Derivative Instruments - Impact on Statements of Income, Fair Value Hedges (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Gains/(losses) recorded in income
Derivatives	$ 7,221	$ 10,434	$ (4,080)
Hedged items	(6,237)	(9,188)	4,411
Total income statement impact	984	1,246	331
Income statement impact due to:
Hedge ineffectiveness	(10)	173	(94)
Excluded components	994	1,073	425
Interest rate
Gains/(losses) recorded in income
Derivatives	38	2,106	(3,469)
Hedged items	911	(801)	4,851
Total income statement impact	949	1,305	1,382
Income statement impact due to:
Hedge ineffectiveness	3	131	(132)
Excluded components	946	1,174	1,514
Foreign exchange
Gains/(losses) recorded in income
Derivatives	6,030	8,279	(1,096)
Hedged items	(6,006)	(8,532)	864
Total income statement impact	24	(253)	(232)
Income statement impact due to:
Hedge ineffectiveness	0	0	0
Excluded components	24	(253)	(232)
Commodity
Gains/(losses) recorded in income
Derivatives	1,153	49	485
Hedged items	(1,142)	145	(1,304)
Total income statement impact	11	194	(819)
Income statement impact due to:
Hedge ineffectiveness	(13)	42	38
Excluded components	$ 24	$ 152	$ (857)