Note 18 - Financial and Off-balance Sheet Instruments (Details) - USD ($)	Dec. 31, 2024	Dec. 31, 2023
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 50,713,000	$ 62,657,000
Available-for-sale	546,559,000	490,182,000
Equity securities	0	5,910,000
Restricted investment in stocks	5,436,000	2,730,000
Loans held for sale	664,000	549,000
Net loans	1,207,304,000	1,084,681,000
Mortgage servicing rights	378,000	415,000
Accrued interest receivable	4,965,000	6,101,000
Deposits	1,628,541,000	1,488,713,000
Federal Funds Purchased and Securities Sold under Agreements to Repurchase	53,844,000	94,094,000
Long-term debt	30,000,000	20,000,000
Subordinated debt	39,068,000
Accrued interest payable	7,580,000	5,294,000
Cash and cash equivalents	50,713,000	62,657,000
Restricted investment in bank stocks	5,436,000	2,730,000
Loans held for sale	664,000	560,000
Net loans	1,212,780,000	1,077,544,000
Mortgage servicing rights	556,000	585,000
Accrued interest receivable	4,965,000	6,101,000
Short-term borrowings	53,844,000	94,094,000
Long-term debt	30,033,000	19,906,000
Subordinated debt	40,600,000
Accrued interest payable	7,580,000	5,294,000
Fair Value, Inputs, Level 1 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Equity securities	0	5,910,000
Cash and cash equivalents	50,713,000	62,657,000
Short-term borrowings	53,844,000	94,094,000
Fair Value, Inputs, Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Available-for-sale	546,508,000	490,130,000
Restricted investment in bank stocks	5,436,000	2,730,000
Loans held for sale	664,000	560,000
Accrued interest receivable	4,965,000	6,101,000
Long-term debt	30,033,000	19,906,000
Subordinated debt	40,600,000
Accrued interest payable	7,580,000	5,294,000
Fair Value, Inputs, Level 3 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Available-for-sale	51,000	52,000
Net loans	1,212,780,000	1,077,544,000
Mortgage servicing rights	556,000	585,000
Standby Letters of Credit [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Commitments to extend credit	59,000	79,000
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	59,000	79,000
With No Stated Maturities [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Deposits	1,247,083,000	1,173,732,000
Deposits	1,247,083,000	1,173,732,000
With No Stated Maturities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Deposits	1,247,083,000	1,173,732,000
With Stated Maturities [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Deposits	381,458,000	314,981,000
Deposits	379,960,000	311,735,000
With Stated Maturities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Deposits	$ 379,960,000	$ 311,735,000