GOODWILL AND INTANGIBLES - Goodwill (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2020
Goodwill [Roll Forward]
Balance at December 31, 2019	$ 2,817,000,000	$ 2,892,000,000	$ 2,892,000,000
Impairment	0	(73,000,000)
Foreign exchange adjustments	0	(2,000,000)
Balance at March 31, 2020	2,817,000,000	2,817,000,000	2,817,000,000
Vacation Ownership
Goodwill [Roll Forward]
Balance at December 31, 2019	2,445,000,000	2,445,000,000	2,445,000,000
Impairment	0	0	0
Foreign exchange adjustments	0	0
Balance at March 31, 2020	2,445,000,000	2,445,000,000	2,445,000,000
Exchange & Third-Party Management
Goodwill [Roll Forward]
Balance at December 31, 2019	372,000,000	447,000,000	447,000,000
Impairment	0	(73,000,000)
Foreign exchange adjustments	0	(2,000,000)
Balance at March 31, 2020	$ 372,000,000	$ 372,000,000	$ 372,000,000