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v3.25.3

Note 1 - Significant Accounting Policies (Details Textual) $ / shares in Units, $ in Thousands |  | 3 Months Ended | 9 Months Ended |
--- | --- | --- | --- | ---
Jul. 22, 2025 USD ($) $ / shares | Sep. 30, 2025 USD ($) shares | Sep. 30, 2024 USD ($) shares | Sep. 30, 2025 USD ($) shares | Sep. 30, 2024 USD ($) shares | Dec. 31, 2024 USD ($)
Number of Unconsolidated Business Trusts Formed to Issue Trust Preferred Securities |  | 5 |  | 5 |  |
Share Price (in dollars per share) | $ / shares | $ 43.14 |  |  |  |  |
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Ending Balance |  | $ 0 |  | $ 0 |  | $ 0
Financing Receivable, Unamortized Loan Cost (Fee) |  | 1,700 |  | $ 1,700 |  | 2,200
Interest Income on Commercial and Mortgage Loans Discontinued Period (Day) |  |  |  | 90 days |  |
Maximum Delinquency Period for Consumer and Credit Card Loans to be Charged Off (Day) |  |  |  | 120 days |  |
Loan, Mortgage, Held-for-Sale, Fair Value Disclosure |  | 17,700 |  | $ 17,700 |  | 16,000
Financing Receivable, Credit Loss, Expense (Reversal) |  | 200 | $ 1,100 | 3,900 | $ 5,900 |
Financing Receivable, Accrued Interest, after Allowance for Credit Loss |  | $ 16,700 |  | $ 16,700 |  | $ 17,300
Financing Receivable, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration] |  | Other Assets |  | Other Assets |  | Other Assets
Continuing Involvement with Transferred Financial Assets, Principal Amount Outstanding |  | $ 1,620,000 |  | $ 1,620,000 |  | $ 1,550,000
Servicing Asset at Amortized Cost |  | 13,100 |  | 13,100 |  | 12,500
Servicing Asset at Fair Value, Amount |  | $ 21,700 |  | 21,700 |  | $ 21,000
Goodwill, Impairment Loss |  |  |  | $ 0 |  |
Restricted Stock [Member] |  |  |  |  |  |
Incremental Common Shares Attributable to Participating Nonvested Shares with Non-forfeitable Dividend Rights (in shares) | shares |  | 277,000 | 311,000 | 277,000 | 311,000 |
Eastern Michigan Financial Corporation [Member] |  |  |  |  |  |
Business Combination, Acquiree's Common Stock Conversion to Cash Ratio (in dollars per share) | $ / shares | $ 32.32 |  |  |  |  |
Business Combination, Acquiree's Common Stock Conversion to Acquire's Common Stock Ratio | 0.7116 |  |  |  |  |
Business Combination, Consideration Transferred | $ 90,300 |  |  |  |  |

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