Derivative Instruments - Impact on Statements of Income, Fair Value Hedges (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Gains/(losses) recorded in income
Derivatives	$ 1,248	$ 3,281	$ 736
Hedged items	142	(1,897)	412
Income statement impact	1,390	1,384	1,148
Income statement impact of excluded components
Amortization approach	(457)	(866)	(566)
Changes in fair value	1,404	1,373	1,125
OCI impact
Derivatives - Gains/(losses) recorded in OCI	25	39	(140)
Interest rate
Gains/(losses) recorded in income
Derivatives	2,962	3,204	(1,145)
Hedged items	(1,889)	(2,373)	1,782
Income statement impact	1,073	831	637
Income statement impact of excluded components
Amortization approach	0	0	0
Changes in fair value	1,093	828	623
OCI impact
Derivatives - Gains/(losses) recorded in OCI	0	0	0
Foreign exchange
Gains/(losses) recorded in income
Derivatives	793	154	1,092
Hedged items	(619)	328	(616)
Income statement impact	174	482	476
Income statement impact of excluded components
Amortization approach	(457)	(866)	(566)
Changes in fair value	174	482	476
OCI impact
Derivatives - Gains/(losses) recorded in OCI	25	39	(140)
Commodity
Gains/(losses) recorded in income
Derivatives	(2,507)	(77)	789
Hedged items	2,650	148	(754)
Income statement impact	143	71	35
Income statement impact of excluded components
Amortization approach	0	0	0
Changes in fair value	137	63	26
OCI impact
Derivatives - Gains/(losses) recorded in OCI	$ 0	$ 0	$ 0

Gain (Loss) from Components Excluded from Assessment of Fair Value Hedge Effectiveness, Amortization Method, Net

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Gain (Loss) from Components Excluded from Assessment of Fair Value Hedge Effectiveness, Changes in Fair Value, Net

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Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

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Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

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Total amount of gain (loss) derived from fair value hedges recognized in earnings in the period.

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Amount, before tax and adjustments, of gain (loss) from increase (decrease) in value of excluded component of derivative designated and qualifying as hedge. Adjustments include, but are not limited to, reclassifications for sale and settlement, and amounts recognized under systematic and rational method.

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