Note 14 - Stock Repurchase Plan (Details Textual) - USD ($) $ in Thousands	12 Months Ended		26 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Oct. 27, 2015
Stock Repurchase Program, Authorized Amount				$ 5,000
Stock Repurchased and Retired During Period, Shares	13,883	241,805	297,020
Stock Repurchased and Retired During Period, Value	$ 62	$ 978	$ 1,195