Loans and ACL - Nonperforming Loans (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Nonperforming [Line Items]
Recorded Investment Without an ALLL	$ 145	$ 152
Recorded Investment With an ALLL	945	1,178
Commercial: \| Commercial and industrial
Financing Receivable, Nonperforming [Line Items]
Recorded Investment Without an ALLL	125	82
Recorded Investment With an ALLL	269	478
Commercial: \| CRE
Financing Receivable, Nonperforming [Line Items]
Recorded Investment Without an ALLL	12	63
Recorded Investment With an ALLL	17	12
Commercial: \| Commercial construction
Financing Receivable, Nonperforming [Line Items]
Recorded Investment Without an ALLL	0	0
Recorded Investment With an ALLL	7	14
Consumer: \| Residential mortgage
Financing Receivable, Nonperforming [Line Items]
Recorded Investment Without an ALLL	4	4
Recorded Investment With an ALLL	292	312
Consumer: \| Residential home equity and direct
Financing Receivable, Nonperforming [Line Items]
Recorded Investment Without an ALLL	3	2
Recorded Investment With an ALLL	138	203
Consumer: \| Indirect auto
Financing Receivable, Nonperforming [Line Items]
Recorded Investment Without an ALLL	1	1
Recorded Investment With an ALLL	217	154
Consumer: \| Indirect other
Financing Receivable, Nonperforming [Line Items]
Recorded Investment Without an ALLL	0	0
Recorded Investment With an ALLL	$ 5	$ 5

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Amount of investment in impaired financing receivables for which there is no related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953550-111524

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Amount of investment in impaired financing receivables for which there is a related allowance for credit losses.

+ References

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