Fair Value Measurements - Additional Information (Details) $ in Millions	3 Months Ended				12 Months Ended
	Dec. 31, 2024 USD ($)	Sep. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Mar. 02, 2022 EUR (€) instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	$ 300		$ 28		$ 300	$ 28
Long term investments available for sale	$ 202				$ 202
Maturity term	4 years				4 years
Unrealized gain (loss) on investments					$ 1
Net gains (losses) from foreign currency forward contracts					(33)	(24)	$ (66)
Gains (losses) on minority equity investments, net					289	16	(345)
Impairment of goodwill					$ 0	$ 297	0
Impairment, Intangible Asset, Indefinite-Lived (Excluding Goodwill), Statement of Income or Comprehensive Income [Extensible Enumeration]					Impairment of intangible assets	Impairment of intangible assets
Impairment of intangible assets					$ 147	$ 129	81
Carrying value of cost method investments	$ 293		$ 330		293	$ 330
Proceeds from minority investment					15
Gain on the transaction					0
Cumulative unrealized downward adjustments	$ 127				$ 127
Measurement Input, Projected Revenues And Royalty Rates | Fair Value, Inputs, Level 3 | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Intangible assets, indefinite-lived (excluding goodwill), measurement input	0.025		0.03		0.025	0.03
Measurement Input, Projected Revenues And Royalty Rates | Fair Value, Inputs, Level 3 | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Intangible assets, indefinite-lived (excluding goodwill), measurement input	0.04		0.04		0.04	0.04
Trade Names
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of indefinite-lived intangible assets					$ 147	$ 129
Trivago
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of goodwill						297
Trivago | Trade Names
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of indefinite-lived intangible assets		$ 33		$ 15		15	81
B2C
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of goodwill						0
B2C | Trade Names
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of indefinite-lived intangible assets	$ 114		$ 114			114
Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment losses related to a minority investment					$ 22	$ 0	0
Global Business Travel Group
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity interest maintained					16.00%	16.00%
Despegar.com Corp.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gains (losses) on minority equity investments, net					$ 94	$ 42	(45)
Global Business Travel Group | Equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gains (losses) on minority equity investments, net					217	(26)	$ (300)
Foreign currency forward contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amount of derivatives	3,900				3,900
Foreign currency forward contracts, liability	2		9		2	9
Gross forward liability	42		28		42	28
Cross-currency interest rate swaps | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amount of derivatives | €								€ 300,000,000
Fixed-to fixed cross currency interest rate swaps entered into | instrument								2
Fair value of derivative, asset	$ 25		$ 8		25	8
Gain on derivative recognized in interest expense					$ 5	$ 5