Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	$ 127,306	[1]	$ 125,226	[2]
Performance Materials [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	25,058	[1]	28,853	[2]
Performance Materials [Member] | Industrial Filtration [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	15,067	[1]	17,873	[2]
Performance Materials [Member] | Thermal Insulation [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	7,485	[1]	8,528	[2]
Performance Materials [Member] | Life Sciences Filtration [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	2,506	[1]	2,452	[2]
Industrial Filtration Segment [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	34,200	[1]	17,656	[2]
Industrial Filtration Segment [Member] | Industrial Filtration [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	34,200	[1]	17,656	[2]
Thermal/Acoustical Metals Segment [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	38,115	[1]	42,456	[2]
Thermal/Acoustical Metals Segment [Member] | Metal Parts [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	35,022	[1]	37,025	[2]
Thermal/Acoustical Metals Segment [Member] | Tooling [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	3,093	[1]	5,431	[2]
Thermal/Acoustical Fibers Segment [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	31,117	[1]	32,513	[2]
Thermal/Acoustical Fibers Segment [Member] | Tooling [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	706	[1]	2,191	[2]
Thermal/Acoustical Fibers Segment [Member] | Fiber Parts [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	30,411	[1]	30,322	[2]
Other Products and Services [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	1,671	[1]	4,724	[2]
Other Products and Services [Member] | Life Sciences Vital Fluids [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	1,671	[1]	4,724	[2]
Intersegment Eliminations [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	$ (2,855)	[1]	$ (976)	[2]

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

[2] Industrial Filtration segment reports results for the period following the date of acquisition of February 20, 2014 through March 31, 2014.