Segment Information - Net Sales By Segment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Net sales	$ 698,437	$ 566,852	$ 524,505
Operating Segments | Performance Materials Segment
Segment Reporting Information [Line Items]
Net sales	116,669	111,128	101,478
Operating Segments | Performance Materials Segment | Filtration
Segment Reporting Information [Line Items]
Net sales	77,254	70,430	62,716
Operating Segments | Performance Materials Segment | Thermal Insulation
Segment Reporting Information [Line Items]
Net sales	29,496	27,783	28,311
Operating Segments | Performance Materials Segment | Life Sciences Filtration
Segment Reporting Information [Line Items]
Net sales	9,919	12,915	10,451
Operating Segments | Technical Nonwovens Segment
Segment Reporting Information [Line Items]
Net sales	269,077	155,505	139,133
Operating Segments | Technical Nonwovens Segment | Industrial Filtration
Segment Reporting Information [Line Items]
Net sales	147,087	90,415	113,044
Operating Segments | Technical Nonwovens Segment | Advanced Materials
Segment Reporting Information [Line Items]
Net sales	121,990	65,090	26,089
Operating Segments | Thermal/Acoustical Metals Segment
Segment Reporting Information [Line Items]
Net sales	188,546	174,974	160,932
Operating Segments | Thermal/Acoustical Metals Segment | Metal parts
Segment Reporting Information [Line Items]
Net sales	168,995	156,187	141,117
Operating Segments | Thermal/Acoustical Metals Segment | Tooling
Segment Reporting Information [Line Items]
Net sales	19,551	18,787	19,815
Operating Segments | Thermal/Acoustical Fibers Segment
Segment Reporting Information [Line Items]
Net sales	157,761	149,412	138,747
Operating Segments | Thermal/Acoustical Fibers Segment | Tooling
Segment Reporting Information [Line Items]
Net sales	4,337	5,067	3,152
Operating Segments | Thermal/Acoustical Fibers Segment | Fiber parts
Segment Reporting Information [Line Items]
Net sales	153,424	144,345	135,595
Operating Segments | Other Products and Services
Segment Reporting Information [Line Items]
Net sales	0	0	1,671
Operating Segments | Other Products and Services | Life Sciences Vital Fluids
Segment Reporting Information [Line Items]
Net sales	0	0	1,671
Eliminations and Other
Segment Reporting Information [Line Items]
Net sales	$ (33,616)	$ (24,167)	$ (17,456)