Long-Term Debt - Loans Assumed In Acquisition (Details) - Comerica Incorporated $ in Millions	Feb. 01, 2026 USD ($)
Debt Instrument [Line Items]
Long-term debt assumed	$ 5,529
FHLB Advances \| Subsidiaries \| Weighted-Average
Debt Instrument [Line Items]
Interest rate	4.588%
Senior Notes \| Fixed-Rate 4.00% Senior Notes Due in 2029
Debt Instrument [Line Items]
Interest rate	4.00%
Long-term debt assumed	$ 547
Senior Notes \| Fixed-Rate 5.982% Senior Notes Due 2030
Debt Instrument [Line Items]
Interest rate	5.982%
Long-term debt assumed	$ 1,046
Subordinated Debt \| Fixed-Rate 3.80% Senior Notes Due 2026
Debt Instrument [Line Items]
Interest rate	3.80%
Long-term debt assumed	$ 250
Subordinated Debt \| Fixed-Rate 7.875% Notes Due 2026
Debt Instrument [Line Items]
Interest rate	7.875%
Long-term debt assumed	$ 152
Subordinated Debt \| Fixed-Rate 5.332% Notes Due 2033
Debt Instrument [Line Items]
Interest rate	5.332%
Long-term debt assumed	$ 506
Federal Home Loan Bank Advances
Debt Instrument [Line Items]
Long-term debt assumed	$ 3,028

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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