Summary of Fair Value of Assets Acquired and Liabilities Assumed in Conjunction with Acquisition (Parenthetical) (Detail) - USD ($) $ in Millions			1 Months Ended	12 Months Ended
	Dec. 15, 2015	Sep. 17, 2015	Nov. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Minimum
Business Acquisition [Line Items]
Estimated useful lives of acquired intangible assets				1 year
Maximum
Business Acquisition [Line Items]
Estimated useful lives of acquired intangible assets				12 years
Home Away Inc
Business Acquisition [Line Items]
Business combination, accounts receivable gross	$ 25
Business combination, accounts receivable estimated to uncollectible	$ 1
Weighted average life of acquired intangible assets	5 years 8 months 23 days
Home Away Inc | Minimum
Business Acquisition [Line Items]
Estimated useful lives of acquired intangible assets	1 year
Home Away Inc | Maximum
Business Acquisition [Line Items]
Estimated useful lives of acquired intangible assets	12 years
Orbitz Worldwide, Inc.
Business Acquisition [Line Items]
Business combination, accounts receivable gross		$ 157
Business combination, accounts receivable estimated to uncollectible		$ 9
Weighted average life of acquired intangible assets		6 years 11 days
Orbitz Worldwide, Inc. | Minimum
Business Acquisition [Line Items]
Estimated useful lives of acquired intangible assets		1 year
Orbitz Worldwide, Inc. | Maximum
Business Acquisition [Line Items]
Estimated useful lives of acquired intangible assets		10 years
Other Acquisitions During Period
Business Acquisition [Line Items]
Weighted average life of acquired intangible assets				5 years 9 months 18 days	6 years 1 month 6 days
Business acquisition, cash acquired				$ 41
Equity method investment, non-cash consideration				$ 99
Other Acquisitions During Period | Minimum
Business Acquisition [Line Items]
Estimated useful lives of acquired intangible assets				4 years
Other Acquisitions During Period | Maximum
Business Acquisition [Line Items]
Estimated useful lives of acquired intangible assets				10 years
Wotif Group
Business Acquisition [Line Items]
Weighted average life of acquired intangible assets			7 years 9 months 18 days
Business acquisition, cash acquired			$ 36
Wotif Group | Minimum
Business Acquisition [Line Items]
Estimated useful lives of acquired intangible assets			1 year
Wotif Group | Maximum
Business Acquisition [Line Items]
Estimated useful lives of acquired intangible assets			10 years
Trivago
Business Acquisition [Line Items]
Weighted average life of acquired intangible assets						3 years 8 months 12 days
Business acquisition, cash acquired						$ 13
Trivago | Minimum
Business Acquisition [Line Items]
Estimated useful lives of acquired intangible assets						3 years
Trivago | Maximum
Business Acquisition [Line Items]
Estimated useful lives of acquired intangible assets						7 years