Imperva 10-Q 9 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 18, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	IMPV
Entity Registrant Name	IMPERVA INC
Entity Central Index Key	1,364,962
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		34,694,179

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
CURRENT ASSETS:
Cash and cash equivalents	$ 214,274	$ 192,538
Short-term investments	164,535	166,993
Restricted cash	51	52
Accounts receivable, net of allowance of $1,121 and $936 as of March 31, 2018 and December 31, 2017, respectively	59,218	75,535
Deferred costs, current	4,452	0
Inventory	162	617
Prepaid expenses and other current assets	16,331	14,894
Total current assets	459,023	450,629
Property and equipment, net	23,693	25,407
Goodwill	36,389	36,389
Intangible assets, net	3,052	3,184
Severance pay fund	6,418	6,554
Restricted cash	2,332	2,284
Deferred tax assets	2,744	2,022
Other assets including non-current deferred cost	15,455	1,593
TOTAL ASSETS	549,106	528,062
CURRENT LIABILITIES:
Accounts payable	5,514	5,869
Accrued compensation and benefits	24,876	22,913
Accrued and other current liabilities	10,576	11,417
Deferred revenue, current	121,818	126,174
Total current liabilities	162,784	166,373
Other non-current liabilities	6,170	6,253
Deferred revenue	34,575	33,081
Long-term accrued severance pay	7,316	7,238
TOTAL LIABILITIES	210,845	212,945
Commitments and contingencies (See note 6)
STOCKHOLDERS' EQUITY:
Common stock, $0.0001 par value - 145,000,000 shares authorized, 34,733,955 and 34,233,888 shares issued and outstanding as of March 31, 2018 and December 31, 2017, respectively	3	3
Additional paid-in capital	586,365	572,106
Accumulated deficit	(246,845)	(256,537)
Accumulated other comprehensive loss	(1,262)	(455)
TOTAL STOCKHOLDERS' EQUITY	338,261	315,117
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 549,106	$ 528,062

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Allowance for doubtful accounts	$ 1,121	$ 936
Common stock, par value, per share	$ 0.0001	$ 0.0001
Common stock, shares authorized	145,000,000	145,000,000
Common stock, shares issued	34,733,955	34,233,888
Common stock, shares outstanding	34,733,955	34,233,888

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net revenue:
Products and license	$ 20,512	$ 19,578
Services	63,732	52,730
Total net revenue	84,244	72,308
Cost of revenue:
Products and license	2,274	1,932
Services	16,566	13,020
Total cost of revenue	18,840	14,952
Gross profit	65,404	57,356
Operating expenses:
Research and development	19,157	17,450
Sales and marketing	39,531	37,124
General and administrative	15,270	13,536
Restructuring charges	2,551	667
Amortization of intangible assets	132	317
Total operating expenses	76,641	69,094
Loss from operations	(11,237)	(11,738)
Gain on sale of business	0	35,871
Other income (loss), net	977	(92)
(Loss) income before provision for income taxes	(10,260)	24,041
Income tax (benefit) expense	(479)	958
Net (loss) income	$ (9,781)	$ 23,083
Earnings per share:
Basic	$ (0.28)	$ 0.70
Diluted	$ (0.28)	$ 0.68
Shares used in computing earnings per share:
Basic	34,457	33,207
Diluted	34,457	33,771

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net (loss) income	$ (9,781)	$ 23,083
Other comprehensive (loss) gain, net of tax:
Net change in net unrealized (loss) gain on investments	(396)	28
Net change in unrealized (loss) gain on hedging instruments	(411)	1,729
Total other comprehensive (loss) income, net of tax	(807)	1,757
Comprehensive (loss) income	$ (10,588)	$ 24,840

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning balance at Dec. 31, 2016	$ 231,963	$ 3	$ 510,257	$ (276,819)	$ (1,478)
Beginning balance, shares at Dec. 31, 2016		33,088,990
Cumulative effect of a change in accounting principle	14		2,601	(2,587)
Issuance of common stock under employee equity plans, net of repurchases	7,149		7,149
Issuance of common stock under employee equity plans, net of repurchases, shares		365,552
Stock-based compensation	13,610		13,610
Shares withheld for tax withholding on vesting of restricted stock units	(4,632)		(4,632)
Component of other comprehensive income (loss), net of tax
Change in unrealized gain (loss) on investments	28				28
Change in unrealized gain (loss) on hedging instruments	1,729				1,729
Net (loss) income	23,083			23,083
Comprehensive (loss) income	24,840
Ending balance at Mar. 31, 2017	272,944	$ 3	528,985	(256,323)	279
Ending balance, shares at Mar. 31, 2017		33,454,542
Beginning balance at Dec. 31, 2017	315,117	$ 3	572,106	(256,537)	(455)
Beginning balance, shares at Dec. 31, 2017		34,233,888
Cumulative effect of a change in accounting principle	19,473			19,473
Issuance of common stock under employee equity plans, net of repurchases	5,293		5,293
Issuance of common stock under employee equity plans, net of repurchases, shares		500,067
Stock-based compensation	14,637		14,637
Shares withheld for tax withholding on vesting of restricted stock units	(5,671)		(5,671)
Component of other comprehensive income (loss), net of tax
Change in unrealized gain (loss) on investments	(396)				(396)
Change in unrealized gain (loss) on hedging instruments	(411)				(411)
Net (loss) income	(9,781)			(9,781)
Comprehensive (loss) income	(10,588)
Ending balance at Mar. 31, 2018	$ 338,261	$ 3	$ 586,365	$ (246,845)	$ (1,262)
Ending balance, shares at Mar. 31, 2018		34,733,955

