PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Details) (USD $)	6 Months Ended				3 Months Ended		6 Months Ended				3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2013 ABF	Jun. 30, 2013 Multiemployer pension plans ABF plan	Jun. 30, 2013 Central States Pension Plan ABF	Jan. 02, 2012 Central States Pension Plan ABF	Jun. 30, 2013 Nonunion Defined Benefit Pension Plan	Jun. 30, 2012 Nonunion Defined Benefit Pension Plan	Jun. 30, 2013 Nonunion Defined Benefit Pension Plan	Jun. 30, 2012 Nonunion Defined Benefit Pension Plan	Jan. 02, 2013 Nonunion Defined Benefit Pension Plan	Dec. 31, 2012 Nonunion Defined Benefit Pension Plan	Jun. 30, 2013 Supplemental Benefit Pension Plan	Jun. 30, 2012 Supplemental Benefit Pension Plan	Jun. 30, 2013 Supplemental Benefit Pension Plan	Jun. 30, 2012 Supplemental Benefit Pension Plan	Jun. 30, 2013 Postretirement Health Benefit Plan	Jun. 30, 2012 Postretirement Health Benefit Plan	Jun. 30, 2013 Postretirement Health Benefit Plan	Jun. 30, 2012 Postretirement Health Benefit Plan
Components of net periodic benefit cost
Service cost					$ 2,367,000	$ 2,297,000	$ 4,734,000	$ 4,594,000							$ 83,000	$ 78,000	$ 166,000	$ 157,000
Interest cost					1,922,000	2,173,000	3,845,000	4,346,000			38,000	53,000	75,000	105,000	187,000	188,000	375,000	375,000
Expected return on plan assets					(3,155,000)	(3,016,000)	(6,309,000)	(6,032,000)
Amortization of prior service credit															(47,000)	(47,000)	(95,000)	(95,000)
Amortization of net actuarial loss and other					2,714,000	2,692,000	5,427,000	5,384,000			65,000	50,000	130,000	101,000	133,000	104,000	267,000	208,000
Net periodic benefit cost					3,848,000	4,146,000	7,697,000	8,292,000			103,000	103,000	205,000	206,000	356,000	323,000	713,000	645,000
Remaining pre-tax unrecognized net actuarial loss					30,600,000		30,600,000
Amortization period for unrecognized net actuarial loss							8 years
Change in projected benefit obligation
Projected benefit obligation at the beginning of the period							260,950,000
Service cost					2,367,000	2,297,000	4,734,000	4,594,000							83,000	78,000	166,000	157,000
Interest cost					1,922,000	2,173,000	3,845,000	4,346,000			38,000	53,000	75,000	105,000	187,000	188,000	375,000	375,000
Actuarial gain and other							(10,747,000)
Benefits paid							(10,745,000)
Curtailment							(29,262,000)
Projected benefit obligation at the end of the period					218,775,000		218,775,000
Changes in plan assets
Fair value of plan assets at beginning of period							181,225,000
Actual return on plan assets							12,575,000
Employer contributions							9,000,000
Benefits paid							(10,745,000)
Fair value of plan assets at end of period					192,055,000		192,055,000
Funded status at the end of the period					26,720,000		26,720,000
Accumulated benefit obligation					218,775,000		218,775,000
Expected return on plan assets (as a percent)							7.50%
Discount rate (as a percent)					3.90%		3.90%			3.10%
Adjusted funding target attainment percentage									92.00%
Curtailment gain recognized in earnings					$ 0		$ 0
Multiemployer Plans
Number of multiemployer plans to which ABF contributes		25
Maximum required increase in employer's contribution to multiemployer plans that enter reorganization status (as a percent)	7.00%
Approximate proportion of multiemployer pension plan contributions made to Central States Pension Fund (as a percent)			50.00%
Actuarially certified funded percentage of multiemployer pension plan				53.90%