Other Comprehensive Income (Schedule of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2020	Mar. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	$ (862)	$ (1,155)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income/(loss) December 28, 2019, attributable to Darling, net of tax	(321,847)
Other comprehensive loss before reclassifications	(63,323)
Amounts reclassified from accumulated other comprehensive loss	590
Net current-period other comprehensive income/(loss)	(62,733)
Noncontrolling interest	(89)
Accumulated Other Comprehensive loss March 28, 2020, attributable to Darling, net of tax	(384,491)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	(214)	(297)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	(648)	(858)
Foreign currency translation	(65,887)	(5,393)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	(651)	(507)
Foreign currency translation	(65,236)	(4,886)
Other Comprehensive income (loss)	(63,682)	(7,172)
Other Comprehensive Income (Loss), Tax	(949)	(1,207)
Total other comprehensive income/(loss), net of tax	(62,733)	(5,965)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Foreign currency translation	(65,147)	(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)
Other comprehensive loss before reclassifications	(65,236)
Amounts reclassified from accumulated other comprehensive loss	0
Net current-period other comprehensive income/(loss)	(65,236)
Noncontrolling interest	(89)
Accumulated Other Comprehensive loss March 28, 2020, attributable to Darling, net of tax	(347,485)
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)
Other comprehensive loss before reclassifications	1,913
Amounts reclassified from accumulated other comprehensive loss	(58)
Net current-period other comprehensive income/(loss)	1,855
Noncontrolling interest	0
Accumulated Other Comprehensive loss March 28, 2020, attributable to Darling, net of tax	(3,650)
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)
Other comprehensive loss before reclassifications	0
Amounts reclassified from accumulated other comprehensive loss	648
Net current-period other comprehensive income/(loss)	648
Noncontrolling interest	0
Accumulated Other Comprehensive loss March 28, 2020, attributable to Darling, net of tax	(33,356)
Corn Option [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	(300)	0
Loss (gain) reclassified to net income	(75)	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	(225)	0
Gain (loss) activity recognized in other comprehensive loss	(119)	0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	(30)	0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(89)	0
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	181	0
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	45	0
Derivative adjustments	136	0
Corn Option [Member] | Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Derivative adjustments	136
Heating Oil Swaps And Options [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Gain (loss) activity recognized in other comprehensive loss	14,494	0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	3,624	0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	10,870	0
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	14,494	0
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	3,624	0
Derivative adjustments	10,870	0
Foreign Exchange Contract [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	412	0
Loss (gain) reclassified to net income	129	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	283	0
Gain (loss) activity recognized in other comprehensive loss	(12,920)	(2,934)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	(4,052)	(997)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(8,868)	(1,937)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	(13,332)	(2,934)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	(4,181)	(997)
Derivative adjustments	(9,151)	(1,937)
Foreign Exchange Contract [Member] | Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Derivative adjustments	$ (9,151)	$ (1,937)