Intangible Assets - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Less: accumulated amortization	$ (52,770)	$ (53,860)
Intangible assets, net	2,476	2,451
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	19,247	19,683
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	27,642	28,269
Intellectual property assets [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 8,357	$ 8,359