Note 3 - Net Income Per Share - Summary of Basic and Diluted Net Income Per Share Calculations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Basic shares (in shares)	6,151,701	6,139,148	6,147,325	6,137,207
Dilutive shares (in shares)	272,550	177,050	272,550	177,050
Diluted shares (in shares)	6,424,251	6,316,198	6,419,875	6,314,257
Net income	$ 550	$ 544	$ 1,329	$ 2,154
Basic net income per share (in dollars per share)	$ 0.09	$ 0.09	$ 0.22	$ 0.35
Diluted net income per share (in dollars per share)	$ 0.09	$ 0.09	$ 0.21	$ 0.34