General Information - Business Combinations and Shutdown and Other Special Charges, Net (Details) $ in Millions		3 Months Ended		12 Months Ended
	Aug. 01, 2019 facility mill	Mar. 31, 2020 USD ($) employee	Mar. 31, 2019 USD ($)	Dec. 31, 2022 USD ($) mill	Dec. 31, 2020 USD ($)
Business Acquisition [Line Items]
Charges Associated with Business Combinations		$ 1.5	$ 2.1
Shutdown and Other Special Charges		4.2	4.1
Exit Activities		13.0	0.0
Total		$ 18.7	$ 6.2
Number of mills to be closed | employee		2
Number of facilities acquired | facility	2
Length of program to dismantle and dispose of abandoned assets		3 years
Artistic Carton Company
Business Acquisition [Line Items]
Number of mills acquired | mill	1
Paperboard Mills
Business Acquisition [Line Items]
Expected costs associated with closures		$ 40.0
Forecast | Facility Closing
Business Acquisition [Line Items]
Number of mills to be closed | mill				2
Forecast | Construction in Progress
Business Acquisition [Line Items]
Investment in new CRB Mill				$ 600.0	$ 600.0