Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Leases [Abstract]
Rent expense	$ 19.3	$ 16.2	$ 19.5
Future minimum rental commitments under non-cancelable operating leases [Abstract]
2018	18.1
2019	14.5
2020	10.7
2021	7.6
2022	6.5
Thereafter	24.9
Future minimum rentals to be received under non-cancelable subleases	5.2
Future minimum payments to be received under direct financing leases [Abstract]
2018	0.4
2019	0.1
2020	0.0
2021	0.0
2022	0.0
Thereafter	$ 0.0