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Note 4 - Loans Receivable and Allowance for Credit Losses on Loans - Schedule of Modified Financing Receivables (Details) - USD ($) | 12 Months Ended
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Dec. 31, 2024 | Dec. 31, 2023
Commercial Real Estate Portfolio Segment [Member] | Commercial Loan [Member] |  |
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage | 0.33% | 0.30%
Commercial Real Estate Portfolio Segment [Member] | Commercial Loan [Member] | Principal Forgiveness [Member] |  |
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount | $ 0 | $ 0
Commercial Real Estate Portfolio Segment [Member] | Commercial Loan [Member] | Payment Deferral [Member] |  |
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount | 0 | 0
Commercial Real Estate Portfolio Segment [Member] | Commercial Loan [Member] | Extended Maturity [Member] |  |
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount | $ 0 | $ 0
Financing Receivable, Excluding Accrued Interest, Modified, Weighted Average Term Extension Payment Delay (Year) | 2 years 6 months | 1 year 6 months
Commercial Real Estate Portfolio Segment [Member] | Commercial Loan [Member] | Extended Maturity and Principal Forgiveness [Member] |  |
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount | $ 0 | $ 0
Commercial Real Estate Portfolio Segment [Member] | Commercial Loan [Member] | Extended Maturity and Payment Delay [Member] |  |
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount | 1,146,000 | $ 1,088,000
Real Estate Portfolio Segment [Member] | Construction Loans [Member] |  |
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount | 1,510 |
Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Principal Forgiveness [Member] |  |
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount | 0 |
Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Payment Deferral [Member] |  |
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount | 0 |
Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Extended Maturity [Member] |  |
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount | $ 0 |
Financing Receivable, Excluding Accrued Interest, Modified, Weighted Average Term Extension Payment Delay (Year) | 6 months |
Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Extended Maturity and Principal Forgiveness [Member] |  |
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount | $ 0 |
Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Extended Maturity and Payment Delay [Member] |  |
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount | $ 4,979,000 |

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- Definition Period of increase in weighted average maturity of financing receivable modified (excluding accrued interest) for debtor experiencing financial difficulty, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days + References No definition available. + Details
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- Definition Amortized cost excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-42 + Details
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- Definition Percentage, excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty to total financing receivables. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-42 + Details
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