Credit Quality and the Allowance for Loan and Lease Losses - Summary of Gross Charge-Offs Within the Commercial Portfolio Segments, by Class and Vintage (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Modifications
Total	$ 686	$ 522	$ 362
Commercial
Financing Receivable, Modifications
Year One	1	25
Year Two	7	7
Year Three	17	12
Year Four	1	1
Year Five	1	0
Prior	2	11
Revolving Loans	238	114
Total	267	170	$ 131
Commercial \| Commercial and industrial loans
Financing Receivable, Modifications
Year One	1	25
Year Two	6	7
Year Three	17	12
Year Four	1	1
Year Five	1	0
Prior	0	11
Revolving Loans	238	112
Total	264	168
Commercial \| Commercial mortgage owner-occupied loans:
Financing Receivable, Modifications
Year One	0	0
Year Two	1	0
Year Three	0	0
Year Four	0	0
Year Five	0	0
Prior	0	0
Revolving Loans	0	1
Total	1	1
Commercial \| Commercial construction loans
Financing Receivable, Modifications
Year One	0	0
Year Two	0	0
Year Three	0	0
Year Four	0	0
Year Five	0	0
Prior	0	0
Revolving Loans	0	1
Total	0	1
Commercial \| Commercial leases
Financing Receivable, Modifications
Year One	0	0
Year Two	0	0
Year Three	0	0
Year Four	0	0
Year Five	0	0
Prior	2	0
Revolving Loans	0	0
Total	$ 2	$ 0

Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease.

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-Topic 326
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-Name Accounting Standards Codification
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-URI https://asc.fasb.org/1943274/2147479319/326-20-50-6

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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