Leases - Operating Lease Costs, and Cash Flow Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Leases [Abstract]
Operating lease cost	$ 14.0	$ 12.8	$ 42.6	$ 38.3
Short-term and variable lease cost	5.6	6.7	16.1	19.5
Total lease cost	$ 19.6	$ 19.5	58.7	57.8
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash outflows - Payments on operating leases			42.1	38.3
Right-of-use assets obtained in exchange for new lease obligations:
Operating leases			$ 52.5	$ 42.0