Note M - Pension and Other Postretirement Benefit Plans - Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Pension Plan [Member]
Net loss	$ (12,464)	$ 4,770
Amortization of transition asset	(40)	(35)
Amortization of prior service (cost) benefit	(43)	(45)
Amortization of net loss	(3,246)	(2,978)
Total recognized in other comprehensive income	(15,793)	1,712
Net periodic benefit cost (benefit)	1,977	2,120
Total recognized in net periodic benefit cost and other comprehensive income	(13,816)	3,832
Other Postretirement Benefits Plan [Member]
Net loss	(397)	211
Amortization of transition asset	0	0
Amortization of prior service (cost) benefit	275	275
Amortization of net loss	0	0
Total recognized in other comprehensive income	(122)	486
Net periodic benefit cost (benefit)	(104)	(38)
Total recognized in net periodic benefit cost and other comprehensive income	$ (226)	$ 448