Acquisitions - Additional Information (Detail) (USD $)	Dec. 31, 2011	Aug. 31, 2011 Motorola Mobility Holdings, Inc.	Apr. 30, 2011 ITA Software, Inc	Dec. 31, 2011 Total Other Acquisitions
Business Acquisition [Line Items]
Purchase price of acquisition			$ 676,000,000	$ 1,300,000,000
Business acquisition, acquired intangible assets			394,000,000	795,000,000
Business acquisition, goodwil			323,000,000	593,000,000
Business acquisition, net liabilities assumed			41,000,000	86,000,000
Amount of goodwill expected to be deductible for tax purposes	29,000,000
Merger agreement, value per share		$ 40
Merger agreement, value		12,500,000,000
Merger agreement, potential termination fee		$ 2,500,000,000