Goodwill and Intangible Assets - Goodwill (Details) - USD ($)		3 Months Ended	12 Months Ended
		Dec. 31, 2022	Dec. 31, 2022		Dec. 31, 2021		Dec. 31, 2020
Goodwill [Line Items]
Beginning Balance			$ 923,500,000		$ 863,500,000
Acquisitions			1,000,000.0	[1]	60,000,000.0	[2]
Impairment of Paper segment		$ 0	0		0		$ (55,200,000)
Adjustment related to sale of corrugated assets (c)	[3]		(100,000)
Ending Balance		922,400,000	922,400,000		923,500,000		$ 863,500,000
Advance Packaging Corporation [Member]
Goodwill [Line Items]
Beginning Balance			60,000,000.0
Ending Balance		1,000,000.0	1,000,000.0		60,000,000.0
Packaging
Goodwill [Line Items]
Beginning Balance			923,500,000
Ending Balance		$ 922,400,000	$ 922,400,000		$ 923,500,000

[1] During 2022, the Company recorded a $1.0 million adjustment to decrease the goodwill balance for the Company's December 2021 acquisition of Advance Packaging

[2] In connection with the December 2021 acquisition of Advance Packaging, the Company recorded $60.0 million of goodwill in the Packaging segment.

[3] During 2022, a corrugated products facility sold part of its operations, which primarily included existing inventory. As a result, the Company recorded a $0.1 million adjustment to decrease the goodwill balance