Note O - 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, 2019	Jun. 30, 2018
Pension Plan [Member]
Net loss	$ 8,098	$ (5,643)
Prior service cost	(211)
Amortization of transition asset	(34)	(34)
Amortization of prior service (cost) benefit	(64)	(67)
Amortization of net (loss) gain	(2,711)	(2,952)
Total recognized in other comprehensive income	5,078	(8,696)
Net periodic benefit cost	2,381	1,932
Total recognized in net periodic benefit cost and other comprehensive income	7,459	(6,764)
Amortization of transition asset	(34)	(34)
Amortization of net (loss) gain	(2,711)	(2,952)
Net periodic benefit cost	2,381	1,932
Other Postretirement Benefits Plan [Member]
Net loss	18	(940)
Prior service cost		(1,668)
Amortization of transition asset
Amortization of prior service (cost) benefit	275	206
Amortization of net (loss) gain		(32)
Total recognized in other comprehensive income	293	(2,434)
Net periodic benefit cost	48	171
Total recognized in net periodic benefit cost and other comprehensive income	341	(2,263)
Amortization of transition asset
Amortization of net (loss) gain		(32)
Net periodic benefit cost	$ 48	$ 171