Other Comprehensive Income (Schedule of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 27, 2020	Mar. 28, 2020	Jun. 29, 2019	Mar. 30, 2019	Jun. 27, 2020	Jun. 29, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	$ (862)		$ (1,156)		$ (1,724)	$ (2,311)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income/(loss) December 28, 2019, attributable to Darling, net of tax		$ (321,847)			(321,847)
Other comprehensive loss before reclassifications					(41,461)
Amounts reclassified from accumulated other comprehensive loss					(1,943)
Net current-period other comprehensive income/(loss)					(43,404)
Noncontrolling interest					(729)
Accumulated Other Comprehensive Income/(loss) June 27, 2020, attributable to Darling, net of tax	(364,522)				(364,522)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	(215)		(297)		(429)	(594)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	(647)		(859)		(1,295)	(1,717)
Foreign currency translation	20,852		16,652		(45,035)	11,259
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	713		326		62	(181)
Foreign currency translation	20,139	(65,236)	16,326	$ (4,886)	(45,097)	11,440
Other Comprehensive income (loss)	20,911		22,853		(42,771)	15,681
Other Comprehensive Income (Loss), Tax	1,582		2,062		633	855
Total other comprehensive income/(loss), net of tax	19,329		20,791		(43,404)	14,826
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Foreign currency translation	20,779	(65,147)	17,797	(6,645)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income/(loss) December 28, 2019, attributable to Darling, net of tax		(282,338)			(282,338)
Other comprehensive loss before reclassifications					(45,097)
Amounts reclassified from accumulated other comprehensive loss					0
Net current-period other comprehensive income/(loss)					(45,097)
Noncontrolling interest					(729)
Accumulated Other Comprehensive Income/(loss) June 27, 2020, attributable to Darling, net of tax	(326,706)				(326,706)
Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income/(loss) December 28, 2019, attributable to Darling, net of tax		(5,505)			(5,505)
Other comprehensive loss before reclassifications					3,636
Amounts reclassified from accumulated other comprehensive loss					(3,238)
Net current-period other comprehensive income/(loss)					398
Noncontrolling interest					0
Accumulated Other Comprehensive Income/(loss) June 27, 2020, attributable to Darling, net of tax	(5,107)				(5,107)
Defined Benefit Pension Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income/(loss) December 28, 2019, attributable to Darling, net of tax		(34,004)			(34,004)
Other comprehensive loss before reclassifications					0
Amounts reclassified from accumulated other comprehensive loss					1,295
Net current-period other comprehensive income/(loss)					1,295
Noncontrolling interest					0
Accumulated Other Comprehensive Income/(loss) June 27, 2020, attributable to Darling, net of tax	(32,709)				(32,709)
Corn Option [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	(639)		37		(939)	37
Loss (gain) reclassified to net income	(160)		10		(235)	10
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	(479)		27		(704)	27
Gain (loss) activity recognized in other comprehensive loss	1,768		67		1,649	67
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	443		18		413	18
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	1,325		49		1,236	49
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	2,407		30		2,588	30
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	603		8		648	8
Derivative adjustments	1,804	136	22		1,940	22
Corn Option [Member] | Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Derivative adjustments	1,804	136	22
Heating Oil Swaps And Options [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Gain (loss) activity recognized in other comprehensive loss	(11,921)		2,874		2,573	2,874
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	(2,981)		741		643	741
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(8,940)		2,133		1,930	2,133
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	(11,921)		2,874		2,573	2,874
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	(2,981)		741		643	741
Derivative adjustments	(8,940)		2,133		1,930	2,133
Foreign Exchange Contract [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	4,835		(287)		5,247	(287)
Loss (gain) reclassified to net income	1,176		(111)		1,305	(111)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	3,659		(176)		3,942	(176)
Gain (loss) activity recognized in other comprehensive loss	13,546		1,854		626	(1,080)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	4,208		579		156	(418)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	9,338		1,275		470	(662)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	8,711		2,141		(4,621)	(793)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	3,032		690		(1,149)	(307)
Derivative adjustments	5,679	(9,151)	1,451	(1,937)	$ (3,472)	$ (486)
Foreign Exchange Contract [Member] | Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Derivative adjustments	$ 5,679	$ (9,151)	$ 1,451	$ (1,937)