Other Comprehensive Income (Schedule of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 26, 2020	Jun. 27, 2020	Mar. 28, 2020	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Sep. 26, 2020	Sep. 28, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	$ (863)			$ (1,155)			$ (2,587)	$ (3,466)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive loss December 28, 2019, attributable to Darling, net of tax			$ (321,847)				(321,847)
Other comprehensive income/(loss) before reclassifications							1,541
Amounts reclassified from accumulated other comprehensive loss							(6,055)
Net current-period other comprehensive income/(loss)							(4,514)
Noncontrolling interest							(753)
Accumulated Other Comprehensive loss September 26, 2020, attributable to Darling, net of tax	(325,608)						(325,608)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	(215)			(296)			(644)	(890)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	(648)			(859)			(1,943)	(2,576)
Foreign currency translation	39,237			(48,954)			(5,798)	(37,695)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	1,383			(1,328)			1,445	(1,509)
Foreign currency translation	37,854	$ 20,139	(65,236)	(47,626)	$ 16,326	$ (4,886)	(7,243)	(36,186)
Other Comprehensive income (loss)	40,902			(56,546)			(1,869)	(40,865)
Other Comprehensive Income (Loss), Tax	2,012			(3,705)			2,645	(2,850)
Total other comprehensive income/(loss), net of tax	38,890			(52,841)			(4,514)	(38,015)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Foreign currency translation	37,878	20,779	(65,147)	(47,630)	17,797	(6,645)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive loss December 28, 2019, attributable to Darling, net of tax			(282,338)				(282,338)
Other comprehensive income/(loss) before reclassifications							(7,243)
Amounts reclassified from accumulated other comprehensive loss							0
Net current-period other comprehensive income/(loss)							(7,243)
Noncontrolling interest							(753)
Accumulated Other Comprehensive loss September 26, 2020, attributable to Darling, net of tax	(288,828)						(288,828)
Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive loss December 28, 2019, attributable to Darling, net of tax			(5,505)				(5,505)
Other comprehensive income/(loss) before reclassifications							8,784
Amounts reclassified from accumulated other comprehensive loss							(7,998)
Net current-period other comprehensive income/(loss)							786
Noncontrolling interest							0
Accumulated Other Comprehensive loss September 26, 2020, attributable to Darling, net of tax	(4,719)						(4,719)
Defined Benefit Pension Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive loss December 28, 2019, attributable to Darling, net of tax			(34,004)				(34,004)
Other comprehensive income/(loss) before reclassifications							0
Amounts reclassified from accumulated other comprehensive loss							1,943
Net current-period other comprehensive income/(loss)							1,943
Noncontrolling interest							0
Accumulated Other Comprehensive loss September 26, 2020, attributable to Darling, net of tax	(32,061)						(32,061)
Corn Option [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	(229)			(206)			(1,168)	(169)
Loss (gain) reclassified to net income	(57)			(54)			(292)	(44)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	(172)			(152)			(876)	(125)
Gain (loss) activity recognized in other comprehensive loss	(3,588)			542			(1,939)	609
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	(898)			141			(485)	159
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(2,690)			401			(1,454)	450
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	(3,359)			748			(771)	778
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	(841)			195			(193)	203
Derivative adjustments	(2,518)	1,804	136	553	22		(578)	575
Corn Option [Member] | Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Derivative adjustments	(2,518)	1,804	136	553	22
Heating Oil Swaps And Options [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Gain (loss) activity recognized in other comprehensive loss	1,992			(2,268)			4,565	606
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	498			(585)			1,141	156
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	1,494			(1,683)			3,424	450
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	1,992			(2,268)			4,565	606
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	498			(585)			1,141	156
Derivative adjustments	1,494			(1,683)			3,424	450
Foreign Exchange Contract [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	5,317			(1,178)			10,564	(1,465)
Loss (gain) reclassified to net income	385			(362)			1,690	(473)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	4,932			(816)			8,874	(992)
Gain (loss) activity recognized in other comprehensive loss	7,486			(8,405)			8,112	(9,485)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	1,142			(2,645)			1,298	(3,063)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	6,344			(5,760)			6,814	(6,422)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	2,169			(7,227)			(2,452)	(8,020)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	757			(2,283)			(392)	(2,590)
Derivative adjustments	1,412	5,679	(9,151)	(4,944)	1,451	(1,937)	$ (2,060)	$ (5,430)
Foreign Exchange Contract [Member] | Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Derivative adjustments	$ 1,412	$ 5,679	$ (9,151)	$ (4,944)	$ 1,451	$ (1,937)