STOCKHOLDERS' EQUITY (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended						6 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Total Comprehensive Loss
Net Income (loss)		$ 11,841			$ 5,451		$ (6,321)	$ (7,336)
Less: noncontrolling interest in net income of subsidiary					153			174
NET INCOME (LOSS) ATTRIBUTABLE TO ARKANSAS BEST CORPORATION		11,841			5,298		(6,321)	(7,510)
Other comprehensive income:
Change in foreign currency translation, net of tax (2012 - Three-month period $17, Six-month period $9; 2011 - Three-month period $9, Six-month period $18)		(27)			12		(14)	28
Change in foreign currency translation, tax		(17)			9		(9)	18
Amortization of unrecognized net periodic benefit costs, net of tax (2012 - Three-month period $1,089, Six-month period $2,178; 2011 - Three-month period $697, Six-month period $1,394)
Net actuarial loss		1,739			1,125		3,478	2,249
Prior service credit		(29)			(29)		(58)	(58)
Amortization of unrecognized net periodic benefit costs, tax		1,089			697		2,178	1,394
Other, net of tax (2011 - Three-month period $2, Six-month period $2)					(4)			(5)
Other, tax					2			2
Total other comprehensive income		1,683			1,104		3,406	2,214
Total comprehensive income (loss)		13,524			6,402		(2,915)	(5,296)
Accumulated other comprehensive loss, pre-tax amounts:
Foreign currency translation		(714)					(714)		(691)
Unrecognized net periodic benefit costs		(82,795)					(82,795)		(88,393)
Total pre-tax amount		(83,509)					(83,509)		(89,084)
Accumulated other comprehensive loss, after-tax amounts:
Foreign currency translation		(437)					(437)		(423)
Unrecognized net periodic benefit costs		(54,559)					(54,559)		(57,979)
Total after-tax amount		(54,996)					(54,996)		(58,402)
Dividends on Common Stock
Dividends declared (in dollars per share)	$ 0.03	$ 0.03	$ 0.03	$ 0.03	$ 0.03	$ 0.03	$ 0.06	$ 0.06
Dividend Amount	$ 807	$ 808	$ 797	$ 798	$ 797	$ 788	$ 1,605