Segment Information (Detail 1) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	[1]	Jun. 30, 2014	[2]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Consolidated Operating Income	$ 17,029	$ 12,573	$ 27,107		$ 20,199
Performance Materials [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Consolidated Operating Income	2,265	3,566	3,571		5,429
Industrial Filtration [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Consolidated Operating Income	4,552	2,198	7,706		2,984
Thermal/Acoustical Metals Segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Consolidated Operating Income	4,853	2,564	8,434		6,217
Thermal/Acoustical Fibers Segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Consolidated Operating Income	10,544	9,279	17,637		16,620
Other Products and Services [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Consolidated Operating Income	0	286	118		706
Corporate Office Expenses [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Consolidated Operating Income	$ (5,185)	$ (5,320)	$ (10,359)		$ (11,757)

[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 June 30, 2014.