Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) on minority equity investments, net			$ 4,000,000	$ (195,000,000)
Net gains (losses) from foreign currency forward contracts	$ (43,000,000)	$ (6,000,000)	(24,000,000)	100,000,000
Impairment of goodwill	0	20,000,000	0	785,000,000
Goodwill	7,370,000,000		7,370,000,000		$ 7,380,000,000
Impairment of intangible assets	0	10,000,000	0	131,000,000
Carrying value of cost method investments	330,000,000		330,000,000		330,000,000
Cumulative unrealized upward adjustments	2,000,000		2,000,000
Cumulative unrealized downward adjustments	105,000,000		105,000,000
trivago
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill					337,000,000
Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, other-than-temporary impairments	0	$ 21,000,000	0	134,000,000
Nonrecurring Basis | Retail
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of goodwill				559,000,000
Goodwill					2,300,000,000
Nonrecurring Basis | trivago
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of goodwill				226,000,000
Foreign currency forward contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amount of foreign currency derivatives	2,200,000,000		2,200,000,000
Net forward liability	26,000,000		26,000,000		14,000,000
Gross forward liability	$ 37,000,000		37,000,000		$ 23,000,000
Despegar.com
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) on minority equity investments, net			$ 4,000,000	$ (60,000,000)