Derivative Instruments - Effect of Derivative Contracts on Condensed Consolidated Statement of Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Foreign Exchange Contract
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized from derivative contracts in the condensed consolidated statement of income	$ (17)	$ 11	$ (47)	$ 27
Foreign Exchange Contract | Revenues | Designated as Hedging Instrument | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized from derivative contracts in the condensed consolidated statement of income	(21)	0	(49)	0
Foreign Exchange Contract | Cost of Net Revenues and Operating Expenses | Designated as Hedging Instrument | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized from derivative contracts in the condensed consolidated statement of income	0	4	0	11
Foreign Exchange Contract | Interest and Other, Net | Designated as Hedging Instrument | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized from derivative contracts in the condensed consolidated statement of income	0	11	0	24
Foreign Exchange Contract | Interest and Other, Net | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized from derivative contracts in the condensed consolidated statement of income	4	(4)	2	(8)
Interest Rate Contract | Interest and Other, Net | Designated as Hedging Instrument | Fair Value Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) from interest rate contracts designated as fair value hedges recognized in interest and other, net	(9)	8	(39)	1
Gain (loss) from hedged items attributable to hedged risk recognized in interest and other, net	9	(8)	39	(1)
Gain (loss) recognized from derivative contracts in the condensed consolidated statement of income	0	0	0	0
Warrant | Interest and Other, Net
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) from hedged items attributable to hedged risk recognized in interest and other, net	$ 106	$ 0	$ 106	$ 0