Income Taxes - Components of the Temporary Differences (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Jun. 30, 2023
Deferred tax assets:
Postretirement benefits	$ 3,290	$ 5,349
Accrued liabilities	2,121	2,642
163(j) Interest Limitation	9,633	7,772
Net operating loss carryforward	54,981	55,566
Intangible assets	5,476	6,481
Right-of-use operating lease liabilities	9,009	6,346
Other	5,128	5,436
Total deferred tax assets	89,638	89,592
Deferred tax liabilities:
Property, plant and equipment	(4,086)	(725)
Right-of-use operating lease assets	(8,865)	(6,194)
Other	(1,284)	(2,238)
Total deferred tax liabilities	(14,235)	(9,157)
Valuation allowance	(75,403)	(80,435)
Net deferred tax liability	$ 0	$ 0