Debt And Financing - Capital Expenditures/Operating Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Acquisition of property and equipment	$ (103.3)	$ (100.6)	$ (108.0)
Minimum annual rentals 2018	116.5
Future minimum payments due	352.5
Revenue Equipment [Member]
Debt Instrument [Line Items]
Operating lease commitment	$ 108.4
Operating lease term	5 years