LONG-TERM DEBT AND FINANCING ARRANGEMENTS (Details 3) (USD $)			3 Months Ended	1 Months Ended			1 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2012 Asset-backed securitization program	Apr. 30, 2012 LC Agreements	Mar. 30, 2012 LC Agreements	Mar. 31, 2012 LC Agreements	Mar. 30, 2012 Surety bonds	Mar. 31, 2012 Surety bonds	Mar. 31, 2012 Notes payable ABF M	Mar. 31, 2012 Separate notes payable ABF
Financing Arrangements
Maximum borrowing capacity			$ 75,000,000			$ 103,100,000			$ 28,500,000
Debt, floating rate of interest basis			LIBOR
Annual fee on unused portion of the accounts receivable facility (as a percent)			0.575%
Tangible net worth required to be maintained			375,000,000
Borrowing capacity for issuance of letters of credit committed by financial institutions subject to the Company's compliance with the requirements of issuance						50,000,000
Available borrowing capacity for issuance of letters of credit committed by financial institutions subject to the Company's compliance with the requirements of issuance						40,300,000
Outstanding letters of credit						26,500,000
Outstanding surety bonds under collateralized bond program								13,800,000
Amounts collateralized by restricted funds	29,544,000	52,693,000				26,000,000		3,500,000
Reduction in amounts collateralized by restricted funds under letters of credit transferred to uncollateralized bond programs				6,500,000	19,600,000
Reduction in amounts collateralized by restricted funds under collateralized bond program							3,500,000
Outstanding surety bonds under uncollateralized bond programs								26,400,000
Notes payable, term (in months)									36
Notes payable to finance revenue equipment purchased									22,500,000	6,000,000
Long-term debt	64,937,000	71,012,000							18,900,000	5,500,000
Remaining borrowing capacity			$ 75,000,000						$ 6,000,000