REVENUE RECOGNITION - Disaggregation of Revenue by Type (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Disaggregation of Revenue
Revenues	$ 202,130	$ 170,031	$ 403,193	$ 328,536
Contract assets	2,100		2,100		$ 1,600
Intersegment Eliminations
Disaggregation of Revenue
Revenues	(6,656)	(14,079)	(19,108)	(27,058)
Trucking
Disaggregation of Revenue
Revenues	122,404	105,102	238,433	207,878
Trucking | Operating Segments
Disaggregation of Revenue
Revenues	122,515	105,361	238,586	208,464
Trucking | Intersegment Eliminations
Disaggregation of Revenue
Revenues	(111)	(259)	(153)	(586)
USAT Logistics
Disaggregation of Revenue
Revenues	79,726	64,929	164,760	120,658
USAT Logistics | Operating Segments
Disaggregation of Revenue
Revenues	86,271	78,749	183,715	147,130
USAT Logistics | Intersegment Eliminations
Disaggregation of Revenue
Revenues	(6,545)	(13,820)	(18,955)	(26,472)
Freight
Disaggregation of Revenue
Revenues	161,523	149,371	334,583	290,244
Freight | Intersegment Eliminations
Disaggregation of Revenue
Revenues	(6,346)	(13,545)	(18,792)	(26,149)
Freight | Trucking | Operating Segments
Disaggregation of Revenue
Revenues	95,653	90,712	193,225	181,727
Freight | USAT Logistics | Operating Segments
Disaggregation of Revenue
Revenues	72,216	72,204	160,150	134,666
Fuel Surcharge
Disaggregation of Revenue
Revenues	35,890	17,073	60,548	31,315
Fuel Surcharge | Intersegment Eliminations
Disaggregation of Revenue
Revenues	(310)	(534)	(316)	(909)
Fuel Surcharge | Trucking | Operating Segments
Disaggregation of Revenue
Revenues	23,535	12,038	39,759	22,358
Fuel Surcharge | USAT Logistics | Operating Segments
Disaggregation of Revenue
Revenues	12,665	5,569	21,105	9,866
Accessorial
Disaggregation of Revenue
Revenues	4,717	3,587	8,062	6,977
Accessorial | Trucking | Operating Segments
Disaggregation of Revenue
Revenues	3,327	2,611	5,602	4,379
Accessorial | USAT Logistics | Operating Segments
Disaggregation of Revenue
Revenues	$ 1,390	$ 976	$ 2,460	$ 2,598