Financial Derivatives (Gains (Losses) Recognized on Fair Value and Cash Flow Hedges in the Consolidated Income Statement) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Loans	$ 2,293	$ 1,996
Investment Securities	544	421
Borrowed Funds	83	95
Noninterest income	1,888	1,872
Other
Derivative Instruments, Gain (Loss) [Line Items]
Noninterest income	211	300
Fair value hedges \| Designated as Hedging Instrument \| Investment Securities \| Interest Income
Derivative Instruments, Gain (Loss) [Line Items]
Hedged items	(18)	(8)
Derivatives	19	9
Amounts related to interest settlements on derivatives	(1)	(1)
Fair value hedges \| Designated as Hedging Instrument \| Borrowed Funds \| Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Hedged items	934	646
Derivatives	(944)	(664)
Amounts related to interest settlements on derivatives	110	134
Cash flow hedges \| Designated as Hedging Instrument \| Loans \| Interest Income
Derivative Instruments, Gain (Loss) [Line Items]
Amount of derivative gains (losses) reclassified from AOCI	92	100
Cash flow hedges \| Designated as Hedging Instrument \| Investment Securities \| Interest Income
Derivative Instruments, Gain (Loss) [Line Items]
Amount of derivative gains (losses) reclassified from AOCI	$ 10	22
Cash flow hedges \| Designated as Hedging Instrument \| Other \| Noninterest Income
Derivative Instruments, Gain (Loss) [Line Items]
Amount of derivative gains (losses) reclassified from AOCI		$ 13

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

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The aggregate interest and fee income generated by: (1) loans the Entity has positive intent and ability to hold for the foreseeable future, or until maturity or payoff, including commercial and consumer loans, whether domestic or foreign, which may consist of: (a) industrial and agricultural; (b) real estate; and (c) real estate construction loans; (d) trade financing; (e) lease financing; (f) home equity lines-of-credit; (g) automobile and other vehicle loans; and (h) credit card and other revolving-type loans and (2) loans and leases held-for-sale which may include mortgage loans, direct financing, and sales-type leases.

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The total amount of noninterest income which may be derived from: (1) fees and commissions; (2) premiums earned; (3) insurance policy charges; (4) the sale or disposal of assets; and (5) other sources not otherwise specified.

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