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net (loss) income		$ (9,781)	$ 23,083
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Net cash provided by operating activities		22,502	18,496
Depreciation and amortization		3,111	2,376
Amortization of deferred costs		1,041	0
Stock-based compensation		14,637	13,610
Amortization of acquired intangibles		132	317
Amortization of premiums/accretion of discounts on short-term investments		(387)	(91)
Gain on sale of business		0	(35,871)
Other adjustments		34	(646)
Changes in operating assets and liabilities:
Accounts receivable, net		16,317	17,689
Inventory		439	110
Deferred costs		(3,626)	0
Prepaid expenses and other assets		(1,529)	(910)
Accounts payable		497	(804)
Accrued compensation and benefits		1,963	2,265
Accrued and other liabilities		(399)	1,169
Severance pay (net)		214	295
Deferred revenue		700	(3,869)
Deferred tax assets		(861)	(227)
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sales/maturities of short-term investments		11,704	28,521
Purchase of short-term investments		(9,255)	(51,130)
Proceeds from sale of business		0	35,015
Net purchases of property and equipment		(2,792)	(1,949)
Net cash (used in) provided by investing activities		(343)	10,457
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock, net of repurchases		5,293	4,026
Shares withheld for tax withholding on vesting of restricted stock units		(5,671)	(4,632)
Net cash used in financing activities		(378)	(606)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash		2	646
NET INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH		21,783	28,993
CASH, CASH EQUIVALENTS AND RESTRICTED CASH - Beginning of period	[1]	194,874	109,295
CASH, CASH EQUIVALENTS AND RESTRICTED CASH - End of period	[1]	216,657	138,288
NONCASH INVESTING AND FINANCING ACTIVITIES:
Property and equipment acquired but not yet paid		$ 233	$ 2,205
[1]	Amounts in As Reported column include cash, cash equivalents and restricted cash as required. Amounts in the As Previously Reported column reflect only cash and cash equivalents.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	1. Basis of Presentation and Summary of Significant Accounting Policies Business Imperva, Inc. (together with its subsidiaries, the “Company”) was incorporated in April 2002 in Delaware. The Company is headquartered in Redwood Shores, California and has subsidiaries located throughout the world including Israel, Asia and Europe. The Company is engaged in the development, marketing, sales, service and support of cyber-security solutions that protect business-critical data and applications whether in the cloud or on premises. Basis of Presentation The Company has prepared the accompanying Condensed Consolidated Financial Statements in accordance with Article 10 of Regulation S-X and pursuant to the rules and regulations for Form 10-Q of the Securities and Exchange Commission (the “SEC”). Pursuant to those rules and regulations, the Company has condensed or omitted certain information and footnote disclosure it normally includes in its annual consolidated financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”). In management’s opinion, the Company has made all adjustments (consisting only of normal, recurring adjustments, except as otherwise indicated) necessary to fairly present its condensed consolidated financial position, results of operations, and cash flows. The Company’s interim period operating results do not necessarily indicate the results that may be expected for any other interim period or for the full fiscal year. These condensed consolidated financial statements and accompanying notes should be read in conjunction with the consolidated financial statements and notes thereto in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017, which was filed with the SEC on February 23, 2018 (the “Annual Report”). The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Concentration of Revenue and Accounts Receivable Significant customers are those which represent 10% or more of the Company’s total revenue or gross accounts receivable balance at each respective balance sheet date. The Company primarily sells products and services through channel partners, including distributors and resellers, which sell to end-user customers. For the three months ended March 31, 2018, there was no significant customer which represented 10% or more of the Company’s total revenue. For the three months ended March 31, 2017, one customer represented 11% of the Company’s total revenue. As of March 31, 2018, no customer represented 10% or more of the Company’s accounts receivable balance. As of December 31, 2017, one customer represented 18% of the Company’s total accounts receivable balance. Significant Accounting Policies Recently Adopted Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) 2014-09, Revenue from Contracts with Customers (Accounting Standards Codification or ASC 606). ASC 606 supersedes the revenue recognition requirements in Revenue Recognition (ASC 605), and requires the recognition of revenue as promised goods or services are transferred to customers in an amount that reflects the consideration which the entity expects to be entitled to in exchange for those goods or services. ASC 606 also includes Subtopic 340-40, Other Assets and Deferred Costs - Contracts with Customers, which requires the deferral of incremental costs of obtaining a contract with a customer. Collectively, we refer to ASC 606 and Subtopic 340-40 as the “new standard”. The Company adopted the new standard as of January 1, 2018, utilizing the modified retrospective method for all contracts not completed as of the date of adoption. For contracts that were modified before the effective date, the Company reflected the aggregate effect of all modifications when identifying performance obligations and allocating transaction price in accordance with practical expedient ASC 606-10-65-1-(f)-4, which did not have a material effect on the adjustment to accumulated deficit. As a result, the Company recognized the cumulative effect of initially applying the new standard as an adjustment to the opening balance of equity on January 1, 2018. The comparative information has not been adjusted and continues to be reported under ASC 605. The details of the new policy with significant changes and quantitative impact of the changes are described in a separate note below. In May 2017, FASB issued an ASU 2017 - 09 Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting. This ASU clarifies and eliminates the diversity of practice as to when a Company must account for the effects of a stock modification. In accordance with the guidance an entity should account for the effects of a modification unless all the following criteria are met: 1. The fair value of the modified award is the same as the fair value of the original award immediately before the original award is modified. If the modification does not affect any of the inputs to the valuation technique that the entity uses to value the award, the entity is not required to estimate the value immediately before and after the modification. 2. The vesting conditions of the modified award are the same as the vesting conditions of the original award immediately before the original award is modified. 3. The classification of the modified award as an equity instrument or a liability instrument is the same as the classification of the original award immediately before the original award is modified. The Company has adopted this guidance in Q1’18. The Company noted the adoption of this ASU did not have any material impact on the condensed consolidated financial statements in the current period and is not expected to have material impacts in future periods as well. The Company adopted ASU 2016-18, “Restricted Cash,” and ASU 2016-15, “Classification of Certain Cash Receipts and Cash Payments.” on January 1, 2018 using the modified retrospective method as of the date of adoption. During the three months ended March 31, 2018. ASU 2016-18 requires an entity to reconcile and explain the period over period change in total cash, cash equivalents and restricted cash within its condensed consolidated statement of cash flows and ASU 2016-15 provides guidance clarifying how certain cash receipts and cash payments should be classified. We adopted these accounting standards retrospectively and, accordingly, certain line items in the condensed consolidated statement of cash flows have been reclassified to conform to the current presentation. The following table summarizes the change in cash flows as reported and as previously reported prior to the adoption of these standards (in thousands): Quarter Ended March 31, 2018 March 31, 2017 As Reported As Reported As previously Reported Change in restricted cash - - $ (18 ) Net cash provided by (used in) investing activities (343 ) $ 10,457 10,439 NET INCREASE (DECREASE) 21,783 28,993 28,975 Balance at beginning of period* 194,874 109,295 107,343 Balance at end of period* 216,657 138,288 136,318 *: Amounts in As Reported column include cash, cash equivalents and restricted cash as required. Amounts in the As Previously Reported column reflect only cash and cash equivalents. In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business. The new standard clarifies the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. ASU 2017-01 is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years, and should be applied prospectively with early adoption permitted under certain scenarios. The impact of this accounting standard update will be fact dependent. The provision of ASU No. 2017-01 did not have a material impact on the accompanying condensed consolidated financial statements. Recently Issued Accounting Pronouncements In February 2018 the FASB issued ASU 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, that gives entities the option to reclassify to retained earnings tax effects related to items that have been stranded in accumulated other comprehensive income as a result of the Tax Cuts and Jobs Act (the Act). An entity that elects to reclassify these amounts must reclassify stranded tax effects related to the Act’s change in US federal tax rate for all items accounted for in other comprehensive income. These entities can also elect to reclassify other stranded effects that relate to the Act but do not directly relate to the change in the federal rate. Entities can choose whether to apply the amendments retrospectively to each period in which the effect of the Act is recognized or to apply the amendments in the period of adoption. The standard is effective for the Company on January 1, 2019, with early adoption permitted. The Company is evaluating the impact of adopting this new accounting guidance on its condensed consolidated financial statements. In August 2017, FASB issued ASU 2017-12 Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. Under the new guidance, more hedging strategies will be eligible for hedge accounting and the application of hedge accounting is simplified. The new guidance amends presentation and disclosure requirements, and how effectiveness is assessed. The standard is effective for the Company on January 1, 2019, with early adoption permitted. The Company is evaluating the impact of adopting this new accounting guidance on its condensed consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment (Topic 350), which simplifies the measurement of goodwill impairment by removing the second step of the goodwill impairment test, which requires the determination of the fair value of individual assets and liabilities of a reporting unit. Under this guidance, goodwill impairment is to be measured as the amount by which a reporting unit’s carrying value exceeds its fair value with the loss recognized not to exceed the total amount of goodwill allocated to the reporting unit. The guidance is effective beginning January 1, 2020 on a prospective basis, with early adoption permitted for interim or annual goodwill impairment tests performed after January 1, 2017. The standard is to be applied on a prospective basis. The Company does not anticipate a material impact to the condensed consolidated financial statements once implemented. In June 2016, the FASB Issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The new standard requires financial assets measured at amortized cost be presented at the net amount expected to be collected, through an allowance for credit losses that is deducted from the amortized cost basis. The standard will be effective for the Company beginning January 1, 2020, with early application permitted. The Company is evaluating the impact of adopting this new accounting guidance on its condensed consolidated financial statements. In February 2016, the FASB issued ASU 2016-02 regarding ASC 842 Leases. The amendments in this guidance require balance sheet recognition of lease assets and lease liabilities by lessees for leases classified as operating leases, with an optional policy election to not recognize lease assets and lease liabilities for leases with a term of 12 months or less. The amendments also require new disclosures, including qualitative and quantitative requirements, providing additional information about the amounts recorded in the financial statements. The standard will be effective for the Company beginning January 1, 2019. The amendments require a modified retrospective approach with optional practical expedients. While the Company continues to evaluate the effect of the standard on its ongoing financial reporting, the Company currently believes that the adoption of the ASU may materially affect its Balance Sheet. Revenue from Contracts with Customers The reported results for three month period ended March 31, 2018 reflect the application of the new revenue standard while the reported results for three month period ended March 31, 2017 were prepared under the guidance of ASC 605, which is also referred to herein as "legacy GAAP" or the "previous guidance". The adoption of the new revenue standard represents a change in accounting principle with the intent to align revenue recognition with the delivery of products and services and provide financial statement readers with enhanced disclosures. In accordance with the new revenue standard, revenue is recognized when a customer obtains control of promised products and services. The amount of revenue recognized reflects the consideration to which the Company expects to be entitled to receive in exchange for these products and services. To achieve this core principle, the Company applies the following five steps: 1) Identify the contract with a customer A contract with a customer exists when (i) the Company enters into an enforceable contract with a customer that defines each party’s rights regarding the products and services to be transferred and identifies the payment terms related to these products and services, (ii) the contract has commercial substance and, (iii) the Company determines that collection of substantially all consideration for products and services that are transferred is probable based on the customer’s intent and ability to pay the promised consideration. The Company applies judgment in determining the customer’s ability and intention to pay, which is based on a variety of factors including the customer’s historical payment experience or, in the case of a new customer, published credit and financial information pertaining to the customer. 2) Identify the performance obligations in the contract Performance obligations promised in a contract are identified based on the products and services that will be transferred to the customer that are both capable of being distinct, whereby the customer can benefit from the products and services either on its own or together with other resources that are readily available from third parties or from the Company, and are distinct in the context of the contract, whereby the transfer of the products and services is separately identifiable from other promises in the contract. To the extent a contract includes multiple promised products and services, the Company must apply judgment to determine whether promised products and services are capable of being distinct and distinct in the context of the contract. If these criteria are not met the promised products and services are accounted for as a combined performance obligation. 3) Determine the transaction price The transaction price is determined based on the consideration to which the Company will be entitled in exchange for transferring products and services to the customer. None of the Company's contracts as of March 31, 2018 contained a significant financing component. Determining the transaction price requires significant judgment, which is discussed by revenue category in further detail below. 