Intangible Assets - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Intangible asset, Gross amount	$ 54,069	$ 53,330
Accumulated amortization	(51,172)	(50,701)
Intangible asset, Net amount	2,897	2,629
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible asset, Gross amount	18,576	18,460
Accumulated amortization	(18,576)	(18,460)
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible asset, Gross amount	26,679	26,513
Accumulated amortization	(26,679)	(26,513)
Intellectual Property Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible asset, Gross amount	8,814	8,357
Accumulated amortization	(5,917)	(5,728)
Intangible asset, Net amount	$ 2,897	$ 2,629