REVENUE AND RECEIVABLES (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements		$ 280		$ 819
Revenue from contracts with customers	$ 585	994	$ 1,933	2,934
Financing	64	72	206	209
Revenues	649	1,066	2,139	3,143
Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements		286		835
Revenue from contracts with customers	507	869	1,680	2,563
Financing	64	71	204	206
Revenues	571	940	1,884	2,769
Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements		22		68
Revenue from contracts with customers	71	110	234	348
Financing	0	1	2	3
Revenues	71	111	236	351
Vacation ownership products
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	98	341	409	975
Vacation ownership products | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	98	341	409	975
Vacation ownership products | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	0	0	0	0
Ancillary revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	17	58	70	174
Ancillary revenues | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	17	57	69	171
Ancillary revenues | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	0	1	1	3
Management fee revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	36	44	113	135
Management fee revenues | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	37	35	113	108
Management fee revenues | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	4	12	14	37
Exchange and other services revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	123	136	365	399
Exchange and other services revenues | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	28	28	85	90
Exchange and other services revenues | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	45	61	145	192
Management and exchange
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	176	238	548	708
Management and exchange | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	82	120	267	369
Management and exchange | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	49	74	160	232
Rental
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	56	135	209	432
Rental | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	46	122	180	384
Rental | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	10	14	29	48
Cost reimbursements
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements	255		767
Revenue from contracts with customers	255	280	767	819
Cost reimbursements | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements	281		824
Cost reimbursements | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements	12		45
Corporate and Other
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements		(28)		(84)
Revenue from contracts with customers	7	15	19	23
Financing	0	0	0	0
Revenues	7	15	19	23
Corporate and Other | Vacation ownership products
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	0	0	0	0
Corporate and Other | Ancillary revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	0	0	0	0
Corporate and Other | Management fee revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	(5)	(3)	(14)	(10)
Corporate and Other | Exchange and other services revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	50	47	135	117
Corporate and Other | Management and exchange
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	45	44	121	107
Corporate and Other | Rental
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	0	$ (1)	0	$ 0
Corporate and Other | Cost reimbursements
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements	$ (38)		$ (102)