Segment Information - Selected Financial Information by Reportable Segment (Parenthetical) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Packaging | Advance Packaging Corporation [Member]
Segment Reporting Information [Line Items]
Acquisition and integration related costs	$ 0.9		$ 0.3
Jackson, Alabama Mill | Corrugated Products Facilities
Segment Reporting Information [Line Items]
Adjustment of asset retirement obligation	$ 3.9	$ 3.8	$ 5.4	$ 4.9
San Lorenzo, California [Member] | Corrugated Products Facilities
Segment Reporting Information [Line Items]
Adjustment of asset retirement obligation		$ 4.7		$ 2.6