Leases - Operating Lease Costs, and Cash Flow Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Leases [Abstract]
Operating lease cost	$ 13.7	$ 12.8
Short-term and variable lease cost	5.2	7.5
Total lease cost	18.9	20.3
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash outflows - Payments on operating leases	13.7	13.0
Right-of-use assets obtained in exchange for new lease obligations:
Operating leases	$ 10.2	$ 11.3