. The lender has the highest claim on the property in case of default.

+ 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 (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromIssuanceOfFirstMortgageBond
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration