Details about Reclassification out of Accumulated Other Comprehensive Income Components (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of revenues	$ (2,006)	$ (1,726)	$ (5,966)	$ (5,030)
Financial income (loss), net	831	821	2,535	2,147
Research and development	(11,897)	(10,031)	(35,756)	(30,413)
Sales and marketing	(2,727)	(3,057)	(9,302)	(9,422)
General and administrative	(2,406)	(2,711)	(8,193)	(7,388)
Income (loss) before taxes on income	2,983	7,031	(882)	14,873
Income tax expense (benefit)	440	1,181	847	1,008
Net income	2,543	5,850	(1,729)	13,865
Reclassification out of accumulated other comprehensive income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income	(87)	2	(260)	142
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)		(5)	4
Research and development	(55)	(2)	(225)	160
Sales and marketing	(3)		(10)	10
General and administrative	(4)		(19)	12
Income (loss) before taxes on income	(63)	(2)	(259)	186
Income tax expense (benefit)	(6)	1	(27)	20
Net income	(57)	(3)	(232)	166
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	(32)	7	(30)	(33)
Income tax expense (benefit)	(2)	2	(2)	(9)
Net income	$ (30)	$ 5	$ (28)	$ (24)

The aggregate cost of goods produced and sold and services rendered during the reporting period.

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The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

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Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount after accretion (amortization) of discount (premium), and investment expense, of interest income and dividend income on nonoperating securities.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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The aggregate total amount of expenses directly related to the marketing or selling of products or services.

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