FINANCIAL INSTRUMENTS - Carrying Values and Estimated Fair Values - Non-securitized Notes Receivable (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	$ 2,014	$ 2,233
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	2,066	2,264
Securitized Vacation Ownership Notes Receivable | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	1,797	1,750
Securitized Vacation Ownership Notes Receivable | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	1,841	1,771
Non-Securitized | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	217	483
Non-Securitized | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	225	493
Non-Securitized | Eligible for securitization | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	35	165
Non-Securitized | Eligible for securitization | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	43	175
Non-Securitized | Not eligible for securitization | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	182	318
Non-Securitized | Not eligible for securitization | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Vacation ownership notes receivable	$ 182	$ 318