Note 7 - Treasury Stock (Details Textual) - shares	12 Months Ended
	Dec. 31, 2015	May. 11, 2015	Dec. 31, 2014	Nov. 08, 2012
Purchase Agreement [Member]
Treasury Stock, Shares, Acquired	0
Treasury Stock, Shares, Acquired	410,591
Stock Repurchase Program, Number of Shares Authorized to be Repurchased		532,235		500,000
Treasury Stock, Shares	119,695		121,663