Segment Information (Classification of Segments) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Operating Income (Loss) from Continuing Operations	$ 28,713	$ 21,378	$ 16,188
Total assets	274,685	251,916	235,185
Capital expenditures	13,826	11,404	8,884
Depreciation and amortization	12,593	13,572	14,478
Performance Materials Segment [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss) from Continuing Operations	9,462	10,400	18,194
Total assets	74,838	74,119	71,379
Capital expenditures	4,604	5,231	3,801
Depreciation and amortization	4,667	5,290	5,718
Thermal/Acoustical Metals Segment [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss) from Continuing Operations	14,088	14,708	15,915
Total assets	104,908	96,019	93,921
Capital expenditures	6,027	4,063	2,413
Depreciation and amortization	4,777	5,019	5,210
Thermal/Acoustical Fibers Segment [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss) from Continuing Operations	21,486	12,851	(3,055)
Total assets	30,176	26,830	28,844
Capital expenditures	1,887	1,033	1,148
Depreciation and amortization	2,217	2,324	2,536
Other Products and Services Segment [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss) from Continuing Operations	778	1,190	(1,040)
Total assets	11,866	11,195	11,064
Capital expenditures	243	128	270
Depreciation and amortization	588	596	726
Corporate Office [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss) from Continuing Operations	(17,101)	(17,771)	(13,826)
Total assets	52,897	43,753	29,977
Capital expenditures	1,065	949	1,252
Depreciation and amortization	$ 344	$ 343	$ 288