Comprehensive Income AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income/(loss) January 2, 2016, attributable to Darling, net of tax	$ (340,006)
Other comprehensive gain before reclassifications	126,702
Amounts reclassified from accumulated other comprehensive income/(loss)	(159)
Net current-period other comprehensive income	126,543	$ (5,984)	$ (156,467)
Noncontrolling interest	(3,939)
Accumulated Other Comprehensive Income/(loss) December 31, 2016, attributable to Darling, net of tax	(209,524)	(340,006)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income/(loss) January 2, 2016, attributable to Darling, net of tax	(308,910)
Other comprehensive gain before reclassifications	121,810
Amounts reclassified from accumulated other comprehensive income/(loss)	0
Net current-period other comprehensive income	121,810
Noncontrolling interest	(3,939)
Accumulated Other Comprehensive Income/(loss) December 31, 2016, attributable to Darling, net of tax	(183,161)	(308,910)
Derivative Instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income/(loss) January 2, 2016, attributable to Darling, net of tax	2,468
Other comprehensive gain before reclassifications	2,099
Amounts reclassified from accumulated other comprehensive income/(loss)	(3,195)
Net current-period other comprehensive income	(1,096)
Noncontrolling interest	0
Accumulated Other Comprehensive Income/(loss) December 31, 2016, attributable to Darling, net of tax	1,372	2,468
Defined Benefit Pension Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income/(loss) January 2, 2016, attributable to Darling, net of tax	(33,564)
Other comprehensive gain before reclassifications	2,793
Amounts reclassified from accumulated other comprehensive income/(loss)	3,036
Net current-period other comprehensive income	5,829
Noncontrolling interest	0
Accumulated Other Comprehensive Income/(loss) December 31, 2016, attributable to Darling, net of tax	$ (27,735)	$ (33,564)