COMMON STOCK AND STOCKHOLDERS' (DEFICIT) EQUITY - SCHEDULE OF SHARE-BASED COMPENSATION (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	$ 220	$ 9
Brokerage and transaction
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	1	0
Technology and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	82	1
Operations
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	4	0
Marketing
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	5	0
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	$ 128	$ 8