Segment Information - Consolidated Net Sales by Segment (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		$ 155,725	$ 131,240	$ 422,660	$ 393,107
Operating Segments | Performance Materials Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		28,831	26,442	85,180	77,532
Operating Segments | Performance Materials Segment | Filtration
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		18,045	16,597	53,861	48,140
Operating Segments | Performance Materials Segment | Thermal Insulation
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		7,081	6,921	20,570	21,445
Operating Segments | Performance Materials Segment | Life Sciences Filtration
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		3,705	2,924	10,749	7,947
Operating Segments | Technical Nonwovens
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	[1]	52,284	34,155	111,331	104,257
Operating Segments | Technical Nonwovens | Industrial Filtration
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	[1]	25,414	27,182	67,805	85,519
Operating Segments | Technical Nonwovens | Advanced Materials
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	[1],[2]	26,870	6,973	43,526	18,738
Operating Segments | Thermal/Acoustical Metals
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		44,637	39,941	131,879	119,488
Operating Segments | Thermal/Acoustical Metals | Metal parts
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		39,807	35,354	117,578	106,735
Operating Segments | Thermal/Acoustical Metals | Tooling
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		4,830	4,587	14,301	12,753
Operating Segments | Thermal/Acoustical Fibers
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		36,429	35,681	112,458	102,268
Operating Segments | Thermal/Acoustical Fibers | Tooling
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		1,356	639	4,829	1,528
Operating Segments | Thermal/Acoustical Fibers | Fiber parts
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		35,073	35,042	107,629	100,740
Operating Segments | Other Products and Services
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		0	0	0	1,671
Operating Segments | Other Products and Services | Life Sciences Vital Fluids
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	[3]	0	0	0	1,671
Intersegment Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	[2]	$ (6,456)	$ (4,979)	$ (18,188)	$ (12,109)

[1] The Technical Nonwovens segment reports results of Texel for the period following the date of acquisition of July 7, 2016 through September 30, 2016.

[2] Included in the Technical Nonwovens segment and Eliminations and Other is $4.5 million and $4.1 million in intercompany sales to the T/A Fibers segment for the quarters ended September 30, 2016 and 2015, respectively, and $13.6 million and $9.5 million for the nine months ended September 30, 2016 and 2015, respectively.

[3] Other Products and Services reports results for the period preceding the date of disposition of January 30, 2015.