Revenue Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	$ 850,569	$ 842,049	$ 2,552,084	$ 2,504,477
Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	483,025	496,978	1,499,340	1,480,244
Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	291,842	276,467	841,070	830,466
Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	75,702	68,604	211,674	193,767
North America
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	462,414	476,225	1,420,549	1,406,880
North America | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	390,182	411,566	1,236,963	1,223,253
North America | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	66,554	53,483	171,517	157,097
North America | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	5,678	11,176	12,069	26,530
Europe
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	308,199	284,601	912,602	852,724
Europe | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	85,803	76,526	244,712	235,381
Europe | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	152,372	150,647	468,285	450,106
Europe | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	70,024	57,428	199,605	167,237
China
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	47,801	49,860	138,577	147,686
China | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	4,310	6,413	10,087	14,318
China | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	43,491	43,447	128,490	133,368
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	11,711	13,154	24,377	37,944
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	11,711	13,154	24,377	37,944
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	20,444	18,209	55,979	59,243
Other | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	2,730	2,473	7,578	7,292
Other | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	17,714	15,736	48,401	51,951
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	188,604	183,204	584,710	537,545
Fats | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	153,496	150,018	484,287	438,436
Fats | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	35,108	33,186	100,423	99,109
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	45,659	45,793	132,274	136,498
Used cooking oil | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	45,659	45,793	132,274	136,498
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	190,663	196,912	596,784	603,110
Proteins | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	190,663	196,912	596,784	603,110
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	44,402	51,570	129,467	141,641
Bakery | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	44,402	51,570	129,467	141,641
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	39,041	40,444	125,669	122,581
Other rendering | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	39,041	40,444	125,669	122,581
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	238,651	221,091	676,970	666,235
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	238,651	221,091	676,970	666,235
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	70,024	57,428	199,605	167,237
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	70,024	57,428	199,605	167,237
Biofuels
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	5,678	11,176	12,069	26,530
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	5,678	11,176	12,069	26,530
Other
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	27,847	34,431	94,536	103,100
Other | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	9,764	12,241	30,859	37,978
Other | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	18,083	22,190	63,677	65,122
Other | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	$ 0	$ 0	$ 0	$ 0