Liquidity (Risks and Uncertainties) (Details) (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012
Risks and Uncertainties [Line Items]
Cash and cash equivalents	$ 181,400,000	$ 170,500,000	$ 176,300,000	$ 208,700,000
Net cash used in operating activities	26,300,000	3,000,000
Long-term Debt, Gross	1,116,800,000		1,361,300,000
Operating Leases, Future Minimum Payments, Due Remainder of Fiscal Year	14,000,000
Operating Leases, Future Minimum Payments Due	153,700,000
Payments to Acquire Property, Plant, and Equipment	47,600,000	56,500,000
Other Postretirement Benefit Plans, Defined Benefit [Member]
Risks and Uncertainties [Line Items]
Defined Benefit Plan, Estimated Benefit Obligation for Remaining Fiscal Year	6,800,000
Multiemployer Plans, Pension [Member]
Risks and Uncertainties [Line Items]
Defined Benefit Plan, Estimated Benefit Obligation for Remaining Fiscal Year	23,200,000
Line of Credit [Member] | 2014 ABL Facility Credit Agreement [Member]
Risks and Uncertainties [Line Items]
Total availability	212,900,000.0
Minimum availability of the lesser of the aggregate amount of commitments from lenders or the borrowing base	10.00%
Revenue Equipment [Member]
Risks and Uncertainties [Line Items]
Operating lease commitment	$ 11,800,000
Operating lease term	3 years