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) - Cash Flow Hedging - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Derivatives designated as hedges | Cross currency swap | Interest
Derivative Instruments Gain Loss [Line Items]
Gain (Loss) Recognized in Income	$ (2)	$ (8)	$ (53)	$ (9)
Derivatives not designated as hedges | Foreign exchange contracts | Cost of revenue
Derivative Instruments Gain Loss [Line Items]
Gain (Loss) Recognized in Income	$ (48)	$ (8)	$ (109)	$ 5