VACATION OWNERSHIP NOTES RECEIVABLE - Legacy-ILG Vacation Ownership Notes Receivable, Brand and FICO score (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	$ 425	$ 439
Acquired | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	170	177
Acquired | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	224	230
Acquired | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	25	26
Acquired | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	6	6
Acquired | 700 +
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	207	216
Acquired | 700 + | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	98	103
Acquired | 700 + | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	92	95
Acquired | 700 + | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	14	15
Acquired | 700 + | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	3	3
Acquired | 600 - 699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	148	151
Acquired | 600 - 699 | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	55	57
Acquired | 600 - 699 | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	82	83
Acquired | 600 - 699 | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	10	10
Acquired | 600 - 699 | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	1	1
Acquired | (less than) 600
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	20	20
Acquired | (less than) 600 | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	4	4
Acquired | (less than) 600 | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	15	15
Acquired | (less than) 600 | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	1	1
Acquired | (less than) 600 | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	0	0
Acquired | No Score
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	50	52
Acquired | No Score | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	13	13
Acquired | No Score | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	35	37
Acquired | No Score | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	0	0
Acquired | No Score | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	2	2
Legacy-ILG
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	854	867
Legacy-ILG | Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	429	428
Legacy-ILG | Originated | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	186	198
Legacy-ILG | Originated | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	221	208
Legacy-ILG | Originated | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	22	22
Legacy-ILG | Originated | 700 +
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	222	235
Legacy-ILG | Originated | 700 + | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	110	122
Legacy-ILG | Originated | 700 + | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	97	97
Legacy-ILG | Originated | 700 + | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	15	16
Legacy-ILG | Originated | 600 - 699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	124	113
Legacy-ILG | Originated | 600 - 699 | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	50	46
Legacy-ILG | Originated | 600 - 699 | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	67	61
Legacy-ILG | Originated | 600 - 699 | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	7	6
Legacy-ILG | Originated | (less than) 600
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	20	18
Legacy-ILG | Originated | (less than) 600 | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	6	5
Legacy-ILG | Originated | (less than) 600 | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	14	13
Legacy-ILG | Originated | (less than) 600 | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	0	0
Legacy-ILG | Originated | No Score
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	63	62
Legacy-ILG | Originated | No Score | Westin
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	20	25
Legacy-ILG | Originated | No Score | Sheraton
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	43	37
Legacy-ILG | Originated | No Score | Hyatt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total vacation ownership notes receivable	$ 0	$ 0