Note 4 - Loans and the Allowance for Credit Losses - Balance of Nonaccrual Loans By Loan Category (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Total nonaccrual	$ 4,503	$ 1,172
Past due 90 days or more and still accruing	5,032	0
Commercial Portfolio Segment [Member] | Commercial Loans [Member]
Total nonaccrual	58	0
Past due 90 days or more and still accruing	0	0
Commercial Portfolio Segment [Member] | Agricultural Loans [Member]
Total nonaccrual	847	0
Past due 90 days or more and still accruing	5,032	0
Commercial Portfolio Segment [Member] | Real Estate Loan [Member]
Total nonaccrual	859	9
Past due 90 days or more and still accruing	0	0
Commercial Portfolio Segment [Member] | Construction Loans [Member]
Total nonaccrual	0	83
Past due 90 days or more and still accruing	0	0
Residential Portfolio Segment [Member] | Real Estate Loan [Member]
Total nonaccrual	199	211
Past due 90 days or more and still accruing	0	0
Residential Portfolio Segment [Member] | Equity Lines of Credit [Member]
Total nonaccrual	727	417
Past due 90 days or more and still accruing	0	0
Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Total nonaccrual	798	452
Past due 90 days or more and still accruing	0	0
Consumer Portfolio Segment [Member] | Other Loans [Member]
Total nonaccrual	1,015	0
Past due 90 days or more and still accruing	0	0
Nonperforming Financial Instruments [Member]
Nonaccrual with no allowance for credit losses	2,593	1,172
Total nonaccrual	4,503	1,172
Past due 90 days or more and still accruing	5,032	0
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Commercial Loans [Member]
Nonaccrual with no allowance for credit losses	0	0
Total nonaccrual	58	0
Past due 90 days or more and still accruing	0	0
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Agricultural Loans [Member]
Nonaccrual with no allowance for credit losses	0	0
Total nonaccrual	847	0
Past due 90 days or more and still accruing	5,032	0
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Real Estate Loan [Member]
Nonaccrual with no allowance for credit losses	859	9
Total nonaccrual	859	9
Past due 90 days or more and still accruing	0	0
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Construction Loans [Member]
Nonaccrual with no allowance for credit losses	0	83
Total nonaccrual	0	83
Past due 90 days or more and still accruing	0	0
Nonperforming Financial Instruments [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member]
Nonaccrual with no allowance for credit losses	199	211
Total nonaccrual	199	211
Past due 90 days or more and still accruing	0	0
Nonperforming Financial Instruments [Member] | Residential Portfolio Segment [Member] | Equity Lines of Credit [Member]
Nonaccrual with no allowance for credit losses	727	417
Total nonaccrual	727	417
Past due 90 days or more and still accruing	0	0
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Nonaccrual with no allowance for credit losses	798	452
Total nonaccrual	798	452
Past due 90 days or more and still accruing	0	0
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Other Loans [Member]
Nonaccrual with no allowance for credit losses	10	0
Total nonaccrual	1,015	0
Past due 90 days or more and still accruing	$ 0	$ 0