REVENUE FROM CONTRACTS WITH CUSTOMERS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Total revenues	$ 4,803,869	$ 3,805,008
NAST
Disaggregation of Revenue [Line Items]
Total revenues	3,211,423	2,823,745
Global Forwarding
Disaggregation of Revenue [Line Items]
Total revenues	1,156,039	530,384
All Other and Corporate
Disaggregation of Revenue [Line Items]
Total revenues	436,407	450,879
Transportation and logistics services
Disaggregation of Revenue [Line Items]
Total revenues	4,560,227	3,542,118
Transportation and logistics services | Performance obligations completed over time
Disaggregation of Revenue [Line Items]
Total revenues	4,560,227	3,542,118
Transportation and logistics services | NAST | Performance obligations completed over time
Disaggregation of Revenue [Line Items]
Total revenues	3,211,423	2,823,745
Transportation and logistics services | Global Forwarding | Performance obligations completed over time
Disaggregation of Revenue [Line Items]
Total revenues	1,156,039	530,384
Transportation and logistics services | All Other and Corporate | Performance obligations completed over time
Disaggregation of Revenue [Line Items]
Total revenues	192,765	187,989
Sourcing
Disaggregation of Revenue [Line Items]
Total revenues	243,642	262,890
Sourcing | Performance obligations completed at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	243,642	262,890
Sourcing | NAST | Performance obligations completed at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Sourcing | Global Forwarding | Performance obligations completed at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Sourcing | All Other and Corporate | Performance obligations completed at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	$ 243,642	$ 262,890