Segment Reporting - Segment Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2021	Sep. 27, 2020	Oct. 03, 2021	Sep. 27, 2020
Segment Reporting Information [Line Items]
Net sales	$ 1,415,193	$ 1,312,314	$ 4,151,251	$ 3,861,095
Operating profit	126,512	106,744	382,112	340,574
Restructuring/Asset impairment charges	(3,488)	(24,149)	(8,889)	(59,633)
Other non-base income/(charges), net	7,570	352	294	(802)
Consumer Packaging
Segment Reporting Information [Line Items]
Net sales	598,969	546,208	1,779,525	1,659,943
Industrial Paper Packaging
Segment Reporting Information [Line Items]
Net sales	635,230	490,369	1,809,159	1,447,886
All Other
Segment Reporting Information [Line Items]
Net sales	180,994	275,737	562,567	753,266
Operating Segments | Consumer Packaging
Segment Reporting Information [Line Items]
Net sales	598,969	546,208	1,779,525	1,659,943
Operating profit	60,918	64,370	196,341	212,575
Operating Segments | Industrial Paper Packaging
Segment Reporting Information [Line Items]
Net sales	635,230	490,369	1,809,159	1,447,886
Operating profit	53,343	41,035	161,414	133,871
Operating Segments | All Other
Segment Reporting Information [Line Items]
Net sales	180,994	275,737	562,567	753,266
Operating profit	8,169	25,136	32,952	54,563
Intersegment Sales
Segment Reporting Information [Line Items]
Net sales	31,901	27,261	94,514	82,687
Intersegment Sales | Consumer Packaging
Segment Reporting Information [Line Items]
Net sales	1,608	919	4,460	3,179
Intersegment Sales | Industrial Paper Packaging
Segment Reporting Information [Line Items]
Net sales	27,975	24,528	82,571	73,538
Intersegment Sales | All Other
Segment Reporting Information [Line Items]
Net sales	$ 2,318	$ 1,814	$ 7,483	$ 5,970