REVENUE - Geographic Revenue (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]
Revenue	$ 325,702	$ 227,375	$ 639,201	$ 492,966
Percent of total revenue	100.00%	100.00%	100.00%	100.00%
U.S.
Disaggregation of Revenue [Line Items]
Revenue	$ 189,297	$ 142,811	$ 383,865	$ 315,228
Other Americas
Disaggregation of Revenue [Line Items]
Revenue	14,058	8,930	25,959	24,272
United Kingdom (“U.K.”)
Disaggregation of Revenue [Line Items]
Revenue	32,553	21,259	60,765	43,096
Europe (excluding U.K.), Middle East, and Africa
Disaggregation of Revenue [Line Items]
Revenue	45,798	34,878	97,457	66,816
Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenue	$ 43,996	$ 19,497	$ 71,155	$ 43,554
Total revenue | U.S. | Geographic Concentration Risk
Disaggregation of Revenue [Line Items]
Percent of total revenue	58.00%	63.00%	60.00%	63.00%
Total revenue | Other Americas | Geographic Concentration Risk
Disaggregation of Revenue [Line Items]
Percent of total revenue	4.00%	4.00%	4.00%	5.00%
Total revenue | United Kingdom (“U.K.”) | Geographic Concentration Risk
Disaggregation of Revenue [Line Items]
Percent of total revenue	10.00%	9.00%	10.00%	9.00%
Total revenue | Europe (excluding U.K.), Middle East, and Africa | Geographic Concentration Risk
Disaggregation of Revenue [Line Items]
Percent of total revenue	14.00%	15.00%	15.00%	14.00%
Total revenue | Asia-Pacific | Geographic Concentration Risk
Disaggregation of Revenue [Line Items]
Percent of total revenue	14.00%	9.00%	11.00%	9.00%