VACATION OWNERSHIP NOTES RECEIVABLE - Notes Receivable Reserves (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020 USD ($)
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Impact of adoption of ASU 2016-02	us-gaap:AccountingStandardsUpdate201602Member
Originated
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Beginning balance	$ 204
Increase in vacation ownership notes receivable reserve	97
Securitizations	0
Clean-up call	0
Write-offs	(27)
Financing Receivable, Allowance for Credit Losses, Repurchase Activity	0
Ending balance	274
Acquired
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Beginning balance	55
Increase in vacation ownership notes receivable reserve	14
Securitizations	0
Clean-up call	0
Write-offs	(16)
Recoveries	8
Ending balance	61
Acquired | Previously Reported
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Beginning balance	0
Acquired | Revision of Prior Period, Accounting Standards Update, Adjustment
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Beginning balance	55
Non-Securitized | Originated
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Beginning balance	90
Increase in vacation ownership notes receivable reserve	49
Securitizations	(70)
Clean-up call	37
Write-offs	(27)
Financing Receivable, Allowance for Credit Losses, Repurchase Activity	72
Ending balance	151
Non-Securitized | Acquired
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Beginning balance	29
Increase in vacation ownership notes receivable reserve	14
Securitizations	(1)
Clean-up call	1
Write-offs	(16)
Recoveries	8
Ending balance	35
Non-Securitized | Acquired | Previously Reported
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Beginning balance	0
Non-Securitized | Acquired | Revision of Prior Period, Accounting Standards Update, Adjustment
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Beginning balance	29
Securitized Vacation Ownership Notes Receivable | Originated
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Beginning balance	114
Increase in vacation ownership notes receivable reserve	48
Securitizations	70
Clean-up call	(37)
Write-offs	0
Financing Receivable, Allowance for Credit Losses, Repurchase Activity	(72)
Ending balance	123
Securitized Vacation Ownership Notes Receivable | Acquired
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Beginning balance	26
Increase in vacation ownership notes receivable reserve	0
Securitizations	1
Clean-up call	(1)
Write-offs	0
Recoveries	0
Ending balance	26
Securitized Vacation Ownership Notes Receivable | Acquired | Previously Reported
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Beginning balance	0
Securitized Vacation Ownership Notes Receivable | Acquired | Revision of Prior Period, Accounting Standards Update, Adjustment
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Beginning balance	26
COVID-19 pandemic | Originated
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Increase in vacation ownership notes receivable reserve	42
COVID-19 pandemic | Acquired
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Increase in vacation ownership notes receivable reserve	10
COVID-19 pandemic | Non-Securitized | Originated
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Increase in vacation ownership notes receivable reserve	16
COVID-19 pandemic | Non-Securitized | Acquired
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Increase in vacation ownership notes receivable reserve	2
COVID-19 pandemic | Securitized Vacation Ownership Notes Receivable | Originated
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Increase in vacation ownership notes receivable reserve	26
COVID-19 pandemic | Securitized Vacation Ownership Notes Receivable | Acquired
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Increase in vacation ownership notes receivable reserve	$ 8