Note D - Net Income (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, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net income	$ (1,891)	$ 484	$ (5,434)	$ (1,103)
Net earnings (loss) per share:
Basic (in dollars per share)	$ (0.08)	$ 0.02	$ (0.23)	$ (0.05)
Diluted (in dollars per share)	$ (0.08)	$ 0.02	$ (0.23)	$ (0.05)
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)	23,562	22,957	23,399	22,752
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)	0	983	0	0
Weighted average number of shares of common stock used to compute diluted net earnings (loss) per share (in thousands) (in shares)	23,562	23,940	23,399	22,752