Derivative Instruments - Impact on Statements of Income, Cash Flow Hedges (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Gains/(losses) recorded in income and other comprehensive income/(loss)
Net losses reclassified from AOCI to other income		$ 150
Recognition of gain (loss) related to cash flow hedges in Income				$ 64
Cash Flow Hedges Status, Terminated [Member]
Gains/(losses) recorded in income and other comprehensive income/(loss)
Maximum length of time hedged in forecasted transactions				9 years
Cash Flow Hedges Status, Open [Member]
Gains/(losses) recorded in income and other comprehensive income/(loss)
Maximum length of time hedged in forecasted transactions				3 years
Cash Flow Hedging
Gains/(losses) recorded in income and other comprehensive income/(loss)
Derivatives - effective portion reclassified from AOCI to income	$ (7)		$ 29	$ (182)	$ 2
Hedge ineffectiveness recorded directly in income	0		0	0	0
Total income statement impact	(7)		29	(182)	2
Effective portion recorded in OCI	120		143	71	215
Total change in OCI for period	127		114	253	213
Cash Flow Hedging | Interest rate contracts
Gains/(losses) recorded in income and other comprehensive income/(loss)
Derivatives - effective portion reclassified from AOCI to income	22		(10)	(127)	(36)
Hedge ineffectiveness recorded directly in income	0		0	0	0
Total income statement impact	22		(10)	(127)	(36)
Effective portion recorded in OCI	(23)		71	(20)	134
Total change in OCI for period	(45)		81	107	170
Cash Flow Hedging | Foreign exchange contracts
Gains/(losses) recorded in income and other comprehensive income/(loss)
Derivatives - effective portion reclassified from AOCI to income	(29)		39	(55)	38
Hedge ineffectiveness recorded directly in income	0		0	0	0
Total income statement impact	(29)		39	(55)	38
Effective portion recorded in OCI	143		72	91	81
Total change in OCI for period	$ 172		$ 33	$ 146	$ 43