REVENUE - Geographic Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 265,591	$ 212,546
Percent of total revenue	100.00%	100.00%
U.S.
Disaggregation of Revenue [Line Items]
Revenue	$ 172,417	$ 103,991
Other Americas
Disaggregation of Revenue [Line Items]
Revenue	15,342	28,829
United Kingdom (“U.K.”)
Disaggregation of Revenue [Line Items]
Revenue	21,837	24,549
Europe (excluding U.K.), Middle East, and Africa
Disaggregation of Revenue [Line Items]
Revenue	31,938	34,186
Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenue	$ 24,057	$ 20,991
Total revenue | U.S.
Disaggregation of Revenue [Line Items]
Percent of total revenue	65.00%	48.00%
Total revenue | Other Americas
Disaggregation of Revenue [Line Items]
Percent of total revenue	6.00%	14.00%
Total revenue | United Kingdom (“U.K.”)
Disaggregation of Revenue [Line Items]
Percent of total revenue	8.00%	12.00%
Total revenue | Europe (excluding U.K.), Middle East, and Africa
Disaggregation of Revenue [Line Items]
Percent of total revenue	12.00%	16.00%
Total revenue | Asia-Pacific
Disaggregation of Revenue [Line Items]
Percent of total revenue	9.00%	10.00%