REVENUE - Loyalty and Other Incentive Programs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Revenues	$ 10,958	$ 6,796	$ 15,066
Loyalty incentive programs | OpenTable
Disaggregation of Revenue [Line Items]
Decrease in liability balance with a corresponding increase to revenue		28
Loyalty incentive programs | Accrued expenses and other current liabilities
Disaggregation of Revenue [Line Items]
Liabilities for loyalty program incentives	13	21
Other incentive programs | Accrued expenses and other current liabilities
Disaggregation of Revenue [Line Items]
Liabilities for loyalty program incentives	$ 58	60
Other incentive programs - additional rebates | Booking.com
Disaggregation of Revenue [Line Items]
Liabilities for loyalty program incentives		25
Revenues		$ (100)