Lease Obligations Lease Obligations (Supplemental Cash Flow) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Leases [Abstract]
Operating cash flows from operating leases	$ 40.7
Operating cash flows from finance leases	0.2
Financing cash flows from finance leases	2.7
Right-of-use assets obtained in exchange for new operating lease liabilities	40.7
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 2.1