Pension and Other Postretirement Benefits - Narrative (Details)	3 Months Ended		12 Months Ended
	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($) person	Dec. 31, 2015 USD ($)
Defined Benefit Plan Disclosure [Line Items]
SERP pension plan settlement charge	$ (400,000)	$ (200,000)	$ (600,000)	$ (800,000)	$ 0
Aggregate contributions to qualified and non-qualified pension trusts and payments of pension benefits for unfunded pension plans	14,700,000		14,700,000
FiberMark
Defined Benefit Plan Disclosure [Line Items]
Multiemployer pension plan expense			100,000
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			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
Defined benefit plan, benefit obligation, payment for settlement			(600,000)	$ (800,000)	$ 0
Assets for plan benefits, defined benefit plan	1,700,000		1,700,000
Estimated net actuarial loss	5,400,000		5,400,000
Estimated prior service cost (credit)	200,000		$ 200,000
Expected long-term return on plan assets (as a percent)			6.31%	6.20%	6.50%
Amount of plan assets invested in the entity's securities	$ 0		$ 0	$ 0	$ 0
Pension Benefits | Minimum
Defined Benefit Plan Disclosure [Line Items]
Expected long-term return on plan assets (as a percent)			6.30%
Postretirement Benefits Other than Pensions
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, benefit obligation, payment for settlement			$ 0	$ 0	$ 0
Health care cost trend rate assumed for next fiscal year	6.80%		6.80%	7.00%
Ultimate health care cost trend rate	4.50%		4.50%	4.50%
Estimated net actuarial loss	$ 600,000		$ 600,000
Estimated prior service cost (credit)	(200,000)		$ (200,000)
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			$ 2,500,000	$ 2,700,000	$ 2,500,000
Supplemental retirement contribution plan
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, cost			400,000	400,000	200,000
Unfunded obligation	$ 1,700,000		1,700,000	1,300,000
Voluntary contribution investment plans
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, cost			$ 3,700,000	$ 3,100,000	$ 2,700,000
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Asset allocation (as a percent)	35.00%		35.00%
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)	48.00%		48.00%
Equity securities | Pension Benefits | Minimum
Defined Benefit Plan Disclosure [Line Items]
Asset allocation (as a percent)	38.00%		38.00%
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)	57.00%		57.00%
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	$ 600,000		$ 600,000
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