BUSINESS SEGMENTS - Revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting, Revenue Reconciling Item [Line Items]
Total Revenues	$ 3,890	$ 2,886	$ 4,259
Revenues excluding cost reimbursement	2,762	1,844	3,151
United States
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues excluding cost reimbursement	2,499	1,664	2,810
All other countries
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues excluding cost reimbursement	263	180	341
Vacation Ownership
Segment Reporting, Revenue Reconciling Item [Line Items]
Total Revenues	3,539	2,530	3,761
Exchange & Third-Party Management
Segment Reporting, Revenue Reconciling Item [Line Items]
Total Revenues	320	309	454
Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Total Revenues	3,859	2,839	4,215
Operating Segments | Vacation Ownership
Segment Reporting, Revenue Reconciling Item [Line Items]
Total Revenues	3,539	2,530	3,761
Operating Segments | Exchange & Third-Party Management
Segment Reporting, Revenue Reconciling Item [Line Items]
Total Revenues	320	309	454
Corporate and other
Segment Reporting, Revenue Reconciling Item [Line Items]
Total Revenues	$ 31	$ 47	$ 44