Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2025	Sep. 28, 2024	Sep. 27, 2025	Sep. 28, 2024
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	$ 1,563,966	$ 1,421,891	$ 4,426,078	$ 4,297,482
Cost of sales and operating expenses (excludes depreciation and amortization, shown separately below)	1,176,957	1,108,319	3,381,801	3,353,406
Gross margin	387,009	313,572	1,044,277	944,076
Loss/(gain) on sale of assets	(375)	251	639	(101)
Selling, general and administrative expenses	139,594	115,717	399,219	384,591
Acquisition and integration costs	6,156	218	11,073	5,402
Change in fair value of contingent consideration	0	16,156	18,024	(42,215)
Depreciation and amortization	124,064	123,553	368,961	375,667
Equity in net income/(loss) of Diamond Green Diesel	(45,844)	2,430	(70,367)	125,046
Operating income	71,726	60,107	175,994	345,778
Equity in net income of other unconsolidated subsidiaries	3,277	3,782	8,431	9,109
Segment income/(loss)	75,003	63,889	184,425	354,887
Total other expense (b)	(55,196)	(62,245)	(171,256)	(185,609)
Income before income taxes	19,807	1,644	13,169	169,278
Investment Income, Interest	1,300	3,600	11,900	12,100
Casualty Gain (Loss)	(200)	3,800	(1,700)	11,600
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	(200)	(400)	(6,900)	(1,300)
Gain on sale of a portion of a small international subsidiary	1,700		1,700
Other Nonoperating Income (Expense), Miscellaneous	(1,900)	(2,300)	(7,500)	(9,600)
Corporate
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	0	0	0	0
Cost of sales and operating expenses (excludes depreciation and amortization, shown separately below)	0	0	0	0
Gross margin	0	0	0	0
Loss/(gain) on sale of assets	0	0	0	0
Selling, general and administrative expenses	22,329	12,164	49,892	52,143
Acquisition and integration costs	6,156	218	11,073	5,402
Change in fair value of contingent consideration		0	0	0
Depreciation and amortization	1,506	2,033	4,549	6,504
Equity in net income/(loss) of Diamond Green Diesel	0	0	0	0
Operating income	(29,991)	(14,415)	(65,514)	(64,049)
Equity in net income of other unconsolidated subsidiaries	0	0	0	0
Segment income/(loss)	(29,991)	(14,415)	(65,514)	(64,049)
Feed Ingredients
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	1,029,115	927,457	2,861,930	2,751,452
Feed Ingredients | Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	1,029,115	927,457	2,861,930	2,751,452
Cost of sales and operating expenses (excludes depreciation and amortization, shown separately below)	779,306	727,642	2,215,402	2,171,282
Gross margin	249,809	199,815	646,528	580,170
Loss/(gain) on sale of assets	(125)	204	1,075	541
Selling, general and administrative expenses	75,938	67,445	224,973	218,598
Acquisition and integration costs	0	0	0	0
Change in fair value of contingent consideration		16,156	18,024	(42,215)
Depreciation and amortization	83,590	85,480	251,139	259,493
Equity in net income/(loss) of Diamond Green Diesel	0	0	0	0
Operating income	90,406	30,530	151,317	143,753
Equity in net income of other unconsolidated subsidiaries	3,277	3,782	8,431	9,109
Segment income/(loss)	93,683	34,312	159,748	152,862
Food Ingredients
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	380,574	357,292	1,115,956	1,127,415
Food Ingredients | Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	380,574	357,292	1,115,956	1,127,415
Cost of sales and operating expenses (excludes depreciation and amortization, shown separately below)	275,751	271,861	804,765	846,766
Gross margin	104,823	85,431	311,191	280,649
Loss/(gain) on sale of assets	(65)	49	(34)	(208)
Selling, general and administrative expenses	33,250	28,351	98,709	88,939
Acquisition and integration costs	0	0	0	0
Change in fair value of contingent consideration		0	0	0
Depreciation and amortization	29,839	26,743	86,792	82,983
Equity in net income/(loss) of Diamond Green Diesel	0	0	0	0
Operating income	41,799	30,288	125,724	108,935
Equity in net income of other unconsolidated subsidiaries	0	0	0	0
Segment income/(loss)	41,799	30,288	125,724	108,935
Fuel Ingredients
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	154,277	137,142	448,192	418,615
Fuel Ingredients | Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	154,277	137,142	448,192	418,615
Cost of sales and operating expenses (excludes depreciation and amortization, shown separately below)	121,900	108,816	361,634	335,358
Gross margin	32,377	28,326	86,558	83,257
Loss/(gain) on sale of assets	(185)	(2)	(402)	(434)
Selling, general and administrative expenses	8,077	7,757	25,645	24,911
Acquisition and integration costs	0	0	0	0
Change in fair value of contingent consideration		0	0	0
Depreciation and amortization	9,129	9,297	26,481	26,687
Equity in net income/(loss) of Diamond Green Diesel	(45,844)	2,430	(70,367)	125,046
Operating income	(30,488)	13,704	(35,533)	157,139
Equity in net income of other unconsolidated subsidiaries	0	0	0	0
Segment income/(loss)	$ (30,488)	$ 13,704	$ (35,533)	$ 157,139