Note 4 - Qualified Affordable Housing Project Investment (Details Textual) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Jun. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Amortization Method Qualified Affordable Housing Project Investments, Amortization	$ 89,000			$ 266,000	$ 266,000
Affordable Housing Tax Credits and Other Tax Benefits, Amount		$ 105,000	$ 106,000	314,000	$ 317,000
Other Assets [Member]
Investments, Total	2,300,000			2,300,000		$ 2,500,000
Other Liabilities [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 216,000			$ 216,000		$ 216,000