Note G - Employee Benefit Plans - Defined Benefit Pension Plan's Weighted Average Asset Association and Weighted Average Target Allocation (Details)	Jun. 30, 2019	Jun. 30, 2018
Weighted-average asset allocation	100.00%	100.00%
Weighted-average target allocation	100.00%
Equity Securities [Member]
Weighted-average asset allocation	52.00%	51.00%
Weighted-average target allocation	49.00%
Debt Securities [Member]
Weighted-average asset allocation	38.00%	47.00%
Weighted-average target allocation	46.00%
Commodity Contract [Member]
Weighted-average asset allocation	2.00%	0.00%
Weighted-average target allocation	2.00%
Cash and Cash Equivalents [Member]
Weighted-average asset allocation	8.00%	2.00%
Weighted-average target allocation	3.00%