Commitments and Contingencies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Commitments and Contingencies
Rent expense, net of sublease income	$ 12.7	$ 13.5	$ 7.1
Capital Leases
2017	1.7
2018	1.7
2019	1.5
2020	1.2
Total	6.1
Operating Leases
2017	11.7
2018	11.5
2019	11.0
2020	10.2
2021	9.1
Thereafter	78.0
Total	131.5
Other Commitments
2017	52.4
2018	22.9
2019	18.3
2020	16.9
2021	15.2
Thereafter	105.4
Total	$ 231.1