Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) on minority equity investments, net				$ (195,000,000)	$ 12,000,000
Net gains (losses) from foreign currency forward contracts	$ (6,000,000)		$ (6,000,000)	100,000,000	(12,000,000)
Impairment of goodwill	20,000,000		0	785,000,000	0
Goodwill	7,330,000,000			7,330,000,000		$ 8,127,000,000
Impairment of intangible assets	10,000,000		$ 0	131,000,000	0
Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of goodwill		$ 765,000,000
Impairment of intangible assets	10,000,000	121,000,000
Carrying value of cost method investments	331,000,000			331,000,000		467,000,000
Impairment losses related to a minority investment	21,000,000			134,000,000
Total cumulative adjustments made to the initial costs bases of investments	103,000,000			103,000,000
Nonrecurring Basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Indefinite-lived intangible assets (excluding goodwill), fair value disclosure	237,000,000			237,000,000
Nonrecurring Basis | Retail
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of goodwill	20,000,000	539,000,000
Goodwill	2,200,000,000			2,200,000,000
Nonrecurring Basis | trivago
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of goodwill		$ 226,000,000
Goodwill	315,000,000			315,000,000
Foreign currency forward contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amount of foreign currency derivatives	2,400,000,000			2,400,000,000
Net forward asset	12,000,000			12,000,000
Gross forward asset	$ 37,000,000			37,000,000
Net forward liability						8,000,000
Gross forward liability						$ 30,000,000
Despegar.com
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) on minority equity investments, net				$ (60,000,000)	$ 14,000,000