Segment Information (Classification of Segments) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Operating Income (Loss) from Continuing Operations	$ 34,048	$ 28,713	$ 21,378
Total assets	361,770us-gaap_Assets	274,685us-gaap_Assets	251,916us-gaap_Assets
Capital Expenditures	19,001	13,826	11,404
Depreciation and amortization	17,646us-gaap_DepreciationAndAmortization	12,703us-gaap_DepreciationAndAmortization	13,682us-gaap_DepreciationAndAmortization
Performance materials segment
Segment Reporting Information [Line Items]
Operating Income (Loss) from Continuing Operations	9,706	9,462	10,400
Total assets	71,325	74,838	74,119
Capital Expenditures	4,124	4,604	5,231
Depreciation and amortization	4,654	4,667	5,290
Industrial Filtration Segment [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss) from Continuing Operations	6,412	0	0
Total assets	100,201	0	0
Capital Expenditures	1,804	0	0
Depreciation and amortization	4,536	0	0
Thermal/Acoustical Metals Segment [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss) from Continuing Operations	13,823	14,088	14,708
Total assets	106,210	104,908	96,019
Capital Expenditures	8,544	6,027	4,063
Depreciation and amortization	4,578	4,777	5,019
Thermalacoustical Fibers Segment [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss) from Continuing Operations	29,167	21,486	12,851
Total assets	33,109	30,176	26,830
Capital Expenditures	3,296	1,887	1,033
Depreciation and amortization	2,166	2,217	2,324
Other Products and Services Segment [Member]
Segment Reporting Information [Line Items]
Total assets	11,580	11,866	11,195
Capital Expenditures	574	243	128
Depreciation and amortization	804	588	596
Corporate Office [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss) from Continuing Operations	(26,642)	(17,101)	(17,771)
Total assets	39,345	52,897	43,753
Capital Expenditures	659	1,065	949
Depreciation and amortization	908	454	453
Life Sciences Vital Fluids [Member] \| Other Products and Services Segment [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss) from Continuing Operations	$ 1,582	$ 778	$ 1,190

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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