Intangible Assets and Goodwill - Narrative (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Intangible assets
Intangible amortization expense	$ 18.1	$ 5.2	$ 49.0	$ 15.0
Impairments					5.4
WMS Acquisition
Intangible assets
Impairments		3.8
Customer relationships
Intangible assets
Weighted average useful life			13 years 7 months 6 days
Licenses
Intangible assets
Weighted average useful life			2 years 10 months 24 days
Increase in carrying amount of licenses			$ 106