Note 7 - Loans and the Allowance for Loan Losses - (Details Textual) - USD ($)	Dec. 31, 2023	Jan. 01, 2023	Dec. 31, 2022
Financing Receivable, Unamortized Loan Cost (Fee)	$ 12,600,000		$ 13,100,000
Loans and Leases Receivable Reclassified from Overdraft	2,200,000		2,000,000
Loan, Securitized or Asset-Backed Financing Arrangement, Principal Outstanding	723,500,000		683,300,000
Servicing Asset	1,100,000		1,700,000
Financing Receivable, 90 Days or More Past Due, Still Accruing	127,000		335,000
Financing Receivable, Nonaccrual	16,943,000	$ 18,088,000	11,054,000
Financing Receivable Accrued Interest Receivable, Loans Deferrals	4,200,000		5,400,000
Financing Receivable, Accrued Interest, after Allowance for Credit Loss	$ 25,200,000		$ 21,200,000
Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, Nonaccrual, Purchased Credit Deteriorated		$ 7,000,000