Note 13 - Loss Per Common Share - Calculation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net loss	$ (1,534)	$ (1,902)	$ (9,561)	$ (7,324)
Basic and diluted weighted average number of shares outstanding (in shares)	28,527,234	20,991,534	28,507,286	20,969,735
Basic and diluted loss per common share (in dollars per share)	$ (0.05)	$ (0.09)	$ (0.34)	$ (0.35)