OPERATING SEGMENT DATA - Revenue from Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenues
Revenues	$ 1,351,831	$ 1,016,657	$ 4,079,834	$ 2,794,843
Asset Based
Revenues
Revenues	778,473	655,737	2,242,964	1,815,606
ArcBest
Revenues
Revenues	503,182	303,076	1,633,684	821,355
FleetNet
Revenues
Revenues	72,318	56,656	207,505	155,041
Corporate and Other
Revenues
Revenues	(2,142)	1,188	(4,319)	2,841
Operating Segments | Asset Based
Revenues
Revenues	791,531	681,164	2,299,464	1,890,288
Operating Segments | ArcBest
Revenues
Revenues	515,235	305,207	1,660,174	828,291
Operating Segments | FleetNet
Revenues
Revenues	89,276	66,514	249,786	185,224
Intersegment revenues
Revenues
Revenues	(42,069)	(37,416)	(125,271)	(111,801)
Intersegment revenues | Asset Based
Revenues
Revenues	13,058	25,427	56,500	74,682
Intersegment revenues | ArcBest
Revenues
Revenues	12,053	2,131	26,490	6,936
Intersegment revenues | FleetNet
Revenues
Revenues	16,958	9,858	42,281	30,183
Other and eliminations
Revenues
Revenues	$ (44,211)	$ (36,228)	$ (129,590)	$ (108,960)