Segment Information - Schedule of Financial and Other Information by Business Unit (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($) T	Jun. 30, 2018 USD ($) T	Jun. 30, 2019 USD ($) T	Jun. 30, 2018 USD ($) T
Segment Reporting Information [Line Items]
Net sales	$ 235,053	$ 215,742	$ 464,186	$ 426,949
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Cost of products sold	$ 197,553	$ 182,443	$ 391,069	$ 357,090
Type of Cost, Good or Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Gross profit	$ 37,500	$ 33,299	$ 73,117	$ 69,859
SG&A	22,800	26,185	47,422	56,116
Gains on dispositions of plant,equipment and timberlands, net	(423)	(574)	(1,092)	(1,690)
Operating income	15,123	7,688	26,787	15,433
Non-operating expense	(3,175)	(4,595)	(8,378)	(8,314)
Income from continuing operations before income taxes	$ 11,948	$ 3,093	$ 18,409	$ 7,119
Supplementary Data
Net tons sold | T	68,500	61,200	133,300	121,400
Depreciation, depletion and amortization	$ 12,700	$ 11,900	$ 25,520	$ 23,195
Capital expenditures	4,800	5,900	10,600	25,900
Composite Fibers [Member]
Segment Reporting Information [Line Items]
Net sales	132,581	$ 142,934	261,298	$ 284,531
Type of Revenue [Extensible List]		us-gaap:ProductMember		us-gaap:ProductMember
Cost of products sold	109,600	$ 118,000	216,100	$ 232,700
Type of Cost, Good or Service [Extensible List]		us-gaap:ProductMember		us-gaap:ProductMember
Gross profit	23,000	$ 24,900	45,200	$ 51,800
SG&A	10,000	11,700	20,800	23,300
Operating income	13,000	13,200	24,400	28,500
Income from continuing operations before income taxes	$ 13,000	$ 13,200	$ 24,400	$ 28,500
Supplementary Data
Net tons sold | T	34,500	36,700	66,100	73,000.0
Depreciation, depletion and amortization	$ 6,600	$ 7,200	$ 13,300	$ 14,600
Capital expenditures	1,500	2,800	4,700	7,900
Advanced Airlaid Materials [Member]
Segment Reporting Information [Line Items]
Net sales	$ 102,472	$ 72,808	$ 202,888	$ 142,418
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Cost of products sold	$ 87,800	$ 62,800	$ 173,800	$ 122,500
Type of Cost, Good or Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Gross profit	$ 14,700	$ 10,000	$ 29,100	$ 19,900
SG&A	4,300	2,400	8,700	5,100
Operating income	10,400	7,600	20,400	14,800
Income from continuing operations before income taxes	$ 10,400	$ 7,600	$ 20,400	$ 14,800
Supplementary Data
Net tons sold | T	34,000.0	24,500	67,200	48,300
Depreciation, depletion and amortization	$ 5,300	$ 3,500	$ 10,500	$ 6,300
Capital expenditures	$ 2,800	$ 2,500	$ 5,000	$ 15,600
Other and Unallocated [Member]
Segment Reporting Information [Line Items]
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Cost of products sold	$ 200	$ 1,600	$ 1,200	$ 1,900
Type of Cost, Good or Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Gross profit	$ (200)	$ (1,600)	$ (1,200)	$ (1,900)
SG&A	8,500	12,100	17,900	27,700
Gains on dispositions of plant,equipment and timberlands, net	(400)	(600)	(1,100)	(1,700)
Operating income	(8,300)	(13,100)	(18,000)	(27,900)
Non-operating expense	(3,200)	(4,600)	(8,400)	(8,300)
Income from continuing operations before income taxes	(11,500)	(17,700)	(26,400)	(36,200)
Supplementary Data
Depreciation, depletion and amortization	800	1,200	1,700	2,300
Capital expenditures	$ 500	$ 600	$ 900	$ 2,400