Note 10 - Net Income Per Share - Computation of Basic and Diluted Net Income per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Net income	$ 7,502	$ 8,098	$ 6,040	$ 5,456	$ 3,515	$ 6,038	$ 21,640	$ 15,009
Basic (in shares)	22,263			21,984			22,196	21,959
Basic earnings per share (in dollars per share)	$ 0.34			$ 0.25			$ 0.97	$ 0.68
Common stock equivalents, if dilutive (in shares)	218			233			215	190
Shares used in computing diluted earnings per common share (in shares)	22,481			22,217			22,411	22,149
Diluted earnings per share (in dollars per share)	$ 0.33			$ 0.25			$ 0.97	$ 0.68
Shares excluded in computing diluted earnings per share as those shares would be anti-dilutive (in shares)	192			159			286	286