Discontinued Operations - Summary of Discontinued Operations included in Condensed Consolidated Statements of Income (Loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Non-operating income (expense)
Income (loss) before income taxes	$ (207,242)	$ 19,868	$ 53,388
Income tax provision (benefit)	(30,086)	6,342	17,657
Income (loss) from discontinued operations	(177,156)	13,526	35,731
Specialty Papers [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Total revenues	664,574	796,061	849,723
Costs of products sold	637,472	751,135	767,320
Gross profit	27,102	44,926	82,403
Selling, general and administrative expenses	32,465	22,538	29,701
(Gains) losses on dispositions of plant, equipment and timberlands, net	(423)	219	101
Operating income (loss)	(4,940)	22,169	52,601
Non-operating income (expense)
Interest expense	(6,942)	(4,455)	(1,972)
Other, net	(51,236)	2,154	2,759
Impairment charge	(144,124)
Income (loss) before income taxes	(207,242)	19,868	53,388
Income tax provision (benefit)	(30,086)	6,342	17,657
Income (loss) from discontinued operations	(177,156)	13,526	35,731
Specialty Papers [Member] | Product [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Total revenues	661,186	790,935	843,582
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	$ 3,388	$ 5,126	$ 6,141