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Note 3 - Investments - Schedule of Contractual Maturities (Details) - USD ($) $ in Thousands | Mar. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Available-for-Sale, Amortized Cost | $ 309,959 | $ 328,695
Fair value, available for sale securities | 279,643 | 292,933
Total securities held-to-maturity, amortized cost | 8,500 | 8,500
Total securities held-to-maturity, fair value | 7,785 | 7,666
Total securities | 318,459 | 337,195
Total securities, fair value | 287,428 | 300,599
US Government Agencies Debt Securities [Member] |  |
Due within one year, amortized cost | 917 | 922
Due within one year, fair value | 914 | 914
Due after one year through five years, amortized cost | 3,951 | 3,947
Due after one year through five years, fair value | 3,537 | 3,544
Due after five years through ten years, amortized cost | 11,973 | 11,972
Due after five years through ten years, fair value | 10,067 | 10,139
Due after ten years, amortized cost | 4,310 | 4,310
Due after ten years, fair value | 3,380 | 3,421
Subtotal, amortized cost | 21,151 | 21,151
Subtotal, fair value | 17,898 | 18,018
Available-for-Sale, Amortized Cost | 21,151 | 21,151
Fair value, available for sale securities | 17,898 | 18,018
Corporate Debt Securities [Member] |  |
Due within one year, amortized cost | 0 | 1,000
Due within one year, fair value | 0 | 1,004
Due after one year through five years, amortized cost | 10,000 | 6,000
Due after one year through five years, fair value | 9,985 | 6,609
Due after five years through ten years, amortized cost | 4,000 | 4,000
Due after five years through ten years, fair value | 3,822 | 3,839
Due after ten years, amortized cost | 2,000 | 2,000
Due after ten years, fair value | 1,393 | 1,420
Subtotal, amortized cost | 16,000 | 13,000
Subtotal, fair value | 15,200 | 12,872
Available-for-Sale, Amortized Cost | 16,000 | 13,000
Fair value, available for sale securities | 15,200 | 12,872
Due after five years through ten years, amortized cost, held to maturity | 8,500 | 8,500
Due after five years through ten years, fair value, held to maturity | 7,785 | 7,666
Municipal Bonds [Member] |  |
Due within one year, amortized cost | 1,006 | 1,013
Due within one year, fair value | 1,000 | 1,003
Due after one year through five years, amortized cost | 82 | 757
Due after one year through five years, fair value | 81 | 751
Due after five years through ten years, amortized cost | 4,037 | 7,603
Due after five years through ten years, fair value | 3,836 | 7,101
Due after ten years, amortized cost | 81,132 | 129,430
Due after ten years, fair value | 68,636 | 110,592
Subtotal, amortized cost | 86,257 | 138,803
Subtotal, fair value | 73,553 | 119,447
Available-for-Sale, Amortized Cost | 86,257 | 138,803
Fair value, available for sale securities | 73,553 | 119,447
Collateralized Mortgage-Backed Securities [Member] |  |
Without single maturity date, amortized cost | 131,594 | 112,855
Without single maturity date, fair value | 119,802 | 101,248
Available-for-Sale, Amortized Cost | 131,594 | 112,855
Fair value, available for sale securities | 119,802 | 101,248
Collateralized Mortgage-Backed Securities [Member] | Federal National Mortgage Association (FNMA) [Member] |  |
Without single maturity date, amortized cost | 83,863 | 76,369
Without single maturity date, fair value | 73,301 | 66,275
Collateralized Mortgage-Backed Securities [Member] | Federal Home Loan Mortgage Corporation (FHLMC) [Member] |  |
Without single maturity date, amortized cost | 36,178 | 32,311
Without single maturity date, fair value | 35,532 | 31,376
Collateralized Mortgage-Backed Securities [Member] | Government National Mortgage Association (GNMA) [Member] |  |
Without single maturity date, amortized cost | 11,553 | 4,175
Without single maturity date, fair value | 10,969 | 3,597
U.S. Small Business Administration Securities [Member] |  |
Due within one year, amortized cost | 42 | 198
Due within one year, fair value | 41 | 196
Due after one year through five years, amortized cost | 1,656 | 1,860
Due after one year through five years, fair value | 1,584 | 1,824
Due after five years through ten years, amortized cost | 27,916 | 21,420
Due after five years through ten years, fair value | 27,317 | 20,929
Due after ten years, amortized cost | 25,343 | 19,408
Due after ten years, fair value | 24,248 | 18,399
Subtotal, amortized cost | 54,957 | 42,886
Subtotal, fair value | 53,190 | 41,348
Available-for-Sale, Amortized Cost | 54,957 | 42,886
Fair value, available for sale securities | $ 53,190 | $ 41,348

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