Segment Information - Schedule of Financial and Other Information by Business Unit (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($) T	Sep. 30, 2017 USD ($) T	Sep. 30, 2018 USD ($) T	Sep. 30, 2017 USD ($) T
Segment Reporting Information [Line Items]
Net sales	$ 209,855	$ 210,120	$ 636,806	$ 591,035
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Cost of products sold	$ 179,983	$ 172,745	$ 537,073	$ 485,783
Type of Cost, Good or Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Gross profit (loss)	$ 29,872	$ 37,375	$ 99,733	$ 105,252
SG&A	25,799	27,083	81,915	81,530
(Gains) losses on dispositions of plant, equipment and timberlands, net	(249)	(93)	(1,939)	(168)
Operating income (loss)	4,322	10,385	19,757	23,890
Non-operating expense	(1,565)	(3,660)	(9,879)	(10,374)
Income (loss) before income taxes	$ 2,757	$ 6,725	$ 9,878	$ 13,516
Supplementary Data
Net tons sold | T	61,500	63,500	182,800	182,400
Depreciation, depletion and amortization	$ 11,500	$ 10,200	$ 34,731	$ 30,276
Capital expenditures	6,200	21,000	32,200	58,000
Composite Fibers [Member]
Segment Reporting Information [Line Items]
Net sales	$ 139,176	$ 142,349	$ 423,707	$ 400,590
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Cost of products sold	$ 116,800	$ 115,000	$ 349,500	$ 322,200
Type of Cost, Good or Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Gross profit (loss)	$ 22,400	$ 27,300	$ 74,200	$ 78,400
SG&A	10,500	10,900	34,000	32,900
Operating income (loss)	11,900	16,400	40,200	45,500
Income (loss) before income taxes	$ 11,900	$ 16,400	$ 40,200	$ 45,500
Supplementary Data
Net tons sold | T	37,400	39,700	110,400	112,900
Depreciation, depletion and amortization	$ 7,100	$ 7,100	$ 21,700	$ 20,900
Capital expenditures	3,000	3,800	10,900	10,600
Advanced Airlaid Materials [Member]
Segment Reporting Information [Line Items]
Net sales	$ 70,679	$ 67,771	$ 213,099	$ 190,445
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Cost of products sold	$ 62,300	$ 57,200	$ 184,700	$ 160,700
Type of Cost, Good or Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Gross profit (loss)	$ 8,400	$ 10,600	$ 28,400	$ 29,700
SG&A	2,900	2,400	8,100	6,900
Operating income (loss)	5,500	8,200	20,300	22,800
Income (loss) before income taxes	$ 5,500	$ 8,200	$ 20,300	$ 22,800
Supplementary Data
Net tons sold | T	24,000	23,800	72,400	69,500
Depreciation, depletion and amortization	$ 3,400	$ 2,500	$ 9,700	$ 7,100
Capital expenditures	$ 1,900	$ 12,600	$ 17,600	$ 36,100
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	$ 900	$ 500	$ 2,900	$ 2,900
Type of Cost, Good or Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Gross profit (loss)	$ (900)	$ (500)	$ (2,900)	$ (2,900)
SG&A	12,400	13,800	39,800	41,700
(Gains) losses on dispositions of plant, equipment and timberlands, net	(200)	(100)	(1,900)	(200)
Operating income (loss)	(13,100)	(14,200)	(40,800)	(44,400)
Non-operating expense	(1,600)	(3,700)	(9,900)	(10,400)
Income (loss) before income taxes	(14,700)	(17,900)	(50,700)	(54,800)
Supplementary Data
Depreciation, depletion and amortization	1,000	600	3,300	2,300
Capital expenditures	$ 1,300	$ 4,600	$ 3,700	$ 11,300