Derivative Instruments - Effect of Derivative Contracts on Condensed Consolidated Statements of Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Total amounts presented in the condensed consolidated statements of income in which the effects of cash flow hedges are recorded	$ 5,261	$ 4,305	$ 9,879	$ 8,433
Designated as Hedging Instrument | Cash Flow Hedging | Foreign Exchange Contract | Net Revenues
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses) recognized from foreign exchange contracts not designated as hedging instruments	33	58	75	110
Not Designated as Hedging Instrument | Foreign Exchange Contract | Other Income (Expense)
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses) recognized from foreign exchange contracts not designated as hedging instruments	$ (5)	$ 9	$ 32	$ (1)