STOCK-BASED COMPENSATION - Schedule of Non-cash Compensation Related to Equity Awards (Details ) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total non-cash compensation	$ 17,335	$ 18,294	$ 32,415	$ 34,730
Cost of revenue
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total non-cash compensation	442	463	835	860
Selling and marketing expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total non-cash compensation	2,285	1,976	4,324	3,778
General and administrative expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total non-cash compensation	11,873	13,254	21,473	25,425
Product development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total non-cash compensation	2,735	2,601	4,700	4,667
Restructuring and severance
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total non-cash compensation	$ 0	$ 0	$ 1,083	$ 0