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Note 8 - Commitments and Off-balance Sheet Risk (Details Textual) - USD ($) | Mar. 31, 2023 | Dec. 31, 2022 | Mar. 31, 2022 | Dec. 31, 2021
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Financing Receivable, Allowance for Credit Loss, Ending Balance | $ 42,877,000 | $ 42,246,000 | $ 35,153,000 | $ 35,363,000
Retail and Commercial Lines of Credit and Credit Card Receivables Reserve on Commitments [Member] | Maximum [Member] |  |  |  |
Financing Receivable, Allowance for Credit Loss, Ending Balance | $ 200,000 | $ 100,000 |  |

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