Acquired Intangible Assets - Schedule of Expected Amortization Expense in Future Periods (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	[1]
Finite-Lived Intangible Assets [Line Items]
Total acquired technology, net	$ 6,935	$ 7,991
Purchased Technology [Member]
Finite-Lived Intangible Assets [Line Items]
2016 (remaining 3 months)	352
2017	1,408
2018	1,408
2019	1,408
2020	1,408
Thereafter	951
Total acquired technology, net	$ 6,935

[1] The Condensed Consolidated Balance Sheet as of December 31, 2015 has been derived from the audited consolidated financial statements at that date but does not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements.