Quarterly Results of Operations (Unaudited) - Summary of Quarterly Financial Data (Parenthetical) (Details) - USD ($)		3 Months Ended				6 Months Ended		12 Months Ended
	May 31, 2020	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2019	Jun. 30, 2019	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Quarterly Financial Data [Line Items]
Goodwill impairment charge		$ 0						$ 0	$ 55,200,000	$ 0
Debt Refinancing [Member]
Quarterly Financial Data [Line Items]
Restructuring charges										38,700,000
Treasury Lock [Member]
Quarterly Financial Data [Line Items]
Income tax benefit from stranded tax effects in accumulated OCI related to write-off of remaining treasury lock				$ 3,200,000
DeRidder Louisiana Mill [Member]
Quarterly Financial Data [Line Items]
Restructuring charges						$ 10,000,000.0
Paper Reporting Unit
Quarterly Financial Data [Line Items]
Goodwill impairment charge	$ 55,200,000						$ 55,200,000
Packaging And Paper [Member]
Quarterly Financial Data [Line Items]
Restructuring charges						27,300,000
Paper [Member]
Quarterly Financial Data [Line Items]
Restructuring charges								800,000
Goodwill impairment charge									$ 55,200,000
Paper [Member] | Wallula Washington Mill [Member]
Quarterly Financial Data [Line Items]
Restructuring charges					$ 200,000
Paper [Member] | Jackson Alabama Mill [Member]
Quarterly Financial Data [Line Items]
Restructuring charges			$ 9,300,000
Packaging [Member]
Quarterly Financial Data [Line Items]
Restructuring charges										300,000
Packaging [Member] | Wallula Washington Mill [Member]
Quarterly Financial Data [Line Items]
Restructuring charges										$ 800,000
Covid Nineteen [Member] | Paper [Member]
Quarterly Financial Data [Line Items]
Incremental out-of-pocket costs								$ 600,000
Covid Nineteen [Member] | Packaging [Member]
Quarterly Financial Data [Line Items]
Restructuring charges						$ 6,300,000