Business Segments - Schedule of Financial Information Concerning Corporation's Reportable Segments (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Sales	$ 104,265	$ 110,215
Costs of products sold (excluding depreciation and amortization)	82,104	92,490
Selling and administrative	13,659	12,973
Depreciation and amortization	4,636	4,670
Income from operations	3,850	82
Reconciliation to income (loss) before income taxes
Interest expense	(2,726)	(2,757)
Income (loss) before income taxes	1,950	(1,752)
Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Sales	104,265	110,215
Income from operations	7,399	3,558
Operating Segments | FCEP
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Sales	72,287	77,189
Costs of products sold (excluding depreciation and amortization)	57,613	65,451
Selling and administrative	6,385	5,732
Depreciation and amortization	4,368	4,430
Loss on disposal of assets	16
Income from operations	3,905	1,576
Operating Segments | ALP
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Sales	31,978	33,026
Costs of products sold (excluding depreciation and amortization)	24,491	27,039
Selling and administrative	3,725	3,765
Depreciation and amortization	268	240
Income from operations	3,494	1,982
Reconciling Item, Excluding Corporate Nonsegment
Reconciliation to income (loss) before income taxes
Interest expense	(2,726)	(2,757)
Other income - net	826	923
Corporate Nonsegment
Reconciliation to income (loss) before income taxes
Unallocated corporate costs	$ (3,549)	$ (3,476)