Leases - Maturities of Operating Lease Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Operating Lease Liabilities, Payments Due [Abstract]
2019 (excluding the nine months ended September 30, 2019)	$ 2.8
2020	9.9
2021	7.7
2022	6.0
2023	4.7
Thereafter	17.6
Total lease payments	48.7
Less: Imputed interest	(9.6)
Total	$ 39.1
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019		$ 8.9
2020		6.2
2021		4.4
2022		3.5
2023		2.5
Thereafter		2.9
Future minimum lease commitments		$ 28.4