Note 4 - Loans and the Allowance for Credit Losses - Outstanding Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Loans	$ 976,212	$ 958,564
Deferred loan costs, net	3,086	2,907
Loans, amortized cost basis	979,298	961,471
Allowance for credit losses	(13,157)	(12,867)		$ (10,717)
Loans, ne	966,141	948,604
Commercial Portfolio Segment [Member] | Commercial Loans [Member]
Loans	82,136	74,271
Loans, amortized cost basis	82,846	74,933
Allowance for credit losses	(1,311)	(1,134)	$ (1,475)	(892)
Commercial Portfolio Segment [Member] | Agricultural Loans [Member]
Loans	123,239	129,389
Loans, amortized cost basis	123,523	129,678
Allowance for credit losses	(1,652)	(1,738)	(1,307)	(1,086)
Commercial Portfolio Segment [Member] | Real Estate Loan [Member]
Loans	562,870	544,339
Loans, amortized cost basis	563,095	544,214
Allowance for credit losses	(6,917)	(6,678)	(6,740)	(4,980)
Commercial Portfolio Segment [Member] | Construction Loans [Member]
Loans	64,547	57,717
Loans, amortized cost basis	64,161	57,360
Allowance for credit losses	(918)	(797)	(763)	(1,500)
Residential Portfolio Segment [Member] | Real Estate Loan [Member]
Loans	11,872	11,914
Loans, amortized cost basis	11,900	11,942
Allowance for credit losses	(134)	(137)	(162)	(138)
Residential Portfolio Segment [Member] | Equity Lines of Credit [Member]
Loans	37,196	37,871
Loans, amortized cost basis	38,041	38,713
Allowance for credit losses	(437)	(439)	(330)	(687)
Consumer Portfolio Segment [Member]
Loans, amortized cost basis	95,732	104,631
Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans	89,399	98,132
Loans, amortized cost basis	90,737	99,660
Allowance for credit losses	(1,700)	(1,865)	(1,504)	(1,289)
Consumer Portfolio Segment [Member] | Other Loans [Member]
Loans	4,953	4,931
Loans, amortized cost basis	4,995	4,971
Allowance for credit losses	$ (88)	$ (79)	$ (49)	$ (145)