Leases - Operating Lease Costs, and Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease cost	$ 53.3	$ 49.7
Short-term and variable lease cost	25.3	31.6
Total lease cost	78.6	81.3
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash outflows - payments on operating leases	53.3	51.7
Right-of-use assets obtained in exchange for new lease obligations:
Operating leases	$ 65.1	$ 157.0