4) Allocate the transaction price to performance obligations in the contract If the contract contains a single performance obligation, the entire transaction price is allocated to the single performance obligation. Contracts that contain multiple performance obligations require an allocation of the transaction price to each performance obligation based on a relative standalone selling price basis. The Company determines standalone selling price based on the price at which the performance obligation is sold separately. If the standalone selling price is not observable through past standalone transactions, the Company estimates the standalone selling price taking into account available information such as past transactions, market conditions and internally approved pricing guidelines related to the performance obligations. 5) Recognize revenue when or as the Company satisfies a performance obligation The Company satisfies performance obligations either over time or at a point in time as discussed in further detail below. Revenue is recognized at the time the related performance obligation is satisfied by transferring a promised products and services to a customer. Revenue Recognition The Company derives revenue from two sources: (i) products and license revenue, which includes hardware and perpetual software license revenue and (ii) services revenue, which includes subscription arrangements, maintenance and support, professional services and training. Substantially all of product and license sales have been sold in combination with maintenance and support services. At contract inception, the Company assesses the products and services promised in its contracts with customers and identifies a performance obligation for each promise to transfer to the customer a product or service (or bundle of products or services) that is distinct – i.e., if a product or service is separately identifiable from other items in the bundled package and if a customer can benefit from it on its own or with other resources that are readily available to the customer. The Company recognizes revenue when or as it satisfies a performance obligation by transferring control of a product or service to a customer. Taxes collected from customers and remitted to governmental authorities are not included in revenue. Shipping and handling costs associated with outbound freight are accounted for as a fulfillment cost and are included in cost of revenues. In rare situations, we may agree to accept a lower consideration than the contractual price. We account for such situations as variable consideration and estimate future price reductions based on our historical experience. The impact of such price reductions on our revenue for the three month period ended March 31’st 2018 was not significant. Once the Company has determined the transaction price, the total transaction price is allocated to each performance obligation in a manner depicting the amount of consideration to which the Company expects to be entitled in exchange for transferring the good(s) or service(s) to the customer (the “allocation objective”). If the allocation objective is met at contractual prices, no further allocations are made. Otherwise, the Company allocates the transaction price to each performance obligation identified in the contract on a relative standalone selling price basis. In order to determine the standalone selling price of its promised goods or services, the Company conducts a regular analysis to determine whether its goods or services have an observable standalone selling price. In determining observable standalone selling price, the Company requires that a substantial majority of the standalone selling prices for a good or service fall within a reasonably narrow pricing range. If the Company does not have a directly observable standalone selling price for a particular good or service, then the Company estimates a standalone selling price by reviewing external and internal market factors including, but not limited to, pricing practices including historical discounting, major service groups, and the geographies in which the Company offers its products and services. The determination of standalone selling price is made through consultation with and approval by the Company’s management. Selling prices are analyzed on a quarterly basis to identify if the Company has experienced significant changes in its selling prices. The upfront payment pattern relative to the delivery of subscription, maintenance and services and associated revenue recognition generates significant deferred revenue. The Company refers to contract liabilities as "deferred revenue" on the condensed consolidated financial statements and related disclosures. The following describes the nature of the Company’s primary types of revenues and the revenue recognition policies and significant payment terms as they pertain to the types of transactions the Company enters into with its customers. Products and License Revenue Product and license revenue consists of hardware and perpetual software license sales. Hardware revenue is recognized at a point in time upon delivery. The Company’s perpetual software licenses sold without hardware generally have significant stand-alone functionality to the customer upon delivery and are considered functional intellectual property (“IP”). Revenue allocated to perpetual software licenses is typically recognized at a point in time upon delivery of the license. Service Revenue Services revenue consists of subscription arrangement, maintenance and support, professional services, and training. Subscription services are offered under renewable, fee-based contracts, which provide access to the Incapsula service and certain functionality within SecureSphere platform. Payments for subscription services are typically due monthly/quarterly/annually in advance. Subscription services are viewed as a stand-ready performance obligation that is satisfied over time and typically have a term of one to three years. Unearned subscription revenue is included in deferred revenue. Maintenance and support arrangements are offered under renewable, fee-based contracts, which include technical support, hardware repair and replacement parts, bug fixes, patches and unspecified upgrades on a when-and-if-available basis. Payments for maintenance and support are typically due annually in advance. Maintenance and support services are viewed as a stand-ready performance obligation that is satisfied over time and typically have a term of one to three years. Unearned maintenance and support revenue is included in deferred revenue. Professional services revenue consists of fees the Company earns related to implementation and consulting services. The Company’s professional services typically are considered distinct from the related software or subscription services as the promise to transfer the software or subscription can be fulfilled independently from the promise to deliver the implementation and consulting services (i.e., customer receives standalone functionality from the license or subscription and the customer obtains the intended benefit of the license or subscription without the professional services). Professional services revenue is typically recognized over time as the services are rendered, using an efforts-expended (labor hours) input method. Professional service arrangements are typically short term in nature and are largely completed within 90 days from the start of service. Training services revenue consists of fees the Company earns related to training customers and partners on the use of its products. Training services are distinct performance obligations recognized upon delivery of the training. Deferred Costs The Company capitalizes contract origination costs that are incremental and recoverable costs of obtaining a contract with a customer. These costs are deferred and amortized over a benefit period of 5 years. We determined the period of benefit by taking into consideration our customer contracts, our technology and other factors. The Company applies the practical expedient to expense costs as incurred if the expected amortization period was 1 year or less. This applies to sales commissions for renewal contracts which would be deferred and then amortized over the related contractual renewal period. Amortization expense is included in Sales and marketing expenses in the accompanying condensed consolidated statements of operations. Allocating the Transaction Price to Performance Obligations For certain arrangements with multiple deliverables, the Company previously allocated the arrangement fee to the non-software element based upon the relative selling price of such element and, if software and software-related elements (e.g., maintenance and support for the software element) were also included in the arrangement, the Company allocated the arrangement fee to each of those software and software-related elements as a group. After such allocations were made, the amount of the arrangement fee allocated to the software and software-related elements was accounted for using the residual method. Under the new standard, the total transaction price is allocated to each performance on a relative standalone selling price basis, irrespective of whether the performance obligations would have been previously categorized as software or non-software elements. Deferred Revenue and Contingent Revenue The Company previously limited the amount of revenue recognized for delivered elements to the amount that was not contingent on the future delivery of products or services, or subject to the Company’s future performance obligation. Under the new standard, there is no requirement to limit the allocated transaction price to non-contingent amounts. There have been no other material changes to the Company’s significant accounting policies as compared to the significant accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. Adoption Date Impact The following tables summarize the impacts of adopting the new standard on the Company’s condensed consolidated financial statements as of adoption on January 1, 2018. Select condensed consolidated balance sheet line items that reflect the adoption of the new standard are as follows (in thousands): As reported on December 31, 2017 Impact of adoption As adjusted on January 1, 2018 ASSETS Deferred costs, current - $ 3,755 $ 3,755 Other assets including non-current deferred cost 1,593 12,156 13,749 LIABILITIES Deferred revenue, current 126,174 (4,159 ) 122,015 Deferred revenue 33,081 597 33,678 STOCKHOLDERS' EQUITY Accumulated deficit $ (256,537 ) $ 19,473 $ (237,064 ) The deferred cost balance as of January 1, 2018 represents the incremental cost to obtain contracts for contracts which were not complete as of the adoption date, that were expensed pursuant to the previous accounting policy, but require capitalization under the new standard. The deferred revenue balance decreased as of January 1, 2018 primarily due to impacts from application of revised Standalone Selling Price (SSP) methodologies, and due to certain hybrid pricing models, more specifically our FlexProtect hybrid licensing program, which was delivered prior to January 1, 2018. Under the previous guidance the entire transaction fee was recognized ratably, however the new standard requires upfront recognition of a portion of the transaction price allocated to the functional license delivered at the inception of the arrangement. Current Period Impact The following tables summarize the impacts of adopting the new standard on the Company’s condensed consolidated financial statements for the three months ended March 31, 2018. Select consolidated balance sheet line items that reflect the adoption of the new standard are as follows: March 31, 2018 As reported Adjustments Balances without adoption of Topic 606 ASSETS Deferred cost, current $ 4,452 $ (4,452 ) - Other assets including non-current deferred cost 15,455 (14,043 ) 1,412 LIABILITIES AND STOCKHOLDERS' EQUITY Deferred revenue, current 121,818 4,402 126,220 Deferred revenue 34,575 204 34,779 STOCKHOLDERS' EQUITY Accumulated deficit $ (246,845 ) $ (23,101 ) $ (269,946 ) Select Condensed Consolidated Statement of operations line items for the three months ended March 31, 2018 that reflect the adoption of the new standard are as follows: Three months ended March 31, 2018 As reported Adjustments Balances without adoption of Topic 606 Net revenue: Products and license $ 20,512 $ (234 ) $ 20,278 Services: Subscriptions 34,953 86 35,039 Maintenance and Support 25,226 (958 ) 24,268 Professional services and training 3,553 62 3,615 Total services 63,732 (810 ) 62,922 Total net revenue 84,244 (1,044 ) 83,200 Operating expenses: Sales and marketing 39,531 2,585 42,116 Loss from operations (11,237 ) (3,629 ) (14,866 ) Net loss (9,781 ) (3,629 ) (13,410 ) Net loss per share of common stock stockholders, basic and diluted $ (0.28 ) $ (0.11 ) $ (0.39 ) Select Condensed Consolidated Statement of Cash Flows for the three months ended March 31, 2018 that reflect the adoption of the new standard are as follows: (in thousands) Three months ended March 31, 2018 Statement of Cash Flows As reported Adjustments Balance without adoption of Topic 606 Net loss $ (9,781 ) $ (3,629 ) $ (13,410 ) Adjustments to reconcile net income (loss) to net cash provided by operating activities Amortization of deferred costs 1,041 (1,041 ) - Changes in operating assets and liabilities: Deferred costs (3,626 ) 3,626 - Deferred revenue 700 1,044 1,744 Net cash provided by operating activities $ 22,502 $ - $ 22,502 Disaggregation of Revenue The Company’s revenue was comprised of the following major product and service lines (in thousands): Three months ended March 31 2018 2017 Major product/service lines Products and licenses $ 20,512 $ 19,578 Services: Subscriptions 34,953 27,252 Maintenance and support 25,226 21,980 Professional services and training 3,553 3,498 Total services revenue 63,732 52,730 Total revenue $ 84,244 $ 72,308 The company’s revenue by geographic region based on the customer’s location is presented in footnote 10. The following table presents the Company’s revenue by timing of revenue recognition (in thousands): Three months ended March 31 2018 2017 Timing of revenue recognition Products and services transferred at a point in time $ 20,512 $ 19,578 Products and services transferred over time 63,732 52,730 Total revenue $ 84,244 $ 72,308 Deferred Revenue The following table provides information about deferred revenues from contracts with customers (in thousands). As of March 31, 2018 Deferred Revenue (current) $ 121,818 Deferred Revenue 34,575 Total Deferred Revenue $ 156,393 The deferred revenue balance includes customer deposits of $0.9 million, primarily related to cancellable professional services which were billed in advance. Standard payment terms to customers range from 30 to 90 days; however, payment terms and conditions in our customer contracts may vary. In some cases, customers prepay for products and services in advance of our delivery of the related products or services; in other cases, payment is due as services are performed or in arrears following the delivery of the related products or services. Unbilled revenues primarily relate to the Company’s rights to consideration for work completed but not billed at the reporting date and typically relate to professional services. The unbilled revenues are transferred to receivables when the rights become unconditional. Deferred revenue relates to the advance consideration received from customers, which precedes our performance to satisfy the associated performance obligation(s). The Company’s deferred revenue primarily result from customer payments received upfront for subscription, maintenance and support on software licenses and certain fixed fee professional services because these performance obligations are satisfied over time. $46.4 million of services revenue was recognized during the three months ended March 31, 2018 that was included in the deferred revenue balances at the beginning of the period. Transaction Price Allocated to the Remaining Performance Obligations The following table includes estimated revenue expected to be recognized over time related to performance obligations that are unsatisfied (or partially unsatisfied) as of March 31, 2018 (in thousands). Remainder of 2018 2019 2020 2021 Thereafter Performance obligations transferred over time $ 109,260 $ 31,104 $ 12,816 $ 2,019 $ 1,194 Total net revenue $ 109,260 $ 31,104 $ 12,816 $ 2,019 $ 1,194 Amortization of Deferred Costs Deferred costs primarily consist of capitalized incremental contract origination costs and were $18,495 and $15,911 as of March 31, 2018 and January 1, 2018 respectively. For the three months ended March 31, 2018, amortization costs of $1,041 were recorded, and there were no impairments of deferred costs.

