Fair Value Measurements - Additional Information (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 EUR (€)	Aug. 31, 2025 EUR (€) instrument	Dec. 31, 2024 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	$ 344		$ 344				$ 300
Long-term investments	$ 276		$ 276				202
Debt securities, available-for-sale, term	5 years		5 years		5 years
Unrealized gains (losses) (less than)			$ 1	$ 1
Net gains (losses) from foreign currency forward contracts	$ (56)	$ 123	144	65
Gains (losses) on minority equity investments, net			(125)	121
Sales and maturities of investments			616	43
Impairment of intangible assets	0	$ 33	0	33
Carrying value of cost method investments	256		256				293
Proceeds from sale of minority investment				15
Gain on transaction				0
Cumulative unrealized downward adjustments	164		164
Fair Value, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment losses related to a minority investment			37
Global Business Travel Group
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gains (losses) on minority equity investments, net			(90)	93
Despegar.com Corp.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gains (losses) on minority equity investments, net			2	28
Sales and maturities of investments			187
Foreign currency forward contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amount of derivatives	5,200		5,200
Net forward liability	22		22				2
Gross forward liability	37		37				42
Cross-currency interest rate swaps | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain on derivative recognized in interest expense			1	$ 4
Cross Currency Interest Rate Contract, 2022 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
Cross Currency Interest Rate Contract, 2025 Swap | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amount of derivatives | €					€ 220,000,000	€ 220,000,000
Fair value of derivative, liability	$ 12		$ 12