INVENTORY - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Inventory Disclosure [Abstract]
Real estate inventory, increase (decrease) true up (less than)		$ 4	$ 2
Inventory impairment	$ (1)	(6)
Amount of completed vacation ownership units classified as property and equipment	173	173
Deposits on future purchases of inventory	$ 42	$ 42		$ 38