Revenue Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 03, 2021	Mar. 28, 2020
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	$ 1,046,716	$ 852,842
Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	651,444	512,625
Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	298,065	270,294
Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	97,207	69,923
North America
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	613,305	479,278
North America | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	549,015	427,463
North America | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	60,940	46,415
North America | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	3,350	5,400
Europe
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	346,865	303,553
Europe | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	97,645	80,443
Europe | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	155,363	158,587
Europe | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	93,857	64,523
China
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	59,870	42,379
China | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	1,938	2,423
China | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	57,932	39,956
China | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
South America
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	10,454	10,586
South America | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
South America | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	10,454	10,586
South America | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
Other
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	16,222	17,046
Other | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	2,846	2,296
Other | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	13,376	14,750
Other | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
Fats
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	270,439	196,760
Fats | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	229,006	163,284
Fats | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	41,433	33,476
Fats | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
Used cooking oil
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	51,029	47,608
Used cooking oil | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	51,029	47,608
Used cooking oil | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
Used cooking oil | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
Proteins
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	255,507	195,980
Proteins | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	255,507	195,980
Proteins | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
Proteins | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
Bakery
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	63,105	47,101
Bakery | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	63,105	47,101
Bakery | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
Bakery | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
Other rendering
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	42,957	47,164
Other rendering | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	42,957	47,164
Other rendering | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
Other rendering | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
Food ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	229,542	214,793
Food ingredients | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
Food ingredients | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	229,542	214,793
Food ingredients | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
Bioenergy
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	93,857	64,523
Bioenergy | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
Bioenergy | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
Bioenergy | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	93,857	64,523
Biofuels
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	3,350	5,400
Biofuels | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
Biofuels | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	0	0
Biofuels | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	3,350	5,400
Other
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	36,930	33,513
Other | Feed Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	9,840	11,488
Other | Food Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	27,090	22,025
Other | Fuel Ingredients
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	$ 0	$ 0