OPERATING SEGMENT DATA - (Rev and Expenses) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
REVENUES
Revenues	$ 688,214	$ 713,923	$ 676,627	$ 621,455	$ 648,134	$ 709,380	$ 696,115	$ 613,276	$ 2,700,219	$ 2,666,905	$ 2,612,693
OPERATING EXPENSES
Salaries, wages, and benefits									1,345,672	1,297,129	1,231,130
Fuel, supplies, and expenses									270,138	292,039	353,489
Depreciation and amortization									103,053	93,042	86,222
Gain on sale of property and equipment									(3,335)	(2,225)	(1,461)
Pension settlement expense									3,229	3,202	6,595
Other									118,390	118,587	118,118
Restructuring costs	10,300								10,313
Total consolidated operating expenses	687,003	693,553	659,973	630,720	640,822	675,942	662,649	611,996	2,671,249	2,591,409	2,543,454
OPERATING INCOME
OPERATING INCOME	1,211	20,370	16,654	(9,265)	7,312	33,438	33,466	1,280	28,970	75,496	69,239
OTHER INCOME (COSTS)
Interest and dividend income									1,523	1,284	851
Interest and other related financing costs									(5,150)	(4,400)	(3,190)
Other, net									2,944	354	3,712
TOTAL OTHER INCOME (COSTS)	$ (115)	$ 185	$ (273)	$ (480)	$ (445)	$ (1,392)	$ (557)	$ (368)	(683)	(2,762)	1,373
INCOME BEFORE INCOME TAXES									28,287	72,734	70,612
Operating Segments | Asset-Based
REVENUES
Revenues									1,916,394	1,916,579	1,928,531
OPERATING EXPENSES
Salaries, wages, and benefits									1,212,411	1,172,489	1,118,830
Fuel, supplies, and expenses									282,627	307,345	360,760
Operating taxes and licenses									48,436	48,992	46,955
Insurance									29,335	28,847	24,938
Communications and utilities									18,079	16,129	15,398
Depreciation and amortization									83,570	74,765	68,752
Rents and purchased transportation									199,156	197,073	229,443
Gain on sale of property and equipment									(2,979)	(1,735)	(1,471)
Pension settlement expense									2,274	2,404	5,309
Other									8,741	7,834	9,524
Restructuring costs									1,173
Total consolidated operating expenses									1,882,823	1,854,143	1,878,438
OPERATING INCOME
OPERATING INCOME									33,571	62,436	50,093
Operating Segments | ArcBest
REVENUES
Revenues									640,734	590,436	535,915
OPERATING EXPENSES
Purchased transportation									501,853	460,238	406,989
Salaries, wages, and benefits									70,857	62,438	55,159
Supplies and expenses									19,279	15,500	20,195
Depreciation and amortization									14,151	13,375	13,329
Other									19,692	18,093	17,589
Restructuring costs									8,038
Total consolidated operating expenses									633,870	569,644	513,261
OPERATING INCOME
OPERATING INCOME									6,864	20,792	22,654
Operating Segments | FleetNet
REVENUES
Revenues									162,629	174,952	158,581
OPERATING EXPENSES
Depreciation and amortization									1,209	1,119	961
Total consolidated operating expenses									160,204	171,998	155,459
OPERATING INCOME
OPERATING INCOME									2,425	2,954	3,122
Other and eliminations
REVENUES
Revenues									(19,538)	(15,062)	(10,334)
OPERATING EXPENSES
Depreciation and amortization									4,123	3,783	3,180
Total consolidated operating expenses									(5,648)	(4,376)	(3,704)
OPERATING INCOME
OPERATING INCOME									$ (13,890)	$ (10,686)	$ (6,630)