VACATION OWNERSHIP NOTES RECEIVABLE - Legacy-ILG Vacation Ownership Notes Receivable, Brand and FICO score (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	$ 487	$ 651
Acquired | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	196	263
Acquired | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	254	345
Acquired | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	30	35
Acquired | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	7	8
Acquired | 700
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	239	323
Acquired | 700 | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	113	154
Acquired | 700 | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	105	145
Acquired | 700 | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	17	20
Acquired | 700 | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	4	4
Acquired | 600 - 699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	167	220
Acquired | 600 - 699 | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	63	82
Acquired | 600 - 699 | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	92	124
Acquired | 600 - 699 | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	11	13
Acquired | 600 - 699 | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	1	1
Acquired | 600
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	23	29
Acquired | 600 | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	5	6
Acquired | 600 | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	17	21
Acquired | 600 | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	1	2
Acquired | 600 | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	0	0
Acquired | No Score
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	58	79
Acquired | No Score | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	15	21
Acquired | No Score | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	40	55
Acquired | No Score | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	1	0
Acquired | No Score | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	2	3
Legacy-ILG | Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	350	126
Legacy-ILG | Originated | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	162	62
Legacy-ILG | Originated | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	169	57
Legacy-ILG | Originated | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	19	7
Legacy-ILG | Originated | 700
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	193	76
Legacy-ILG | Originated | 700 | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	101	43
Legacy-ILG | Originated | 700 | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	79	28
Legacy-ILG | Originated | 700 | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	13	5
Legacy-ILG | Originated | 600 - 699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	96	30
Legacy-ILG | Originated | 600 - 699 | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	39	11
Legacy-ILG | Originated | 600 - 699 | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	51	17
Legacy-ILG | Originated | 600 - 699 | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	6	2
Legacy-ILG | Originated | 600
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	14	4
Legacy-ILG | Originated | 600 | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	4	1
Legacy-ILG | Originated | 600 | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	10	3
Legacy-ILG | Originated | 600 | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	0	0
Legacy-ILG | Originated | No Score
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	47	16
Legacy-ILG | Originated | No Score | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	18	7
Legacy-ILG | Originated | No Score | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	29	9
Legacy-ILG | Originated | No Score | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	$ 0	$ 0