Intangible Assets and Goodwill - Intangible Assets (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Amortizable intangible assets [Line Items]
Carrying Amount	$ 400.7	$ 232.1
Accumulated Amortization	110.4	89.5
Customer relationships
Amortizable intangible assets [Line Items]
Carrying Amount	372.4	203.6
Accumulated Amortization	89.9	71.0
Other
Amortizable intangible assets [Line Items]
Carrying Amount	28.3	28.5
Accumulated Amortization	$ 20.5	$ 18.5