Guarantor Financial Information (Condensed Consolidated Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Net sales	$ 835,104	$ 875,374
Costs and expenses:
Cost of sales and operating expenses	646,663	678,099
Selling, general and administrative expenses	85,003	86,902
Depreciation and amortization	79,164	78,619
Total costs and expenses	810,830	843,620
Operating income	24,274	31,754
Interest expense	(19,876)	(23,124)
Foreign currency loss	(732)	(1,481)
Gain/(loss) on disposal of subsidiaries	0
Other expense, net	(2,525)	(2,516)
Equity in net income of unconsolidated subsidiaries	23,773	97,154
Earnings in investments in subsidiaries	0	0
Income before income taxes	24,914	101,787
Income tax expense	5,274	3,712
Net income attributable to noncontrolling interests	(1,628)	(770)
Net income attributable to Darling	18,012	97,305
Parent [Member]
Net sales	160,230	119,625
Costs and expenses:
Cost of sales and operating expenses	128,392	95,868
Selling, general and administrative expenses	47,423	43,778
Depreciation and amortization	14,373	11,059
Total costs and expenses	190,188	150,705
Operating income	(29,958)	(31,080)
Interest expense	(14,027)	(14,364)
Foreign currency loss	(4)	(23)
Gain/(loss) on disposal of subsidiaries	0
Other expense, net	(1,567)	(3,410)
Equity in net income of unconsolidated subsidiaries	(891)	(498)
Earnings in investments in subsidiaries	54,627	144,880
Income before income taxes	8,180	95,505
Income tax expense	(9,832)	(1,800)
Net income attributable to noncontrolling interests	0	0
Net income attributable to Darling	18,012	97,305
Guarantors [Member]
Net sales	329,991	344,603
Costs and expenses:
Cost of sales and operating expenses	267,194	271,237
Selling, general and administrative expenses	11,947	12,837
Depreciation and amortization	26,112	26,291
Total costs and expenses	305,253	310,365
Operating income	24,738	34,238
Interest expense	(32)	3,763
Foreign currency loss	0	(63)
Gain/(loss) on disposal of subsidiaries	0
Other expense, net	(1,212)	(1,326)
Equity in net income of unconsolidated subsidiaries	0	0
Earnings in investments in subsidiaries	0	0
Income before income taxes	23,494	36,612
Income tax expense	4,973	1,335
Net income attributable to noncontrolling interests	0	0
Net income attributable to Darling	18,521	35,277
Non-guarantors [Member]
Net sales	403,911	467,808
Costs and expenses:
Cost of sales and operating expenses	310,105	367,656
Selling, general and administrative expenses	25,633	30,287
Depreciation and amortization	38,679	41,269
Total costs and expenses	374,417	439,212
Operating income	29,494	28,596
Interest expense	(5,817)	(12,523)
Foreign currency loss	(728)	(1,395)
Gain/(loss) on disposal of subsidiaries	0
Other expense, net	254	2,220
Equity in net income of unconsolidated subsidiaries	24,664	97,652
Earnings in investments in subsidiaries	0	0
Income before income taxes	47,867	114,550
Income tax expense	10,133	4,177
Net income attributable to noncontrolling interests	(1,628)	(770)
Net income attributable to Darling	36,106	109,603
Eliminations [Member]
Costs and expenses:
Gain/(loss) on disposal of subsidiaries	0
Eliminations [Member]
Net sales	(59,028)	(56,662)
Costs and expenses:
Cost of sales and operating expenses	(59,028)	(56,662)
Selling, general and administrative expenses	0	0
Depreciation and amortization	0	0
Total costs and expenses	(59,028)	(56,662)
Operating income	0	0
Interest expense	0	0
Foreign currency loss	0	0
Other expense, net	0	0
Equity in net income of unconsolidated subsidiaries	0	0
Earnings in investments in subsidiaries	(54,627)	(144,880)
Income before income taxes	(54,627)	(144,880)
Income tax expense	0	0
Net income attributable to noncontrolling interests	0	0
Net income attributable to Darling	$ (54,627)	$ (144,880)