Restructuring and Asset Impairment - Restructuring and Restructuring-related Asset Impairment Expenses by Type Incurred and by Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2020	Sep. 29, 2019	Sep. 27, 2020	Sep. 29, 2019
Restructuring Cost and Reserve [Line Items]
Total Restructuring/Asset Impairment Charges	$ 24,149	$ 6,615	$ 59,633	$ 30,642
Severance and Termination Benefits
Restructuring Cost and Reserve [Line Items]
Total Restructuring/Asset Impairment Charges	4,607	4,922	29,866	16,421
Severance and Termination Benefits | Operating Segments | Consumer Packaging
Restructuring Cost and Reserve [Line Items]
Total Restructuring/Asset Impairment Charges	16,662	6,363	22,274	24,105
Severance and Termination Benefits | Operating Segments | Display and Packaging
Restructuring Cost and Reserve [Line Items]
Total Restructuring/Asset Impairment Charges	1,391	106	4,939	992
Severance and Termination Benefits | Operating Segments | Paper and Industrial Converted Products
Restructuring Cost and Reserve [Line Items]
Total Restructuring/Asset Impairment Charges	6,990	1,066	30,035	3,540
Severance and Termination Benefits | Operating Segments | Protective Solutions
Restructuring Cost and Reserve [Line Items]
Total Restructuring/Asset Impairment Charges	(793)	(930)	375	73
Asset Impairment/ Disposal of Assets
Restructuring Cost and Reserve [Line Items]
Total Restructuring/Asset Impairment Charges	16,605	(948)	25,364	6,336
Other Costs
Restructuring Cost and Reserve [Line Items]
Total Restructuring/Asset Impairment Charges	2,937	2,641	4,403	7,885
Other Costs | Corporate
Restructuring Cost and Reserve [Line Items]
Total Restructuring/Asset Impairment Charges	$ (101)	$ 10	$ 2,010	$ 1,932