Cash, Cash Equivalents, Restric

Cash, Cash Equivalents, Restricted Cash and Short-Term Investments	3 Months Ended
	Mar. 31, 2018
Cash And Cash Equivalents [Abstract]
Cash, Cash Equivalents, Restricted Cash and Short-Term Investments	2. Cash, Cash Equivalents, Restricted Cash and Short-Term Investments The following table provides a summary of cash, cash equivalents, and restricted cash reported within the Condensed Consolidated Balance Sheets that reconciles to the corresponding amount in the Condensed Consolidated Statements of Cash Flows (in thousands): As of March 31, 2018 As of December 31, 2017 As of March 31, 2017 As of December 31, 2016 Cash and cash equivalents $ 214,274 $ 192,538 $ 136,318 $ 107,343 Restricted cash included in Current assets 51 52 72 68 Restricted cash included in Non-current assets 2,332 2,284 1,898 1,884 Total cash, cash equivalents, and restricted cash shown in the Statements of Cash Flows $ 216,657 $ 194,874 $ 138,288 $ 109,295 The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Cash and cash equivalents consist of cash on hand, highly liquid investments in commercial paper, money market funds, corporate debt obligations and various deposit accounts. Restricted cash represents bank deposits to secure bank guarantees provided to its lessors for its operating lease arrangements. The Company considers all high quality investments purchased with original maturities at the date of purchase greater than three months to be short-term investments. Investments are available to be used for current operations and are, therefore, classified as current assets even though maturities may extend beyond one year. Cash equivalents and short-term investments are classified as available-for-sale and are, therefore, recorded at fair value on the condensed consolidated balance sheets, with any unrealized gains and losses reported in accumulated other comprehensive income (loss), which is reflected as a separate component of stockholders’ equity in its condensed consolidated balance sheets, until realized. The Company uses the specific-identification method to compute gains and losses on the investments. The amortized cost of securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion is included as a component of other income (expense), net in the condensed consolidated statements of operations. Cash, cash equivalents and short-term investments consist of the following (in thousands): As of March 31, 2018 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value Cash and cash equivalents: Cash $ 110,746 - - $ 110,746 Commercial paper 3,995 - 2 3,993 Money market funds 84,081 - - 84,081 US government and US government agencies 15,455 - 1 15,454 Total $ 214,277 - $ 3 $ 214,274 Short-term investments: Commercial paper - - - - Corporate debt obligations 118,628 - 799 117,829 US government and US government agencies 46,426 - 199 46,227 Bank deposits 480 - 1 479 Total $ 165,534 - $ 999 $ 164,535 As of December 31, 2017 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value Cash and cash equivalents: Cash $ 92,030 - - $ 92,030 Commercial paper - - - - Money market funds 84,144 - - 84,144 US government and US government agencies 16,367 - 3 16,364 Total $ 192,541 - $ 3 $ 192,538 Short-term investments: Commercial paper $ 699 - - $ 699 Corporate debt obligations 123,320 - 488 122,832 US government and US government agencies 43,097 - 114 42,983 Bank deposits 480 - 1 479 Total $ 167,596 - $ 603 $ 166,993 The following table summarizes the cost and estimated fair value of short-term investments based on stated effective maturities as of March 31, 2018 (in thousands): As of March 31, 2018 Estimated Amortized Fair Cost Value Short-term investments: Due within one year $ 110,202 $ 109,734 Due within two years 55,332 54,801 Total $ 165,534 $ 164,535 The gross unrealized loss related to these securities was due primarily to changes in interest rates. The Company reviews its short-term investments on a regular basis to evaluate whether or not any security has experienced an other-than-temporary decline in fair value. The Company considers factors such as the length of time and extent to which the market value has been less than the cost, the financial condition and near-term prospects of the issuer and its intent to sell, or whether it is more likely than not the Company will be required to sell, the investment before recovery of the investment’s amortized cost basis. If the Company believes that an other-than-temporary decline exists in one of these securities, the Company will write down these investments to fair value. For debt securities, the portion of the write-down related to credit loss would be recorded to other income (expense), net, in the Company’s condensed consolidated statements of operations. Any portion not related to credit loss would be recorded to accumulated other comprehensive income (loss), which is reflected as a separate component of stockholders’ equity in the Company’s condensed consolidated balance sheets. During the three months ended March 31, 2018 and 2017, the Company did not consider any of its investments to be other-than-temporarily impaired. The following tables show the short-term investments in an unrealized loss position and the related gross unrealized losses and fair value and length of time that the short-term investments have been in a continuous unrealized loss position (in thousands): As of March 31, 2018 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Commercial paper $ - $ - $ - $ - Corporate debt obligations 47,967 492 69,863 307 117,830 799 US government and US government agencies 34,753 173 11,473 26 46,226 199 Bank deposits 479 1 479 1 $ 82,720 $ 665 $ 81,815 $ 334 $ 164,535 $ 999 As of December 31, 2017 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Commercial paper $ 699 $ - $ - $ - $ 699 $ - Corporate debt obligations 77,715 377 45,117 111 122,832 488 US government and US government agencies 29,093 76 11,461 38 40,554 114 Bank deposits - - 479 1 479 1 $ 107,507 $ 453 $ 57,057 $ 150 $ 164,564 $ 603

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	3. Fair Value of Financial Instruments The Company evaluates assets and liabilities subject to fair value measurements on a recurring basis to determine the appropriate level to classify them for each reporting period. There have been no transfers between fair value measurement levels during the three months ended March 31, 2018. The Company’s cash equivalents and short-term investment instruments are classified within Level I or Level II of the fair value hierarchy because they are valued using quoted market prices, broker or dealer quotations, or alternative pricing sources with reasonable levels of price transparency. The types of instruments valued based on quoted market prices in active markets include mutual funds and money market securities, and are generally classified within Level I of the fair value hierarchy. The types of instruments valued based on quoted prices in less active markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the asset or liability include U.S. agency securities, investment-grade corporate bonds, bank deposits, and commercial paper. Such instruments are generally classified within Level II of the fair value hierarchy. The Company executes its foreign currency contracts primarily in the retail market in an over-the-counter environment with a relatively high level of price transparency. The market participants usually are large multi-national and regional banks. The Company’s foreign currency contracts valuation inputs are based on quoted prices and quoted pricing intervals from public data sources and do not involve management judgment. These contracts are typically classified within Level II of the fair value hierarchy. The following table sets forth the Company’s assets and liabilities that were measured at fair value as of March 31, 2018 and December 31, 2017, by level within the fair value hierarchy (in thousands): As of March 31, 2018 Level I Level II Level III Fair Financial Assets: Cash equivalents: Money market funds $ 84,081 - - $ 84,081 Commercial paper - 3,993 - 3,993 US government and US government agencies - 15,454 - 15,454 Short-term investments: Commercial paper - - - - Corporate debt obligations - 117,829 - 117,829 US government and US government agencies - 46,227 - 46,227 Bank deposits - 479 - 479 Prepaid expenses and other current assets - Forward foreign exchange contracts - 175 - 175 Total financial assets $ 84,081 $ 184,157 - $ 268,238 As of December 31, 2017 Level I Level II Level III Fair Value Financial Assets: Cash equivalents: Money market funds $ 84,144 $ - $ - $ 84,144 US government and US government agencies 16,364 16,364 Short-term investments: Commercial paper - 699 - 699 Corporate debt obligations - 122,832 - 122,832 US government and US government agencies - 42,983 - 42,983 Bank deposits - 479 - 479 Prepaid expenses and other current assets - Forward foreign exchange contracts - 551 - 551 Total financial assets $ 84,144 $ 183,908 $ - $ 268,052 In addition to the amounts disclosed in the above table, the fair value of the Company’s Israeli severance pay assets, totaling $6.4 million and $6.6 million as of March 31, 2018 and December 31, 2017, respectively comprised of Level II assets.

Derivative Instruments

Derivative Instruments	3 Months Ended
	Mar. 31, 2018
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Instruments	4. Derivative Instruments The Company’s primary objective for holding derivative instruments is to reduce its exposure to foreign currency rate changes. The Company reduces its exposure by entering into forward foreign exchange contracts with respect to operating expenses that are forecast to be incurred in currencies other than U.S. dollars. Substantially all of the Company’s revenue and capital purchasing activities and a majority of its operating expenditures are transacted in U.S. dollars. However, certain operating expenditures are incurred in or exposed to other currencies, primarily the Israeli shekel and the Euro. The Company has established forecasted transaction currency risk management programs to protect against fluctuations in fair value and the volatility of future cash flows caused by changes in exchange rates. The Company’s currency risk management program includes forward foreign exchange contracts designated as cash flow hedges. These forward foreign exchange contracts generally mature within 12 months. The Company does not enter into derivative financial instruments for trading purposes. Derivative instruments measured at fair value and their classification on the condensed consolidated balance sheets are presented in the following tables (in thousands): As of March 31, 2018 As of December 31, 2017 Notional Amount Fair Value Notional Amount Fair Value Foreign exchange forward contract derivatives in cash flow hedging relationships - included in prepaid expenses and other current assets $ 48,495 $ 175 $ 66,560 $ 551 Gains (losses) on derivative instruments and their classification on the condensed consolidated statement of operations are presented in the following table (in thousands): For the three months ended March 31 2018 2017 Foreign Exchange Forward Contract Derivatives in cash flow hedging relationships: Gains recognized in OCI (a) $ 356 $ 2,887 Losses recognized in OCI (a) $ (510 ) - Gains recognized from accumulated OCI into net income (b) $ 257 $ 206 Losses recognized from accumulated OCI into net income (b) $ - $ (5 ) (a) Net change in the fair value of the effective portion classified in other comprehensive income (loss) (“OCI”). (b) Effective portion of cash flow hedges reclassified from accumulated other comprehensive income (loss) into net income, of which $84 and $173 were recognized within cost of sales and operating expenses, respectively, for the three months ended March 31, 2018; $14 and $187 were recognized within cost of sales and operating expenses, respectively, for the three months ended March 31, 2017. All amounts are reflected within the respective condensed consolidated statement of operations.

Goodwill and Acquired Intangibl

Goodwill and Acquired Intangible Assets	3 Months Ended
	Mar. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Acquired Intangible Assets	5. Goodwill and Acquired Intangible Assets Goodwill represents the excess of the purchase price in a business combination over the fair value of net assets acquired. Goodwill amounts are not amortized, but rather tested for impairment at least annually. The Company did not have any goodwill impairments during three months ended March 31, 2018 and 2017. The changes in the carrying amount of goodwill for the period ended March 31, 2018 were as follows (in thousands): Balance as of January 1 $ 36,389 Changes during the three month period - Balance as of March 31 $ 36,389 The Company amortizes intangible assets, which consist of purchased technologies that have estimated useful lives ranging from 7 to 10 years, using the straight-line method when the consumption pattern of the asset cannot be reliably determined. The Company reviews such assets for impairment whenever an impairment indicator exists and continually monitors events and changes in circumstances that could indicate carrying amounts of the intangible assets may not be recoverable. When such events or changes in circumstances occur, the Company assesses recoverability by determining whether the carrying value of such assets exceed the estimates of future undiscounted future cash flows expected to be generated by such assets. Should impairment exist, the impairment loss would be measured based on the excess carrying value of the asset over the asset’s estimated fair value. There was no impairment of intangible assets recorded for the three months ended March 31, 2018 and 2017. Acquired intangible assets subject to amortization are presented as follows (in thousands): As of March 31, 2018 Weighted Average Remaining Useful life (years) Gross Carrying Amount Accumulated Amortization Net Book Value Acquired technology 5.8 $ 3,753 $ (1,321 ) $ 2,432 Customer relationships 5.7 480 (90 ) 390 Trade name and other 5.7 280 (50 ) 230 Total acquired intangibles 5.7 $ 4,513 $ (1,461 ) $ 3,052 As of December 31, 2017 Weighted Average Remaining Useful life (years) Gross Carrying Amount Accumulated Amortization Net Book Value Acquired technology 6.0 $ 3,753 $ (1,216 ) $ 2,537 Customer relationships 6.0 480 (71 ) 409 Trade name and other 6.0 280 (42 ) 238 Total acquired intangibles 6.0 $ 4,513 $ (1,329 ) $ 3,184 As of March 31, 2018, the amortization expense in future periods is expected to be as follows (in thousands): Acquired Fiscal Year Technology 2018 (remaining 9 months) 397 2019 529 2020 529 2021 529 Thereafter 1,068 Total expected amortization expense $ 3,052

