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Note 2 - Securities (Details Textual) $ in Thousands | 12 Months Ended
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Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($)
Debt Securities, Held-to-Maturity, Fair Value, Total | $ 353,901 |
Other-than-temporary Impairment Loss, Debt Securities, Available-for-Sale | $ 0 | $ 0
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions | 611 | 247
US Treasury Securities [Member] | AA or Better [Member] |  |
Debt Securities, Percent | 100.00% |
US States and Political Subdivisions Debt Securities [Member] |  |
Debt Securities, Held-to-Maturity, Fair Value, Total | $ 162,536 |
US States and Political Subdivisions Debt Securities [Member] | AA or Better [Member] |  |
Debt Securities, Percent | 86.00% |
Collateralized Mortgage-Backed Securities [Member] |  |
Debt Securities, Held-to-Maturity, Fair Value, Total | $ 170,605 |
Collateralized Mortgage-Backed Securities [Member] | AA or Better [Member] |  |
Debt Securities, Percent | 100.00% |
Collateralized Mortgage-Backed Securities [Member] | AA [Member] |  |
Debt Securities, Percent | 38.00% |
Collateralized Mortgage-Backed Securities [Member] | AAA [Member] |  |
Debt Securities, Percent | 31.00% |
Collateralized Mortgage-Backed Securities [Member] | Unrated [Member] |  |
Debt Securities, Percent | 13.00% |
Reclassified From Available-for-sale Securities [Member] |  |
Debt Securities, Held-to-Maturity, Fair Value, Total | $ 428,400 |
OCI, Debt Securities, Available-for-Sale, Transfer to Held-to-Maturity, Adjustment from AOCI for Amortization of Gain (Loss), after Tax | 2,700 |
OCI, Debt Securities, Available-for-Sale, Transfer to Held-to-Maturity, Adjustment from AOCI Unamortized, After Tax | $ 2,400 |

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- Definition Amount, after tax, of adjustment from accumulated other comprehensive income (loss) stay unamortized on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) from transfer to investment in debt security measured at amortized cost (held-to-maturity). + References No definition available. + Details
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- Definition Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (b)(3) -URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 4 -Subparagraph (b)(3) -URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455 + Details
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