VACATION OWNERSHIP NOTES RECEIVABLE - Notes Receivable Reserves (Details) $ in Millions	6 Months Ended
	Jun. 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	81
Securitizations	0
Write-offs	(25)
Defaulted vacation ownership notes receivable repurchase activity	0
Ending balance	260
Acquired
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Beginning balance	55
Increase in vacation ownership notes receivable reserve	14
Securitizations	0
Write-offs	(16)
Time sharing transactions direct recoveries charged against allowance	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	41
Securitizations	(33)
Write-offs	(25)
Defaulted vacation ownership notes receivable repurchase activity	37
Ending balance	110
Non-Securitized | Acquired
Time Sharing Transactions, Allowance for Uncollectible Accounts [Roll Forward]
Beginning balance	29
Increase in vacation ownership notes receivable reserve	8
Securitizations	(1)
Write-offs	(16)
Time sharing transactions direct recoveries charged against allowance	8
Ending balance	28
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	40
Securitizations	33
Write-offs	0
Defaulted vacation ownership notes receivable repurchase activity	(37)
Ending balance	150
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	6
Securitizations	1
Write-offs	0
Time sharing transactions direct recoveries charged against allowance	0
Ending balance	33
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