Note 6 - Earnings Per Share - Calculation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Net income	$ 1,957	$ 1,600	$ 5,367	$ 4,170
Basic earnings per share (in dollars per share)	$ 0.40	$ 0.33	$ 1.11	$ 0.87
Diluted earnings per share (in dollars per share)	$ 0.39	$ 0.32	$ 1.06	$ 0.82
Basic shares (in shares)	4,868	4,824	4,856	4,812
Diluted shares (in shares)	5,035	5,067	5,052	5,061