COMMON STOCK AND STOCKHOLDERS' (DEFICIT) EQUITY - Schedule of Share-Based Compensation (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	$ 83	$ 110		$ 790	$ 494
Workforce Reduction | April 2022 Restructuring
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation		53	$ 24
Market-Based RSUs
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	10	79		563	245
Time-Based RSUs
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	70	27		218	235
Brokerage and transaction
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	2	2		6	4
Technology and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	51	25		161	166
Technology and development | Time-Based RSUs | Workforce Reduction | April 2022 Restructuring
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation		22	16
Operations
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	3	0		6	5
Marketing
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	1	0		3	3
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	$ 26	83		614	$ 316
General and administrative | Market-Based RSUs
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation				$ 485
General and administrative | Time-Based RSUs | Workforce Reduction | April 2022 Restructuring
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation		$ 28	$ 6