Goodwill and Intangible Assets (Changes in Carrying Amount of Goodwill by Reporting Unit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Goodwill [Roll Forward]
Beginning Balance	$ 21,943	$ 18,589
Goodwill adjustment	(4,660)	3,943
Currency translation adjustment	(442)	(589)
Ending Balance	16,841	21,943
Performance Materials
Goodwill [Roll Forward]
Beginning Balance	13,340	13,929
Goodwill adjustment	0	0
Currency translation adjustment	(442)	(589)
Ending Balance	12,898	13,340
Industrial Filtration
Goodwill [Roll Forward]
Beginning Balance	3,943	0
Goodwill adjustment	0	3,943
Currency translation adjustment	0	0
Ending Balance	3,943	3,943
Other Products and Services
Goodwill [Roll Forward]
Beginning Balance	4,660	4,660
Goodwill adjustment	(4,660)	0
Currency translation adjustment	0	0
Ending Balance	$ 0	$ 4,660