MEZZANINE EQUITY, COMMON STOCK AND STOCKHOLDERS' (DEFICIT) EQUITY - Schedule Of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Number of Shares
Beginning balance (in shares)	21,543,828
Granted during the period (in shares)	0
Exercised during the period (in shares)	(6,706,616)
Cancelled and forfeited during the period (in shares)	(309,744)
Ending balance (in shares)	14,527,468	21,543,828
Options vested and expected to vest (in shares)	14,527,468
Options exercisable (in shares)	13,521,686
Weighted-Average Exercise Price
Beginning balance, weighted-average exercise price (in dollars per share)	$ 2.19
Granted, weighted-average exercise price (in dollars per share)	0	$ 3.64	$ 2.31
Exercised, weighted-average exercise price (in dollars per share)	2.06
Cancelled and forfeited, weighted-average exercise price (in dollars per share)	4.52
Ending balance, weighted-average exercise price (in dollars per share)	2.20	$ 2.19
Options vested and expected to vest, weighted-average exercise price (in dollars per share)	2.20
Options exercisable, weighted-average exercise price (in dollars per share)	$ 1.87
Weighted- Average Remaining Life
Weighted- Average Remaining Life	5 years 4 months 13 days	6 years 6 months 7 days
Options vested and expected to vest, weighted-average remaining life	5 years 4 months 13 days
Options exercisable, weighted-average remaining life	5 years 2 months 23 days
Total Intrinsic Value (in thousands)
Total Intrinsic Value (in thousands)	$ 226,000	$ 304,590
Options vested and expected to vest, total intrinsic value	226,000
Options exercisable, total intrinsic value	$ 214,813