Commitments, Contingencies and Legal Proceedings - Additional Information (Detail) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2019 USD ($)	Dec. 31, 2019 USD ($) Operable_Unit	Dec. 31, 2018 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Commitments Contingencies And Litigation [Line Items]
Annual payments due under operating leases		$ 18,400
Aggregate contractual obligation		$ 118,400
Number of operable units | Operable_Unit		5
Term of agreement wih third party for monitoring and maintenance in OU1-OU4a		30 years
Difference recorded in escrow account		$ 2,000
Assumption of escrow		4,700	$ 4,746
Total amount available in escrow account		8,900
Reserve for Environmental liabilities, current portion		9,000	$ 23,000
Other Long-Term Liabilities [Member]
Commitments Contingencies And Litigation [Line Items]
Reserve for Environmental liabilities, remaining portion		$ 12,900
Minimum [Member]
Commitments Contingencies And Litigation [Line Items]
Period over which cash expenditure to be incurred for monitoring activities		30 years
Glatfelter Consent Decree [Member]
Commitments Contingencies And Litigation [Line Items]
Payments for governments unreimbursed past costs	$ 20,500	$ 20,500
OU2-5 [Member]
Commitments Contingencies And Litigation [Line Items]
Estimated future cost of cleanup work				$ 13,400	$ 13,400
Expected cleanup work continuation year		through 2020