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	6. Commitments and Contingencies (a) Operating Leases The Company rents its facilities under operating leases with lease periods expiring through 2023. Future minimum payments under these facility operating leases and minimum rentals to be received under non-cancellable subleases are as follows as of March 31, 2018 (in thousands): Operating Leases Estimated Sublease Income Period Ending March 31: 2018 (remaining 9 months) 4,350 515 2019 5,003 - 2020 4,714 - 2021 557 - Thereafter 396 - Total $ 15,020 $ 515 Rent expense for the Company’s operating leases is recognized on a straight-line basis over the lease term. Rent expense for the three months ended March 31, 2018 and 2017 was $1.7 million and $1.6 million, respectively. In connection with leases of office space, the Company may receive tenant improvement allowances from lessors for certain improvements the Company makes to the leased properties. The Company records the tenant improvement allowances as a leasehold improvement within property and equipment, net, and as deferred rent within other liabilities on the condensed consolidated balance sheets. The deferred rent liability is amortized to rent expense over the term of the lease on a straight-line basis. The leasehold improvements are amortized to expense over the period from when the improvements were placed into service until the end of their useful life, which is the end of the lease term. For the three months ending March 31, 2018 and 2017, the Company did not receive any tenant improvement allowances. In addition, certain of the Company’s operating lease agreements for office space also include rent holidays and scheduled rent escalations during the initial lease term. The Company has recorded the rent holidays as a deferred rent within other liabilities on the condensed consolidated balance sheets. The Company recognizes the deferred rent liability and scheduled rent increase on a straight-line basis into rent expense over the lease term commencing on the date the Company takes possession of the lease space. As of March 31, 2018 and December 31, 2017 the Company had $2,332 thousand and $2,284 thousand, respectively, in restricted deposits to secure bank guarantees provided to its lessors. (b) Cancelable Lease Agreements The Company leases motor vehicles under cancelable operating lease agreements. The Company has an option to cancel the lease agreements, which may result in penalties in a maximum amount of $0.1 million as of March 31, 2018. Motor vehicle lease expenses for the three months ended March 31, 2018 and 2017 were $1.2 million and $0.7 million, respectively. (c) Purchase Commitments As of March 31, 2018 and December 31, 2017, the Company had purchase commitments of $2.5 million and $2.6 million, respectively, to purchase inventory, trial units, and research and development equipment from its vendors. The purchase commitments result from the Company’s contractual obligation to order or build inventory in advance of anticipated sales. According to the Company’s agreements with its vendors, the Company committed to purchase inventory within six months from the date the inventory arrived at the vendor’s warehouse. (d) Litigation From time to time, the Company may be subject to other legal proceedings and claims in the ordinary course of business. On August 25, 2017, a purported class action lawsuit was filed against us and others, alleging that current, former and prospective employees are entitled to monetary damages for violations of the notice provisions of the Fair Credit Reporting Act and similar California laws governing background checks. The lawsuit was filed in the Superior Court for San Mateo County and on September 29, 2017, we removed the action to the U.S. District Court for the Northern District of California. On November 6, 2017, we filed a motion to dismiss the action. On April 9, 2018, the Court granted the motion, dismissing several claims with prejudice and giving plaintiff thirty days to file an amended complaint with regards to the remaining claims. On August 25, 2017, the same plaintiff filed a second purported class action lawsuit against us and others in the Superior Court for San Mateo County, alleging, among other claims, violation of California wage and hour, overtime, meal break and rest break rules and regulations, failure to provide for proper expense reimbursements, failure to maintain accurate and complete payroll records, failure to pay commissions and unfair business practices, and seeking unspecified monetary damages, injunctive relief and attorneys’ fees. We filed an answer to the complaint on September 29, 2017. On November 3, 2017, the plaintiff amended his complaint to assert an additional representative Private Attorney General Act (PAGA) claim against us. On December 6, 2017, we filed an answer to the amended complaint. The plaintiff’s motion for class certification is due on or before September 7, 2018. Our opposition is due on or before November 6, 2018. Any reply is due on or before November 20, 2018. A hearing on the motion for class certification has been set for Friday, December 7, 2018. In addition, the Company has received, and may in the future continue to receive, claims from third parties asserting, among other things, infringement of their intellectual property rights. Future litigation may be necessary to defend the Company, its channel partners and its customers by determining the scope, enforceability and validity of third-party proprietary rights or to establish its proprietary rights. In the opinion of management, liabilities associated with these claims from third parties, while possible, are not probable at this time, and therefore the Company has not recorded any accrual for them as of March 31, 2018 and December 31, 2017. Further, any possible range of loss cannot be reasonably estimated at this time. The ultimate outcome of any litigation is uncertain and, regardless of outcome, litigation can have an adverse impact on the Company because of defense costs, potential negative publicity, diversion of management resources and other factors. Accordingly, there can be no assurance that existing or future legal proceedings arising in the ordinary course of business or otherwise will not have a material adverse effect on the Company’s business, condensed consolidated financial position, results of operations or cash flows. (e) Indemnification Under the indemnification provisions of its standard sales contracts, the Company agrees to defend its end customers and certain channel partners against third-party claims asserting infringement of certain intellectual property rights, which may include patents, copyrights, trademarks, or trade secrets, and to pay judgments and settlements entered on such claims. The Company’s exposure under these indemnification provisions is generally limited to the total amount paid under the agreement. However, some agreements include indemnification provisions that could potentially expose the Company to losses in excess of the amount received under the agreement. To date, there have been no claims under such indemnification provisions. Accordingly, the Company has not recorded a liability on its condensed consolidated balance sheets for these indemnification provisions. In addition to the foregoing, the Company maintains director and officer insurance, which may cover certain liabilities arising from its obligation to indemnify its directors and officers.

Stockholders_ Equity and Employ

Stockholders’ Equity and Employee Stock Plans	3 Months Ended
	Mar. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stockholders’ Equity and Employee Stock Plans	7. Stockholders’ Equity and Employee (a) Preferred Stock Our board of directors is authorized, subject to any limitations prescribed by law, without stockholder approval, to issue from time to time up to an aggregate of 5,000,000 shares of preferred stock, in one or more series, each series to have such rights and preferences, including voting rights, dividend rights, conversion rights, redemption privileges and liquidation preferences as the Company’s board of directors determines. The rights of the holders of common stock will be subject to, and may be adversely affected by, the rights of holders of any preferred stock that may be issued in the future. The Company currently has no shares of preferred stock outstanding and the Company has no present plans to issue any shares of preferred stock. (b) 2003 Stock Plan During 2003, the Board of Directors adopted the 2003 Stock Plan (the “2003 Plan”), which allowed for the grant of both incentive stock options and non-qualified stock options and the direct award or sale of shares of the Company’s common stock (including restricted common stock) to officers, employees, directors, consultants and other key persons. In connection with the Company’s initial public offering, which was completed in November 2011, the Board of Directors determined not to grant any further awards under the 2003 Plan upon completion of the public offering. The 2011 Stock Option and Incentive Plan (the “2011 Plan”) replaced the 2003 Plan in November 2011. Under the 2003 Plan, incentive stock options could have been granted to employees with exercise prices of no less than the fair value of the common stock on the grant date, and non-qualified options could have been granted to employees, directors, or consultants at exercise prices of no less than 85% of the fair value of the common stock on the grant date, as determined by the Board of Directors. If, at the time the Company granted an option, the optionee directly or by attribution owned stock possessing more than 10% of the total combined voting power of all classes of stock of the Company, the option price had to have been at least 110% of the fair value. Options granted under the 2003 Plan generally expire no later than ten years from the date of grant and, in general, vest four years from the date of grant. (c) 2011 Stock Option and Incentive Plan In September 2011, the Board of Directors adopted the 2011 Plan which was subsequently approved by the Company’s stockholders. The 2011 Plan replaced the 2003 Plan and the Company no longer grants awards under the 2003 Plan. The Company initially reserved a total of 1,000,000 shares of common stock for issuance under the 2011 Plan. In addition, 955,568 reserved but unissued shares under the 2003 Stock Plan were added to the number of shares reserved for issuance under the 2011 Plan. The 2011 Plan also provided that the number of shares reserved and available for issuance under the plan would automatically increase each January 1, beginning in 2012 and ending in 2015, by 4% of the outstanding number of shares of common stock on the immediately preceding December 31. The last automatic increase occurred on January 1, 2015. In May 2016 and April 2017, the Company’s stockholders approved an increase to the share reserve under the 2011 Plan by 1,300,000 shares and 850,000 shares respectively. The 2011 Plan permits the granting of incentive stock options, non-qualified stock options, restricted stock units (“RSUs”), stock appreciation rights, restricted shares of common stock and performance share awards. The exercise price of stock options may not be less than 100% of the fair market value of the common stock on the date of grant. Options granted pursuant to the 2011 Plan generally expire no later than ten years from the date of grant. The Company also grants RSUs. RSUs granted to new hires and merit grants to existing employees generally vest over a four-year period with 25% vesting at the end of one year and the remainder vesting quarterly thereafter. Additionally, from time to time, the Company grants performance-based RSUs (“PRSUs”). The Company granted PRSUs to its executives to align with the Company’s pay-for-performance philosophy. The PRSUs provide for a target number of shares that generally vest over three years which includes a one-year performance period and two years of service-based vesting. The PRSUs vest contingent upon the Company’s achievement of annual revenue and annual operating margin targets for fiscal 2018 relative to the Company’s annual operating plan. The amount of PRSUs earned may vary from zero to 200% of the target award amount depending on the achievement percentage, and provided the award recipient remains employed through each applicable vesting date Of the PRSUs awarded to executives during the year ended December 31, 2017, an aggregate of 74,621 PRSUs were issued to executives during the quarter ended March 31, 2018, based on the Company’s achievement against its annual contract value of subscription bookings target for fiscal year 2017 and achieving total operating expenses for 2017 that were 110% or less of the internal operating plan. The PRSUs are subject to vest over eight quarter period and vest quarterly through November 2019. (d) 2011 Employee Stock Purchase Plan In September 2011, the Board of Directors adopted the 2011 Employee Stock Purchase Plan (the “ESPP”) which was subsequently approved by the Company’s stockholders. The ESPP took effect on November 8, 2011, the effective date of the registration statement for the Company’s initial public offering. The ESPP permits eligible employees to acquire shares of the Company’s common stock by accumulating funds through periodic payroll deductions of up to 15% of base salary. Each offering period may run for no more than 24 months and consist of no more than five purchase periods. The purchase price for shares of the Company’s common stock purchased under the ESPP will be 85% of the lesser of the fair market value of the Company’s common stock on the first day of the offering period or the last trading day of the applicable purchase period within that offering period. The Company initially reserved a total of 500,000 shares of common stock for future issuance under the ESPP. The number of shares reserved for issuance under the ESPP increases automatically on January 1 of each of the first eight years commencing in 2012 by the number of shares equal to 1% of the Company’s total outstanding shares as of the immediately preceding December 31. The Board of Directors or compensation committee may reduce the amount of the increase in any particular year. No more than 20,000,000 shares of common stock may be issued under the ESPP and no other shares may be added to the ESPP without the approval of the Company’s stockholders. On January 1, 2018, the share reserved under the 2011 Employee Stock Purchase Plan were automatically increased by 342,338 shares. (e) Inducement Stock Option Plan and Agreement and Inducement Restricted Stock Unit Plan and Agreement In August 2014 and August 2015, the Compensation Committee of the Board of Directors adopted Inducement Stock Option Plans and Agreements (the “Inducement Option Plans”) and Inducement Restricted Stock Unit Plans and Agreements (the “Inducement RSU Plans”), in each case created as employment inducement awards. In accordance with the terms of the Inducement Option Plans, the Company issued options to purchase an aggregate of 290,000 shares of the Company’s common stock at an exercise price equal to the fair market value of a share of the Company’s common stock on the dates of grant of the options. The options, which have a ten-year term, vest at the rate of 25% of the shares on each of the first anniversary of the vesting commencement date with an additional 6.25% of the shares subject to the option vesting each quarter thereafter so long as the participant has not been terminated. In accordance with the terms of the Inducement RSU Plans, the Company issued RSUs representing an aggregate of 290,000 shares of the Company’s common stock. The RSUs, which expire following settlement, vest at the rate of 25% of the shares on each of the first anniversary of the vesting commencement date with an additional 6.25% of the shares subject to the RSU vesting each quarter thereafter so long as the participant has not been terminated. (f) 2015 Equity Inducement Plan In October 2015, the Board of Directors adopted the 2015 Equity Inducement Plan (the “2015 Plan”), a non-stockholder approved plan that provides for the granting of stock options and RSUs as employment inducement awards and in connection with acquisitions, subject to compliance with applicable securities laws and stock exchange requirements for such plans. Under the terms of the 2015 Plan, the exercise price of stock options may not be less than 100% of the fair market value of common stock on the date of grant and generally expire no later than ten years from the date of grant. The Company initially reserved 100,000 shares of common stock for issuance under the 2015 Plan. During the fiscal year ended December 31, 2017, the Board of Directors amended the 2015 Plan to increase the number of shares available for grant by 350,000 shares. During the year ended December 31, 2017, the Company granted 101,200 RSUs under the 2015 Plan and during the three months ended March 31, 2018, the Company granted an additional 221,400 RSUs under the 2015 Plan. Option Activity The following table summarizes option activity under the Plans and related information: Options Outstanding Weighted- Average Remaining Number of Shares Weighted Average Exercis e Contractual Term (in years) Aggregate Intrinsic Value (i n Balances - January 1, 2018 997,674 $ 41.87 5.72 $ 5,689 Granted - - Exercised (168,408 ) $ 31.43 Cancelled or forfeited (93,193 ) $ 48.28 Balances - March 31, 2018 736,073 $ 43.45 5.27 $ 4,823 Vested and expected to vest - March 31, 2018 736,073 $ 43.45 5.27 $ 4,823 Exercisable - March 31, 2018 640,637 $ 42.38 5.00 $ 4,727 (1) The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying awards and the closing stock price of $43.30 of the Company’s common stock on March 31, 2018. RSU Activity The following table summarizes RSU activity under the Plans and related information: Number of Restricted Stock Units Outstanding Weighted- Average Grant Date Fair Value Unvested - January 1, 2018 2,353,315 $ 47.42 Granted 785,400 $ 43.31 Granted, performance RSUs 438,980 $ 44.48 Released (407,535 ) $ 41.49 Cancelled or forfeited (504,423 ) $ 43.74 Unvested - March 31, 2018 2,665,737 $ 47.33 The aggregate intrinsic value of options exercised under the Plans was $2.6 million for the three months ended March 31, 2018. The aggregate intrinsic value is calculated as the difference between the fair market value of the Company’s common stock on the date of the exercise and the exercise price of each option multiplied by the number of options exercised. As of March 31, 2018, total compensation cost related to unvested stock-based awards granted to employees under the Plans, but not yet recognized, was $96.8 million. As of March 31, 2018, this cost will be amortized to expense over a weighted-average remaining period of 3 years. Future stock-based award grants will increase the amount of compensation expense to be recorded in these periods. There was no capitalized stock-based compensation expense during the three months ended March 31, 2018 and 2017. (g) Stock Compensation Expense The Company recognized stock-based compensation expense under the 2003 Plan, 2011 Plan, ESPP, Inducement Option and RSU Plans, the Incapsula 2010 Share Incentive Plan and the 2015 Plan in the condensed consolidated statements of operations as follows (in thousands): For the three months ended March 31 2018 2017 Cost of revenue $ 1,321 $ 1,269 Research and development 2,445 4,768 Sales and marketing 3,314 3,466 General and administrative 7,557 3,432 Restructuring charges - 675 Total stock-based compensation expense $ 14,637 $ 13,610 The Company did not issue stock option grants for the three months ended March 31, 2018 and 2017. Additionally there were no ESPP grants during the first quarter ended March 31, 2018. The fair value of the RSUs is determined using the closing price of the Company’s common stock on the date of the grant. Compensation is generally recognized on a straight-line basis over the requisite service period of each grant, except for awards with performance or market conditions for which the accelerated recognition method is used.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	8. Accumulated Other Comprehensive Income (Loss) The changes in the balances of accumulated other comprehensive income (loss) by component are as follows (in thousands): For the three months ended March 31, 2018 For the three months ended March 31, 2017 Unrealized gain (loss) on cash flow hedges Unrealized gain (loss) on investments Total Unrealized gain (loss) on cash flow hedges Unrealized gain (loss) on investments Total Balance at January 1 $ 160 $ (615 ) $ (455 ) $ (1,065 ) $ (413 ) $ (1,478 ) Other comprehensive income (loss) before reclassifications (154 ) (396 ) (550 ) 1,930 28 1,958 Amounts reclassified to net income (loss) (257 ) - (257 ) (201 ) - (201 ) Change in other comprehensive income (loss) (411 ) (396 ) (807 ) 1,729 28 1,757 Balance at March 31 $ (251 ) $ (1,011 ) $ (1,262 ) $ 664 $ (385 ) $ 279 The following is a summary of reclassifications out of accumulated other comprehensive income (loss) for the three months ended March 31, 2018 and 2017 (in thousands): For the three months ended March 31, 2018 For the three months ended March 31, 2017 Pre-Tax Amount Tax (Expense) Benefit After-Tax Amount Pre-Tax Amount Tax (Expense) Benefit After-Tax Amount Unrealized gains (losses) on cash flow hedges: Current period unrealized gain (loss) $ (154 ) $ - $ (154 ) $ 2,887 (957 ) $ 1,930 Reclassification adjustments 1 (257 ) - (257 ) (201 ) - (201 ) Unrealized gains (losses) on cash flow hedges, net (411 ) — (411 ) 2,686 (957 ) 1,729 Unrealized gains (losses) on investments: Current period unrealized gain (loss) $ (396 ) — (396 ) $ 44 (16 ) 28 Unrealized gains (losses) on investments: (396 ) — (396 ) 44 (16 ) 28 Other comprehensive income (loss) $ (807 ) $ — $ (807 ) $ 2,730 $ (973 ) $ 1,757 1

