Derivatives - Derivatives Associated With Cash Flow Hedges and Mortgage Banking Hedges (Details) - Hedging Instruments And Hedged Items - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Cash Flow Hedges \| Interest Rate Contract
Derivative Instruments, Gain (Loss) [Line Items]
Variability in cash flows related to debt instruments (primarily loans)	$ 1,100	$ 1,250
Cash Flow Hedges \| Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional	1,100	1,250
Assets	13	32
Liabilities	0	0
Mortgage Banking Hedges \| Interest Rate Lock
Derivative Instruments, Gain (Loss) [Line Items]
Notional	241	667
Assets	4	20
Liabilities	0	0
Mortgage Banking Hedges \| Forward contracts written
Derivative Instruments, Gain (Loss) [Line Items]
Notional	404	725
Assets	0	0
Liabilities	$ 0	$ 6

Held-to-maturity trust preferred loans.

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- Definition

Fair value of all asset derivatives designated as cash flow hedging instruments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959

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- Definition

Fair value of all liability derivatives designated as cash flow hedging instruments.

+ References

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- Definition

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.

+ References

No definition available.

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- Definition

Aggregate fair value of all derivative assets designated as hedging instruments. Includes instruments designated as cash flow hedges, fair value hedges, and hedges of net investments in foreign operations.

+ References

No definition available.

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- Definition

Aggregate fair value of all derivative liabilities designated as hedging instruments. Includes instruments designated as cash flow hedges, fair value hedges, and hedges of net investments in foreign operations.

+ References

No definition available.

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- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959

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