EMPLOYEE BENEFIT PLANS (Details 7) (Freight Transportation (ABF Freight), USD $) In Thousands, unless otherwise specified	12 Months Ended	0 Months Ended			12 Months Ended		0 Months Ended	12 Months Ended
	Dec. 31, 2014	Aug. 01, 2014	Aug. 01, 2013	Aug. 01, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2005	Jan. 31, 2014	Jan. 31, 2013	Jan. 01, 2014	Jan. 01, 2013	Jan. 01, 2012
Multiemployer Plans
Maximum increase in combined contribution rates for health, welfare, and pension benefits each August 1	1.00
Multiemployer pension plans
Multiemployer Plans
Number of multiemployer plans to which ABF Freight currently contributes	25
Maximum funded percentage of plans in yellow zone	80.00%
Maximum funded percentage of plans in red zone	65.00%
Maximum projected time to insolvency for plans in "critical and declining" status	14 years
Maximum projected time to insolvency for plans in "critical and declining" status if additional criteria apply	19 years
Threshold ratio of inactive to active participants for greater insolvency period to determine "critical and declining" status	2
Threshold funded percentage for greater insolvency period to determine "critical and declining" status	80.00%
Percentage of contributions to the multiemployer pension plans that are in critical status					64.00%
Percentage of contributions to the multiemployer pension plans that are in endangered status					3.00%
Total contributions to multiemployer plans	$ 144,177				$ 136,233	$ 131,895
Percentage increase in contribution rate for time worked related to benefit costs		0.020	0.020	0.023
Multiemployer pension plans | Central States Pension Plan
Multiemployer Plans
Total contributions to multiemployer plans	74,001				70,020	68,683
Threshold percentage of the entity's contributions relative to total fund contributions, which was exceeded during the period					5.00%	5.00%
Actuarially certified funded percentage of multiemployer pension plan										48.40%	47.60%	53.90%
Period of extension granted by Internal Revenue Service for amortization of unfunded liabilities							10 years
Multiemployer pension plans | Central States Pension Plan | Maximum
Multiemployer Plans
Percentage of contributions to multiemployer pension plan	55.00%				55.00%	55.00%
Multiemployer pension plans | Central States Pension Plan | Minimum
Multiemployer Plans
Percentage of contributions to multiemployer pension plan	50.00%				50.00%	50.00%
Multiemployer pension plans | Western Conference of Teamsters Pension Plan
Multiemployer Plans
Total contributions to multiemployer plans	23,030				20,601	20,774
Multiemployer pension plans | Central Pennsylvania Teamsters Pension Plan
Multiemployer Plans
Total contributions to multiemployer plans	12,810				12,143	11,170
Threshold percentage of the entity's contributions relative to total fund contributions, which was exceeded during the period					5.00%	5.00%
Multiemployer pension plans | Local 710 Pension Fund
Multiemployer Plans
Total contributions to multiemployer plans	9,186				10,001	9,567
Threshold percentage of the entity's contributions relative to total fund contributions, which was exceeded during the period								5.00%	5.00%
Multiemployer pension plans | All Other Pension Plans in Aggregate
Multiemployer Plans
Total contributions to multiemployer plans	25,150				23,468	21,701
Multiemployer health and welfare plans
Multiemployer Plans
Number of multiemployer plans to which ABF Freight currently contributes	44
Total contributions to multiemployer plans	$ 130,500				$ 118,000	$ 113,000
Percentage increase in contribution rate for time worked related to benefit costs		0.054	0.076	0.053
Unionized employees concentration risk | Number of employees
Multiemployer Plans
Percentage of ABF Freight's employees covered under collective bargaining agreement with the IBT	79.00%