Goodwill and Other Intangible Assets - Components of Other Intangible Assets and Changes in Gross Carrying Values (Detail) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Other Finite-Lived Intangible Assets, Gross Carrying Value		$ 34,156	$ 34,297
Other Finite-Lived Intangible Assets, Accumulated Amortization		15,618	11,958
Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Other Finite-Lived Intangible Assets, Gross Carrying Value		6,947	6,947
Other Finite-Lived Intangible Assets, Accumulated Amortization		3,893	3,294
Non-compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Other Finite-Lived Intangible Assets, Gross Carrying Value		453	461
Other Finite-Lived Intangible Assets, Accumulated Amortization		113	15
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Other Finite-Lived Intangible Assets, Gross Carrying Value		4,087	4,087
Other Finite-Lived Intangible Assets, Accumulated Amortization		1,870	1,525
Customer Lists [Member]
Finite-Lived Intangible Assets [Line Items]
Other Finite-Lived Intangible Assets, Gross Carrying Value		12,150	12,238
Other Finite-Lived Intangible Assets, Accumulated Amortization		4,299	3,337
Know-how [Member]
Finite-Lived Intangible Assets [Line Items]
Other Finite-Lived Intangible Assets, Gross Carrying Value	[1]	8,043	8,043
Other Finite-Lived Intangible Assets, Accumulated Amortization	[1]	4,669	3,682
Supply Contract [Member]
Finite-Lived Intangible Assets [Line Items]
Other Finite-Lived Intangible Assets, Gross Carrying Value		2,476	2,521
Other Finite-Lived Intangible Assets, Accumulated Amortization		$ 774	$ 105

[1] Know-how includes intellectual property rights covering proprietary information, written formulae, trade secrets or secret processes, inventions and developmental products (whether patentable or not), discoveries, improvements, compositions, manufacturing processes, manuals, specifications and technical data