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	9. Income Taxes The Company is subject to income tax in the United States as well as other tax jurisdictions in which it conducts business. For the three months ended March 31, 2018 and 2017, the Company recorded an income tax benefits of $0.5 million and an income tax expense of $1.0 million respectively. The income tax benefit for the three months ended March 31, 2018, includes tax expense based on the projected effective tax rate for 2018, net of share-based award tax benefit recognized during the quarter. The income tax expense for the three months ended March 31, 2017 was primarily attributable to the gain related to the sale of the Skyfence business, offset in part by an intraperiod tax benefit allocation related to unrealized gains reported in other comprehensive income. Factors that impact the income tax provision include, but are not limited to, stock-based compensation expense, permanent tax adjustments, foreign operations and a valuation allowance against the Company’s domestic deferred tax assets.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Segment Information	10. Segment Information The Company operates its business in one operating segment, which is the development, marketing, sales, service and support of cyber-security solutions that protect business-critical data and applications whether in cloud or on premises. Operating segments are defined as components of an enterprise that engage in business activities for which separate financial information is available and evaluated by the chief operating decision maker in deciding how to allocate resources and assessing performance. The chief operating decision maker is the Company’s Chief Executive Officer. The Company’s net revenue by geographic region, based on the customer’s location, is summarized as follows (in thousands): Three months ended March 31 2018 2017 Primary geographical markets Americas United States $ 36,404 $ 37,645 Other 9,478 7,177 Americas sub-total $ 45,882 $ 44,822 EMEA 17,124 13,780 APAC 21,238 13,706 Total revenue $ 84,244 $ 72,308 The following table presents long-lived assets by location (in thousands): As of March 31, As of December 31, 2018 2017 United States $ 21,615 $ 23,697 Israel 4,882 4,640 Rest of world 248 254 Total long-lived assets $ 26,745 $ 28,591

Restructuring Charges

Restructuring Charges	3 Months Ended
	Mar. 31, 2018
Restructuring Charges [Abstract]
Restructuring Charges	11. Restructuring Charges In January 2018, the Company implemented a restructuring plan to improve customer experiences, fuel product innovation and increase operational effectiveness. The restructuring charge during the three months ended March 31, 2018 was $2.6 million, of which substantially all were paid out by March 31, 2018. The restructuring activity was substantially completed by the end of the first quarter of 2018 and we do not expect material costs associated with the activity in future periods. All restructuring charges are reported in Restructuring and other, net on the Condensed Consolidated Statements of Operations. The Company’s restructuring activity is summarized as follows: Balance as of December 31, 2017 Additions Adjustments Cash payments Balance as of March 31, 2018 Severance and termination-related costs - 2,451 - (2,361 ) 90 Legal and other exit costs - 100 - (100 ) - Total $ - $ 2,551 $ - $ (2,461 ) $ 90 Balance as of December 31, 2016 Additions Adjustments* Cash payments Balance as of March 31, 2017 Severance and termination-related costs 1,132 667 (797 ) (1,002 ) — Legal and other exit costs - - - - - Total $ 1,132 $ 667 $ (797 ) $ (1,002 ) $ - * includes amounts representing non-cash stock-based compensation

Net Income (Loss) per Share

Net Income (Loss) per Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Net Income (Loss) per Share	12. Net Income (Loss) per Share Basic and diluted net income (loss) per share is computed by dividing net income (loss) by the weighted-average number of common shares outstanding during the period. The computation of net income (loss) per share for each period, including the number of weighted-average shares outstanding, is shown on the face of the condensed consolidated statements of operations. Diluted earnings per share is calculated using our weighted-average outstanding common shares including the dilutive effect of stock awards as determined under the treasury stock method. In periods when the Company recognizes a net loss, the Company excludes the impact of outstanding stock awards from the diluted loss per share calculation as their inclusion would have an antidilutive effect. The table below shows the reconciliation of the basic and diluted shares for the three months ended March 31, 2018, in thousands: For the three months ended March 31, 2018 2017 Weighted average number of shares outstanding: Basic 34,457 33,207 Dilutive effects of: Employee stock options, RSU’s and share based payment awards issued to employees - 564 Diluted 34,457 33,771 The following outstanding shares of common stock and potential common shares were excluded from the computation of diluted net income (loss) per share of common stock for the three months ended March 31, 2018 and 2017 because the impact of them would have been antidilutive: For the three months ended March 31, 2018 2017 Stock options to purchase common stock 736,073 761,710 Restricted stock units for common stock 2,665,737 598,503 Employee share purchase plan 111,357 -

