Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended				9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 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					$ (202,000,000)	$ (13,000,000)
Net gains (losses) from foreign currency forward contracts	$ (1,000,000)			$ 15,000,000	99,000,000	3,000,000
Impairment of goodwill	14,000,000			0	799,000,000	0
Goodwill	7,343,000,000				7,343,000,000		$ 8,127,000,000
Impairment of intangible assets	41,000,000			$ 0	172,000,000	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					134,000,000
Total cumulative adjustments made to the initial costs bases of investments	103,000,000				103,000,000
Nonrecurring Basis | Retail
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of goodwill		$ 20,000,000			559,000,000
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	14,000,000				240,000,000
Goodwill	322,000,000				322,000,000
Foreign currency forward contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amount of foreign currency derivatives	1,300,000,000				1,300,000,000
Net forward asset	2,000,000				2,000,000
Gross forward asset	$ 13,000,000				13,000,000
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					$ (68,000,000)	$ (10,000,000)