GOODWILL AND OTHER INTANGIBLE ASSETS - Carrying Amount of Goodwill (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2023 USD ($)
Goodwill [Roll Forward]
Balance, beginning of period	$ 1,470,813
Foreign currency translation	(1,406)
Balance, end of period	1,469,407
NAST
Goodwill [Roll Forward]
Balance, beginning of period	1,188,076
Foreign currency translation	(1,853)
Balance, end of period	1,186,223
Global Forwarding
Goodwill [Roll Forward]
Balance, beginning of period	206,189
Foreign currency translation	224
Balance, end of period	206,413
All Other and Corporate
Goodwill [Roll Forward]
Balance, beginning of period	76,548
Foreign currency translation	223
Balance, end of period	$ 76,771