Note 1 - Significant Accounting Policies - Noninterest Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Service Charges on Deposit and Sweep Accounts [Member]
Noninterest revenue	$ 4,954	$ 5,952	$ 5,078
Credit and Debit Card [Member]
Noninterest revenue	8,914	8,216	7,516
Payroll Processing [Member]
Noninterest revenue	2,509	2,178	1,815
Customer Service [Member]
Noninterest revenue	$ 801	$ 852	$ 857