Guarantor Financial Information (Condensed Consolidated Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Net sales	$ 850,569	$ 842,049	$ 2,552,084	$ 2,504,477
Costs and expenses:
Cost of sales and operating expenses	638,368	652,923	1,917,623	1,948,552
Loss (gain) on disposal of property, plant, equipment and other assets	122	(2,669)	210	(20,845)
Selling, general and administrative expenses	89,993	83,549	276,379	249,569
Depreciation and amortization	85,730	80,407	253,711	239,057
Total costs and expenses	814,213	814,210	2,447,923	2,416,333
Equity in net income of Diamond Green Diesel	91,099	32,020	252,411	94,390
Operating income	127,455	59,859	356,572	182,534
Interest expense	(18,793)	(19,359)	(55,803)	(60,088)
Foreign currency gain/(loss)	(1,239)	466	(709)	(654)
Other expense, net	(1,912)	(2,614)	(5,278)	(7,158)
Equity in net income/(loss) of other unconsolidated subsidiaries	906	(665)	2,467	(1,087)
Earnings in investments in subsidiaries	0	0	0	0
Income before income taxes	106,417	37,687	297,249	101,421
Income tax expense	4,812	10,850	43,058	23,900
Net income attributable to noncontrolling interests	(480)	(1,116)	(2,117)	(7,530)
Net income attributable to Darling	101,125	25,721	252,074	69,991
Debt extinguishment costs	0	0	0	(12,126)
Parent [Member]
Net sales	173,659	164,488	540,493	481,645
Costs and expenses:
Cost of sales and operating expenses	134,887	130,498	419,771	384,408
Loss (gain) on disposal of property, plant, equipment and other assets	89	(86)	127	(44)
Selling, general and administrative expenses	42,103	41,225	135,114	129,218
Depreciation and amortization	17,167	15,071	51,428	43,668
Total costs and expenses	194,246	186,708	606,440	557,250
Equity in net income of Diamond Green Diesel	0	0	0	0
Operating income	(20,587)	(22,220)	(65,947)	(75,605)
Interest expense	(13,152)	(13,862)	(39,378)	(42,967)
Foreign currency gain/(loss)	(93)	(30)	(603)	(31)
Other expense, net	(1,336)	(2,026)	(4,076)	(4,878)
Equity in net income/(loss) of other unconsolidated subsidiaries	0	(1,172)	0	(3,090)
Earnings in investments in subsidiaries	135,357	52,697	346,144	176,004
Income before income taxes	100,189	13,387	236,140	37,307
Income tax expense	(936)	(12,334)	(15,934)	(32,684)
Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Darling	101,125	25,721	252,074	69,991
Debt extinguishment costs				(12,126)
Guarantors [Member]
Net sales	309,837	330,655	930,788	986,390
Costs and expenses:
Cost of sales and operating expenses	249,004	273,238	741,292	813,491
Loss (gain) on disposal of property, plant, equipment and other assets	119	(2,343)	174	(7,331)
Selling, general and administrative expenses	11,520	12,319	35,061	35,042
Depreciation and amortization	26,362	25,317	79,178	76,594
Total costs and expenses	287,005	308,531	855,705	917,796
Equity in net income of Diamond Green Diesel	0	0	0	0
Operating income	22,832	22,124	75,083	68,594
Interest expense	(37)	(52)	(139)	(108)
Foreign currency gain/(loss)	3	(4)	(22)	(3)
Other expense, net	(562)	(431)	(1,191)	(2,407)
Equity in net income/(loss) of other unconsolidated subsidiaries	0	0	0	0
Earnings in investments in subsidiaries	0	0	0	0
Income before income taxes	22,236	21,637	73,731	66,076
Income tax expense	360	6,472	10,680	15,571
Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Darling	21,876	15,165	63,051	50,505
Debt extinguishment costs				0
Non-guarantors [Member]
Net sales	416,297	403,749	1,225,680	1,206,999
Costs and expenses:
Cost of sales and operating expenses	303,701	306,030	901,437	921,210
Loss (gain) on disposal of property, plant, equipment and other assets	(86)	(240)	(91)	(13,470)
Selling, general and administrative expenses	36,370	30,005	106,204	85,309
Depreciation and amortization	42,201	40,019	123,105	118,795
Total costs and expenses	382,186	375,814	1,130,655	1,111,844
Equity in net income of Diamond Green Diesel	91,099	32,020	252,411	94,390
Operating income	125,210	59,955	347,436	189,545
Interest expense	(5,604)	(5,445)	(16,286)	(17,013)
Foreign currency gain/(loss)	(1,149)	500	(84)	(620)
Other expense, net	(14)	(157)	(11)	127
Equity in net income/(loss) of other unconsolidated subsidiaries	906	507	2,467	2,003
Earnings in investments in subsidiaries	0	0	0	0
Income before income taxes	119,349	55,360	333,522	174,042
Income tax expense	5,388	16,712	48,312	41,013
Net income attributable to noncontrolling interests	(480)	(1,116)	(2,117)	(7,530)
Net income attributable to Darling	113,481	37,532	283,093	125,499
Debt extinguishment costs				0
Eliminations [Member]
Costs and expenses:
Equity in net income of Diamond Green Diesel	0	0	0	0
Eliminations [Member]
Net sales	(49,224)	(56,843)	(144,877)	(170,557)
Costs and expenses:
Cost of sales and operating expenses	(49,224)	(56,843)	(144,877)	(170,557)
Loss (gain) on disposal of property, plant, equipment and other assets	0	0	0	0
Selling, general and administrative expenses	0	0	0	0
Depreciation and amortization	0	0	0	0
Total costs and expenses	(49,224)	(56,843)	(144,877)	(170,557)
Operating income	0	0	0	0
Interest expense	0	0	0	0
Foreign currency gain/(loss)	0	0	0	0
Other expense, net	0	0	0	0
Equity in net income/(loss) of other unconsolidated subsidiaries	0	0	0	0
Earnings in investments in subsidiaries	(135,357)	(52,697)	(346,144)	(176,004)
Income before income taxes	(135,357)	(52,697)	(346,144)	(176,004)
Income tax expense	0	0	0	0
Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Darling	$ (135,357)	$ (52,697)	$ (346,144)	(176,004)
Debt extinguishment costs				$ 0