Note F - Debt (Details Textual) - Wells Fargo Bank, N.A. [Member] - Credit Agreement [Member] - USD ($)			12 Months Ended
	May 24, 2021	Feb. 02, 2021	Jun. 30, 2020	Jun. 30, 2021
Line of Credit Facility, Maximum Borrowing Capacity	$ 20,000,000
Debt Instrument Covenant Minimum, Net Income Required	1
Debt Instrument Covenant Capital Expenditures Limitation, Amount, Next Twelve Years				$ 10,000,000
Debt Instrument Covenant Capital Expenditures Limitation, Amount, After Twelve Years				7,500,000
Long-term Debt, Percentage Bearing Fluctuating Interest, Threshold Amount	100,000
Minimum Prepayment Amount Under Line of Credit	$ 100,000
Line of Credit Facility, Commitment Fee Percentage	0.125%
Proceeds from Long-term Lines of Credit			$ 10,000,000
Repayments of Lines of Credit		$ 10,000,000
Line of Credit Facility, Remaining Borrowing Capacity				$ 20,000,000
London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate	1.25%
Debt Instrument Basis Spread on Elected Fixed Rate Borrowing	1.25%
Maximum [Member]
Ratio of Indebtedness to Net Capital	1.25
Ratio of Total Current Assets to Total Current Liabilities	1.75