Segment Reporting - Segment Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Net sales	$ 1,245,485	$ 1,359,721	$ 2,548,781	$ 2,711,426
Operating profit	103,727	129,768	233,830	246,656
Restructuring/Asset impairment charges	(22,885)	(13,355)	(35,484)	(24,027)
Consumer Packaging
Segment Reporting Information [Line Items]
Net sales	614,621	602,750	1,203,038	1,192,466
Display and Packaging
Segment Reporting Information [Line Items]
Net sales	107,303	134,833	228,659	272,387
Paper and Industrial Converted Products
Segment Reporting Information [Line Items]
Net sales	434,452	491,328	909,422	987,365
Protective Solutions
Segment Reporting Information [Line Items]
Net sales	89,109	130,810	207,662	259,208
Operating Segments | Consumer Packaging
Segment Reporting Information [Line Items]
Net sales	614,621	602,750	1,203,038	1,192,466
Operating profit	86,129	62,942	153,930	125,057
Operating Segments | Display and Packaging
Segment Reporting Information [Line Items]
Net sales	107,303	134,833	228,659	272,387
Operating profit	5,981	5,889	14,075	12,343
Operating Segments | Paper and Industrial Converted Products
Segment Reporting Information [Line Items]
Net sales	434,452	491,328	909,422	987,365
Operating profit	29,964	61,229	83,977	109,616
Operating Segments | Protective Solutions
Segment Reporting Information [Line Items]
Net sales	89,109	130,810	207,662	259,208
Operating profit	4,482	14,275	18,486	25,279
Intersegment Sales
Segment Reporting Information [Line Items]
Net sales	31,799	34,134	64,954	70,338
Intersegment Sales | Consumer Packaging
Segment Reporting Information [Line Items]
Net sales	2,451	1,122	4,724	2,043
Intersegment Sales | Display and Packaging
Segment Reporting Information [Line Items]
Net sales	1,169	1,114	2,467	2,281
Intersegment Sales | Paper and Industrial Converted Products
Segment Reporting Information [Line Items]
Net sales	27,848	31,535	57,060	65,189
Intersegment Sales | Protective Solutions
Segment Reporting Information [Line Items]
Net sales	331	363	703	825
Segment Reconciling Items
Segment Reporting Information [Line Items]
Other, net	$ 56	$ (1,212)	$ (1,154)	$ (1,612)