Lease Obligations (Lease Information) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Leases [Abstract]
Amortization of right-of-use assets	$ 5.8
Interest on lease liabilities	1.0
Operating lease cost	42.6
Short-term lease cost	0.5
Sublease income	(3.1)
Total lease cost	46.8
Operating cash flows from finance leases	0.0
Operating cash flows from operating leases	43.0
Financing cash flows from finance leases	8.7
Right-of-use assets obtained in exchange for new finance lease liabilities	7.7
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 18.7
Weighted-average remaining lease term — finance leases (years)	2 years
Weighted-average remaining lease term — operating leases (years)	5 years 1 month 6 days
Weighted-average discount rate — finance leases (percent)	6.50%
Weighted-average discount rate — operating leases (percent)	6.70%