Note C - Marketable Equity Securities - Cost, Market Value and Unrealized Gain/(Loss) on Equity Securities (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Fair market value	$ 25,614	$ 24,575
Cost	15,594	16,015
Unrealized gain	$ 10,020	$ 8,560