Goodwill and Other Intangibles - Components of Identifiable Intangible Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 25,491	$ 19,173
Accumulated Amortization	12,001	10,939
Net Carrying Value of Intangible Assets	13,490	8,234
Product Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	10,143	10,267
Accumulated Amortization	5,483	4,908
Net Carrying Value of Intangible Assets	4,660	5,359
Trademarks and Licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	3,465	1,948
Accumulated Amortization	1,530	1,468
Net Carrying Value of Intangible Assets	1,935	480
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	9,787	5,383
Accumulated Amortization	3,636	3,299
Net Carrying Value of Intangible Assets	6,151	2,084
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	2,096	1,575
Accumulated Amortization	1,352	1,264
Net Carrying Value of Intangible Assets	$ 744	$ 311