Segment Information - Schedule of Revenue by Services (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2025	Mar. 31, 2024
Segment Reporting Information [Line Items]
Revenue	$ 2,988	$ 2,889
Lodging
Segment Reporting Information [Line Items]
Revenue	2,289	2,228
Air
Segment Reporting Information [Line Items]
Revenue	107	115
Advertising and media - EG
Segment Reporting Information [Line Items]
Revenue	174	145
Advertising and media - trivago
Segment Reporting Information [Line Items]
Revenue	85	70
Other
Segment Reporting Information [Line Items]
Revenue	333	331
Merchant \| Sales Channel, Through Intermediary
Segment Reporting Information [Line Items]
Revenue	2,046	1,964
Agency \| Sales Channel, Through Intermediary
Segment Reporting Information [Line Items]
Revenue	652	678
Advertising, media and other \| Sales Channel, Through Intermediary
Segment Reporting Information [Line Items]
Revenue	$ 290	$ 247

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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