Derivative Instruments - Impact on Statements of Income, Fair Value Hedges (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Gains/(losses) recorded in income
Derivatives	$ (712)	$ (1,570)	$ (7,823)	$ 4,621
Hedged items	1,304	1,821	8,785	(3,937)
Income statement impact	592	251	962	684
Income statement impact of excluded components:
Amortization approach	(72)	(121)	(150)	(300)
Changes in fair value	573	283	1,039	634
OCI impact
Derivatives - Gains/(losses) recorded in OCI	(31)	21	(68)	136
Interest rate
Gains/(losses) recorded in income
Derivatives	2,184	464	(2,937)	4,551
Hedged items	(1,630)	(288)	3,816	(4,076)
Income statement impact	554	176	879	475
Income statement impact of excluded components:
Amortization approach	0	0	0	0
Changes in fair value	544	205	980	419
OCI impact
Derivatives - Gains/(losses) recorded in OCI	0	0	0	0
Foreign exchange
Gains/(losses) recorded in income
Derivatives	230	(304)	(499)	272
Hedged items	(221)	338	526	(150)
Income statement impact	9	34	27	122
Income statement impact of excluded components:
Amortization approach	(72)	(121)	(150)	(300)
Changes in fair value	9	34	27	122
OCI impact
Derivatives - Gains/(losses) recorded in OCI	(31)	21	(68)	136
Commodity
Gains/(losses) recorded in income
Derivatives	(3,126)	(1,730)	(4,387)	(202)
Hedged items	3,155	1,771	4,443	289
Income statement impact	29	41	56	87
Income statement impact of excluded components:
Amortization approach	0	0	0	0
Changes in fair value	20	44	32	93
OCI impact
Derivatives - Gains/(losses) recorded in OCI	$ 0	$ 0	$ 0	$ 0