VACATION OWNERSHIP NOTES RECEIVABLE - Legacy-ILG Vacation Ownership Notes Receivable, Brand and FICO score (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	$ 454	$ 439
Acquired | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	181	177
Acquired | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	239	230
Acquired | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	28	26
Acquired | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	6	6
Acquired | 700
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	223	216
Acquired | 700 | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	105	103
Acquired | 700 | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	99	95
Acquired | 700 | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	16	15
Acquired | 700 | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	3	3
Acquired | 600 - 699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	156	151
Acquired | 600 - 699 | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	58	57
Acquired | 600 - 699 | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	87	83
Acquired | 600 - 699 | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	10	10
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	22	20
Acquired | 600 | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	5	4
Acquired | 600 | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	16	15
Acquired | 600 | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	1	1
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	53	52
Acquired | No Score | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	13	13
Acquired | No Score | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	37	37
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	2
Legacy-ILG | Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	464	428
Legacy-ILG | Originated | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	211	198
Legacy-ILG | Originated | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	229	208
Legacy-ILG | Originated | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	24	22
Legacy-ILG | Originated | 700
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	246	235
Legacy-ILG | Originated | 700 | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	126	122
Legacy-ILG | Originated | 700 | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	103	97
Legacy-ILG | Originated | 700 | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	17	16
Legacy-ILG | Originated | 600 - 699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	126	113
Legacy-ILG | Originated | 600 - 699 | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	52	46
Legacy-ILG | Originated | 600 - 699 | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	67	61
Legacy-ILG | Originated | 600 - 699 | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	7	6
Legacy-ILG | Originated | 600
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	20	18
Legacy-ILG | Originated | 600 | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	6	5
Legacy-ILG | Originated | 600 | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	14	13
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	72	62
Legacy-ILG | Originated | No Score | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	27	25
Legacy-ILG | Originated | No Score | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	45	37
Legacy-ILG | Originated | No Score | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Vacation ownership notes receivable	$ 0	$ 0