LONG-TERM DEBT AND FINANCING ARRANGEMENTS (Details 3) (USD $)							3 Months Ended	6 Months Ended		0 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2014 Letter of Credit Agreements	Dec. 31, 2013 Letter of Credit Agreements	Jun. 30, 2014 Surety bonds	Dec. 31, 2013 Surety bonds	Jun. 30, 2014 Notes payable Revenue Equipment ABF Freight	Jun. 30, 2014 Notes payable Revenue Equipment ABF Freight	Jun. 30, 2014 Credit Agreement Revolving commitments	Jun. 15, 2012 Credit Agreement Term Loan	Jun. 30, 2014 Accounts receivable securitization program	Jun. 30, 2014 Accounts receivable securitization program Letter of Credit Agreements	Dec. 31, 2013 Accounts receivable securitization program Letter of Credit Agreements
Financing Arrangements
Debt instrument, term										5 years
Face amount of term loan										$ 100,000,000
Maximum borrowing capacity									75,000,000		75,000,000
Amount outstanding									0		0
Equipment financed during the period under notes payable							22,800,000	22,800,000
Outstanding letters of credit			19,500,000	22,800,000								17,500,000	20,300,000
Remaining borrowing capacity			58,600,000								57,500,000
Amounts collateralized by restricted funds	1,385,000	1,902,000	1,400,000	1,900,000
Outstanding surety bonds under uncollateralized bond programs					56,100,000	43,800,000
Outstanding surety bonds under collateralized bond program						12,700,000
Letters of credit, outstanding amount used as collateral						$ 3,800,000