Note 2 - Summary of Significant Accounting Policies - Calculation of Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Net loss	$ (1,582)	$ (4,189)
Weighted average shares of common stock outstanding, basic and diluted (in shares)	27,978	17,093
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.06)	$ (0.25)