Segment Information - Reconciliation of Net Income to EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Segment Reporting, Other Significant Reconciling Item, Consolidated
Net income	$ 25,480	$ 17,042	$ 48,347	$ 55,175
Income tax expense	15,969	22,500	27,569	45,030
Depreciation and amortization	33,538	34,921	99,755	99,749
Interest expense, net	18,784	17,571	54,464	53,719
Impairment and restructuring charges	1,355	8,217	10,393	18,534
(Gain) loss on sale of property and equipment	(287)	1	(2,697)	1,081
Stock-based compensation	2,767	4,108	11,662	10,585
Non-cash foreign exchange transaction/translation (income) loss	2,963	(182)	10,558	3,615
Other items	30,181	4,770	70,755	37,586
Costs relating to debt restructuring and debt refinancing	0	0	170	0
Other non-cash items	0	0	0	734
Adjusted EBITDA	130,750	108,948	330,976	325,808
Legal fees	27,760	3,599	62,460	9,887
Consolidation and reorganization cost	1,289	2,557	5,366	15,708
Realized loss on hedge	1,142		1,142
Realized gain on hedges		(3,021)		(3,053)
Acquisition-related costs		1,435		13,432
One-time lease termination charges			1,235
Employee retention cost				7,077
Miscellaneous cost				987
Executive compensation expense				625
Cost of sales
Segment Reporting, Other Significant Reconciling Item, Consolidated
Impairment and restructuring charges	$ 36	$ 282	$ 263	$ 1,146