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Note 13 - Commitments and Contingencies (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2035	Dec. 31, 2024	Dec. 31, 2023
Loans and Leases Receivable, Gross, Total	$ 1,357,161,000	$ 1,154,033,000
US Treasury and Government [Member]
Investments, Total	99,800,000	$ 151,000,000.0
US States and Political Subdivisions Debt Securities [Member]
Investments, Total	$ 113,400,000
Credit Concentration Risk [Member] \| Loans Receivable [Member] \| Loans Secured by Real Estate [Member]
Concentration Risk, Percentage	82.50%	80.50%
Investment Concentration Risk [Member] \| Investments [Member] \| US Treasury and Government [Member]
Concentration Risk, Percentage	28.60%	40.80%
Investment Concentration Risk [Member] \| Investments [Member] \| US States and Political Subdivisions Debt Securities [Member]
Concentration Risk, Percentage	32.40%
Real Estate Loan [Member]
Loans and Leases Receivable, Gross, Total	$ 1,120,000,000	$ 929,200,000
Low Income Housing Tax Credit Investments [Member]
Amortization Method Qualified Affordable Housing Project Investments	4,900,000	0
Amortization Method Qualified Affordable Housing Project Investments, Amortization	0	0
Qualified Affordable Housing Project Investments, Commitment	4,700,000	0
Affordable Housing Project Investment, Write-down, Amount	$ 0	$ 0
Low Income Housing Tax Credit Investments [Member] \| Forecast [Member]
Qualified Affordable Housing Project Investments, Commitment			$ 87,000	$ 3,400,000	$ 1,200,000