REVENUE - Revenue with Customers (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	$ 938	$ 966
Cost reimbursements		287
Financing	72	68
Total Revenues	1,010	1,034
Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	837	838
Cost reimbursements		291
Financing	71	67
Total Revenues	908	905
Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	106	123
Cost reimbursements		24
Financing	1	1
Total Revenues	107	124
Sale of vacation ownership products
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	258	293
Sale of vacation ownership products | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	258	293
Sale of vacation ownership products | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	0	0
Ancillary revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	47	58
Ancillary revenues | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	46	57
Ancillary revenues | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	1	1
Management fee revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	44	47
Management fee revenues | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	38	36
Management fee revenues | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	10	15
Other services revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	136	134
Other services revenues | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	28	32
Other services revenues | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	61	66
Management and exchange
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	227	239
Management and exchange | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	112	125
Management and exchange | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	72	82
Rental
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	135	147
Rental | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	122	129
Rental | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	13	17
Cost reimbursements
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	318	287
Cost reimbursements	318
Cost reimbursements | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements	345
Cost reimbursements | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements	21
Corporate and other
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	(5)	5
Cost reimbursements		(28)
Financing	0	0
Total Revenues	(5)	5
Corporate and other | Sale of vacation ownership products
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	0	0
Corporate and other | Ancillary revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	0	0
Corporate and other | Management fee revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	(4)	(4)
Corporate and other | Other services revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	47	36
Corporate and other | Management and exchange
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	43	32
Corporate and other | Rental
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	0	$ 1
Corporate and other | Cost reimbursements
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements	$ (48)