REVENUE AND RECEIVABLES - Timing of Revenue from Contracts with Customers (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]
Revenue from contracts with customers	$ 585	$ 994	$ 1,933	$ 2,934
Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	507	869	1,680	2,563
Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	71	110	234	348
Services transferred over time
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	436	538	1,335	1,593
Services transferred over time | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	394	469	1,197	1,405
Services transferred over time | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	35	54	119	165
Goods or services transferred at a point in time
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	149	456	598	1,341
Goods or services transferred at a point in time | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	113	400	483	1,158
Goods or services transferred at a point in time | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	36	56	115	183
Corporate and Other
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	7	15	19	23
Corporate and Other | Services transferred over time
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	7	15	19	23
Corporate and Other | Goods or services transferred at a point in time
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	$ 0	$ 0	$ 0	$ 0