REVENUE AND RECEIVABLES (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements		$ 252		$ 539
Revenue from contracts with customers	$ 410	974	$ 1,348	1,940
Financing	70	69	142	137
Total Revenues	480	1,043	1,490	2,077
Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements		258		549
Revenue from contracts with customers	336	856	1,173	1,694
Financing	69	68	140	135
Total Revenues	405	924	1,313	1,829
Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements		22		46
Revenue from contracts with customers	57	115	163	238
Financing	1	1	2	2
Total Revenues	58	116	165	240
Sale of vacation ownership products
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	53	341	311	634
Sale of vacation ownership products | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	53	341	311	634
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	0	0
Ancillary revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	6	58	53	116
Ancillary revenues | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	6	57	52	114
Ancillary revenues | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	0	1	1	2
Management fee revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	33	44	77	91
Management fee revenues | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	38	37	76	73
Management fee revenues | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	0	10	10	25
Exchange and other services revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	106	129	242	263
Exchange and other services revenues | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	29	30	57	62
Exchange and other services revenues | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	39	65	100	131
Management and exchange
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	145	231	372	470
Management and exchange | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	73	124	185	249
Management and exchange | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	39	76	111	158
Rental
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	18	150	153	297
Rental | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	12	133	134	262
Rental | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	6	17	19	34
Cost reimbursements
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements	194		512
Revenue from contracts with customers	194	252	512	539
Cost reimbursements | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements	198		543
Cost reimbursements | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements	12		33
Corporate and Other
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements		(28)		(56)
Revenue from contracts with customers	17	3	12	8
Financing	0	0	0	0
Total Revenues	17	3	12	8
Corporate and Other | Sale of 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)	(9)	(7)
Corporate and Other | Exchange and other services revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	38	34	85	70
Corporate and Other | Management and exchange
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	33	31	76	63
Corporate and Other | Rental
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	0	$ 0	0	$ 1
Corporate and Other | Cost reimbursements
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost reimbursements	$ (16)		$ (64)