Loans and Leases and the Allowance for Credit Losses - Loan and Leases Considered Nonaccrual and Interest Income Recognized on Loans (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024	Jan. 01, 2024	Jan. 01, 2023
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	$ 1,139	$ 1,232
Amortized Cost without Allowance	401	1,070
Total	1,540	2,302	$ 1,690	$ 1,690	$ 2,166
Amortized Cost	1,540	2,302	1,690	1,690	2,166
Interest Income Recognized	18	13
Commercial and industrial
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	522	590
Amortized Cost without Allowance	140	274
Total	662	864	696	696	670
Amortized Cost	662	864	696	696	670
Interest Income Recognized	6	2
Commercial Real Estate \| Commercial
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	341	379
Amortized Cost without Allowance	53	476
Total	394	855	468	468	869
Amortized Cost	394	855	468	468	869
Interest Income Recognized	7	6
Commercial Real Estate \| Residential builder and developer
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	1	3
Amortized Cost without Allowance	0	0
Total	1	3	2	2	3
Amortized Cost	1	3	2	2	3
Interest Income Recognized	0	0
Commercial Real Estate \| Other commercial construction
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	23	33
Amortized Cost without Allowance	5	108
Total	28	141	66	66	171
Amortized Cost	28	141	66	66	171
Interest Income Recognized	0	0
Residential Real Estate \| Residential
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	135	100
Amortized Cost without Allowance	149	155
Total	284	255	279	279	270
Amortized Cost	284	255	279	279	270
Interest Income Recognized	3	4
Consumer: \| Home equity lines and loans
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	36	48
Amortized Cost without Allowance	42	39
Total	78	87	81	81	81
Amortized Cost	78	87	81	81	81
Interest Income Recognized	2	1
Consumer: \| Recreational finance
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	17	18
Amortized Cost without Allowance	9	12
Total	26	30	31	31	36
Amortized Cost	26	30	31	31	36
Interest Income Recognized	0	0
Consumer: \| Automobile
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	8	7
Amortized Cost without Allowance	3	6
Total	11	13	12	12	14
Amortized Cost	11	13	12	12	14
Interest Income Recognized	0	0
Consumer: \| Other
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	56	54
Amortized Cost without Allowance	0	0
Total	56	54	55	55	52
Amortized Cost	56	54	$ 55	$ 55	$ 52
Interest Income Recognized	$ 0	$ 0

Financing Receivable, Excluding Accrued Interest, Nonaccrual, With Allowance

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- Definition

Impaired financing receivable nonaccrual interest income.

+ References

No definition available.

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- Definition

Amortized cost excluding accrued interest, of financing receivable on nonaccrual status. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

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- Definition

Amortized cost excluding accrued interest, of financing receivable on nonaccrual status with no allowance for credit loss. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

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+ References

No definition available.

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