Note 5 - Allowance for Loan Losses on Loans and Nonperforming Assets - Allowance for Credit Losses on Unfunded Commitments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Balance	$ 8,225	$ 7,674
Provision for credit losses	(1,278)	706
Balance	9,094	8,225
Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
Balance	2,342
Balance		2,342
Unfunded Loan Commitment [Member]
Balance	35
Provision for credit losses	17
Balance	259	35
Unfunded Loan Commitment [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
Balance	$ 207
Balance		$ 207