Note 7 - Net Loss Per Common Share - Calculation of Diluted Shares (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net income (loss) attributable to common stockholders	$ 427	$ (103)
Weighted average shares outstanding used to compute basic earnings per share (in shares)	18,648,397	14,098,610
Effect of dilutive securities (in shares)	5,710,078
Weighted average diluted shares (in shares)	24,358,475	14,098,610
Basic net income (loss) per common share (in dollars per share)	$ 0.02	$ (0.01)
Diluted net income (loss) per common share (in dollars per share)	$ 0.02	$ (0.01)