Summary of Gross Carrying Amount and Accumulated Amortization for Intangible Assets Resulting from Acquisitions (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Acquired Finite Lived Intangible Assets [Line Items]
Gross carrying amount	$ 15,871	$ 15,871
Accumulated amortization	(8,232)	(7,141)
Intangible Assets, net	$ 7,639	8,730
Existing Technology
Acquired Finite Lived Intangible Assets [Line Items]
Amortization period (in years)	11 years 9 months
Gross carrying amount	$ 4,600	4,600
Accumulated amortization	(2,250)	(1,914)
Intangible Assets, net	2,350	2,686
Customer Relationship
Acquired Finite Lived Intangible Assets [Line Items]
Gross carrying amount	10,701	10,701
Accumulated amortization	(5,412)	(4,657)
Intangible Assets, net	$ 5,289	6,044
Customer Relationship | Minimum
Acquired Finite Lived Intangible Assets [Line Items]
Amortization period (in years)	4 years
Customer Relationship | Maximum
Acquired Finite Lived Intangible Assets [Line Items]
Amortization period (in years)	11 years 9 months
Trade Name
Acquired Finite Lived Intangible Assets [Line Items]
Amortization period (in years)	1 year
Gross carrying amount	$ 570	570
Accumulated amortization	$ (570)	$ (570)