Note 17 - Financial and Off-balance Sheet Instruments (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 62,657,000	$ 15,899,000
Investment securities available-for-sale, debt securities	490,182,000	546,525,000
Equity Securities, FV-NI, Current	5,910,000	12,056,000
Restricted investment in bank stocks	2,730,000	5,193,000
Loans held for sale	549,000
Net loans	1,084,681,000	1,028,854,000
Mortgage servicing rights	415,000	469,000
Accrued interest receivable	6,101,000	5,038,000
Deposits	1,488,713,000	1,418,369,000
Federal Funds Purchased and Securities Sold under Agreements to Repurchase	94,094,000	161,327,000
Long-term debt	20,000,000	10,000,000
Accrued interest payable	5,294,000	467,000
Cash and cash equivalents	62,657,000	15,899,000
Restricted investment in bank stocks	2,730,000	5,193,000
Loans held for sale	560,000
Net loans	1,077,544,000	1,001,103,000
Mortgage servicing rights	585,000	638,000
Accrued interest receivable	6,101,000	5,038,000
Short-term borrowings	94,094,000	161,327,000
Long-term debt	19,906,000	10,000,000
Accrued interest payable	5,294,000	467,000
Fair Value, Inputs, Level 1 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Equity Securities, FV-NI, Current	5,910,000	12,056,000
Cash and cash equivalents	62,657,000	15,899,000
Short-term borrowings	94,094,000	161,327,000
Long-term debt	19,906,000	10,000,000
Fair Value, Inputs, Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investment securities available-for-sale, debt securities	490,130,000	546,472,000
Restricted investment in bank stocks	2,730,000	5,193,000
Accrued interest receivable	6,101,000	5,038,000
Accrued interest payable	5,294,000	467,000
Fair Value, Inputs, Level 3 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investment securities available-for-sale, debt securities	52,000	53,000
Net loans	1,077,544,000	1,001,103,000
Mortgage servicing rights	585,000	638,000
Standby Letters of Credit [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Commitments to extend credit	79,000	69,000
Standby Letters of Credit [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Commitments to extend credit	79,000	69,000
With No Stated Maturities [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Deposits	1,173,732,000	1,242,920,000
Deposits	1,173,732,000	1,242,920,000
With No Stated Maturities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Deposits	1,173,732,000	1,242,920,000
With Stated Maturities [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Deposits	314,981,000	175,449,000
Deposits	311,735,000	168,554,000
With Stated Maturities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Deposits	$ 311,735,000	$ 168,554,000