Segment Information - Consolidated Net Sales by Segment (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		$ 180,041	$ 155,725	$ 520,407	$ 422,660
Operating Segments | Performance Materials
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		29,547	28,831	87,599	85,180
Operating Segments | Performance Materials | Filtration
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		19,946	18,045	58,047	53,861
Operating Segments | Performance Materials | Thermal Insulation
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		7,283	7,081	22,116	20,570
Operating Segments | Performance Materials | Life Sciences Filtration
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		2,318	3,705	7,436	10,749
Operating Segments | Technical Nonwovens
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	[1]	73,306	52,284	199,322	111,331
Operating Segments | Technical Nonwovens | Industrial Filtration
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	[1]	38,346	25,414	108,884	67,805
Operating Segments | Technical Nonwovens | Advanced Materials
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	[1],[2]	34,960	26,870	90,438	43,526
Operating Segments | Thermal/Acoustical Metals
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		49,819	44,637	137,484	131,879
Operating Segments | Thermal/Acoustical Metals | Metal parts
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		41,522	39,807	124,043	117,578
Operating Segments | Thermal/Acoustical Metals | Tooling
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		8,297	4,830	13,441	14,301
Operating Segments | Thermal/Acoustical Fibers
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		35,623	36,429	120,494	112,458
Operating Segments | Thermal/Acoustical Fibers | Fiber parts
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		34,739	35,073	116,430	107,629
Operating Segments | Thermal/Acoustical Fibers | Tooling
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		884	1,356	4,064	4,829
Eliminations and Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	[2]	$ (8,254)	$ (6,456)	$ (24,492)	$ (18,188)

[1] The Technical Nonwovens segment reports results of Texel and Gutsche for the period following the dates of acquisition of July 7, 2016 and December 31, 2016, respectively.

[2] Included in the Technical Nonwovens segment and Eliminations and Other is $6.5 million and $4.5 million in intercompany sales to the T/A Fibers segment for the quarters ended September 30, 2017 and 2016, respectively, and $19.5 million and $13.6 million for the nine months ended September 30, 2017 and 2016, respectively.