Note 4 - Loans and Allowance for Credit Losses - Schedule of Total Loans Outstanding by Portfolio Segment (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Mar. 31, 2026	Dec. 31, 2025	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	$ 1,106,100		$ 1,064,259
Allowance for credit losses	(14,795)	$ (14,803)	(14,519)	$ (16,122)	$ (16,535)	$ (15,885)
Deferred origination fees and costs, net	793		733
Loans, net	1,092,098		1,050,473
Commercial Portfolio Segment [Member]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	214,185		146,178
Allowance for credit losses	(2,670)	(2,608)	(2,425)	(2,523)	(2,064)	(1,622)
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	688,569		702,455
Allowance for credit losses	(9,122)	(9,185)	(9,343)	(9,782)	(8,871)	(10,245)
Agricultural Portfolio Segment [Member]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	86,474		93,627
Allowance for credit losses	(1,120)	(1,149)	(1,074)	(1,983)	(3,932)	(1,555)
Residential Mortgage [Member]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	98,448		100,684
Allowance for credit losses	(1,220)	(1,212)	(1,005)	(1,038)	(980)	(1,779)
Residential Portfolio Segment [Member]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	4,292		5,837
Allowance for credit losses	(353)	(364)	(376)	(499)	(407)	(433)
Consumer Portfolio Segment [Member]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	14,132		15,478
Allowance for credit losses	$ (310)	$ (285)	$ (296)	$ (297)	$ (281)	$ (251)