GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)

6 Months Ended

Jun. 30, 2015

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of identifiable intangible assets other than goodwill

The identifiable intangible assets other than goodwill listed below are part of other long-term assets on the balance sheets.

	June 30, 2015							December 31, 2014
(Millions)	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Amortized intangible assets (1)	$	27.1	$	(11.6	)	$	15.5	$	34.9	$	(11.9	)	$	23.0
Unamortized intangible assets (2)	10.7		—			10.7		10.2		—			10.2
Total intangible assets	$	37.8	$	(11.6	)	$	26.2	$	45.1	$	(11.9	)	$	33.2

⁽¹⁾  Primarily relates to contractual service agreements that provide for major maintenance and protection against unforeseen maintenance costs related to the combustion turbine generators at the Fox Energy Center. The remaining weighted-average amortization period for our amortized intangible assets at June 30, 2015, was approximately five years.

⁽²⁾  Consists primarily of trade names.