Leases - Summary of Balances of Right of Use Assets and Liabilities of Finance Leases and Operating Leases (Details) - USD ($) $ in Millions		Mar. 31, 2019	Dec. 31, 2018
Right-of-use assets
Operating leases, gross		$ 35.6
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]		us-gaap:OtherAssetsNoncurrent
Finance leases, gross		$ 40.9
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]		us-gaap:PropertyPlantAndEquipmentGross
Current:
Operating leases		$ 2.7
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]		us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent
Finance leases	[1]	$ 10.5	$ 0.0
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]		us-gaap:LiabilitiesCurrent
Non-current:
Operating leases		$ 47.8
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]		us-gaap:OtherLiabilitiesNoncurrent
Finance leases		$ 27.7	$ 0.0
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]		us-gaap:LiabilitiesNoncurrent

[1] While we consolidate the debt of the Partnership in our financial statements, we do not have the obligation to make interest payments or debt payments with respect to the debt of the Partnership.