Segment Reporting - Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2025	Sep. 27, 2024	Sep. 26, 2025	Sep. 27, 2024
Segment Reporting Information [Line Items]
Net sales	$ 444,808	$ 436,715	$ 1,296,796	$ 1,247,868
Cost of sales	358,685	355,777	1,051,836	1,014,859
Selling, general, and administrative expense	38,256	35,009	108,740	104,454
Other segment items	12,213	14,028	35,319	41,060
Depreciation, depletion, and amortization	17,504	18,593	51,551	51,291
Segment EBITDA	53,158	50,494	152,452	138,786
Income tax expense	2,698	768	9,960	6,836
Interest expense—net	7,544	8,839	22,691	25,920
Net income	25,412	22,294	68,250	54,739
Performance Materials
Segment Reporting Information [Line Items]
Net sales	170,787	177,376	527,552	533,534
Cost of sales	125,909	125,587	385,435	392,935
Selling, general, and administrative expense	14,228	14,046	42,451	41,344
Other segment items	4,018	3,655	10,889	10,938
Depreciation, depletion, and amortization	10,279	10,714	29,901	27,576
Segment EBITDA	36,911	44,802	118,678	115,893
Electronic Materials
Segment Reporting Information [Line Items]
Net sales	246,837	236,906	696,059	641,564
Cost of sales	213,746	213,503	611,969	568,010
Selling, general, and administrative expense	10,731	9,728	30,475	29,443
Other segment items	5,878	5,893	16,982	17,634
Depreciation, depletion, and amortization	4,443	4,527	12,971	13,641
Segment EBITDA	20,925	12,309	49,604	40,118
Precision Optics
Segment Reporting Information [Line Items]
Net sales	27,184	22,433	73,185	72,770
Cost of sales	18,892	16,602	54,211	53,810
Selling, general, and administrative expense	4,896	4,941	13,598	15,460
Other segment items	2,442	3,824	8,720	10,825
Depreciation, depletion, and amortization	2,277	2,895	7,192	8,622
Segment EBITDA	3,231	(39)	3,848	1,297
Other
Segment Reporting Information [Line Items]
Net sales	0	0	0	0
Cost of sales	138	85	221	104
Selling, general, and administrative expense	8,401	6,294	22,216	18,207
Other segment items	(125)	656	(1,272)	1,663
Depreciation, depletion, and amortization	505	457	1,487	1,452
Segment EBITDA	(7,909)	(6,578)	(19,678)	(18,522)
Advanced Material Technologies | Intersegment Eliminations
Segment Reporting Information [Line Items]
Net sales	$ 1,000	$ 1,600	$ 5,600	$ 4,800