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Note 2 - Debt Securities (Details Textual) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2025 | Dec. 31, 2024 | Dec. 31, 2023
Debt Securities, Held-to-Maturity, Allowance for Credit Loss, Excluding Accrued Interest | $ 0 | $ 0 |
Debt Securities, Available-for-Sale, Realized Gain (Loss) | (16,375) | 0 | $ 0
US Treasury Securities and Residential Mortgage-Backed Securities [Member] |  |  |
Debt Securities, Held-to-Maturity, Allowance for Credit Loss, Excluding Accrued Interest | 0 | 0 |
Collateralized Mortgage-Backed Securities [Member] |  |  |
Debt Securities, Available-for-Sale, Sold at Par Value | 153,900 |  |
Debt Securities, Available-for-Sale, Realized Gain (Loss) | 16,400 |  |
US States and Political Subdivisions Debt Securities [Member] |  |  |
Debt Securities, Held-to-Maturity, Allowance for Credit Loss, Excluding Accrued Interest | 0 | 0 |
Asset Not Pledged as Collateral and Asset Pledged as Collateral without Right [Member] |  |  |
Debt Securities | $ 1,230,000 | $ 1,430,000 |

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with interest rate reset through auction process, sold at par value. + References No definition available. + Details
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X
- Definition Amount, after allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), investment in debt security measured at amortized cost (held-to-maturity), and investment in debt security measured at fair value with change in fair value recognized in net income (trading). + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 80 -Name Accounting Standards Codification -Section 55 -Paragraph 14 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480078/944-80-55-14 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 80 -Name Accounting Standards Codification -Section 55 -Paragraph 9 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480078/944-80-55-9 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481830/320-10-45-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)(6)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 + Details
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X
- Definition Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-9 + Details
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X
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