Details about Reclassification out of Accumulated Other Comprehensive Income Components (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of revenues	$ (1,972)	$ (1,696)
Financial income (loss), net	927	571
Research and development	(12,016)	(9,873)
Sales and marketing	(3,176)	(2,938)
General and administrative	(2,954)	(2,125)
Income (loss) before taxes on income	(1,981)	4,917
Income tax expense (benefit)	201	810
Net income	(2,182)	4,107
Reclassification out of accumulated other comprehensive income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income	(14)	103
Reclassification out of accumulated other comprehensive income | Unrealized gains (losses) on cash flow hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of revenues	(1)	3
Research and development	(16)	125
Sales and marketing	(1)	8
General and administrative	(1)	10
Income (loss) before taxes on income	(19)	146
Income tax expense (benefit)	(2)	15
Net income	(17)	131
Reclassification out of accumulated other comprehensive income | Unrealized gains (losses) on available-for-sale marketable securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Financial income (loss), net	4	(38)
Income tax expense (benefit)	1	(10)
Net income	$ 3	$ (28)