Leases - Supplemental cash flow information related to leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 71.9	$ 64.7
Operating cash flows from finance leases	7.9	7.8
Financing cash flows from finance leases	4.6	4.2
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	70.5	73.1
Finance leases	$ 0.1	$ 15.5