Note 10 - Financial Instrument Commitments (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Commitments And Contingencies Disclosure [Line Items]
Total financial instrument commitments	$ 387,281	$ 346,770
Commitments to Extend Credit [Member]
Commitments And Contingencies Disclosure [Line Items]
Total financial instrument commitments	368,719	325,449
Standby Letters of Credit [Member]
Commitments And Contingencies Disclosure [Line Items]
Total financial instrument commitments	$ 18,562	$ 21,321