Guarantor Financial Information (Condensed Consolidated Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Net sales	$ 848,673	$ 827,324	$ 1,701,515	$ 1,662,428
Costs and expenses:
Cost of sales and operating expenses	632,347	644,716	1,279,255	1,295,629
Loss (gain) on disposal of property, plant, equipment and other assets	27	(13,926)	88	(18,176)
Selling, general and administrative expenses	90,193	81,017	186,386	166,020
Depreciation and amortization	83,310	79,486	167,981	158,650
Total costs and expenses	805,877	791,293	1,633,710	1,602,123
Equity in net income of Diamond Green Diesel	63,492	38,093	161,312	62,370
Operating income	106,288	74,124	229,117	122,675
Interest expense	(17,920)	(20,853)	(37,010)	(40,729)
Foreign currency gain/(loss)	(1,134)	(388)	530	(1,120)
Other income/(expense), net	(1,485)	(2,019)	(3,366)	(4,544)
Equity in net income/(loss) of other unconsolidated subsidiaries	692	82	1,561	(422)
Earnings in investments in subsidiaries	0	0	0	0
Income before income taxes	86,441	38,820	190,832	63,734
Income tax expense	19,946	7,776	38,246	13,050
Net income attributable to noncontrolling interests	(1,056)	(4,786)	(1,637)	(6,414)
Net income attributable to Darling	65,439	26,258	150,949	44,270
Debt extinguishment costs	0	(12,126)	0	(12,126)
Parent [Member]
Net sales	185,915	156,927	366,834	317,157
Costs and expenses:
Cost of sales and operating expenses	140,742	125,586	284,884	253,910
Loss (gain) on disposal of property, plant, equipment and other assets	76	(26)	38	42
Selling, general and administrative expenses	44,937	40,570	93,011	87,993
Depreciation and amortization	16,989	14,224	34,261	28,597
Total costs and expenses	202,744	180,354	412,194	370,542
Equity in net income of Diamond Green Diesel	0	0	0	0
Operating income	(16,829)	(23,427)	(45,360)	(53,385)
Interest expense	(12,451)	(15,078)	(26,226)	(29,105)
Foreign currency gain/(loss)	(184)	3	(510)	(1)
Other income/(expense), net	(1,200)	(1,285)	(2,740)	(2,852)
Equity in net income/(loss) of other unconsolidated subsidiaries	0	(1,027)	0	(1,918)
Earnings in investments in subsidiaries	88,848	68,680	210,787	123,307
Income before income taxes	58,184	15,740	135,951	23,920
Income tax expense	(7,255)	(10,518)	(14,998)	(20,350)
Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Darling	65,439	26,258	150,949	44,270
Debt extinguishment costs		(12,126)		(12,126)
Guarantors [Member]
Net sales	310,650	325,744	620,951	655,735
Costs and expenses:
Cost of sales and operating expenses	245,968	268,582	492,288	540,253
Loss (gain) on disposal of property, plant, equipment and other assets	(8)	(511)	55	(4,988)
Selling, general and administrative expenses	11,024	10,776	23,541	22,723
Depreciation and amortization	26,223	25,165	52,816	51,277
Total costs and expenses	283,207	304,012	568,700	609,265
Equity in net income of Diamond Green Diesel	0	0	0	0
Operating income	27,443	21,732	52,251	46,470
Interest expense	(44)	(24)	(102)	(56)
Foreign currency gain/(loss)	(1)	1	(25)	1
Other income/(expense), net	(290)	(764)	(629)	(1,976)
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	27,108	20,945	51,495	44,439
Income tax expense	6,045	4,126	10,320	9,099
Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Darling	21,063	16,819	41,175	35,340
Debt extinguishment costs		0		0
Non-guarantors [Member]
Net sales	404,358	399,339	809,383	803,250
Costs and expenses:
Cost of sales and operating expenses	297,887	305,234	597,736	615,180
Loss (gain) on disposal of property, plant, equipment and other assets	(41)	(13,389)	(5)	(13,230)
Selling, general and administrative expenses	34,232	29,671	69,834	55,304
Depreciation and amortization	40,098	40,097	80,904	78,776
Total costs and expenses	372,176	361,613	748,469	736,030
Equity in net income of Diamond Green Diesel	63,492	38,093	161,312	62,370
Operating income	95,674	75,819	222,226	129,590
Interest expense	(5,425)	(5,751)	(10,682)	(11,568)
Foreign currency gain/(loss)	(949)	(392)	1,065	(1,120)
Other income/(expense), net	5	30	3	284
Equity in net income/(loss) of other unconsolidated subsidiaries	692	1,109	1,561	1,496
Earnings in investments in subsidiaries	0	0	0	0
Income before income taxes	89,997	70,815	214,173	118,682
Income tax expense	21,156	14,168	42,924	24,301
Net income attributable to noncontrolling interests	(1,056)	(4,786)	(1,637)	(6,414)
Net income attributable to Darling	67,785	51,861	169,612	87,967
Debt extinguishment costs		0		0
Eliminations [Member]
Costs and expenses:
Equity in net income of Diamond Green Diesel	0	0	0	0
Eliminations [Member]
Net sales	(52,250)	(54,686)	(95,653)	(113,714)
Costs and expenses:
Cost of sales and operating expenses	(52,250)	(54,686)	(95,653)	(113,714)
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	(52,250)	(54,686)	(95,653)	(113,714)
Operating income	0	0	0	0
Interest expense	0	0	0	0
Foreign currency gain/(loss)	0	0	0	0
Other income/(expense), net	0	0	0	0
Equity in net income/(loss) of other unconsolidated subsidiaries	0	0	0	0
Earnings in investments in subsidiaries	(88,848)	(68,680)	(210,787)	(123,307)
Income before income taxes	(88,848)	(68,680)	(210,787)	(123,307)
Income tax expense	0	0	0	0
Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Darling	$ (88,848)	(68,680)	$ (210,787)	(123,307)
Debt extinguishment costs		$ 0		$ 0