Leases - Lease Obligations (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Leases [Abstract]
Finance leases - ROU assets	$ 58.9	$ 54.8
Finance leases - Accumulated depreciation	(19.9)	(15.0)
Operating leases - ROU assets	120.6	118.8
Operating leases - Accumulated depreciation	(38.9)	(28.7)
Total lease assets	120.7	129.9
Finance leases	(10.5)	(10.4)
Operating leases	(24.9)	(26.2)
Finance leases	(27.4)	(28.7)
Operating leases	(58.7)	(65.7)
Total lease liabilities	$ (121.5)	$ (131.0)
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssetsNoncurrent	us-gaap:OtherAssetsNoncurrent
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:LongTermDebtNoncurrent	us-gaap:LongTermDebtNoncurrent
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:LongTermDebtCurrent	us-gaap:LongTermDebtCurrent