Note 4 - Loans and the Allowance for Credit Losses - Aging Analysis of the Loan Portfolio (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Total, gross	$ 918,352	$ 914,685
90 Days and Still Accruing	368
Financing Receivable, Nonaccrual	3,603
Financial Asset, 30 to 59 Days Past Due [Member]
Total, gross	6,431
Financial Asset, 60 to 89 Days Past Due [Member]
Total, gross	2,847
Financial Asset, Past Due [Member]
Total, gross	13,249
Financial Asset, Not Past Due [Member]
Total, gross	905,103
Commercial Portfolio Segment [Member] | Commercial Loans [Member]
Total, gross	77,214
90 Days and Still Accruing	0
Financing Receivable, Nonaccrual	58
Commercial Portfolio Segment [Member] | Commercial Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Total, gross	1,667
Commercial Portfolio Segment [Member] | Commercial Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Total, gross	2,261
Commercial Portfolio Segment [Member] | Commercial Loans [Member] | Financial Asset, Past Due [Member]
Total, gross	3,986
Commercial Portfolio Segment [Member] | Commercial Loans [Member] | Financial Asset, Not Past Due [Member]
Total, gross	73,228
Commercial Portfolio Segment [Member] | Agricultural Loans [Member]
Total, gross	118,466
90 Days and Still Accruing	214
Financing Receivable, Nonaccrual	847
Commercial Portfolio Segment [Member] | Agricultural Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Total, gross	373
Commercial Portfolio Segment [Member] | Agricultural Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Total, gross	0
Commercial Portfolio Segment [Member] | Agricultural Loans [Member] | Financial Asset, Past Due [Member]
Total, gross	1,434
Commercial Portfolio Segment [Member] | Agricultural Loans [Member] | Financial Asset, Not Past Due [Member]
Total, gross	117,032
Commercial Portfolio Segment [Member] | Real Estate Loan [Member]
Total, gross	521,670
90 Days and Still Accruing	154
Financing Receivable, Nonaccrual	965
Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Total, gross	1,888
Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Total, gross	0
Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Financial Asset, Past Due [Member]
Total, gross	3,007
Commercial Portfolio Segment [Member] | Real Estate Loan [Member] | Financial Asset, Not Past Due [Member]
Total, gross	518,663
Commercial Portfolio Segment [Member] | Construction Loans [Member]
Total, gross	42,342
90 Days and Still Accruing	0
Financing Receivable, Nonaccrual	0
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Total, gross	938
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Total, gross	0
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Financial Asset, Past Due [Member]
Total, gross	938
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Financial Asset, Not Past Due [Member]
Total, gross	41,404
Residential Portfolio Segment [Member] | Real Estate Loan [Member]
Total, gross	14,775
90 Days and Still Accruing	0
Financing Receivable, Nonaccrual	201
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Total, gross	0
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Total, gross	0
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Financial Asset, Past Due [Member]
Total, gross	201
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Financial Asset, Not Past Due [Member]
Total, gross	14,574
Residential Portfolio Segment [Member] | Equity Lines of Credit [Member]
Total, gross	36,613
90 Days and Still Accruing	0
Financing Receivable, Nonaccrual	648
Residential Portfolio Segment [Member] | Equity Lines of Credit [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Total, gross	64
Residential Portfolio Segment [Member] | Equity Lines of Credit [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Total, gross	134
Residential Portfolio Segment [Member] | Equity Lines of Credit [Member] | Financial Asset, Past Due [Member]
Total, gross	846
Residential Portfolio Segment [Member] | Equity Lines of Credit [Member] | Financial Asset, Not Past Due [Member]
Total, gross	35,767
Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Total, gross	102,272
90 Days and Still Accruing	0
Financing Receivable, Nonaccrual	863
Consumer Portfolio Segment [Member] | Automobile Loan [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Total, gross	1,426
Consumer Portfolio Segment [Member] | Automobile Loan [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Total, gross	452
Consumer Portfolio Segment [Member] | Automobile Loan [Member] | Financial Asset, Past Due [Member]
Total, gross	2,741
Consumer Portfolio Segment [Member] | Automobile Loan [Member] | Financial Asset, Not Past Due [Member]
Total, gross	99,531
Consumer Portfolio Segment [Member] | Other Loans [Member]
Total, gross	5,000
90 Days and Still Accruing	0
Financing Receivable, Nonaccrual	21
Consumer Portfolio Segment [Member] | Other Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Total, gross	75
Consumer Portfolio Segment [Member] | Other Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Total, gross	0
Consumer Portfolio Segment [Member] | Other Loans [Member] | Financial Asset, Past Due [Member]
Total, gross	96
Consumer Portfolio Segment [Member] | Other Loans [Member] | Financial Asset, Not Past Due [Member]
Total, gross	$ 4,904