Note A - Basis of Presentation and Summary of Significant Accounting Policies - Calculation of Basic and Diluted Net Income Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		105 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022	Sep. 25, 2031
Numerator
Net income	$ (2,381)	$ 2,504	$ 485	$ 7,607	$ (2,381)
Denominator
Basic weighted average common shares outstanding (in shares)	5,816,000	6,003,036	5,867,400	6,167,539	5,816,058
Dilutive effect of restricted stock (in shares)	0	38,000	18,000	48,000
Diluted weighted average common shares outstanding (in shares)	5,816,000	6,041,424	5,885,116	6,216,422	5,816,058
Basic net (loss) income per common share (in dollars per share)	$ (0.41)	$ 0.42	$ 0.08	$ 1.23	$ (0.41)
Diluted net (loss) income per common share (in dollars per share)	$ (0.41)	$ 0.41	$ 0.08	$ 1.22	$ (0.41)