PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Details) (USD $)	9 Months Ended		3 Months Ended		9 Months Ended					3 Months Ended		9 Months Ended					3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 ABF	Sep. 30, 2012 ABF	Sep. 30, 2013 ABF	Sep. 30, 2012 ABF	Sep. 30, 2013 Multiemployer pension plans ABF plan	Sep. 30, 2013 Central States Pension Plan ABF	Jan. 02, 2012 Central States Pension Plan ABF	Sep. 30, 2013 Nonunion Defined Benefit Pension Plan	Sep. 30, 2012 Nonunion Defined Benefit Pension Plan	Sep. 30, 2013 Nonunion Defined Benefit Pension Plan	Sep. 30, 2012 Nonunion Defined Benefit Pension Plan	Jun. 30, 2013 Nonunion Defined Benefit Pension Plan	Jan. 02, 2013 Nonunion Defined Benefit Pension Plan	Dec. 31, 2012 Nonunion Defined Benefit Pension Plan	Sep. 30, 2013 Supplemental Benefit Pension Plan	Sep. 30, 2012 Supplemental Benefit Pension Plan	Sep. 30, 2013 Supplemental Benefit Pension Plan	Sep. 30, 2012 Supplemental Benefit Pension Plan	Sep. 30, 2013 Postretirement Health Benefit Plan	Sep. 30, 2012 Postretirement Health Benefit Plan	Sep. 30, 2013 Postretirement Health Benefit Plan	Sep. 30, 2012 Postretirement Health Benefit Plan
Components of net periodic benefit cost
Service cost										$ 0	$ 2,298,000	$ 4,734,000	$ 6,892,000				$ 0	$ 0	$ 0	$ 0	$ 82,000	$ 79,000	$ 248,000	$ 236,000
Interest cost										2,039,000	2,173,000	5,884,000	6,519,000				37,000	52,000	112,000	157,000	188,000	187,000	563,000	562,000
Expected return on plan assets										(3,438,000)	(3,016,000)	(9,747,000)	(9,048,000)				0	0	0	0	0	0	0	0
Amortization of prior service credit										0	0	0	0				0	0	0	0	(47,000)	(47,000)	(142,000)	(142,000)
Pension settlement expense	1,834,000	0	1,612,000	0	1,612,000	0				1,834,000	0	1,834,000	0				0	0	0	0	0	0	0	0
Amortization of net actuarial loss and other										961,000	2,692,000	6,388,000	8,076,000				65,000	51,000	195,000	152,000	134,000	103,000	401,000	311,000
Net periodic benefit cost										1,396,000	4,147,000	9,093,000	12,439,000				102,000	103,000	307,000	309,000	357,000	322,000	1,070,000	967,000
Pension settlement expense, per share amount										$ 0.04		$ 0.04
Remaining pre-tax unrecognized net actuarial loss										24,000,000		24,000,000
Approximate 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										0	2,298,000	4,734,000	6,892,000				0	0	0	0	82,000	79,000	248,000	236,000
Interest cost										2,039,000	2,173,000	5,884,000	6,519,000				37,000	52,000	112,000	157,000	188,000	187,000	563,000	562,000
Actuarial gain and other												(9,126,000)
Benefits paid												(18,201,000)
Curtailment												(29,262,000)
Projected benefit obligation at the end of the period										214,979,000		214,979,000
Changes in plan assets
Fair value of plan assets at beginning of period												181,225,000
Actual return on plan assets												21,496,000
Employer contributions												17,800,000
Benefits paid												(18,201,000)
Fair value of plan assets at end of period										202,320,000		202,320,000
Funded status at the end of the period										(12,659,000)		(12,659,000)
Accumulated benefit obligation										214,979,000		214,979,000
Expected return on plan assets (as a percent)												7.50%
Discount rate (as a percent)										3.70%		3.70%		3.90%		3.10%
Curtailment gain recognized in earnings										$ 0		$ 0
Adjusted funding target attainment percentage															102.70%
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%