Segment Information - Schedule of Financial and Other Information by Business Unit (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($) T	Mar. 31, 2017 USD ($) T
Segment Reporting Information [Line Items]
Net sales	$ 410,647	$ 390,713
Energy and related sales, net	1,428	1,129
Total revenues	412,075	391,842
Cost of products sold	363,169	336,213
Gross profit	48,906	55,629
SG&A	37,063	34,877
(Gains) losses on dispositions of plant, equipment and timberlands, net	(1,554)	32
Operating income	13,397	20,720
Non-operating expense	(4,912)	(3,083)
Income before income taxes	$ 8,485	$ 17,637
Supplementary Data
Net tons sold | T	254,800	260,800
Depreciation, depletion and amortization	$ 19,431	$ 17,282
Capital expenditures	26,600	36,800
Composite Fibers [Member]
Segment Reporting Information [Line Items]
Net sales	141,600	125,100
Total revenues	141,600	125,100
Cost of products sold	114,700	99,600
Gross profit	26,900	25,500
SG&A	11,600	11,100
Operating income	15,300	14,400
Income before income taxes	$ 15,300	$ 14,400
Supplementary Data
Net tons sold | T	40,000	38,800
Depreciation, depletion and amortization	$ 7,400	$ 6,800
Capital expenditures	5,100	4,700
Advanced Airlaid Materials [Member]
Segment Reporting Information [Line Items]
Net sales	69,600	59,800
Total revenues	69,600	59,800
Cost of products sold	59,700	50,500
Gross profit	9,900	9,300
SG&A	2,700	2,200
Operating income	7,200	7,100
Income before income taxes	$ 7,200	$ 7,100
Supplementary Data
Net tons sold | T	26,300	24,800
Depreciation, depletion and amortization	$ 2,800	$ 2,300
Capital expenditures	13,200	10,600
Specialty Papers [Member]
Segment Reporting Information [Line Items]
Net sales	199,400	205,800
Energy and related sales, net	1,400	1,100
Total revenues	200,800	206,900
Cost of products sold	186,500	179,900
Gross profit	14,300	27,000
SG&A	11,900	13,500
Operating income	2,400	13,500
Income before income taxes	$ 2,400	$ 13,500
Supplementary Data
Net tons sold | T	188,400	197,200
Depreciation, depletion and amortization	$ 8,100	$ 7,200
Capital expenditures	6,500	18,300
Other and Unallocated [Member]
Segment Reporting Information [Line Items]
Cost of products sold	2,300	6,200
Gross profit	(2,300)	(6,200)
SG&A	10,900	8,100
(Gains) losses on dispositions of plant, equipment and timberlands, net	(1,600)
Operating income	(11,600)	(14,300)
Non-operating expense	(4,900)	(3,100)
Income before income taxes	(16,500)	(17,400)
Supplementary Data
Depreciation, depletion and amortization	1,100	1,000
Capital expenditures	$ 1,800	$ 3,200