FINANCIAL INSTRUMENTS - Carrying Values and Estimated Fair Values - Non-securitized Notes Receivable (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	$ 2,159	$ 2,233
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	2,224	2,264
Securitized Vacation Ownership Notes Receivable | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	1,822	1,750
Securitized Vacation Ownership Notes Receivable | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	1,875	1,771
Non-Securitized Vacation Ownership Notes Receivable | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	337	483
Non-Securitized Vacation Ownership Notes Receivable | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	349	493
Non-Securitized Vacation Ownership Notes Receivable | Eligible for securitization | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	77	165
Non-Securitized Vacation Ownership Notes Receivable | Eligible for securitization | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	89	175
Non-Securitized Vacation Ownership Notes Receivable | Not eligible for securitization | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	260	318
Non-Securitized Vacation Ownership Notes Receivable | Not eligible for securitization | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	$ 260	$ 318