Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Segment Reporting, Revenue Reconciling Item [Line Items]
Eliminations and Other	$ (890)	$ (850)
Net sales	99,029	96,754
Performance Materials
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	27,483	29,088
Performance Materials | Industrial Filtration
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	16,650	18,176
Performance Materials | Industrial Thermal Insulation
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	8,156	8,731
Performance Materials | Life Sciences Filtration
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	2,677	2,181
Thermal/Acoustical Metals Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	40,202	42,113
Thermal/Acoustical Metals Segment | Metal Parts
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	33,109	37,808
Thermal/Acoustical Metals Segment | Tooling
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	7,093	4,305
Thermal/Acoustical Fibers Segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	27,927	22,172
Thermal/Acoustical Fibers Segment | Fiber Parts
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	27,784	22,146
Thermal/Acoustical Fibers Segment | Tooling
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	143	26
Other Products and Services
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	4,307	4,231
Other Products and Services | Life Sciences Vital Fluids
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	$ 4,307	$ 4,231