Note N - Pension and Other Postretirement Benefit Plans - Schedule of Assumptions (Details)	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Pension Plan [Member]
Discount rate	2.49%	3.22%
Expected return on plan assets	5.89%	6.04%
Discount rate	3.22%	4.01%
Expected return on plan assets	6.04%	6.74%
Other Postretirement Benefits Plan [Member]
Discount rate	2.37%	3.15%
Expected return on plan assets
Discount rate	3.15%	4.09%
Expected return on plan assets