ACQUISITIONS AND DISPOSITIONS - Additional Information (Details) $ in Millions	1 Months Ended	3 Months Ended			9 Months Ended
	Dec. 31, 2019 USD ($)	Sep. 30, 2020 USD ($)	Mar. 31, 2020 USD ($) vacation_ownership_unit	Sep. 30, 2019 USD ($) vacation_ownership_unit	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($) vacation_ownership_unit
Business Acquisition [Line Items]
Purchase of vacation ownership units					$ 61	$ 0
(Losses) gains and other (expense) income, net		$ 0		$ (5)	(42)	5
Dispositions, net					15	$ 0
Note receivable (less than)		1			$ 1
Joint Venture
Business Acquisition [Line Items]
(Losses) gains and other (expense) income, net		(5)
Land
Business Acquisition [Line Items]
(Losses) gains and other (expense) income, net		6
Dispositions, net		$ 15
New York City, New York
Business Acquisition [Line Items]
Number of vacation ownership units acquired | vacation_ownership_unit			57
Asset acquisition, consideration transferred			$ 89
Purchase of vacation ownership units	$ 20		22
Asset acquisition, recognized identifiable assets acquired, inventory			22
Asset acquisition, recognized identifiable assets acquired, property and equipment			$ 67
San Francisco, California
Business Acquisition [Line Items]
Number of vacation ownership units acquired | vacation_ownership_unit			34	78		78
Asset acquisition, consideration transferred			$ 26	$ 58
Purchase of vacation ownership units			5
Asset acquisition, recognized identifiable assets acquired, inventory			18	48		$ 48
Asset acquisition, recognized identifiable assets acquired, other assets			5
Asset acquisition, recognized identifiable assets acquired, property and equipment			$ 3	$ 10		$ 10