REVENUE, DEFERRED REVENUE, AND REMAINING PERFORMANCE OBLIGATIONS - Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Total revenue	$ 184,358	$ 141,860	$ 334,494	$ 281,977
United States | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total revenue	119,385	92,681	217,303	183,278
All other countries | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total revenue	$ 64,973	$ 49,179	$ 117,191	$ 98,699