Components of Interest and Other Income net (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Component of Other Income, Nonoperating [Line Items]
Interest income	$ 713	$ 812	$ 579
Interest expense	(84)	(58)	(5)
Realized gains on available-for-sale investments, net	282	254	185
Impairment of equity investments	0	(110)	0
Foreign currency exchange losses	(531)	(379)	(355)
Gain on divestiture of business	188	0	0
Other	58	65	11
Interest and other income, net	$ 626	$ 584	$ 415