Restructuring and Other Items, net (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 28, 2020 USD ($) Mill	Jul. 04, 2021 USD ($)	Jun. 28, 2020 USD ($) Mill
Restructuring Reserve [Roll Forward]
Restructuring liability, beginning of period		$ 3.6
Additional provision		0.0
Cash payments		(0.8)
Restructuring liability, ending of period		2.8
Restructuring and Other Items, Net [Abstract]
Asset write-down charges		$ 0.0	$ 6.0
Paper PCC [Member]
Restructuring and Other Items, Net [Abstract]
Asset write-down charges	$ 6.0		6.0
Severance costs	0.3		0.3
Lease termination costs	$ 0.2		$ 0.2
Number of mills with lease terminations | Mill	1		1
Verso Papers [Member]
Restructuring and Other Items, Net [Abstract]
Number of paper mills being idled indefinitely | Mill	2		2