Note 3 - Net Income Per Share - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Net income	$ 20,007	$ 15,213	$ 12,091
Weighted-average shares outstanding (in shares)	30,386	30,571	30,648
Effect of dilutive shares (in shares)	158	102	69
Weighted-average diluted shares (in shares)	30,544	30,673	30,717
Net income per share:
Basic (in dollars per share)	$ 0.66	$ 0.5	$ 0.39
Diluted (in dollars per share)	$ 0.66	$ 0.5	$ 0.39