Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Deferred tax assets:
Post-retirement benefit obligation	$ 1,229	$ 1,350
Expenses currently not deductible	59,518	52,526
Net operating loss carryforward	86,716	107,395
Tax credit carryforward	5,137	4,581
Depreciation and amortization	4,286	7,404
Inventory	10,795	12,238
Capitalized R&D costs	20,556	18,178
Leases	21,490	23,987
Other	0	2,867
Valuation allowance	(65,007)	(79,355)
Deferred tax assets, net	144,720	151,171
Deferred tax liabilities:
Depreciation and amortization	(125,227)	(120,055)
Leases	(22,084)	(23,987)
Outside basis differences and other	(87,434)	(79,985)
Total deferred tax liabilities	(234,745)	(224,027)
Total deferred tax liabilities, net	$ (90,025)	$ (72,856)