Leases - Lease Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Leases [Abstract]
Operating lease expense	$ 14.7	$ 13.4
Finance lease expense amortization of leased assets	0.3	0.3
Short-term and variable lease expense	0.1	0.1
Sublease income	(0.1)	(0.1)
Total	$ 15.0	$ 13.7