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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Derivatives designated as hedges | Cross currency swap | Interest
Derivative Instruments Gain Loss [Line Items]
Gain (Loss) Recognized in Income (Loss)	$ 29	$ (6)	$ 47	$ 4
Derivatives not designated as hedges | Foreign exchange contracts | Cost of services/sales
Derivative Instruments Gain Loss [Line Items]
Gain (Loss) Recognized in Income (Loss)	$ 1	$ (57)	$ 7	$ (138)