Leases - Operating Lease Costs, and Cash Flow Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Operating lease cost	$ 12.8	$ 12.4	$ 38.3	$ 37.5
Short-term and variable lease cost	6.7	7.9	19.5	21.8
Total lease cost	$ 19.5	$ 20.3	57.8	59.3
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash outflows - Payments on operating leases			38.3	37.5
Right-of-use assets obtained in exchange for new lease obligations:
Operating leases			$ 42.0	$ 142.8