Goodwill and Intangible Assets (Gross and Net Carrying Amounts of Goodwill) (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Line Items]
Goodwill	$ 29,001	$ 35,230
Accumulated amortization/impairment	(12,160)	(13,287)
Goodwill	16,841	21,943	$ 18,589
Performance Materials
Goodwill [Line Items]
Goodwill	12,898	13,340
Accumulated amortization/impairment	0	0
Goodwill	12,898	13,340
Industrial Filtration
Goodwill [Line Items]
Goodwill	3,943	3,943
Accumulated amortization/impairment	0	0
Goodwill	3,943	3,943	$ 0
Thermal/ Acoustical Metals
Goodwill [Line Items]
Goodwill	12,160	12,160
Accumulated amortization/impairment	(12,160)	(12,160)
Goodwill	0	0
Other Products and Services
Goodwill [Line Items]
Goodwill	0	5,787
Accumulated amortization/impairment	0	(1,127)
Goodwill	$ 0	$ 4,660

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

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Amount before accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a,h)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

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Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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+ References

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