Disposition of Business

Disposition of Business	3 Months Ended
	Mar. 31, 2018
Discontinued Operations And Disposal Groups [Abstract]
Disposition of Business	13. Disposition of Business On February 23, 2017, the Company completed the sale of the assets of its Skyfence cloud access security broker business (“Skyfence”) to Forcepoint LLC and its Israeli subsidiary for consideration of approximately $40 million in cash. Of the total consideration, approximately $5.0 million was remitted directly to escrow to secure the Company’s indemnification obligations. This escrowed amount is recorded in prepaid expenses and other current assets on our condensed consolidated balance sheet as of March 31, 2018, As a result of the sale, the Company recognized a gain of $35.9 million during the first quarter of 2017 included in gain on sale of Skyfence in our condensed consolidated statement of operations. The following table presents the carrying amounts of Skyfence immediately preceding the disposition on February 23, 2017: (dollars Assets Prepaid and other current assets $ 46 Property and equipment, net 219 Goodwill 1,058 Acquired intangible assets, net 4,496 Total assets $ 5,819 Liabilities Accounts payable $ 104 Accrued and other current liabilities 117 Deferred revenue 1,454 Total liabilities $ 1,675 The Company evaluated the disposition of Skyfence and determined it did not meet the criteria for classification as a discontinued operation and determined that the disposition is not expected to have a material impact to our quarterly consolidated operating loss and net income. However, the Company determined that the disposition does represent an individually significant component of our business. The following table presents certain amounts related to Skyfence in our consolidated results of operations through its disposal on February 23, 2017: For March 31, 2018 2017 (dollars in thousands) Operating loss - $ (3,567 ) Loss before taxes - (3,648 ) Net loss - (3,659 )

Subsequent Event

Subsequent Event	3 Months Ended
	Mar. 31, 2018
Subsequent Events [Abstract]
Subsequent Event	14. Subsequent Event We are currently under audit by the Israeli Tax Authority. The audit includes the review of various matters, including employee equity based compensation. On April 22, 2018, the Israeli Supreme Court published a decision, confirming the Tel-Aviv District Court ruling in Kontera Technologies Ltd. vs. Tel Aviv Field Office 3, that expenses for employee equity based compensation should be included in the cost base of an Israeli R&D subsidiary implementing a cost-plus arrangement and denied the corresponding tax deduction to the Israeli subsidiary in accordance with the specific provisions of section 102 of the Israeli Income Tax Ordinance. Our policy is to review and update tax reserves as facts and circumstances change. As a result of this decision, we are reassessing our uncertain tax positions. We currently expect to record an adjustment to our tax reserves in the second quarter of the fiscal 2018 between $18 million and $21 million which includes tax liability and interest.

