Leases - Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Leases [Abstract]
Operating cash flows from operating leases	$ 26.6	$ 51.0
Operating cash flows from finance leases	3.1	6.4
Financing cash flows from finance leases	1.1	2.8
Leased assets obtained in exchange for new finance lease liabilities	0.8	0.8
Leased assets obtained in exchange for new operating lease liabilities	$ 7.7	$ 9.4