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Note 3 - Securities (Tables) | 12 Months Ended
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Dec. 31, 2021
Notes Tables |
Debt Securities, Available-for-sale [Table Text Block] |
|  | December 31, 2021 |
Available for sale: |  | Amortized Cost |  |  | Gross Unrealized Gains |  |  | Gross Unrealized Losses |  |  | Fair Value |
U.S. Government agencies and corporations |  | $ | 279,934 |  |  | $ | 2,795 |  |  | $ | 4,710 |  |  | $ | 278,019 |
States and political subdivisions |  |  | 195,365 |  |  |  | 5,314 |  |  |  | 2,007 |  |  |  | 198,672 |
Mortgage-backed securities |  |  | 204,164 |  |  |  | 2,323 |  |  |  | 313 |  |  |  | 206,174 |
Corporate debt securities |  |  | 3,004 |  |  |  | 248 |  |  |  | 37 |  |  |  | 3,215 |
Total securities available for sale |  | $ | 682,467 |  |  | $ | 10,680 |  |  | $ | 7,067 |  |  | $ | 686,080 |
|  | December 31, 2020 |
Available for sale: |  | Amortized Cost |  |  | Gross Unrealized Gains |  |  | Gross Unrealized Losses |  |  | Fair Value |
U.S. Government agencies and corporations |  | $ | 86,859 |  |  | $ | 4,477 |  |  | $ | 173 |  |  | $ | 91,163 |
States and political subdivisions |  |  | 196,435 |  |  |  | 7,778 |  |  |  | 252 |  |  |  | 203,961 |
Mortgage-backed securities |  |  | 244,780 |  |  |  | 4,473 |  |  |  | 78 |  |  |  | 249,175 |
Corporate debt securities |  |  | 2,001 |  |  |  | 442 |  |  |  | - |  |  |  | 2,443 |
Total securities available for sale |  | $ | 530,075 |  |  | $ | 17,170 |  |  | $ | 503 |  |  | $ | 546,742 |
Investments Classified by Contractual Maturity Date [Table Text Block] |
|  | December 31, 2021 |
Available for sale: |  | Amortized Cost |  |  | Fair Value |
Due in one year or less |  | $ | 2,519 |  |  | $ | 2,540 |
Due after one year through five years |  |  | 24,034 |  |  |  | 24,051 |
Due after five years through ten years |  |  | 313,966 |  |  |  | 313,288 |
Due after ten years |  |  | 341,948 |  |  |  | 346,201 |
Total securities available for sale |  | $ | 682,467 |  |  | $ | 686,080 |
Schedule of Temporary Impairment Losses, Investments [Table Text Block] |
|  | December 31, 2021 |
|  | Less Than 12 Months |  |  | 12 Months or More |
|  | Fair Value |  |  | Unrealized Loss |  |  | Fair Value |  |  | Unrealized Loss |
U.S. Government agencies and corporations |  | $ | 201,650 |  |  | $ | 3,530 |  |  | $ | 26,792 |  |  | $ | 1,180 |
State and political subdivisions |  |  | 50,659 |  |  |  | 1,214 |  |  |  | 20,542 |  |  |  | 793 |
Mortgage-backed securities |  |  | 13,139 |  |  |  | 141 |  |  |  | 4,665 |  |  |  | 172 |
Corporate debt securities |  |  | 966 |  |  |  | 37 |  |  |  | - |  |  |  | - |
Total temporarily impaired securities |  | $ | 266,414 |  |  | $ | 4,922 |  |  | $ | 51,999 |  |  | $ | 2,145 |
|  | December 31, 2020 |
|  | Less Than 12 Months |  |  | 12 Months or More |
|  | Fair Value |  |  | Unrealized Loss |  |  | Fair Value |  |  | Unrealized Loss |
U.S. Government agencies and corporations |  | $ | 28,798 |  |  | $ | 173 |  |  | $ | - |  |  | $ | - |
State and political subdivisions |  |  | 32,353 |  |  |  | 249 |  |  |  | 635 |  |  |  | 3 |
Mortgage-backed securities |  |  | 8,816 |  |  |  | 76 |  |  |  | 4,060 |  |  |  | 2 |
Total temporarily impaired securities |  | $ | 69,967 |  |  | $ | 498 |  |  | $ | 4,695 |  |  | $ | 5 |
Schedule of Realized Gain (Loss) on Called Securities [Table Text Block] |
|  | For the year ended December 31, 2021 |
|  | Proceeds |  |  | Book Value |  |  | Gross Gain |  |  | Gross Loss |  |  | Net Gain |
Available for sale |  | $ | 20,377 |  |  | $ | 20,371 |  |  | $ | 6 |  |  | $ | - |  |  | $ | 6 |
|  | For the year ended December 31, 2020 |
|  | Proceeds |  |  | Book Value |  |  | Gross Gain |  |  | Gross Loss |  |  | Net Gain |
Available for sale |  | $ | 126,840 |  |  | $ | 126,732 |  |  | $ | 110 |  |  | $ | 2 |  |  | $ | 108 |

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