Note N - Pension and Other Postretirement Benefit Plans - Net Funded Status of Pension and Postretirement Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Actuarial loss (gain)	$ 2,079
Net amount recognized	(8,062)	$ (5,948)
Pension Plan [Member]
Benefit obligation, beginning of year	72,242	79,549
Service cost	373	340
Interest cost	3,609	3,571
Prior service cost	0	20
Actuarial loss (gain)	254	(3,361)
Contributions by plan participants	116	112
Benefits paid	(8,484)	(7,989)
Benefit obligation, end of year	68,110	72,242
Fair value of assets, Balance	67,338	73,338
Actual return on plan assets	3,101	1,141
Employer contribution	589	736
Contributions by plan participants	116	112
Benefits paid	(8,484)	(7,989)
Fair value of assets, Balance	62,660	67,338
Funded status	(5,450)	(4,904)
Other assets - noncurrent	0	28
Accrued liabilities - current	(260)	(308)
Accrued retirement benefits - noncurrent	(5,190)	(4,624)
Net amount recognized	(5,450)	(4,904)
Net transition obligation	53	83
Prior service benefit	(145)	(42)
Actuarial net loss (gain)	8,768	7,064
Net amount recognized	8,676	7,105
Other Postretirement Benefits Plan [Member]
Benefit obligation, beginning of year	3,685	4,785
Service cost	8	10
Interest cost	191	213
Prior service cost	0	0
Actuarial loss (gain)	(166)	(633)
Contributions by plan participants	0	0
Benefits paid	(549)	(690)
Benefit obligation, end of year	3,169	3,685
Fair value of assets, Balance	0	0
Actual return on plan assets	0	0
Employer contribution	549	690
Contributions by plan participants	0	0
Benefits paid	(549)	(690)
Fair value of assets, Balance	0	0
Funded status	(3,169)	(3,685)
Other assets - noncurrent	0	0
Accrued liabilities - current	(505)	(701)
Accrued retirement benefits - noncurrent	(2,664)	(2,984)
Net amount recognized	(3,169)	(3,685)
Net transition obligation	0	0
Prior service benefit	0	(67)
Actuarial net loss (gain)	(614)	(1,090)
Net amount recognized	$ (614)	$ (1,157)