Derivative Instruments and Hedging Activities - Effect of Derivative Instruments Designated as Fair Value Hedges and Not Designated as Hedges on Consolidated Statement of Income (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income	$ (57)	$ 3	$ (56)	$ 15
Fair Value Hedging [Member] | Foreign exchange contracts [Member] | Cost of revenue [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income	(58)	1	(58)	8
Fair Value Hedging [Member] | Interest rate swaps [Member] | Interest expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income	1	2	2	7
Derivatives not designated as hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income	(22)	(17)	10	(4)
Derivatives not designated as hedges [Member] | Foreign exchange contracts [Member] | Cost of revenue [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income	(22)	(12)	10	3
Derivatives not designated as hedges [Member] | Commodity contracts [Member] | Cost of revenue [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income		$ (5)		$ (7)