SEGMENT REPORTING - Reportable Segment Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($) employee	Mar. 31, 2023 USD ($) employee	Dec. 31, 2023 USD ($)
Segment Reporting Information [Line Items]
Total revenues	$ 4,412,311	$ 4,611,670
Income (loss) from operations	127,133	161,033
Depreciation and amortization	23,878	24,380
Total assets	$ 5,472,088	$ 5,595,584	$ 5,225,280
Average headcount (employee) | employee	14,990	16,902
NAST
Segment Reporting Information [Line Items]
Total revenues	$ 3,000,313	$ 3,304,187
Income (loss) from operations	108,895	134,022
Depreciation and amortization	5,350	5,651
Total assets	$ 3,065,996	$ 3,240,898
Average headcount (employee) | employee	6,004	6,870
Global Forwarding
Segment Reporting Information [Line Items]
Total revenues	$ 858,637	$ 789,978
Income (loss) from operations	31,552	30,116
Depreciation and amortization	2,844	5,480
Total assets	$ 1,257,675	$ 1,194,575
Average headcount (employee) | employee	4,876	5,471
All Other and Corporate
Segment Reporting Information [Line Items]
Total revenues	$ 553,361	$ 517,505
Income (loss) from operations	(13,314)	(3,105)
Depreciation and amortization	15,684	13,249
Total assets	$ 1,148,417	$ 1,160,111
Average headcount (employee) | employee	4,110	4,561