Revenue Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	$ 848,673	$ 827,324	$ 1,701,515	$ 1,662,428
Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	503,690	487,447	1,016,315	983,266
Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	278,934	274,835	549,228	553,999
Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	66,049	65,042	135,972	125,163
North America
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	478,857	465,895	958,135	930,655
North America | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	419,318	401,450	846,781	811,687
North America | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	58,548	54,801	104,963	103,614
North America | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	991	9,644	6,391	15,354
Europe
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	300,850	282,062	604,403	568,123
Europe | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	78,466	78,857	158,909	158,855
Europe | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	157,326	147,807	315,913	299,459
Europe | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	65,058	55,398	129,581	109,809
China
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	48,397	47,937	90,776	97,826
China | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	3,354	4,953	5,777	7,905
China | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	45,043	42,984	84,999	89,921
China | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
South America
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	2,080	12,121	12,666	24,790
South America | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
South America | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	2,080	12,121	12,666	24,790
South America | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
Other
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	18,489	19,309	35,535	41,034
Other | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	2,552	2,187	4,848	4,819
Other | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	15,937	17,122	30,687	36,215
Other | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
Fats
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	199,346	174,327	396,106	354,341
Fats | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	167,507	143,542	330,791	288,418
Fats | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	31,839	30,785	65,315	65,923
Fats | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
Used cooking oil
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	39,007	45,299	86,615	90,705
Used cooking oil | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	39,007	45,299	86,615	90,705
Used cooking oil | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
Used cooking oil | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
Proteins
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	210,141	200,385	406,121	406,198
Proteins | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	210,141	200,385	406,121	406,198
Proteins | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
Proteins | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
Bakery
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	37,964	44,415	85,065	90,071
Bakery | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	37,964	44,415	85,065	90,071
Bakery | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
Bakery | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
Other rendering
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	39,464	40,883	86,628	82,137
Other rendering | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	39,464	40,883	86,628	82,137
Other rendering | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
Other rendering | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
Food ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	223,526	223,236	438,319	445,144
Food ingredients | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
Food ingredients | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	223,526	223,236	438,319	445,144
Food ingredients | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
Bioenergy
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	65,058	55,398	129,581	109,809
Bioenergy | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
Bioenergy | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
Bioenergy | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	65,058	55,398	129,581	109,809
Biofuels
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	991	9,644	6,391	15,354
Biofuels | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
Biofuels | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0	0	0
Biofuels | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	991	9,644	6,391	15,354
Other
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	33,176	33,737	66,689	68,669
Other | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	9,607	12,923	21,095	25,737
Other | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	23,569	20,814	45,594	42,932
Other | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	$ 0	$ 0	$ 0	$ 0