Segment Information - Classification of Segments (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Mar. 31, 2017
Segment Reporting Information [Line Items]
Operating Income	$ 65,427	$ 54,792	$ 52,477
Total Assets	560,871	527,029	358,260
Capital Expenditures	24,915	28,159	21,555
Depreciation and Amortization	26,130	19,559	17,275
Performance Materials Segment
Segment Reporting Information [Line Items]
Total Assets				$ 1,300
Operating Segments | Performance Materials Segment
Segment Reporting Information [Line Items]
Operating Income	12,043	12,339	6,790
Total Assets	72,837	66,965	66,706
Capital Expenditures	3,610	4,098	3,519
Depreciation and Amortization	3,999	4,023	4,499
Operating Segments | Technical Nonwovens Segment
Segment Reporting Information [Line Items]
Operating Income	26,047	15,584	13,431
Total Assets	271,713	268,104	89,566
Capital Expenditures	2,903	1,248	968
Depreciation and Amortization	12,633	6,778	4,996
Operating Segments | Thermal/Acoustical Metals Segment
Segment Reporting Information [Line Items]
Operating Income	10,072	11,562	15,517
Total Assets	139,655	119,494	111,195
Capital Expenditures	12,316	15,425	11,494
Depreciation and Amortization	5,489	5,094	4,233
Operating Segments | Thermal/Acoustical Fibers Segment
Segment Reporting Information [Line Items]
Operating Income	42,870	41,452	37,086
Total Assets	49,646	47,097	38,881
Capital Expenditures	5,146	6,899	4,807
Depreciation and Amortization	3,135	2,570	2,400
Operating Segments | Other Products and Services
Segment Reporting Information [Line Items]
Operating Income	0	0	118
Total Assets	0	0	0
Capital Expenditures	0	0	22
Depreciation and Amortization	0	0	45
Corporate
Segment Reporting Information [Line Items]
Operating Income	(25,605)	(26,145)	(20,465)
Total Assets	27,020	25,369	51,912
Capital Expenditures	940	489	745
Depreciation and Amortization	$ 874	$ 1,094	$ 1,102