Goodwill and Intangible Assets Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2015

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill [Table Text Block]

The following table summarizes changes to goodwill by reportable segment for the year ended December 31, 2015:

	ALLETE Clean Energy		U.S. Water Services		Total
Millions
Balance as of December 31, 2014		$2.9	—			$2.9
Acquired Goodwill	0.4			$127.3	127.7
Balance as of December 31, 2015		$3.3		$127.3		$130.6

Schedule of Intangible Assets [Table Text Block]

Balances of intangible assets, net, excluding goodwill as of December 31, 2015, are as follows:

	December 31, 2014		Additions (a)		Amortization	Other (b)	December 31, 2015
Millions
Intangible Assets
Definite-Lived Intangible Assets
Customer Relationships	—			$64.0	$(3.2)	—		$60.8
Developed Technology and Other (c)		$1.9	6.4		(0.8)	$(0.3)	7.2
Total Definite-Lived Intangible Assets	1.9		70.4		(4.0)	(0.3)	68.0
Indefinite-Lived Intangible Assets
Trademarks and Trade Names	—		16.6		n/a	—	16.6
Total Intangible Assets		$1.9		$87.0	$(4.0)	$(0.3)		$84.6

(a) Additions are primarily the result of the U.S. Water Services acquisition. (See Note 7. Acquisitions.)

(b) Armenia Mountain was acquired on July 1, 2015, at which time the purchase option intangible asset was reclassified as a component of the acquisition consideration.

(c) Developed Technology and Other includes patents, non-compete agreements, and land easements.