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	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Financing Receivable, Modifications
Total	$ 194	$ 182	$ 366	$ 328
Commercial
Financing Receivable, Modifications
Year One			0	0
Year Two			8	2
Year Three			23	3
Year Four			6	1
Year Five			6	1
Prior			14	0
Revolving Loans			99	116
Total	$ 90	$ 83	156	123
Commercial \| Commercial and industrial loans
Financing Receivable, Modifications
Year One			0	0
Year Two			8	2
Year Three			22	3
Year Four			5	1
Year Five			3	1
Prior			1	0
Revolving Loans			98	116
Total			137	123
Commercial \| Commercial mortgage owner-occupied loans
Financing Receivable, Modifications
Year One			0	0
Year Two			0	0
Year Three			0	0
Year Four			0	0
Year Five			3	0
Prior			11	0
Revolving Loans			1	0
Total			15	0
Commercial \| Commercial leases
Financing Receivable, Modifications
Year One			0	0
Year Two			0	0
Year Three			1	0
Year Four			1	0
Year Five			0	0
Prior			2	0
Revolving Loans			0	0
Total			$ 4	$ 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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