REVENUE Disaggregation of Revenue - Industry (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Revenues	$ 2,382,237	$ 1,895,282	$ 4,603,859	$ 4,056,588
SCS
Disaggregation of Revenue [Line Items]
Revenues	775,630	519,318	1,482,330	1,147,765
Automotive | SCS
Disaggregation of Revenue [Line Items]
Revenues	307,499	147,749	579,054	397,674
Technology and healthcare | SCS
Disaggregation of Revenue [Line Items]
Revenues	109,950	84,766	207,035	175,899
Consumer packaged goods and retail | SCS
Disaggregation of Revenue [Line Items]
Revenues	286,262	236,499	559,486	466,431
Industrial and other | SCS
Disaggregation of Revenue [Line Items]
Revenues	$ 71,919	$ 50,304	$ 136,755	$ 107,761