LONG-TERM DEBT AND FINANCING ARRANGEMENTS (Details 3) (USD $)			0 Months Ended	3 Months Ended			3 Months Ended		0 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	May 03, 2013 ABF Forecast	Mar. 31, 2013 Accounts receivable securitization program	Mar. 31, 2013 Letter of Credit Agreements	Mar. 31, 2013 Surety bonds	Mar. 31, 2013 Credit Agreement	Mar. 31, 2013 Revolving commitments	Jun. 15, 2012 Term Loan
Financing Arrangements
Debt instrument, term									5 years
Face amount of term loan									$ 100,000,000
Maximum borrowing capacity				75,000,000				75,000,000
Fixed charge coverage ratio							1.5
Minimum fixed charge coverage ratio required to be maintained							1.25
Amount borrowed				0				0
Outstanding letters of credit				19,800,000	26,300,000
Remaining borrowing capacity				55,200,000	69,100,000
Period of collective bargaining agreement			5 years
Available liquidity required to be maintained until a new collective bargaining agreement is in place				50,000,000
Available liquidity maintained under the terms of the debt arrangement				160,200,000
Outstanding surety bonds under collateralized bond program						13,800,000
Amounts collateralized by restricted funds under letters of credit	5,904,000	9,658,000			5,900,000
Amounts collateralized by letters of credit						3,800,000
Outstanding surety bonds under uncollateralized bond programs						$ 41,200,000