Consolidated Balance Sheet Components - Accrued and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accrued Liabilities And Other Liabilities [Abstract]
Accrued expenses	$ 4,633	$ 3,352
Derivative liability	595	1,002
Income tax payable	323	317
Short-term deferred rent	283	297
Short-term stock repurchase liability	0	767
Skyfence holdback liability	7,556	0
Other	893	641
Total accrued and other current liabilities	$ 14,283	$ 6,376