Note 5 - Amounts Reclassified Out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	$ 3,996	$ 4,820	$ 8,530	$ 11,143
Tax effect	(647)	(951)	(1,471)	(2,224)
Net income	3,349	3,869	7,059	8,919
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Unrealized net holding gains on available-for-sale securities	3	2	4	5
Income before income taxes	3	2	4	5
Tax effect	(1)		(1)	(1)
Net income	$ 2	$ 2	$ 3	$ 4