Accounting Policies (Details) $ in Millions			12 Months Ended
	Nov. 30, 2011	Sep. 30, 2010	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Impaired Long-Lived Assets Held and Used [Line Items]
Reverse stock split, conversion ratio	0.003333
Rerate reserve as a reduction to accounts receivable			$ 8.8	$ 10.4
Allowance for doubtful accounts			12.0	9.5
Foreign currency transactions gains			$ 4.0	$ 0.9	$ 9.3
Risk-free rate for maturities of workers' compensation claims			1.50%	1.01%	1.00%
Risk-free rate for property damage and liability claims			1.30%	0.80%	0.70%
Accrued claims and insurance			$ 360.7	$ 364.4
Reclassification of foreign currency translation gains to net income				(10.4)
Payments for tax withheld on equity-based compensation			2.4	0.7	$ 6.8
Net periodic pension cost			$ 20.3	19.9	46.6
Labor Force Concentration Risk [Member] | Workforce Subject to Collective Bargaining Arrangements [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Percentage of labor force			78.00%
February 17, 2010 Amendment [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Reverse stock split, conversion ratio		0.04
Accumulated Other Comprehensive Income (Loss) [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Reclassification of net losses to net income			$ 12.9	$ 13.7	14.1
Reclassification of foreign currency translation gains to net income			$ 0.0		$ 0.0