Leases - Lease Obligations (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Finance leases - ROU assets	$ 58.2	$ 58.0
Finance leases - Accumulated depreciation	(28.8)	(27.3)
Operating leases - ROU assets	139.8	133.5
Operating leases - Accumulated depreciation	(74.3)	(69.7)
Total lease assets	94.9	94.5
Finance leases	(9.2)	(10.2)
Operating leases	(21.2)	(21.2)
Finance leases	(18.9)	(19.2)
Operating leases	(45.8)	(44.5)
Total lease liabilities	$ (95.1)	$ (95.1)