Segment Information - Consolidated Net Sales by Segment (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		$ 129,700	$ 127,306
Operating Segments | Performance Materials Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		26,383	25,058
Operating Segments | Performance Materials Segment | Industrial Filtration
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		17,159	15,067
Operating Segments | Performance Materials Segment | Thermal Insulation
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		6,275	7,485
Operating Segments | Performance Materials Segment | Life Sciences Filtration
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		2,949	2,506
Operating Segments | Industrial Filtration Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		31,207	34,200
Operating Segments | Industrial Filtration Segment | Industrial Filtration
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	[1]	31,207	34,200
Operating Segments | Thermal/Acoustical Metals
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		41,997	38,115
Operating Segments | Thermal/Acoustical Metals | Metal parts
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		36,783	35,022
Operating Segments | Thermal/Acoustical Metals | Tooling
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		5,214	3,093
Operating Segments | Thermal/Acoustical Fibers
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		35,861	31,117
Operating Segments | Thermal/Acoustical Fibers | Tooling
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		184	706
Operating Segments | Thermal/Acoustical Fibers | Fiber parts
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		35,677	30,411
Operating Segments | Other Products and Services
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		0	1,671
Operating Segments | Other Products and Services | Life Sciences Vital Fluids
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		0	1,671
Intersegment Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	[1]	$ (5,748)	$ (2,855)

[1] Included in the Industrial Filtration segment and Eliminations and Other is $4.5 million and $2.0 million in intercompany sales to the T/A Fibers segment for the quarters ended March 31, 2016