Discontinued Operations - Summary of Discontinued Operations included in Condensed Consolidated Statements of Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Non-operating income (expense)
Income (loss) before income taxes	$ 1,062	$ (114,656)	$ 1,291	$ (128,714)
Income tax benefit	(2,519)	(19,530)	(2,511)	(28,361)
Income (loss) from discontinued operations	3,581	(95,126)	3,802	(100,353)
Specialty Papers [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Total revenues		202,132		593,974
Costs of products sold		181,628		572,820
Gross profit		20,504		21,154
Selling, general and administrative expenses	(2,455)	6,058	(2,684)	18,566
Gains on dispositions of plant, equipment and timberlands, net		3		(440)
Operating income	2,455	14,443	2,684	3,028
Non-operating income (expense)
Interest expense		(2,281)		(6,017)
Other, net	(1,393)	(1,174)	(1,393)	(81)
Impairment charge		(125,644)		(125,644)
Income (loss) before income taxes	1,062	(114,656)	1,291	(128,714)
Income tax benefit	(2,519)	(19,530)	(2,511)	(28,361)
Income (loss) from discontinued operations	$ 3,581	(95,126)	$ 3,802	(100,353)
Specialty Papers [Member] | Product [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Total revenues		201,288		590,757
Specialty Papers [Member] | Energy and Related Sales Net [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Total revenues		$ 844		$ 3,217