Goodwill and Other Intangibles - Components of Identifiable Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 19,173	$ 18,886
Accumulated Amortization	10,939	8,989
Net Carrying Value of Intangible Assets	8,234	9,897
Product Technology and Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	10,267	10,173
Accumulated Amortization	4,908	4,017
Net Carrying Value of Intangible Assets	5,359	6,156
Trademarks, Tradenames and Licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	1,948	1,939
Accumulated Amortization	1,468	1,359
Net Carrying Value of Intangible Assets	480	580
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	5,383	5,216
Accumulated Amortization	3,299	2,588
Net Carrying Value of Intangible Assets	2,084	2,628
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	1,575	1,558
Accumulated Amortization	1,264	1,025
Net Carrying Value of Intangible Assets	$ 311	$ 533