Discontinued Operations - Summary of Discontinued Operations included in Condensed Consolidated Statements of Income (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Non-operating income (expense)
Income before income taxes	$ 714	$ 4,459
Income tax provision (benefit)	31	1,007
Income from discontinued operations	683	3,452
Specialty Papers [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Total revenues		200,867
Costs of products sold		188,521
Gross profit		12,346
Selling, general and administrative expenses	(714)	7,132
Gains on dispositions of plant, equipment and timberlands, net		(438)
Operating income	714	5,652
Non-operating income (expense)
Interest expense		(1,745)
Other, net		552
Income before income taxes	714	4,459
Income tax provision (benefit)	(31)	1,007
Income from discontinued operations	$ 683	3,452
Specialty Papers [Member] | Product [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Total revenues		199,438
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		$ 1,429