Guarantor Financial Information Guarantor Financial Information Condensed Consolidating Statements of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 28, 2019	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Dec. 29, 2018	Sep. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Net income	$ 243,446	$ 26,837	$ 31,044	$ 19,640	$ 42,144	$ (5,137)	$ (29,138)	$ 98,075	$ 320,967	$ 105,944	$ 133,354
Foreign currency translation adjustments									(11,934)	(87,474)	121,810
Pension liability adjustments, net of tax									1,535	(2,730)	5,829
Total other comprehensive income/(loss), net of tax									(16,985)	(90,787)	126,543
Total comprehensive income									303,982	15,157	259,897
Comprehensive income attributable to noncontrolling interests									8,690	3,894	947
Comprehensive income/(loss) attributable to Darling									295,292	11,263	258,950
Natural Gas Swap [Member]
Total derivatives									(3,141)	23	(18)
Total derivatives, net of tax									0	23	(18)
Corn Option [Member]
Total derivatives									278	(1,687)	(1,078)
Total derivatives, net of tax									278	(1,687)	(1,078)
Heating Oil Swaps And Options [Member]
Total derivatives, net of tax									(3,141)	0	0
Foreign Exchange Contract [Member]
Total derivatives									(3,723)	1,081
Total derivatives, net of tax									(3,723)	1,081	0
Parent Company [Member]
Net income									320,967	105,944	133,354
Foreign currency translation adjustments									837	1,724	0
Pension liability adjustments, net of tax									4,287	(4,184)	4,797
Total other comprehensive income/(loss), net of tax									5,402	(4,124)	3,701
Total comprehensive income									326,369	101,820	137,055
Comprehensive income attributable to noncontrolling interests									0	0	0
Comprehensive income/(loss) attributable to Darling									326,369	101,820	137,055
Parent Company [Member] | Natural Gas Swap [Member]
Total derivatives										23	(18)
Parent Company [Member] | Corn Option [Member]
Total derivatives									278	(1,687)	(1,078)
Parent Company [Member] | Heating Oil Swaps And Options [Member]
Total derivatives, net of tax									0
Parent Company [Member] | Foreign Exchange Contract [Member]
Total derivatives, net of tax									0	0
Guarantors [Member]
Net income									72,074	99,353	251,667
Foreign currency translation adjustments									0	(53,387)	0
Pension liability adjustments, net of tax									0	0	0
Total other comprehensive income/(loss), net of tax									0	(53,387)	0
Total comprehensive income									72,074	45,966	251,667
Comprehensive income attributable to noncontrolling interests									0	0	0
Comprehensive income/(loss) attributable to Darling									72,074	45,966	251,667
Guarantors [Member] | Natural Gas Swap [Member]
Total derivatives										0	0
Guarantors [Member] | Corn Option [Member]
Total derivatives									0	0	0
Guarantors [Member] | Heating Oil Swaps And Options [Member]
Total derivatives, net of tax									0
Guarantors [Member] | Foreign Exchange Contract [Member]
Total derivatives, net of tax									0	0
Non-guarantors [Member]
Net income									399,753	171,590	186,913
Foreign currency translation adjustments									(12,771)	(35,811)	121,810
Pension liability adjustments, net of tax									(2,752)	1,454	1,032
Total other comprehensive income/(loss), net of tax									(22,387)	(33,276)	122,842
Total comprehensive income									377,366	138,314	309,755
Comprehensive income attributable to noncontrolling interests									8,690	3,894	947
Comprehensive income/(loss) attributable to Darling									368,676	134,420	308,808
Non-guarantors [Member] | Natural Gas Swap [Member]
Total derivatives										0	0
Non-guarantors [Member] | Corn Option [Member]
Total derivatives									0	0	0
Non-guarantors [Member] | Heating Oil Swaps And Options [Member]
Total derivatives, net of tax									(3,141)
Non-guarantors [Member] | Foreign Exchange Contract [Member]
Total derivatives, net of tax									(3,723)	1,081
Consolidation, Eliminations [Member]
Net income									(471,827)	(270,943)	(438,580)
Foreign currency translation adjustments									0	0	0
Pension liability adjustments, net of tax									0	0	0
Total derivatives, net of tax									0
Total other comprehensive income/(loss), net of tax									0	0	0
Total comprehensive income									(471,827)	(270,943)	(438,580)
Comprehensive income attributable to noncontrolling interests									0	0	0
Comprehensive income/(loss) attributable to Darling									(471,827)	(270,943)	(438,580)
Consolidation, Eliminations [Member] | Natural Gas Swap [Member]
Total derivatives										0	0
Consolidation, Eliminations [Member] | Corn Option [Member]
Total derivatives									0	0	$ 0
Consolidation, Eliminations [Member] | Foreign Exchange Contract [Member]
Total derivatives, net of tax									$ 0	$ 0