Note 5 - Financial Instruments and Fair Value Measurements - Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Fair Value, Inputs, Level 1 [Member] | Reported Value Measurement [Member]
Cash and cash equivalents	$ 180,300	$ 216,568
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value Measurement [Member]
Cash and cash equivalents	180,300	216,568
Fair Value, Inputs, Level 2 [Member] | Reported Value Measurement [Member]
Restricted equity securities	6,285	5,956
Interest receivable	8,350	8,386
Interest payable	(200)	(128)
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member]
Restricted equity securities	6,285	5,956
Interest receivable	8,350	8,386
Interest payable	(200)	(128)
Fair Value, Inputs, Level 3 [Member] | Reported Value Measurement [Member]
Loans, net	1,057,598	1,004,277
Deposits	(1,644,748)	(1,650,534)
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member]
Loans, net	982,842	917,242
Deposits	(1,644,038)	(1,649,808)
Commitments and standby letters of credit	$ (1,638)	$ (1,863)