Debt and Other Financing Arrangements - Debt Maturity Schedule (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Long-Term Debt, Excluding Capital Leases, Current	$ 6.0
Finance Lease, Liability, Current	0.8
Long-Term Debt, Excluding Capital Leases, Repayments of Principal in Year Two	6.0
Finance Lease, Liability, Payments, Due Year Two	1.1
Long-Term Debt, Excluding Capital Leases, Repayments of Principal in Year Three	182.6
Finance Lease, Liability, Payments, Due Year Three	1.1
Long-Term Debt, Excluding Capital Leases, Repayments of Principal in Year Four	24.0
Finance Lease, Liability, Payments, Due Year Four	0.1
Long-Term Debt, Excluding Capital Leases, Repayments of Principal in Year Five	28.3
Finance Lease, Liability, Payments, Due Year Five	0.0
Long-Term Debt, Excluding Capital Leases, Repayments of Principal After Year Five	1,631.4
Finance Lease, Liability, Payments, Due after Year Five	0.0
Long-Term Debt, Excluding Capital Leases, Gross	1,878.3
Finance Lease, Liability	3.1
Capital Leases, Future Principal Payments Due, Repayments of Principal in Next Twelve Months	13.4
Capital Leases, Future Principal Payments Due in Two Years	10.5
Capital Leases, Future Principal Payments Due in Three Years	7.1
Capital Leases, Future Principal Payments Due in Four Years	5.0
Capital Leases, Future Principal Payments Due in Five Years	3.8
Capital Leases, Future Principal Payments Due Thereafter	34.1
Capital Leases, Future Minimum Principal Payments Due	73.9
Debt Instrument, Unamortized Discount	0.0
Debt Issuance Costs, Net	0.0
Long-term Debt and Capital Lease Obligations, Repayments of Principal in Next Twelve Months	20.2
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two	17.6
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three	190.8
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four	29.1
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five	32.1
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five	1,665.5
Long-term Debt, Gross	1,955.3
Net unamortized premium	1.7	$ 1.9
Debt Issuance Costs, Noncurrent, Net	27.2	22.3
Long-Term Debt, Excluding Capital Leases, Net	1,852.8
Debt and Capital Lease Obligations	1,929.8	$ 1,747.7
Capital Leases, Future Minimum Payments Due, Next Twelve Months	18.0
Capital Leases, Future Minimum Payments Due in Two Years	14.4
Capital Leases, Future Minimum Payments Due in Three Years	10.6
Capital Leases, Future Minimum Payments Due in Four Years	8.0
Capital Leases, Future Minimum Payments Due in Five Years	6.5
Capital Leases, Future Minimum Payments Due Thereafter	$ 42.6