Note 8 - Short-term Borrowings - Components of Short-term Borrowings (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Short-term borrowings	$ 117,000	$ 12,940
Maximum outstanding at any month end	149,010	12,940
Average Outstanding Amount	49,860	1,031
Overnight Borrowings [Member]
Short-term borrowings	60,000	12,930
Maximum outstanding at any month end	92,000	12,930
Average Outstanding Amount	$ 22,148	$ 1,025
Weighted Average Interest Rate	5.08%	4.39%
Interest Rate At Year End	5.50%	4.45%
Other Short-term Borrowings [Member]
Short-term borrowings	$ 57,000	$ 10
Maximum outstanding at any month end	10	10
Average Outstanding Amount	5	$ 6
Weighted Average Interest Rate		0.00%
Federal Reserve Bank Term Funding Program [Member]
Maximum outstanding at any month end	57,000
Average Outstanding Amount	$ 27,707
Weighted Average Interest Rate	4.49%
Interest Rate At Year End	4.59%