Note 10 - Stock Repurchase Plan (Details Textual) - USD ($) $ in Thousands	9 Months Ended		23 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Oct. 27, 2015
Stock Repurchase Program, Authorized Amount				$ 5,000
Stock Repurchased and Retired During Period, Shares	13,883	209,271	297,020
Stock Repurchased and Retired During Period, Value	$ 62	$ 841	$ 1,195