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Note 7 - Investment Securities (Details Textual) $ in Thousands | 3 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Mar. 31, 2025 USD ($) | Mar. 31, 2024 USD ($) | Mar. 31, 2025 USD ($) | Dec. 31, 2024 USD ($)
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss | $ 3,900 |  | $ 3,900 | $ 4,600
Equity Securities, FV-NI, Unrealized Gain (Loss) | (4,191) | $ (9,026) |  |
Equity Securities, FV-NI, Decrease in Unrealized Loss |  |  | (4,800) |
Equity Securities, FV-NI, Current | $ 30,238 |  | $ 30,238 | $ 34,429
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions | 183 |  | 183 | 182
Debt Securities, Available-for-Sale, Allowance for Credit Loss | $ 0 |  | $ 0 |
Debt Securities, Available-for-Sale, Transfer in, Allowance for Credit Loss, Expense | 0 |  |  |
Debt Securities, Available-for-Sale | 1,434,040 |  | 1,434,040 | $ 1,547,128
Asset Pledged as Collateral [Member] | Public Deposits and Other Borrowings [Member] |  |  |  |
Debt Securities, Available-for-Sale | $ 17,100 |  | $ 17,100 | $ 17,800
Collateralized Mortgage-Backed Securities [Member] |  |  |  |
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions | 149 |  | 149 | 154
Debt Securities, Available-for-Sale | $ 679,675 |  | $ 679,675 | $ 684,016
Corporate Debt Securities [Member] |  |  |  |
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions | 10 |  | 10 | 16
Debt Securities, Available-for-Sale | $ 179,335 |  | $ 179,335 | $ 207,945
US Government Corporations and Agencies Securities [Member] |  |  |  |
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions | 7 |  | 7 | 9
Debt Securities, Available-for-Sale | $ 8,723 |  | $ 8,723 | $ 9,149
Collateralized Mortgage Obligations [Member] |  |  |  |
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions | 3 |  | 3 | 3
Debt Securities, Available-for-Sale | $ 24,663 |  | $ 24,663 | $ 24,556

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