REVENUE FROM CONTRACTS WITH CUSTOMERS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Total revenues	$ 6,263,695	$ 4,224,800	$ 16,600,290	$ 11,657,654
NAST
Disaggregation of Revenue [Line Items]
Total revenues	3,814,988	2,923,842	10,611,892	8,222,879
Global Forwarding
Disaggregation of Revenue [Line Items]
Total revenues	1,978,901	831,957	4,585,734	2,070,161
All Other and Corporate
Disaggregation of Revenue [Line Items]
Total revenues	469,806	469,001	1,402,664	1,364,614
Transportation and logistics services
Disaggregation of Revenue [Line Items]
Total revenues	5,999,901	3,944,981	15,800,576	10,835,710
Transportation and logistics services | Performance obligations completed over time
Disaggregation of Revenue [Line Items]
Total revenues	5,999,901	3,944,981	15,800,576	10,835,710
Transportation and logistics services | NAST | Performance obligations completed over time
Disaggregation of Revenue [Line Items]
Total revenues	3,814,988	2,923,842	10,611,892	8,222,879
Transportation and logistics services | Global Forwarding | Performance obligations completed over time
Disaggregation of Revenue [Line Items]
Total revenues	1,978,901	831,957	4,585,734	2,070,161
Transportation and logistics services | All Other and Corporate | Performance obligations completed over time
Disaggregation of Revenue [Line Items]
Total revenues	206,012	189,182	602,950	542,670
Sourcing
Disaggregation of Revenue [Line Items]
Total revenues	263,794	279,819	799,714	821,944
Sourcing | Performance obligations completed at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	263,794	279,819	799,714	821,944
Sourcing | NAST | Performance obligations completed at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Sourcing | Global Forwarding | Performance obligations completed at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Sourcing | All Other and Corporate | Performance obligations completed at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	$ 263,794	$ 279,819	$ 799,714	$ 821,944