OPERATING SEGMENT DATA - Revenue (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
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
Other and eliminations
Revenues
Revenues	$ (44,211)	$ (36,228)	$ (129,590)	$ (108,960)