REVENUE - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation of Revenue [Line Items]
Revenues	$ 4,294	$ 2,160	$ 6,989	$ 3,301
Online accommodation reservation services \| Revenue Benchmark \| Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk percentage	88.00%	83.00%	87.00%	84.00%
Other sources of online travel reservation services and advertising and other revenues \| Revenue Benchmark \| Product Concentration Risk \| Maximum
Disaggregation of Revenue [Line Items]
Concentration risk percentage	10.00%	10.00%	10.00%	10.00%
United States
Disaggregation of Revenue [Line Items]
Revenues	$ 594	$ 393	$ 1,069	$ 590
The Netherlands
Disaggregation of Revenue [Line Items]
Revenues	3,340	1,601	5,309	2,412
Other
Disaggregation of Revenue [Line Items]
Revenues	$ 360	$ 166	$ 611	$ 299

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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Name:	us-gaap_Revenues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration