Derivative Instruments and Hedging Activities - Effect of Derivative Instruments Designated as Fair Value Hedges and Not Designated as Hedges on Consolidated Statement of Income (Loss) (Detail) - Cash Flow Hedging - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivatives designated as hedges | Cross currency swap | Interest
Derivative Instruments Gain Loss [Line Items]
Gain (Loss) Recognized in Income (Loss)	$ 19	$ 5	$ 66	$ 9
Derivatives not designated as hedges | Foreign exchange contracts | Cost of services/sales
Derivative Instruments Gain Loss [Line Items]
Gain (Loss) Recognized in Income (Loss)	$ (10)	$ (28)	$ (3)	$ (166)