Income Taxes - Components of the Temporary Differences (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Jun. 30, 2021
Deferred Tax Assets: [Abstract]
Postretirement benefits	$ 7,284	$ 9,364
Accrued liabilities	4,759	4,245
163(j) Interest Limitation	4,040	3,069
Net operating loss carryforward	51,413	48,195
Intangible assets	6,936	7,377
Right-of-use operating lease liabilities	7,041	6,592
Other	7,650	6,292
Total deferred tax assets	89,123	85,134
Deferred tax liabilities: [Abstract]
Property, plant and equipment	(15,726)	(15,448)
Right-of-use operating lease assets	7,174	6,606
Other	(79)	72
Total deferred tax liabilities	(22,979)	(21,982)
Valuation allowance	(66,879)	(64,312)
Net deferred tax liability	$ (735)	$ (1,160)