Guarantor Financial Information Condensed Consolidated Statements of Operations (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
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
Costs and expenses:
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
Acquisition and integration costs									0	401	8,299
Total costs and expenses									3,525,438	3,239,861	3,248,611
Operating income	35,026	33,310	37,063	31,414	35,380	35,528	54,467	26,692	136,813	152,067	142,644
Interest expense									(88,926)	(94,187)	(105,530)
Foreign currency losses									(6,898)	(1,854)	(4,911)
Other expense, net									(5,293)	(3,866)	(6,839)
Equity in net income of unconsolidated subsidiaries									28,504	70,379	73,416
Earnings in investments in subsidiaries									0	0	0
Income from operations 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
Income taxes (benefit)									(69,154)	15,315	13,501
Net income attributable to noncontrolling interests	(1,215)	(923)	(1,179)	(1,569)	(1,139)	(196)	(1,992)	(1,584)	(4,886)	(4,911)	(6,748)
Net income attributable to Darling	$ 105,729	$ 7,761	$ 9,149	$ 5,829	$ 40,541	$ 28,694	$ 31,999	$ 1,079	128,468	102,313	78,531
Parent Company [Member]
Net Sales									545,699	501,856	475,213
Costs and expenses:
Cost of sales and operating expenses									429,681	392,876	369,928
Selling, general and administrative expense									151,896	130,573	122,509
Depreciation and amortization									42,366	41,106	34,889
Acquisition and integration costs										0	3,177
Total costs and expenses									623,943	564,555	530,503
Operating income									(78,244)	(62,699)	(55,290)
Interest expense									(55,336)	(60,971)	(60,945)
Foreign currency losses									(234)	122	(123)
Other expense, net									(13,635)	(13,538)	(22,455)
Equity in net income of unconsolidated subsidiaries									(1,847)	(1,236)	0
Earnings in investments in subsidiaries									438,580	223,347	198,371
Income from operations before income taxes									289,284	85,025	59,558
Income taxes (benefit)									160,816	(17,288)	(18,973)
Net income attributable to noncontrolling interests									0	0	0
Net income attributable to Darling									128,468	102,313	78,531
Guarantors [Member]
Net Sales									1,464,920	1,341,925	1,363,279
Costs and expenses:
Cost of sales and operating expenses									1,198,271	1,085,582	1,108,864
Selling, general and administrative expense									55,053	51,029	55,691
Depreciation and amortization									106,406	105,261	98,400
Acquisition and integration costs										0	0
Total costs and expenses									1,359,730	1,241,872	1,262,955
Operating income									105,190	100,053	100,324
Interest expense									15,818	17,492	18,839
Foreign currency losses									114	(283)	(1,649)
Other expense, net									37	106	435
Equity in net income of unconsolidated subsidiaries									0	0	0
Earnings in investments in subsidiaries									0	0	0
Income from operations before income taxes									121,159	117,368	117,949
Income taxes (benefit)									(130,508)	14,669	16,121
Net income attributable to noncontrolling interests									0	0	0
Net income attributable to Darling									251,667	102,699	101,828
Non-guarantors [Member]
Net Sales									1,893,304	1,746,657	1,753,609
Costs and expenses:
Cost of sales and operating expenses									1,489,571	1,355,599	1,376,079
Selling, general and administrative expense									140,538	132,403	138,183
Depreciation and amortization									153,328	143,541	136,615
Acquisition and integration costs										401	5,122
Total costs and expenses									1,783,437	1,631,944	1,655,999
Operating income									109,867	114,713	97,610
Interest expense									(49,408)	(50,708)	(63,424)
Foreign currency losses									(6,778)	(1,693)	(3,139)
Other expense, net									8,305	9,566	15,181
Equity in net income of unconsolidated subsidiaries									30,351	71,615	73,416
Earnings in investments in subsidiaries									0	0	0
Income from operations before income taxes									92,337	143,493	119,644
Income taxes (benefit)									(99,462)	17,934	16,353
Net income attributable to noncontrolling interests									(4,886)	(4,911)	(6,748)
Net income attributable to Darling									186,913	120,648	96,543
Eliminations [Member]
Net Sales									(241,672)	(198,510)	(200,846)
Costs and expenses:
Cost of sales and operating expenses									(241,672)	(198,510)	(200,846)
Selling, general and administrative expense									0	0	0
Depreciation and amortization									0	0	0
Acquisition and integration costs										0	0
Total costs and expenses									(241,672)	(198,510)	(200,846)
Operating income									0	0	0
Interest expense									0	0	0
Foreign currency losses									0	0	0
Other expense, net									0	0	0
Equity in net income of unconsolidated subsidiaries									0	0	0
Earnings in investments in subsidiaries									(438,580)	(223,347)	(198,371)
Income from operations before income taxes									(438,580)	(223,347)	(198,371)
Income taxes (benefit)									0	0	0
Net income attributable to noncontrolling interests									0	0	0
Net income attributable to Darling									$ (438,580)	$ (223,347)	$ (198,371)