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v3.3.1.900

Goodwill and Intangible Assets - Goodwill (Details) $ in Millions | 12 Months Ended
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Dec. 31, 2015 USD ($)
Goodwill [Roll Forward] |
Beginning Balance | $ 2.9
Acquired Goodwill | 127.7
Ending Balance | 130.6
ALLETE Clean Energy [Member] |
Goodwill [Roll Forward] |
Beginning Balance | 2.9
Acquired Goodwill | 0.4
Ending Balance | 3.3
U.S. Water Services [Member] |
Goodwill [Roll Forward] |
Beginning Balance | 0.0
Acquired Goodwill | 127.3
Ending Balance | $ 127.3

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- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266 + Details
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- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 + Details
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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- Details
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- Details
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Period Type: |