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Note 6 - Investments and Equity Securities- Amortized Cost and Fair Values of Securities Available for Sale (Details) - USD ($) $ in Thousands | Jun. 30, 2024 | Dec. 31, 2023
--- | --- | ---
Amortized cost | $ 191,067 | [1] | $ 191,146 | [2]
Gross unrealized gains | 76 |  | 223 |
Gross unrealized losses | (24,719) |  | (20,590) |
Investment securities available for sale, at fair value | 166,424 |  | 170,779 |
Subordinated Debt Securities [Member] |  |  |  |
Amortized cost | 34,300 | [1] | 34,300 | [2]
Gross unrealized gains | 57 |  | 70 |
Gross unrealized losses | (2,427) |  | (2,451) |
Investment securities available for sale, at fair value | 31,930 |  | 31,919 |
Nontaxable Municipal Bonds [Member] |  |  |  |
Amortized cost | 148,254 | [1] | 149,881 | [2]
Gross unrealized gains | 7 |  | 153 |
Gross unrealized losses | (21,573) |  | (17,492) |
Investment securities available for sale, at fair value | 126,688 |  | 132,542 |
Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member] |  |  |  |
Amortized cost | 8,513 | [1] | 6,965 | [2]
Gross unrealized gains | 12 |  | 0 |
Gross unrealized losses | (719) |  | (647) |
Investment securities available for sale, at fair value | $ 7,806 |  | $ 6,318 |
[1] | Amortized cost excludes accrued interest receivable of $1.7 million for the period ending June 30, 2024.
[2] | Amortized cost excludes accrued interest receivable of $1.7 million for the period ending December 31, 2023.

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