Leases - Maturity of Lease Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jan. 01, 2019
Leases [Abstract]
Finance Lease, Liability, Payments, Remainder of Fiscal Year	$ 2.0
2019	227.5
Finance Lease, Liability, Payments, Due Year Two	2.0
2020	198.2
Finance Lease, Liability, Payments, Due Year Three	2.0
2021	170.3
Finance Lease, Liability, Payments, Due Year Four	2.0
2022	162.3
Finance Lease, Liability, Payments, Due Year Five	2.0
2023	157.8
Finance Lease, Liability, Payments, Due after Year Five	9.4
Thereafter	493.4
Finance Lease, Liability, Payments, Due	19.4
Total minimum lease payments	1,409.5
Finance Lease, Liability, Undiscounted Excess Amount	5.2
Less: effect of discounting	413.4
Finance Lease, Liability	14.2
Present value of future minimum lease payments	996.1	$ 853.9
Finance Lease, Liability, Current	1.1
Less: current obligations under leases	153.8
Finance Lease, Liability, Noncurrent	13.1
Long-term lease obligations	$ 842.3