Segment Information - Geographic Information (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net revenues to external customers and long-lived assets located by geographic area
Total revenues	$ 409.0	$ 408.2	$ 412.6	$ 369.0	$ 404.9	$ 386.2	$ 347.2	$ 327.5	$ 1,598.8	$ 1,465.8	$ 1,288.5
Other revenue										5.2	9.0
Long-lived assets by geographic area	489.3				495.8				489.3	495.8	478.4
United States
Net revenues to external customers and long-lived assets located by geographic area
Total revenues									1,461.9	1,353.0	1,180.8
Long-lived assets by geographic area	481.1				481.2				481.1	481.2	462.4
Rest-of-World
Net revenues to external customers and long-lived assets located by geographic area
Total revenues									136.9	112.8	107.7
Long-lived assets by geographic area	$ 8.2				$ 14.6				$ 8.2	$ 14.6	$ 16.0