Leases - Lease Liability Maturity (Details) $ in Millions	Jun. 30, 2019 USD ($)
Leases [Abstract]
2019 (excluding the six months ended June 30, 2019)	$ 7.3
2020	13.9
2021	12.7
2022	8.6
2023	3.8
Thereafter	7.4
Total lease payments	53.7
Less imputed interest	(5.1)
Total	$ 48.6