Pension and Other Postretirement Benefits - Narrative (Details)	1 Months Ended		3 Months Ended		12 Months Ended
	Dec. 31, 2018 USD ($) person employee	Jun. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2018 USD ($) person employee	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($) person
Defined Benefit Plan Disclosure [Line Items]
SERP pension plan settlement charge			$ (1,000,000)	$ (600,000)	$ (800,000)	$ (600,000)
Number of regular full-time employees | person	2,641				2,641
Threshold period of service for participation in new pension plan	25 years
Aggregate contributions to qualified and non-qualified pension trusts and payments of pension benefits for unfunded pension plans	$ 9,400,000				$ 9,400,000
Maximum
Defined Benefit Plan Disclosure [Line Items]
Multiemployer plans accumulated funding deficiency demand liability	1,250,000				1,250,000
Minimum
Defined Benefit Plan Disclosure [Line Items]
Multiemployer plans accumulated funding deficiency demand liability	1,000,000				1,000,000
FiberMark | Maximum
Defined Benefit Plan Disclosure [Line Items]
Multiemployer pension plan expense					100,000
Matching contribution (as a percent)						5.00%
Supplemental Employee Retirement Plan
Defined Benefit Plan Disclosure [Line Items]
Payment for pension and other postretirement benefits					2,200,000	$ 1,300,000
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Number of eligible participants who accepted settlement | person							265
Cash paid for lump-sum payments							$ 8,100,000
Amount of settlement loss recognized							$ 800,000
Assets for plan benefits, defined benefit plan	1,600,000				1,600,000
Estimated net actuarial loss	5,600,000				5,600,000
Estimated prior service cost (credit)	200,000				$ 200,000
Expected long-term return on plan assets (as a percent)					5.78%	6.31%	6.20%
Amount of plan assets invested in the entity's securities	$ 0			$ 0	$ 0	$ 0	$ 0
Pension Benefits | Minimum
Defined Benefit Plan Disclosure [Line Items]
Expected long-term return on plan assets (as a percent)					6.00%
Postretirement Benefits Other than Pensions
Defined Benefit Plan Disclosure [Line Items]
Initial healthcare cost trend rate	6.80%			6.80%	6.80%	6.80%
Ultimate healthcare cost trend rate	4.50%			4.50%	4.50%	4.50%	4.50%
Estimated net actuarial loss	$ 800,000				$ 800,000
Estimated prior service cost (credit)	0				$ 0
Expected long-term return on plan assets (as a percent)					0.00%	0.00%	0.00%
Defined contribution retirement plans
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, cost					$ 2,300,000	$ 2,500,000	$ 2,700,000
Supplemental retirement contribution plan
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, cost					0	400,000	400,000
Unfunded obligation	$ 1,700,000			$ 1,700,000	1,700,000	1,700,000
Voluntary contribution investment plans
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, cost					$ 4,000,000	3,700,000	3,100,000
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Asset allocation (as a percent)	33.00%				33.00%
Equity securities | Maximum
Defined Benefit Plan Disclosure [Line Items]
Expected long-term return on plan assets (as a percent)					10.00%
Equity securities | Minimum
Defined Benefit Plan Disclosure [Line Items]
Expected long-term return on plan assets (as a percent)					8.00%
Equity securities | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Asset allocation (as a percent)	35.00%				35.00%
Equity securities | Pension Benefits | Maximum
Defined Benefit Plan Disclosure [Line Items]
Asset allocation (as a percent)	40.00%				40.00%
Equity securities | Pension Benefits | Minimum
Defined Benefit Plan Disclosure [Line Items]
Asset allocation (as a percent)	30.00%				30.00%
Hedge Funds
Defined Benefit Plan Disclosure [Line Items]
Asset allocation (as a percent)	8.00%				8.00%
Hedge Funds | Maximum
Defined Benefit Plan Disclosure [Line Items]
Expected long-term return on plan assets (as a percent)					8.00%
Hedge Funds | Minimum
Defined Benefit Plan Disclosure [Line Items]
Expected long-term return on plan assets (as a percent)					6.00%
Hedge Funds | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Asset allocation (as a percent)	8.00%				8.00%
Hedge Funds | Pension Benefits | Maximum
Defined Benefit Plan Disclosure [Line Items]
Asset allocation (as a percent)	12.00%				12.00%
Hedge Funds | Pension Benefits | Minimum
Defined Benefit Plan Disclosure [Line Items]
Asset allocation (as a percent)	3.00%				3.00%
U.S. and Non-U.S. Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Asset allocation (as a percent)	58.00%				58.00%
U.S. and Non-U.S. Fixed Income Securities | Maximum
Defined Benefit Plan Disclosure [Line Items]
Expected long-term return on plan assets (as a percent)					5.00%
U.S. and Non-U.S. Fixed Income Securities | Minimum
Defined Benefit Plan Disclosure [Line Items]
Expected long-term return on plan assets (as a percent)					3.00%
U.S. and Non-U.S. Fixed Income Securities | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Asset allocation (as a percent)	57.00%				57.00%
U.S. and Non-U.S. Fixed Income Securities | Pension Benefits | Maximum
Defined Benefit Plan Disclosure [Line Items]
Asset allocation (as a percent)	62.00%				62.00%
U.S. and Non-U.S. Fixed Income Securities | Pension Benefits | Minimum
Defined Benefit Plan Disclosure [Line Items]
Asset allocation (as a percent)	52.00%				52.00%
Prepaid Expenses and Other Current Assets | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Assets for plan benefits, defined benefit plan	$ 500,000				$ 500,000
Other assets | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Assets for plan benefits, defined benefit plan	1,100,000				1,100,000
Level 1 | Other assets | Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of marketable securities	$ 3,600,000				3,600,000
Pace Industry Union-Management Pension Fund
Defined Benefit Plan Disclosure [Line Items]
Multiemployer pension plan expense					100,000
Multiemployer plans withdrawal obligation		$ 1,000,000	1,000,000
Multiemployer plans minimum contribution		$ 100,000	$ 100,000
Multiemployer plans minimum contribution period		20 years
Measurement Input, Risk Free Interest Rate | Pace Industry Union-Management Pension Fund
Defined Benefit Plan Disclosure [Line Items]
Multiemployer plans withdrawal obligation measurement input		0.057
Adjustment to pension and other benefit liabilities | Reclassification out of Accumulated Other Comprehensive Income | Pension Plan Settlement Charge
Defined Benefit Plan Disclosure [Line Items]
Reclassification from AOCI, before tax					$ 800,000	$ 600,000	$ 800,000
Munising Mill, Whiting Mill, Neenah Mill and Neenah Finishing Center
Defined Benefit Plan Disclosure [Line Items]
Number of hourly employees | employee	375				375
Number of regular full-time employees | employee	690				690