FINANCIAL INSTRUMENTS - Carrying Values and Estimated Fair Values - Non-securitized Notes Receivable (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	$ 2,026	$ 1,840
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	2,084	1,886
Securitized | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	1,486	1,493
Securitized | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	1,532	1,530
Non-Securitized | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	540	347
Non-Securitized | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	552	356
Non-Securitized | Eligible for securitization | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	244	128
Non-Securitized | Eligible for securitization | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	256	137
Non-Securitized | Not eligible for securitization | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	296	219
Non-Securitized | Not eligible for securitization | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	$ 296	$ 219