REVENUE FROM CONTRACTS WITH CUSTOMERS - Total Revenues Disaggregated by Major Service Line and Timing of Recognition (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Total revenues	$ 23,102,138	$ 16,207,106	$ 15,309,508
NAST
Disaggregation of Revenue [Line Items]
Total revenues	14,507,917	11,312,553	11,283,692
Global Forwarding
Disaggregation of Revenue [Line Items]
Total revenues	6,729,790	3,100,525	2,327,913
All Other and Corporate
Disaggregation of Revenue [Line Items]
Total revenues	1,864,431	1,794,028	1,697,903
Operating Segments | NAST
Disaggregation of Revenue [Line Items]
Total revenues	14,507,917	11,312,553	11,283,692
Operating Segments | Global Forwarding
Disaggregation of Revenue [Line Items]
Total revenues	6,729,790	3,100,525	2,327,913
Operating Segments | All Other and Corporate
Disaggregation of Revenue [Line Items]
Total revenues	1,864,431	1,794,028	1,697,903
Transportation
Disaggregation of Revenue [Line Items]
Total revenues	22,046,574	15,147,562	14,322,295
Transportation | Performance obligations completed over time
Disaggregation of Revenue [Line Items]
Total revenues	22,046,574	15,147,562	14,322,295
Transportation | Operating Segments | NAST | Performance obligations completed over time
Disaggregation of Revenue [Line Items]
Total revenues	14,507,917	11,312,553	11,283,692
Transportation | Operating Segments | Global Forwarding | Performance obligations completed over time
Disaggregation of Revenue [Line Items]
Total revenues	6,729,790	3,100,525	2,327,913
Transportation | Operating Segments | All Other and Corporate | Performance obligations completed over time
Disaggregation of Revenue [Line Items]
Total revenues	808,867	734,484	710,690
Sourcing
Disaggregation of Revenue [Line Items]
Total revenues	1,055,564	1,059,544	987,213
Sourcing | Performance obligations completed at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	1,055,564	1,059,544	987,213
Sourcing | Operating Segments | NAST | Performance obligations completed at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Sourcing | Operating Segments | Global Forwarding | Performance obligations completed at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Sourcing | Operating Segments | All Other and Corporate | Performance obligations completed at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	$ 1,055,564	$ 1,059,544	$ 987,213