Note 5 - Qualified Affordable Housing Project Investment (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Investment Program, Proportional Amortization Method, Applied, Amortization Expense	$ 72,000	$ 89,000
Investment Program, Proportional Amortization Method, Elected, Income Tax Credit and Other Income Tax Benefit, before Amortization Expense	102,000	$ 104,000
Other Assets [Member]
Investments	1,800,000		$ 1,900,000
Other Liabilities [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 168,000		$ 168,000