Note C - Net Earnings (Loss) Per Share - Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net income	$ 405	$ 578	$ (1,637)	$ (2,874)
Income (loss) per share:
Basic (in dollars per share)	$ 0.02	$ 0.03	$ (0.07)	$ (0.13)
Diluted (in dollars per share)	$ 0.02	$ 0.02	$ (0.07)	$ (0.13)
Weighted average number of shares of common stock outstanding during the period used to compute basic net earnings (loss) per share (in thousands) (in shares)	22,449	22,276	22,603	22,186
Incremental shares attributable to exercise of outstanding options, stock appreciation rights and restricted stock units (assuming proceeds would be used to purchase treasury stock) (in thousands) (in shares)	889	967
Weighted average number of shares of common stock used to compute diluted net earnings (loss) per share (in thousands) (in shares)	23,338	23,243	22,603	22,186