SHARE-BASED AWARDS - Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020
Number of Options
Temporary equity, shares outstanding (in shares)		22,633
Retroactive conversion of shares due to Business Combination (in shares)		13,976
Beginning balance (in shares)	36,609
Granted (in shares)	0
Exercised (in shares)	(5,649)
Forfeited (in shares)	(5,513)
Expired (in shares)	(1,289)
Ending balance (in shares)	24,158	36,609
Exercisable (in shares)			18,961
Weighted-Average Exercise Price
Weighted-Average Exercise Price (in dollars per share)		$ 3.00
Retroactive conversion of shares due to Business Combination (in dollars per share)		(1.15)
Beginning balance (in dollars per share)	$ 1.85
Granted (in dollars per share)
Exercised (in dollars per share)	1.33
Forfeited (in dollars per share)	2.04
Expired (in dollars per share)	2.22
Ending balance (in dollars per share)	$ 1.85	$ 1.85	$ 1.91
Exercisable (in dollars per share)			$ 1.55
Weighted-Average Remaining Contractual Term (in years) and Aggregate Intrinsic Value
Weighted-average remaining contractual term (in years), outstanding	5 years 4 months 24 days	6 years 10 months 24 days
Weighted-average remaining contractual term (in years), exercisable	4 years 7 months 6 days
Aggregate intrinsic values		$ 110,481	$ 502,767
Exercisable, aggregate intrinsic value			$ 401,436