Segment Information (Detail) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Net Sales	$ 480.5		$ 452.0	$ 958.4	$ 880.8
Income from operations	48.1		15.3	67.0	29.7
Other operating charges, net	(3.0)	$ (8.5)	(0.4)	(11.5)	(0.1)
Consumer Products
Segment Reporting Information [Line Items]
Net Sales	275.1		224.3	540.8	447.7
Income from operations	36.6		(5.1)	50.9	(3.9)
Pulp And Paperboard [Member]
Segment Reporting Information [Line Items]
Net Sales	205.4		227.7	417.6	433.1
Income from operations	32.2		33.6	58.7	63.0
Corporate
Segment Reporting Information [Line Items]
Income from operations	(17.6)		(12.7)	(31.1)	(29.3)
Retail tissue [Domain]
Segment Reporting Information [Line Items]
Net Sales	260.4		210.5	508.4	415.1
Paperboard [Domain]
Segment Reporting Information [Line Items]
Net Sales	204.1		226.2	415.1	429.2
Non-retail tissue [Domain]
Segment Reporting Information [Line Items]
Net Sales	10.2		12.3	24.1	30.7
Other [Domain]
Segment Reporting Information [Line Items]
Net Sales	$ 5.8		$ 3.0	$ 10.7	$ 5.8