Note 6 - Equity and Other Investments (Details Textual)	12 Months Ended
	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Federal Home Loan Bank Stock	$ 11,300,000	$ 6,800,000
Number of Limited Partnerships	4
Investment in a Limited Partnership	$ 4,800,000	4,100,000
Investment Tax Credit	1,440,000	1,087,000	$ 746,000
Amortization on Investment in Limited Partnership	1,177,000	877,000	549,000
Income Tax Benefit Recognized on Limited Partnerships	$ 214,000	$ 206,000	$ 248,000