Goodwill and Intangible Assets - Summary of Other Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Cost	$ 30,148	$ 30,148
Accumulated Amortization	27,046	25,544
Net Book Value	3,102	4,604
Customer Contracts and Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	17,381	17,381
Accumulated Amortization	15,571	14,386
Net Book Value	1,810	2,995
Patents and Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	6,781	6,781
Accumulated Amortization	6,487	6,419
Net Book Value	294	362
Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	3,988	3,988
Accumulated Amortization	3,080	2,864
Net Book Value	908	1,124
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	1,998	1,998
Accumulated Amortization	1,908	1,875
Net Book Value	$ 90	$ 123