Segment Information - Analysis of Operations by Reportable Segment (Parenthetical) (Details) - USD ($)			1 Months Ended	3 Months Ended			6 Months Ended		12 Months Ended
		May 31, 2020	Oct. 31, 2021	Dec. 31, 2021	Mar. 31, 2021	Jun. 30, 2019	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Goodwill impairment charge				$ 0					$ 0	$ 55,200,000	$ 0
Charges for disposal of fixed assets									(6,100,000)	(6,800,000)	(8,200,000)
Acquisition and integration related costs	[1]								600,000	0	0
Gain on Sale of Transportation Assets									800,000
Business Combination Acquisition And Integration Related Costs	[1]								600,000	0	0
Debt Refinancing Cost			$ 58,900,000
Advance Packaging Corporation [Member]
Segment Reporting Information [Line Items]
Restructuring charges					$ 400,000
Acquisition and integration related costs									500,000
Business Combination Acquisition And Integration Related Costs									500,000
Debt Refinancing
Segment Reporting Information [Line Items]
Restructuring charges											38,700,000
Packaging
Segment Reporting Information [Line Items]
Restructuring charges											300,000
Acquisition and integration related costs									400,000
Business Combination Acquisition And Integration Related Costs									400,000
Packaging | COVID-19
Segment Reporting Information [Line Items]
Restructuring charges							$ 6,300,000
Paper
Segment Reporting Information [Line Items]
Restructuring charges									800,000
Goodwill impairment charge										$ 55,200,000
Paper | COVID-19
Segment Reporting Information [Line Items]
Incremental Out Of Pocket Costs									600,000
Packaging and Paper
Segment Reporting Information [Line Items]
Restructuring charges							27,300,000
Paper Reporting Unit
Segment Reporting Information [Line Items]
Goodwill impairment charge		$ 55,200,000						$ 55,200,000
DeRidder, Louisiana Mill
Segment Reporting Information [Line Items]
Restructuring charges							$ 10,000,000.0
DeRidder, Louisiana Mill | Packaging
Segment Reporting Information [Line Items]
Charges for disposal of fixed assets											3,000,000.0
Wallula, Washington Mill | Packaging
Segment Reporting Information [Line Items]
Restructuring charges											$ 800,000
Wallula, Washington Mill | Paper
Segment Reporting Information [Line Items]
Restructuring charges						$ 200,000
Jackson Alabama Mill [Member] | Corrugated Products Facilities
Segment Reporting Information [Line Items]
Adjustment of asset retirement obligation					4,300,000
Jackson Alabama Mill [Member] | Paper
Segment Reporting Information [Line Items]
Restructuring charges					$ 9,300,000
San Lorenzo, California [Member]
Segment Reporting Information [Line Items]
Restructuring charges									$ 2,800,000

[1] Includes charges related to the December 2021 Advance Packaging Corporation acquisition.