GEOGRAPHIC INFORMATION - Revenue and Long-Lived Assets (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue and Long-lived Assets by Geography
Revenue	$ 806,070	$ 801,835	$ 707,760	$ 667,612	$ 651,407	$ 639,770	$ 555,450	$ 544,642	$ 2,983,277	$ 2,391,269	$ 2,051,258
Long-lived assets (excluding goodwill and intangible assets)	163,256				107,799				163,256	107,799
United States
Revenue and Long-lived Assets by Geography
Revenue									1,362,658	1,121,957	972,747
Long-lived assets (excluding goodwill and intangible assets)	133,513				91,683				$ 133,513	91,683
United States | Revenue Benchmark | Geographic Concentration Risk
Revenue and Long-lived Assets by Geography
Concentration risk (percent)									10.00%
United States | Property, Plant and Equipment | Geographic Concentration Risk
Revenue and Long-lived Assets by Geography
Concentration risk (percent)									10.00%
All other countries
Revenue and Long-lived Assets by Geography
Revenue									$ 1,620,619	1,269,312	$ 1,078,511
Long-lived assets (excluding goodwill and intangible assets)	$ 29,743				$ 16,116				$ 29,743	$ 16,116