Leases - Cash Flow Classifications (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating cash flows for operating leases	$ 41.9	$ 43.9
Operating cash flows for finance leases	0.8	0.6
Financing cash flows for finance leases	4.4	3.0
Leased assets obtained in exchange for new finance lease liabilities	7.6	20.2
Leased assets obtained in exchange for new operating lease liabilities	$ 86.9	$ 10.3