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, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Derivatives designated as hedges | Cross currency swap | Interest expense
Derivative Instruments Gain Loss [Line Items]
Gain (Loss) Recognized in Income	$ (70)	$ (1)
Derivatives not designated as hedges | Foreign exchange contracts | Cost of revenue
Derivative Instruments Gain Loss [Line Items]
Gain (Loss) Recognized in Income	$ (118)	$ 13