Credit Quality and the Allowance for Loan and Lease Losses - Summary of Recorded Investment in Portfolio Loans and Leases by Age and Class (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	$ 119,791	$ 117,234
Commercial
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	73,293	72,746
90 Days Past Due and Still Accruing	6	8
Commercial | Current
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	73,047	72,547
Commercial | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	246	199
Commercial | 30-89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	155	93
Commercial | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	91	106
Commercial | Commercial and industrial loans
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	52,271	53,270
90 Days Past Due and Still Accruing	5	8
Commercial | Commercial and industrial loans | Current
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	52,098	53,107
Commercial | Commercial and industrial loans | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	173	163
Commercial | Commercial and industrial loans | 30-89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	90	61
Commercial | Commercial and industrial loans | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	83	102
Commercial | Commercial mortgage owner-occupied loans:
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	6,023	5,200
90 Days Past Due and Still Accruing	0	0
Commercial | Commercial mortgage owner-occupied loans: | Current
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	5,980	5,196
Commercial | Commercial mortgage owner-occupied loans: | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	43	4
Commercial | Commercial mortgage owner-occupied loans: | 30-89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	40	1
Commercial | Commercial mortgage owner-occupied loans: | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	3	3
Commercial | Commercial mortgage nonowner-occupied loans:
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	6,223	6,076
90 Days Past Due and Still Accruing	0	0
Commercial | Commercial mortgage nonowner-occupied loans: | Current
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	6,215	6,061
Commercial | Commercial mortgage nonowner-occupied loans: | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	8	15
Commercial | Commercial mortgage nonowner-occupied loans: | 30-89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	6	14
Commercial | Commercial mortgage nonowner-occupied loans: | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	2	1
Commercial | Commercial construction loans
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	5,588	5,621
90 Days Past Due and Still Accruing	0	0
Commercial | Commercial construction loans | Current
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	5,587	5,621
Commercial | Commercial construction loans | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	1	0
Commercial | Commercial construction loans | 30-89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	1	0
Commercial | Commercial construction loans | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	0	0
Commercial | Commercial leases
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	3,188	2,579
90 Days Past Due and Still Accruing	1	0
Commercial | Commercial leases | Current
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	3,167	2,562
Commercial | Commercial leases | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	21	17
Commercial | Commercial leases | 30-89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	18	17
Commercial | Commercial leases | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	$ 3	$ 0