Retirement Plans and Other Post-Retirement Benefits - Additional Information (Detail) $ in Thousands			1 Months Ended	12 Months Ended
	Jun. 01, 2019	Oct. 31, 2018 USD ($)	Oct. 31, 2018 USD ($)	Dec. 31, 2020 USD ($) Age	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Pension settlement charge, net of post settlement adjustments				$ (6,154)	$ (75,326)
Employer contribution of employee's eligible earnings, percentage	7.00%			11.00%
Comprehensive medical plan for retiree employees eligible age to participate in health care benefit plan | Age				65
Comprehensive medical plan for retiree employees eligible age for avail defray costs of Medicare | Age				65
Projected benefit obligation				$ 47,300	45,700
Accumulated benefit obligation for all defined benefit pension plans				$ 47,300	45,700
Defined contribution plans Employees contribution				50.00%
Expense associated with Defined Contribution Plans				$ 2,000	1,900	$ 400
Non-qualified Plans [Member] | Unfunded [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation				47,300
Specialty Papers [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension liabilities assumed		$ 210,000	$ 210,000
Retiree healthcare liabilities		38,000	38,000
Related assets transferred from existing pension plan		$ 274,000	$ 274,000
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Decrease in projected benefit obligation					309,500
Decrease in plan assets					309,500
Pension plan settlement charge					75,300
Assets remain in pension trust				(47,300)	7,700
Pension settlement charge, net of post settlement adjustments				2,300	(75,300)
Amount transferred to suspense account to fund future 401(k) contributions				14,100
Paying of excise taxes				8,300
Available for general corporate purposes				$ 33,300
Related assets transferred from existing pension plan					$ 5,700
Discount rates				2.17%	2.70%
Pension Benefits [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rates				2.61%
Pension Benefits [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rates				1.22%
Pension Benefits [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets remain in pension trust					$ 53,400
Pension Benefits [Member] | Cash and Cash Equivalents [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets remain in pension trust				$ 53,400
Deferred Compensation Plan [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contribution of employee's eligible earnings, percentage				7.00%
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets remain in pension trust				$ (6,000)	$ (6,500)
Discount rates				2.30%	3.11%