Note 10 - Financial Instrument Commitments (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Commitments And Contingencies Disclosure [Line Items]
Total financial instrument commitments	$ 401,749	$ 397,774
Commitments to Extend Credit [Member]
Commitments And Contingencies Disclosure [Line Items]
Total financial instrument commitments	383,941	378,954
Standby Letters of Credit [Member]
Commitments And Contingencies Disclosure [Line Items]
Total financial instrument commitments	$ 17,808	$ 18,820