Derivative Instruments and Other Financial Instruments Used For Hedging - Notional Amounts and Fair Value Amounts of Derivative Instruments (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Derivative Instruments and Other Financial Instruments
Notional Amount	$ 211,849		$ 241,444
Assets Derivatives	2,697		1,233
Liability Derivatives	1,185		523
Interest rate derivative contracts \| Not designated as hedging instruments
Derivative Instruments and Other Financial Instruments
Notional Amount	182,060		214,805
Assets Derivatives	2,217		981
Liability Derivatives	938		446
Interest rate derivative contracts \| Cash Flow Hedges \| Designated as Hedging Instrument
Derivative Instruments and Other Financial Instruments
Notional Amount	13,303		13,319
Assets Derivatives	0		0
Liability Derivatives	1		0
Commodity derivative contracts \| Not designated as hedging instruments
Derivative Instruments and Other Financial Instruments
Notional Amount	9		9
Assets Derivatives	0		0
Liability Derivatives	0		0
Foreign exchange derivative contracts \| Not designated as hedging instruments
Derivative Instruments and Other Financial Instruments
Notional Amount	13,181		11,219
Assets Derivatives	427		230
Liability Derivatives	207		64
Equity derivative contracts \| Not designated as hedging instruments
Derivative Instruments and Other Financial Instruments
Notional Amount	54		72
Assets Derivatives	3		8
Liability Derivatives	3		8
Other derivative contracts \| Not designated as hedging instruments
Derivative Instruments and Other Financial Instruments
Notional Amount	9		72
Assets Derivatives	0		0
Liability Derivatives	0		0
Trading derivatives \| Not designated as hedging instruments
Derivative Instruments and Other Financial Instruments
Notional Amount	195,313		226,177
Assets Derivatives	2,647		1,219
Liability Derivatives	1,148		518
Other Risk Management \| Not designated as hedging instruments
Derivative Instruments and Other Financial Instruments
Notional Amount	3,233		1,948
Assets Derivatives	50		14
Liability Derivatives	36		$ 5
Net gains (losses) on derivatives included in other noninterest income	$ 23	$ 9

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

+ References

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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

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Nominal or face amount used to calculate payment on derivative.

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