Business Segments (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Segment Reporting Information [Line Items]
Net Sales		$ 952,549	$ 936,262	$ 894,930	$ 878,510	$ 885,758	$ 852,018	$ 875,777	$ 778,375	$ 3,662,251	$ 3,391,928	$ 3,391,255
Cost of sales and operating expenses										2,875,851	2,635,547	2,654,025
Selling, general and administrative expense										347,487	314,005	316,383
Depreciation and amortization										302,100	289,908	269,904
Segment operating income/(loss)		35,026	33,310	37,063	31,414	35,380	35,528	54,467	26,692	136,813	152,067	142,644
Equity in net income of unconsolidated subsidiaries										28,504	70,379	73,416
Total other expense										(101,117)	(99,907)	(117,280)
Income before income taxes		21,934	$ 14,980	$ 18,070	$ 9,216	47,893	$ 28,146	$ 41,974	$ 4,526	64,200	122,539	98,780
Segment assets		4,958,225				4,698,017				4,958,225	4,698,017
Capital expenditures:	[1]									274,168	243,523	229,848
Long-Lived Assets		4,001,780				3,804,715				4,001,780	3,804,715
North America
Segment Reporting Information [Line Items]
Net Sales										1,937,027	1,817,659	1,951,421
Long-Lived Assets		2,468,111				2,411,489				2,468,111	2,411,489
Europe
Segment Reporting Information [Line Items]
Net Sales										1,372,750	1,225,397	1,066,779
Long-Lived Assets		1,292,020				1,158,087				1,292,020	1,158,087
China
Segment Reporting Information [Line Items]
Net Sales										209,780	218,480	234,978
Long-Lived Assets		151,760				152,150				151,760	152,150
South America
Segment Reporting Information [Line Items]
Net Sales										60,111	55,089	62,035
Long-Lived Assets		81,247				74,837				81,247	74,837
Other
Segment Reporting Information [Line Items]
Net Sales										82,583	75,303	76,042
Long-Lived Assets		8,642				8,152				8,642	8,152
Feed Ingredients [Member]
Segment Reporting Information [Line Items]
Net Sales										2,239,492	2,089,145	2,074,333
Cost of sales and operating expenses										1,744,768	1,624,858	1,613,402
Gross Margin										494,724	464,287	460,931
Selling, general and administrative expense										180,866	169,648	178,624
Acquisition costs											0	0
Depreciation and amortization										184,172	178,845	165,854
Segment operating income/(loss)										129,686	115,794	116,453
Equity in net income of unconsolidated subsidiaries										265	467	1,521
Segment income										129,951	116,261	117,974
Segment assets		2,614,545				2,464,509				2,614,545	2,464,509
Capital expenditures:										191,953	167,313	153,894
Food Ingredients [Member]
Segment Reporting Information [Line Items]
Net Sales										1,156,976	1,055,725	1,088,727
Cost of sales and operating expenses										920,575	828,223	863,562
Gross Margin										236,401	227,502	225,165
Selling, general and administrative expense										104,982	96,170	97,110
Acquisition costs											0	0
Depreciation and amortization										75,010	70,120	66,817
Segment operating income/(loss)										56,409	61,212	61,238
Equity in net income of unconsolidated subsidiaries										0	0	0
Segment income										56,409	61,212	61,238
Segment assets		1,499,027				1,414,409				1,499,027	1,414,409
Capital expenditures:										50,099	50,020	49,066
Fuel Ingredients [Member]
Segment Reporting Information [Line Items]
Net Sales										265,783	247,058	228,195
Cost of sales and operating expenses										210,508	182,466	177,061
Gross Margin										55,275	64,592	51,134
Selling, general and administrative expense										10,467	6,895	7,264
Acquisition costs											0	0
Depreciation and amortization										31,019	28,531	26,711
Segment operating income/(loss)										13,789	29,166	17,159
Equity in net income of unconsolidated subsidiaries										28,239	69,912	71,895
Segment income										42,028	99,078	89,054
Segment assets		688,890				657,637				688,890	657,637
Capital expenditures:										24,707	22,323	19,478
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Net Sales										0	0	0
Cost of sales and operating expenses										0	0	0
Gross Margin										0	0	0
Selling, general and administrative expense										51,172	41,292	33,385
Acquisition costs											401	8,299
Depreciation and amortization										11,899	12,412	10,522
Segment operating income/(loss)										(63,071)	(54,105)	(52,206)
Equity in net income of unconsolidated subsidiaries										0	0	0
Segment income										(63,071)	(54,105)	(52,206)
Segment assets		155,763				161,462				155,763	161,462
Capital expenditures:										7,409	3,867	7,410
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Sales										3,662,251	3,391,928	3,391,255
Cost of sales and operating expenses										2,875,851	2,635,547	2,654,025
Gross Margin										786,400	756,381	737,230
Selling, general and administrative expense										347,487	314,005	316,383
Acquisition costs											401	8,299
Depreciation and amortization										302,100	289,908	269,904
Segment operating income/(loss)										136,813	152,067	142,644
Equity in net income of unconsolidated subsidiaries										28,504	70,379	73,416
Segment income										165,317	222,446	$ 216,060
Segment assets		$ 4,958,225				$ 4,698,017				$ 4,958,225	$ 4,698,017

[1] Excludes immaterial capital assets acquired by acquisition in fiscal 2017, fiscal 2016 and fiscal 2015.