Other Income (Expense), Net - Schedule of Other Income (Expense), Net (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other Income:
Interest income	$ 1,369	$ 701	$ 163
Foreign currency forward contract gains, net	9	0	0
Foreign currency exchange gains, net	209	5	8
Total other income	1,587	706	171
Other Expense:
Skyfence holdback liability accretion	(6)	(212)	(186)
Foreign currency exchange losses, net	(708)	(322)	0
Bank charges and Other expenses	(950)	(574)	(205)
Total other expense	(1,664)	(1,108)	(391)
Total other income (expense), net	$ (77)	$ (402)	$ (220)