Note G - Employee Benefit Plans - Defined Benefit Pension Plan's Weighted Average Asset Association and Weighted Average Target Allocation (Details)	Jun. 30, 2018	Jun. 30, 2017
Weighted-average asset allocation	100.00%	100.00%
Weighted-average target allocation	100.00%
Equity Securities [Member]
Weighted-average asset allocation	51.00%	41.00%
Weighted-average target allocation	49.00%
Debt Securities [Member]
Weighted-average asset allocation	47.00%	44.00%
Weighted-average target allocation	46.00%
Commodity Contract [Member]
Weighted-average asset allocation	0.00%	2.00%
Weighted-average target allocation	2.00%
Cash and Cash Equivalents [Member]
Weighted-average asset allocation	2.00%	13.00%
Weighted-average target allocation	3.00%