Note H - Earnings Per Share - Computations of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Net income	$ 3,451	$ 5,795	$ 10,378	$ 18,203
Basic (in shares)	6,439	7,186	6,703	7,346
Dilutive effect of common stock equivalents (in shares)	19	33	22	39
Diluted (in shares)	6,458	7,219	6,725	7,385
Basic (in dollars per share)	$ 0.54	$ 0.81	$ 1.55	$ 2.48
Diluted (in dollars per share)	$ 0.53	$ 0.80	$ 1.54	$ 2.46