Note D - Marketable Securities - Details of Marketable Securities (Details) - Iron Net [Member] - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Equity Funds And Other Securities [Member]
Fair value	$ 16,852	$ 16,539
Basis	17,024	17,024
Cumulative unrealized (loss) gain	(172)	(485)
Iron Net Securities [Member]
Fair value	16,887	16,585
Basis	19,152	21,297
Cumulative unrealized (loss) gain	(2,265)	(4,712)
Common Stock [Member]
Fair value	35	46
Basis	2,128	4,273
Cumulative unrealized (loss) gain	$ (2,093)	$ (4,227)