Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jul. 03, 2021	Apr. 03, 2021	Jun. 27, 2020	Jul. 03, 2021	Jun. 27, 2020	Jan. 02, 2021
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	$ 1,198,669		$ 848,673	$ 2,245,385	$ 1,701,515
Cost of sales and operating expenses	878,073		632,347	1,650,857	1,279,255
Loss/(gain) on sale of assets	228		(27)	292	(88)
Selling, general and administrative expenses	99,132		90,193	196,530	186,386
Restructuring and asset impairment charges	0	$ 800	0	778	0
Depreciation and amortization	79,222		83,310	157,756	167,981
Equity in net income of Diamond Green Diesel	125,788		63,492	228,013	161,312
Operating income	268,258		106,288	467,769	229,117
Equity in net income of other unconsolidated subsidiaries	1,940		692	2,552	1,561
Total other expense	(17,150)		(20,539)	(35,147)	(39,846)
Income before income taxes	253,048		86,441	435,174	190,832
Segment Assets	5,833,323			5,833,323		$ 5,613,331
Feed Ingredients
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	771,932		503,690	1,423,376	1,016,315
Cost of sales and operating expenses	556,424		367,902	1,031,005	756,355
Gross Margin	215,508		135,788	392,371	259,960
Loss/(gain) on sale of assets	(122)		76	(261)	126
Selling, general and administrative expenses	54,977		50,484	107,597	104,431
Restructuring and asset impairment charges				0
Depreciation and amortization	53,971		52,683	108,580	106,204
Equity in net income of Diamond Green Diesel	0		0	0	0
Operating income	106,682		32,545	176,455	49,199
Equity in net income of other unconsolidated subsidiaries	1,940		692	2,552	1,561
Segment income/(loss)	108,622		33,237	179,007	50,760
Segment Assets	2,748,192			2,748,192		2,708,922
Food Ingredients
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	317,031		278,934	615,096	549,228
Cost of sales and operating expenses	238,539		220,159	464,952	425,589
Gross Margin	78,492		58,775	150,144	123,639
Loss/(gain) on sale of assets	(48)		(48)	7	(46)
Selling, general and administrative expenses	25,542		22,564	50,733	48,040
Restructuring and asset impairment charges				0
Depreciation and amortization	15,850		19,972	30,733	40,277
Equity in net income of Diamond Green Diesel	0		0	0	0
Operating income	37,148		16,287	68,671	35,368
Equity in net income of other unconsolidated subsidiaries	0		0	0	0
Segment income/(loss)	37,148		16,287	68,671	35,368
Segment Assets	1,253,856			1,253,856		1,335,769
Fuel Ingredients
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	109,706		66,049	206,913	135,972
Cost of sales and operating expenses	83,110		44,286	154,900	97,311
Gross Margin	26,596		21,763	52,013	38,661
Loss/(gain) on sale of assets	(58)		(1)	(38)	8
Selling, general and administrative expenses	4,474		3,953	9,341	5,607
Restructuring and asset impairment charges				778
Depreciation and amortization	6,698		7,980	12,853	16,072
Equity in net income of Diamond Green Diesel	125,788		63,492	228,013	161,312
Operating income	141,270		73,323	257,092	178,286
Equity in net income of other unconsolidated subsidiaries	0		0	0	0
Segment income/(loss)	141,270		73,323	257,092	178,286
Segment Assets	1,348,148			1,348,148		1,160,132
Corporate
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	0		0	0	0
Cost of sales and operating expenses	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	14,139		13,192	28,859	28,308
Restructuring and asset impairment charges				0
Depreciation and amortization	2,703		2,675	5,590	5,428
Equity in net income of Diamond Green Diesel	0		0	0	0
Operating income	(16,842)		(15,867)	(34,449)	(33,736)
Equity in net income of other unconsolidated subsidiaries	0		0	0	0
Segment income/(loss)	(16,842)		(15,867)	(34,449)	(33,736)
Segment Assets	483,127			483,127		408,508
Total
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	1,198,669		848,673	2,245,385	1,701,515
Cost of sales and operating expenses	878,073		632,347	1,650,857	1,279,255
Gross Margin	320,596		216,326	594,528	422,260
Loss/(gain) on sale of assets	(228)		27	(292)	88
Selling, general and administrative expenses	99,132		90,193	196,530	186,386
Restructuring and asset impairment charges				778
Depreciation and amortization	79,222		83,310	157,756	167,981
Equity in net income of Diamond Green Diesel	125,788		63,492	228,013	161,312
Operating income	268,258		106,288	467,769	229,117
Equity in net income of other unconsolidated subsidiaries	1,940		692	2,552	1,561
Segment income/(loss)	270,198		$ 106,980	470,321	$ 230,678
Segment Assets	$ 5,833,323			$ 5,833,323		$ 5,613,331