REVENUE AND RECEIVABLES - Timing of Revenue from Contracts with Customers (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]
Revenue from contracts with customers	$ 410	$ 974	$ 1,348	$ 1,940
Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	336	856	1,173	1,694
Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	57	115	163	238
Services transferred over time
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	322	510	901	1,055
Services transferred over time | Vacation Ownership
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	275	455	805	937
Services transferred over time | Exchange & Third-Party Management
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	30	52	84	110
Goods or services transferred at a point in time
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	88	464	447	885
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	61	401	368	757
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	27	63	79	128
Corporate and Other
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	17	3	12	8
Corporate and Other | Services transferred over time
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers	17	3	12	8
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