SEGMENT REPORTING - Reportable Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($) employee	Sep. 30, 2021 USD ($) employee	Sep. 30, 2022 USD ($) employee	Sep. 30, 2021 USD ($) employee	Dec. 31, 2021 USD ($)
Segment Reporting Information [Line Items]
Total revenues	$ 6,015,376	$ 6,263,695	$ 19,629,804	$ 16,600,290
Income (loss) from operations	287,609	310,769	1,102,748	794,702
Depreciation and amortization	22,975	22,406	68,723	68,621
Total assets	$ 6,795,530	$ 6,602,606	$ 6,795,530	$ 6,602,606	$ 7,028,112
Average headcount (employee) | employee	18,045	15,968	17,652	15,482
NAST
Segment Reporting Information [Line Items]
Total revenues	$ 4,002,461	$ 3,814,988	$ 12,264,396	$ 10,611,892
Income (loss) from operations	211,899	149,035	670,752	436,911
Depreciation and amortization	5,739	6,620	18,101	19,779
Total assets	$ 3,624,333	$ 3,437,461	$ 3,624,333	$ 3,437,461
Average headcount (employee) | employee	7,493	6,764	7,420	6,650
Global Forwarding
Segment Reporting Information [Line Items]
Total revenues	$ 1,511,115	$ 1,978,901	$ 5,798,702	$ 4,585,734
Income (loss) from operations	85,953	165,155	421,148	363,956
Depreciation and amortization	5,368	5,427	16,394	17,352
Total assets	$ 2,266,923	$ 2,438,106	$ 2,266,923	$ 2,438,106
Average headcount (employee) | employee	5,861	5,167	5,735	4,951
All Other and Corporate
Segment Reporting Information [Line Items]
Total revenues	$ 501,800	$ 469,806	$ 1,566,706	$ 1,402,664
Income (loss) from operations	(10,243)	(3,421)	10,848	(6,165)
Depreciation and amortization	11,868	10,359	34,228	31,490
Total assets	$ 904,274	$ 727,039	$ 904,274	$ 727,039
Average headcount (employee) | employee	4,691	4,037	4,497	3,881