Income Taxes - Components of the Temporary Differences (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Jun. 30, 2024
Deferred tax assets:
Postretirement benefits	$ 1,820	$ 3,290
Accrued liabilities	3,061	2,121
163(j) Interest Limitation	10,330	9,633
Net operating loss carryforward	51,318	54,981
Intangible assets	4,921	5,476
Right-of-use operating lease liabilities	9,687	9,009
Other	7,617	5,128
Total deferred tax assets	88,754	89,638
Deferred tax liabilities:
Property, plant and equipment	(3,524)	(4,086)
Right-of-use operating lease assets	(9,532)	(8,865)
Other	(1,186)	(1,284)
Total deferred tax liabilities	(14,242)	(14,235)
Valuation allowance	(74,512)	(75,403)
Net deferred tax liability	$ 0	$ 0