Goodwill and Other Intangible Assets - Intangible Assets Other than Goodwill (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Intangible assets other than goodwill
Amortized intangible assets, gross carrying amount	$ 16.0
Amortized intangible assets, accumulated amortization	(7.0)
Amortized intangible assets, net carrying amount	9.0
Unamortized intangible assets, carrying amount	5.7
Total intangible assets, gross carrying amount	21.7
Total intangible assets, net carrying amount	$ 14.7	$ 0.0
Remaining weighted-average amortization period	3 years