Note 8 - Treasury Stock (Details Textual) - USD ($) $ / shares in Units, $ in Thousands			12 Months Ended			96 Months Ended
	Dec. 12, 2018	Aug. 01, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2016	Dec. 31, 2019	Dec. 31, 2013	Dec. 31, 2012
Stock Repurchase Program, Number of Shares Authorized to be Repurchased					1,500,000		1,000,000	500,000
Stock Repurchase Program, Additional Shares Authorized					500,000
Treasury Stock, Shares, Acquired	50,000	100,000	45,707			1,309,861
Treasury Stock Acquired, Average Cost Per Share			$ 5.66			$ 4.85
Treasury Stock, Value, Acquired, Cost Method			$ 259	$ 1,200		$ 6,400
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased			190,139			190,139