REVENUE - Timing of Revenue from Contracts 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
Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	837	838
Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	106	123
Services transferred over time
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	579	553
Services transferred over time | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	530	489
Services transferred over time | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	54	59
Goods or services transferred at a point in time
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	359	413
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	307	349
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	52	64
Corporate and other
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	(5)	5
Corporate and other | Services transferred over time
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	(5)	5
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