v3.26.1
Segment Reporting - Schedule of Segment Financial Information (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 28, 2026
Jun. 29, 2025
Jun. 28, 2026
Jun. 29, 2025
Segment Reporting [Line Items]        
Sales from reportable segments $ 1,919,728 $ 1,874,887 $ 3,627,313 $ 3,560,074
Other sales   65,754   120,947
Total consolidated sales 1,885,485 1,910,441 3,561,927 3,619,669
Cost of sales (1,493,108) (1,504,164) (2,823,922) (2,859,705)
Segment operating profit 192,837 175,667 319,929 302,527
Other segment disclosures:        
Equity in earnings of affiliates, net of tax 2,263 2,270 2,953 4,191
Depreciation and amortization     256,125 250,967
Consumer Packaging        
Segment Reporting [Line Items]        
Sales from reportable segments 1,244,720 1,229,581 2,344,781 2,298,943
Industrial Paper Packaging        
Segment Reporting [Line Items]        
Sales from reportable segments 675,008 645,306 1,282,532 1,261,131
Operating Segments        
Segment Reporting [Line Items]        
Sales from reportable segments 1,885,485 1,844,694 3,561,927 3,498,819
Segment operating profit 241,084 246,287 435,979 463,389
Other segment disclosures:        
Equity in earnings of affiliates, net of tax 2,263 2,270 2,953 4,191
Operating Segments | Consumer Packaging        
Segment Reporting [Line Items]        
Sales from reportable segments 1,241,839 1,227,033 2,338,914 2,293,626
Total consolidated sales 1,241,839 1,227,033 2,338,914 2,293,626
Cost of sales (1,007,245) (989,484) (1,896,335) (1,843,216)
Other segment items (85,770) (79,744) (171,092) (154,603)
Segment operating profit 151,705 160,353 277,354 301,124
Other segment disclosures:        
Equity in earnings of affiliates, net of tax 276 170 274 119
Depreciation and amortization 54,675 52,801 105,625 101,756
Operating Segments | Industrial Paper Packaging        
Segment Reporting [Line Items]        
Sales from reportable segments 643,646 617,661 1,223,013 1,205,193
Total consolidated sales 643,646 617,661 1,223,013 1,205,193
Cost of sales (484,936) (464,247) (922,277) (907,325)
Other segment items (100,693) (95,125) (201,630) (191,541)
Segment operating profit 89,379 85,934 158,625 162,265
Other segment disclosures:        
Equity in earnings of affiliates, net of tax 1,987 2,100 2,679 4,072
Depreciation and amortization 30,851 30,711 60,610 59,868
Intersegment Eliminations        
Segment Reporting [Line Items]        
Sales from reportable segments 34,243 30,193 65,386 61,255
Total consolidated sales (34,243) (30,200) (65,386) (61,352)
Intersegment Eliminations | Consumer Packaging        
Segment Reporting [Line Items]        
Sales from reportable segments 2,881 2,548 5,867 5,317
Intersegment Eliminations | Industrial Paper Packaging        
Segment Reporting [Line Items]        
Sales from reportable segments $ 31,362 $ 27,645 $ 59,519 $ 55,938