Intangible Assets - Summary of Intangible Assets (Detail) - USD ($)
$ in Thousands
Sep. 30, 2016
Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]    
Intangible asset, Gross amount $ 57,664 $ 53,330
Accumulated amortization (54,435) (50,701)
Intangible asset, Net amount 3,229 2,629
Technology [Member]    
Finite-Lived Intangible Assets [Line Items]    
Intangible asset, Gross amount 19,735 18,460
Accumulated amortization (19,735) (18,460)
Customer Relationships [Member]    
Finite-Lived Intangible Assets [Line Items]    
Intangible asset, Gross amount 28,343 26,513
Accumulated amortization (28,343) (26,513)
Intellectual Property Assets [Member]    
Finite-Lived Intangible Assets [Line Items]    
Intangible asset, Gross amount 9,586 8,357
Accumulated amortization (6,357) (5,728)
Intangible asset, Net amount $ 3,229 $ 2,629