Components of Lease Expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Leases [Abstract]
Operating lease expense	$ 23.3	$ 21.5	$ 47.3	$ 42.1
Amortization of Right-of-Use Assets	0.4	0.2	0.7	0.3
Finance Lease, Interest Expense	0.2	0.1	0.3	0.2
Variable lease expense	$ 2.8	$ 5.0	$ 4.6	$ 8.2