Note 9 - Net Loss Per Share of Common Stock - Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Net loss	$ (1,696)	$ (3,630)
Basic (in shares)	23,103	22,546
Effect of stock -based awards (in shares)	0	0
Diluted (in shares)	23,103	22,546
Basic net loss per share (in dollars per share)	$ (0.07)	$ (0.16)
Diluted net loss per share (in dollars per share)	$ (0.07)	$ (0.16)