SEGMENT REPORTING - Reportable Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) employee	Sep. 30, 2022 USD ($) employee	Sep. 30, 2023 USD ($) employee	Sep. 30, 2022 USD ($) employee	Dec. 31, 2022 USD ($)
Segment Reporting Information [Line Items]
Total revenues	$ 4,341,030	$ 6,015,376	$ 13,374,556	$ 19,629,804
Income (loss) from operations	113,522	287,609	407,178	1,102,748
Depreciation and amortization	25,544	22,975	75,899	68,723
Total assets	$ 5,317,667	$ 6,795,530	$ 5,317,667	$ 6,795,530	$ 5,954,564
Average headcount (employee) | employee	15,577	18,045	16,240	17,652
NAST
Segment Reporting Information [Line Items]
Total revenues	$ 3,086,970	$ 4,002,461	$ 9,470,425	$ 12,264,396
Income (loss) from operations	112,121	211,899	364,002	670,752
Depreciation and amortization	5,882	5,739	17,389	18,101
Total assets	$ 3,162,720	$ 3,624,333	$ 3,162,720	$ 3,624,333
Average headcount (employee) | employee	6,278	7,493	6,574	7,420
Global Forwarding
Segment Reporting Information [Line Items]
Total revenues	$ 719,045	$ 1,511,115	$ 2,288,890	$ 5,798,702
Income (loss) from operations	3,491	85,953	63,254	421,148
Depreciation and amortization	5,446	5,368	16,410	16,394
Total assets	$ 1,081,262	$ 2,266,923	$ 1,081,262	$ 2,266,923
Average headcount (employee) | employee	5,082	5,861	5,276	5,735
All Other and Corporate
Segment Reporting Information [Line Items]
Total revenues	$ 535,015	$ 501,800	$ 1,615,241	$ 1,566,706
Income (loss) from operations	(2,090)	(10,243)	(20,078)	10,848
Depreciation and amortization	14,216	11,868	42,100	34,228
Total assets	$ 1,073,685	$ 904,274	$ 1,073,685	$ 904,274
Average headcount (employee) | employee	4,217	4,691	4,390	4,497