COMMITMENTS AND CONTINGENCIES - Guarantees (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings	$ 299
Recorded Liability for Guarantees	151
Debt service
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings	53
Recorded Liability for Guarantees	6
Operating profit
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings	231
Recorded Liability for Guarantees	142
Other
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings	15
Recorded Liability for Guarantees	3
Sheraton Grand Chicago Hotel
Commitments and Contingencies Disclosure [Line Items]
Recorded Liability for Guarantees	57
Sheraton Grand Chicago Hotel | Land and Hotel
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings	300
Sheraton Grand Chicago Hotel | Land
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings	200
Not Yet In Effect Condition | Debt service
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings	3
Not Yet In Effect Condition | Operating profit
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings	114
Not Yet In Effect Condition | Other
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings	5
Accrued Expenses and Other
Commitments and Contingencies Disclosure [Line Items]
Recorded Liability for Guarantees	16
Other noncurrent liabilities
Commitments and Contingencies Disclosure [Line Items]
Recorded Liability for Guarantees	$ 135
Minimum
Commitments and Contingencies Disclosure [Line Items]
Guarantee obligations, term	3 years
Maximum
Commitments and Contingencies Disclosure [Line Items]
Guarantee obligations, term	10 years