Note 4 - Earnings Per Share - 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 Income (Loss) Attributable to Parent, Total	$ 621	$ 246	$ (1,018)	$ 346
Weighted average shares used in basic net income per share calculation (in dollars per share)	$ 20,654	$ 20,602	$ 20,650	$ 20,633
Weighted average shares used in diluted net income per share calculation (in dollars per share)	21,320	21,320	20,650	21,331
Basic and diluted net income (loss) per common share (in dollars per share)	$ 0.03	$ 0.01	$ (0.05)	$ 0.02