Derivative Instruments - Effect of Derivative Contracts on Condensed Consolidated Financial Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Foreign Exchange Contract
Derivative Instruments, Gain (Loss)
Gain (loss) recognized from derivative contracts in the consolidated statement of income	$ 70	$ 10	$ 2
Designated as Hedging Instrument | Cost Of Revenues And Operating Expenses | Cash Flow Hedging | Foreign Exchange Contract
Derivative Instruments, Gain (Loss)
Gain (loss) recognized from derivative contracts in the consolidated statement of income	71	0	(9)
Designated as Hedging Instrument | Interest and Other, Net | Fair Value Hedging | Interest Rate Contract
Derivative Instruments, Gain (Loss)
Gain (loss) recognized from derivative contracts in the consolidated statement of income	0	0	0
Gain (loss) from interest rate contracts designated as fair value hedges recognized in interest and other, net	19	22	0
Gain (loss) from hedged items attributable to hedged risk recognized in interest and other, net	(19)	(22)	0
Not Designated as Hedging Instrument | Interest and Other, Net | Foreign Exchange Contract
Derivative Instruments, Gain (Loss)
Gain (loss) recognized from derivative contracts in the consolidated statement of income	$ (1)	$ 10	$ 11