Leases - Maturity of Lease Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2019	Jan. 01, 2019
Leases [Abstract]
Finance Lease, Liability, Payments, Remainder of Fiscal Year	$ 2.0
2019	221.2
Finance Lease, Liability, Payments, Due Year Two	2.0
2020	197.5
Finance Lease, Liability, Payments, Due Year Three	2.0
2021	159.1
Finance Lease, Liability, Payments, Due Year Four	2.0
2022	150.1
Finance Lease, Liability, Payments, Due Year Five	2.0
2023	146.0
Finance Lease, Liability, Payments, Due after Year Five	9.8
Thereafter	350.1
Finance Lease, Liability, Payments, Due	19.8
Total minimum lease payments	1,224.0
Finance Lease, Liability, Undiscounted Excess Amount	5.4
Less: effect of discounting	305.0
Finance Lease, Liability	14.4
Present value of future minimum lease payments	919.0	$ 689.2
Finance Lease, Liability, Current	1.1
Less: current obligations under leases	152.6
Finance Lease, Liability, Noncurrent	13.3
Long-term lease obligations	$ 766.4