Note H - Employee Benefit Plans - Defined Benefit Pension Plan's Weighted Average Asset Association and Weighted Average Target Allocation (Details)	Jun. 30, 2020	Jun. 30, 2019
Weighted-average asset allocation	100.00%	100.00%
Weighted-average target allocation	100.00%
Equity Securities [Member]
Weighted-average asset allocation	52.00%	52.00%
Weighted-average target allocation	54.00%
Debt Securities [Member]
Weighted-average asset allocation	32.00%	38.00%
Weighted-average target allocation	43.00%
Commodity Contract [Member]
Weighted-average asset allocation	12.00%	2.00%
Weighted-average target allocation	0.00%
Cash and Cash Equivalents [Member]
Weighted-average asset allocation	4.00%	8.00%
Weighted-average target allocation	3.00%