VACATION OWNERSHIP NOTES RECEIVABLE - Additional Information (Details) $ in Millions		3 Months Ended		9 Months Ended
	Jan. 01, 2020 USD ($)	Sep. 30, 2020 USD ($) credit_score	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) credit_score	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) credit_score
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit loss, percentage increase		50.00%		50.00%
Allowance for credit loss, percentage increase, period				15 months
Allowance, purchased with credit deterioration, increase	$ 2
Notes receivable estimated average remaining default rates		7.35%		7.35%		7.04%
Estimated default rate increases that would have resulted an increase in allowance for credit losses		0.50%		0.50%
Financing receivable, allowance for credit losses, that would have been increased		$ 7		$ 7		$ 8
Average estimated rate of default for all outstanding loans		14.71%		14.71%		12.65%
Weighted average FICO score within originated loan pool | credit_score		708		708		712
Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase in vacation ownership notes receivable reserve				$ (97)
Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase in vacation ownership notes receivable reserve				$ (14)
Estimated default rate increases that would have resulted an increase in allowance for credit losses		0.50%		0.50%
Financing receivable, allowance for credit losses, that would have been increased		$ 3		$ 3		$ 2
COVID-19 pandemic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit loss, period increase		52
COVID-19 pandemic | Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase in vacation ownership notes receivable reserve				(42)
COVID-19 pandemic | Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase in vacation ownership notes receivable reserve				(10)
Vacation ownership products
Accounts, Notes, Loans and Financing Receivable [Line Items]
Expenses		$ (27)	$ (89)	(110)	$ (258)
Vacation ownership products | COVID-19 pandemic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Expenses				$ 15