Basis of Presentation and Sum22

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Business	Business Imperva, Inc. (together with its subsidiaries, the “Company”) was incorporated in April 2002 in Delaware. The Company is headquartered in Redwood Shores, California and has subsidiaries located throughout the world including Israel, Asia and Europe. The Company is engaged in the development, marketing, sales, service and support of cyber-security solutions that protect business-critical data and applications whether in the cloud or on premises.
Basis of Presentation	Basis of Presentation The Company has prepared the accompanying Condensed Consolidated Financial Statements in accordance with Article 10 of Regulation S-X and pursuant to the rules and regulations for Form 10-Q of the Securities and Exchange Commission (the “SEC”). Pursuant to those rules and regulations, the Company has condensed or omitted certain information and footnote disclosure it normally includes in its annual consolidated financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”). In management’s opinion, the Company has made all adjustments (consisting only of normal, recurring adjustments, except as otherwise indicated) necessary to fairly present its condensed consolidated financial position, results of operations, and cash flows. The Company’s interim period operating results do not necessarily indicate the results that may be expected for any other interim period or for the full fiscal year. These condensed consolidated financial statements and accompanying notes should be read in conjunction with the consolidated financial statements and notes thereto in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017, which was filed with the SEC on February 23, 2018 (the “Annual Report”). The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Concentration of Revenue and Accounts Receivable	Concentration of Revenue and Accounts Receivable Significant customers are those which represent 10% or more of the Company’s total revenue or gross accounts receivable balance at each respective balance sheet date. The Company primarily sells products and services through channel partners, including distributors and resellers, which sell to end-user customers. For the three months ended March 31, 2018, there was no significant customer which represented 10% or more of the Company’s total revenue. For the three months ended March 31, 2017, one customer represented 11% of the Company’s total revenue. As of March 31, 2018, no customer represented 10% or more of the Company’s accounts receivable balance. As of December 31, 2017, one customer represented 18% of the Company’s total accounts receivable balance.
Significant Accounting Policies	Significant Accounting Policies
Recent Accounting Pronouncements	Recently Adopted Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) 2014-09, Revenue from Contracts with Customers (Accounting Standards Codification or ASC 606). ASC 606 supersedes the revenue recognition requirements in Revenue Recognition (ASC 605), and requires the recognition of revenue as promised goods or services are transferred to customers in an amount that reflects the consideration which the entity expects to be entitled to in exchange for those goods or services. ASC 606 also includes Subtopic 340-40, Other Assets and Deferred Costs - Contracts with Customers, which requires the deferral of incremental costs of obtaining a contract with a customer. Collectively, we refer to ASC 606 and Subtopic 340-40 as the “new standard”. The Company adopted the new standard as of January 1, 2018, utilizing the modified retrospective method for all contracts not completed as of the date of adoption. For contracts that were modified before the effective date, the Company reflected the aggregate effect of all modifications when identifying performance obligations and allocating transaction price in accordance with practical expedient ASC 606-10-65-1-(f)-4, which did not have a material effect on the adjustment to accumulated deficit. As a result, the Company recognized the cumulative effect of initially applying the new standard as an adjustment to the opening balance of equity on January 1, 2018. The comparative information has not been adjusted and continues to be reported under ASC 605. The details of the new policy with significant changes and quantitative impact of the changes are described in a separate note below. In May 2017, FASB issued an ASU 2017 - 09 Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting. This ASU clarifies and eliminates the diversity of practice as to when a Company must account for the effects of a stock modification. In accordance with the guidance an entity should account for the effects of a modification unless all the following criteria are met: 1. The fair value of the modified award is the same as the fair value of the original award immediately before the original award is modified. If the modification does not affect any of the inputs to the valuation technique that the entity uses to value the award, the entity is not required to estimate the value immediately before and after the modification. 2. The vesting conditions of the modified award are the same as the vesting conditions of the original award immediately before the original award is modified. 3. The classification of the modified award as an equity instrument or a liability instrument is the same as the classification of the original award immediately before the original award is modified. The Company has adopted this guidance in Q1’18. The Company noted the adoption of this ASU did not have any material impact on the condensed consolidated financial statements in the current period and is not expected to have material impacts in future periods as well. The Company adopted ASU 2016-18, “Restricted Cash,” and ASU 2016-15, “Classification of Certain Cash Receipts and Cash Payments.” on January 1, 2018 using the modified retrospective method as of the date of adoption. During the three months ended March 31, 2018. ASU 2016-18 requires an entity to reconcile and explain the period over period change in total cash, cash equivalents and restricted cash within its condensed consolidated statement of cash flows and ASU 2016-15 provides guidance clarifying how certain cash receipts and cash payments should be classified. We adopted these accounting standards retrospectively and, accordingly, certain line items in the condensed consolidated statement of cash flows have been reclassified to conform to the current presentation. The following table summarizes the change in cash flows as reported and as previously reported prior to the adoption of these standards (in thousands): Quarter Ended March 31, 2018 March 31, 2017 As Reported As Reported As previously Reported Change in restricted cash - - $ (18 ) Net cash provided by (used in) investing activities (343 ) $ 10,457 10,439 NET INCREASE (DECREASE) 21,783 28,993 28,975 Balance at beginning of period* 194,874 109,295 107,343 Balance at end of period* 216,657 138,288 136,318 *: Amounts in As Reported column include cash, cash equivalents and restricted cash as required. Amounts in the As Previously Reported column reflect only cash and cash equivalents. In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business. The new standard clarifies the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. ASU 2017-01 is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years, and should be applied prospectively with early adoption permitted under certain scenarios. The impact of this accounting standard update will be fact dependent. The provision of ASU No. 2017-01 did not have a material impact on the accompanying condensed consolidated financial statements. Recently Issued Accounting Pronouncements In February 2018 the FASB issued ASU 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, that gives entities the option to reclassify to retained earnings tax effects related to items that have been stranded in accumulated other comprehensive income as a result of the Tax Cuts and Jobs Act (the Act). An entity that elects to reclassify these amounts must reclassify stranded tax effects related to the Act’s change in US federal tax rate for all items accounted for in other comprehensive income. These entities can also elect to reclassify other stranded effects that relate to the Act but do not directly relate to the change in the federal rate. Entities can choose whether to apply the amendments retrospectively to each period in which the effect of the Act is recognized or to apply the amendments in the period of adoption. The standard is effective for the Company on January 1, 2019, with early adoption permitted. The Company is evaluating the impact of adopting this new accounting guidance on its condensed consolidated financial statements. In August 2017, FASB issued ASU 2017-12 Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. Under the new guidance, more hedging strategies will be eligible for hedge accounting and the application of hedge accounting is simplified. The new guidance amends presentation and disclosure requirements, and how effectiveness is assessed. The standard is effective for the Company on January 1, 2019, with early adoption permitted. The Company is evaluating the impact of adopting this new accounting guidance on its condensed consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment (Topic 350), which simplifies the measurement of goodwill impairment by removing the second step of the goodwill impairment test, which requires the determination of the fair value of individual assets and liabilities of a reporting unit. Under this guidance, goodwill impairment is to be measured as the amount by which a reporting unit’s carrying value exceeds its fair value with the loss recognized not to exceed the total amount of goodwill allocated to the reporting unit. The guidance is effective beginning January 1, 2020 on a prospective basis, with early adoption permitted for interim or annual goodwill impairment tests performed after January 1, 2017. The standard is to be applied on a prospective basis. The Company does not anticipate a material impact to the condensed consolidated financial statements once implemented. In June 2016, the FASB Issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The new standard requires financial assets measured at amortized cost be presented at the net amount expected to be collected, through an allowance for credit losses that is deducted from the amortized cost basis. The standard will be effective for the Company beginning January 1, 2020, with early application permitted. The Company is evaluating the impact of adopting this new accounting guidance on its condensed consolidated financial statements. In February 2016, the FASB issued ASU 2016-02 regarding ASC 842 Leases. The amendments in this guidance require balance sheet recognition of lease assets and lease liabilities by lessees for leases classified as operating leases, with an optional policy election to not recognize lease assets and lease liabilities for leases with a term of 12 months or less. The amendments also require new disclosures, including qualitative and quantitative requirements, providing additional information about the amounts recorded in the financial statements. The standard will be effective for the Company beginning January 1, 2019. The amendments require a modified retrospective approach with optional practical expedients. While the Company continues to evaluate the effect of the standard on its ongoing financial reporting, the Company currently believes that the adoption of the ASU may materially affect its Balance Sheet.
Revenue from Contracts with Customers	Revenue from Contracts with Customers The reported results for three month period ended March 31, 2018 reflect the application of the new revenue standard while the reported results for three month period ended March 31, 2017 were prepared under the guidance of ASC 605, which is also referred to herein as "legacy GAAP" or the "previous guidance". The adoption of the new revenue standard represents a change in accounting principle with the intent to align revenue recognition with the delivery of products and services and provide financial statement readers with enhanced disclosures. In accordance with the new revenue standard, revenue is recognized when a customer obtains control of promised products and services. The amount of revenue recognized reflects the consideration to which the Company expects to be entitled to receive in exchange for these products and services. To achieve this core principle, the Company applies the following five steps: 1) Identify the contract with a customer A contract with a customer exists when (i) the Company enters into an enforceable contract with a customer that defines each party’s rights regarding the products and services to be transferred and identifies the payment terms related to these products and services, (ii) the contract has commercial substance and, (iii) the Company determines that collection of substantially all consideration for products and services that are transferred is probable based on the customer’s intent and ability to pay the promised consideration. The Company applies judgment in determining the customer’s ability and intention to pay, which is based on a variety of factors including the customer’s historical payment experience or, in the case of a new customer, published credit and financial information pertaining to the customer. 2) Identify the performance obligations in the contract Performance obligations promised in a contract are identified based on the products and services that will be transferred to the customer that are both capable of being distinct, whereby the customer can benefit from the products and services either on its own or together with other resources that are readily available from third parties or from the Company, and are distinct in the context of the contract, whereby the transfer of the products and services is separately identifiable from other promises in the contract. To the extent a contract includes multiple promised products and services, the Company must apply judgment to determine whether promised products and services are capable of being distinct and distinct in the context of the contract. If these criteria are not met the promised products and services are accounted for as a combined performance obligation. 3) Determine the transaction price The transaction price is determined based on the consideration to which the Company will be entitled in exchange for transferring products and services to the customer. None of the Company's contracts as of March 31, 2018 contained a significant financing component. Determining the transaction price requires significant judgment, which is discussed by revenue category in further detail below. 4) Allocate the transaction price to performance obligations in the contract If the contract contains a single performance obligation, the entire transaction price is allocated to the single performance obligation. Contracts that contain multiple performance obligations require an allocation of the transaction price to each performance obligation based on a relative standalone selling price basis. The Company determines standalone selling price based on the price at which the performance obligation is sold separately. If the standalone selling price is not observable through past standalone transactions, the Company estimates the standalone selling price taking into account available information such as past transactions, market conditions and internally approved pricing guidelines related to the performance obligations. 5) Recognize revenue when or as the Company satisfies a performance obligation The Company satisfies performance obligations either over time or at a point in time as discussed in further detail below. Revenue is recognized at the time the related performance obligation is satisfied by transferring a promised products and services to a customer. Revenue Recognition The Company derives revenue from two sources: (i) products and license revenue, which includes hardware and perpetual software license revenue and (ii) services revenue, which includes subscription arrangements, maintenance and support, professional services and training. Substantially all of product and license sales have been sold in combination with maintenance and support services. At contract inception, the Company assesses the products and services promised in its contracts with customers and identifies a performance obligation for each promise to transfer to the customer a product or service (or bundle of products or services) that is distinct – i.e., if a product or service is separately identifiable from other items in the bundled package and if a customer can benefit from it on its own or with other resources that are readily available to the customer. The Company recognizes revenue when or as it satisfies a performance obligation by transferring control of a product or service to a customer. Taxes collected from customers and remitted to governmental authorities are not included in revenue. Shipping and handling costs associated with outbound freight are accounted for as a fulfillment cost and are included in cost of revenues. In rare situations, we may agree to accept a lower consideration than the contractual price. We account for such situations as variable consideration and estimate future price reductions based on our historical experience. The impact of such price reductions on our revenue for the three month period ended March 31’st 2018 was not significant. Once the Company has determined the transaction price, the total transaction price is allocated to each performance obligation in a manner depicting the amount of consideration to which the Company expects to be entitled in exchange for transferring the good(s) or service(s) to the customer (the “allocation objective”). If the allocation objective is met at contractual prices, no further allocations are made. Otherwise, the Company allocates the transaction price to each performance obligation identified in the contract on a relative standalone selling price basis. In order to determine the standalone selling price of its promised goods or services, the Company conducts a regular analysis to determine whether its goods or services have an observable standalone selling price. In determining observable standalone selling price, the Company requires that a substantial majority of the standalone selling prices for a good or service fall within a reasonably narrow pricing range. If the Company does not have a directly observable standalone selling price for a particular good or service, then the Company estimates a standalone selling price by reviewing external and internal market factors including, but not limited to, pricing practices including historical discounting, major service groups, and the geographies in which the Company offers its products and services. The determination of standalone selling price is made through consultation with and approval by the Company’s management. Selling prices are analyzed on a quarterly basis to identify if the Company has experienced significant changes in its selling prices. The upfront payment pattern relative to the delivery of subscription, maintenance and services and associated revenue recognition generates significant deferred revenue. The Company refers to contract liabilities as "deferred revenue" on the condensed consolidated financial statements and related disclosures. The following describes the nature of the Company’s primary types of revenues and the revenue recognition policies and significant payment terms as they pertain to the types of transactions the Company enters into with its customers. Products and License Revenue Product and license revenue consists of hardware and perpetual software license sales. Hardware revenue is recognized at a point in time upon delivery. The Company’s perpetual software licenses sold without hardware generally have significant stand-alone functionality to the customer upon delivery and are considered functional intellectual property (“IP”). Revenue allocated to perpetual software licenses is typically recognized at a point in time upon delivery of the license. Service Revenue Services revenue consists of subscription arrangement, maintenance and support, professional services, and training. Subscription services are offered under renewable, fee-based contracts, which provide access to the Incapsula service and certain functionality within SecureSphere platform. Payments for subscription services are typically due monthly/quarterly/annually in advance. Subscription services are viewed as a stand-ready performance obligation that is satisfied over time and typically have a term of one to three years. Unearned subscription revenue is included in deferred revenue. Maintenance and support arrangements are offered under renewable, fee-based contracts, which include technical support, hardware repair and replacement parts, bug fixes, patches and unspecified upgrades on a when-and-if-available basis. Payments for maintenance and support are typically due annually in advance. Maintenance and support services are viewed as a stand-ready performance obligation that is satisfied over time and typically have a term of one to three years. Unearned maintenance and support revenue is included in deferred revenue. Professional services revenue consists of fees the Company earns related to implementation and consulting services. The Company’s professional services typically are considered distinct from the related software or subscription services as the promise to transfer the software or subscription can be fulfilled independently from the promise to deliver the implementation and consulting services (i.e., customer receives standalone functionality from the license or subscription and the customer obtains the intended benefit of the license or subscription without the professional services). Professional services revenue is typically recognized over time as the services are rendered, using an efforts-expended (labor hours) input method. Professional service arrangements are typically short term in nature and are largely completed within 90 days from the start of service. Training services revenue consists of fees the Company earns related to training customers and partners on the use of its products. Training services are distinct performance obligations recognized upon delivery of the training. Deferred Costs The Company capitalizes contract origination costs that are incremental and recoverable costs of obtaining a contract with a customer. These costs are deferred and amortized over a benefit period of 5 years. We determined the period of benefit by taking into consideration our customer contracts, our technology and other factors. The Company applies the practical expedient to expense costs as incurred if the expected amortization period was 1 year or less. This applies to sales commissions for renewal contracts which would be deferred and then amortized over the related contractual renewal period. Amortization expense is included in Sales and marketing expenses in the accompanying condensed consolidated statements of operations. Allocating the Transaction Price to Performance Obligations For certain arrangements with multiple deliverables, the Company previously allocated the arrangement fee to the non-software element based upon the relative selling price of such element and, if software and software-related elements (e.g., maintenance and support for the software element) were also included in the arrangement, the Company allocated the arrangement fee to each of those software and software-related elements as a group. After such allocations were made, the amount of the arrangement fee allocated to the software and software-related elements was accounted for using the residual method. Under the new standard, the total transaction price is allocated to each performance on a relative standalone selling price basis, irrespective of whether the performance obligations would have been previously categorized as software or non-software elements. Deferred Revenue and Contingent Revenue The Company previously limited the amount of revenue recognized for delivered elements to the amount that was not contingent on the future delivery of products or services, or subject to the Company’s future performance obligation. Under the new standard, there is no requirement to limit the allocated transaction price to non-contingent amounts. There have been no other material changes to the Company’s significant accounting policies as compared to the significant accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. Adoption Date Impact The following tables summarize the impacts of adopting the new standard on the Company’s condensed consolidated financial statements as of adoption on January 1, 2018. Select condensed consolidated balance sheet line items that reflect the adoption of the new standard are as follows (in thousands): As reported on December 31, 2017 Impact of adoption As adjusted on January 1, 2018 ASSETS Deferred costs, current - $ 3,755 $ 3,755 Other assets including non-current deferred cost 1,593 12,156 13,749 LIABILITIES Deferred revenue, current 126,174 (4,159 ) 122,015 Deferred revenue 33,081 597 33,678 STOCKHOLDERS' EQUITY Accumulated deficit $ (256,537 ) $ 19,473 $ (237,064 ) The deferred cost balance as of January 1, 2018 represents the incremental cost to obtain contracts for contracts which were not complete as of the adoption date, that were expensed pursuant to the previous accounting policy, but require capitalization under the new standard. The deferred revenue balance decreased as of January 1, 2018 primarily due to impacts from application of revised Standalone Selling Price (SSP) methodologies, and due to certain hybrid pricing models, more specifically our FlexProtect hybrid licensing program, which was delivered prior to January 1, 2018. Under the previous guidance the entire transaction fee was recognized ratably, however the new standard requires upfront recognition of a portion of the transaction price allocated to the functional license delivered at the inception of the arrangement. Current Period Impact The following tables summarize the impacts of adopting the new standard on the Company’s condensed consolidated financial statements for the three months ended March 31, 2018. Select consolidated balance sheet line items that reflect the adoption of the new standard are as follows: March 31, 2018 As reported Adjustments Balances without adoption of Topic 606 ASSETS Deferred cost, current $ 4,452 $ (4,452 ) - Other assets including non-current deferred cost 15,455 (14,043 ) 1,412 LIABILITIES AND STOCKHOLDERS' EQUITY Deferred revenue, current 121,818 4,402 126,220 Deferred revenue 34,575 204 34,779 STOCKHOLDERS' EQUITY Accumulated deficit $ (246,845 ) $ (23,101 ) $ (269,946 ) Select Condensed Consolidated Statement of operations line items for the three months ended March 31, 2018 that reflect the adoption of the new standard are as follows: Three months ended March 31, 2018 As reported Adjustments Balances without adoption of Topic 606 Net revenue: Products and license $ 20,512 $ (234 ) $ 20,278 Services: Subscriptions 34,953 86 35,039 Maintenance and Support 25,226 (958 ) 24,268 Professional services and training 3,553 62 3,615 Total services 63,732 (810 ) 62,922 Total net revenue 84,244 (1,044 ) 83,200 Operating expenses: Sales and marketing 39,531 2,585 42,116 Loss from operations (11,237 ) (3,629 ) (14,866 ) Net loss (9,781 ) (3,629 ) (13,410 ) Net loss per share of common stock stockholders, basic and diluted $ (0.28 ) $ (0.11 ) $ (0.39 ) Select Condensed Consolidated Statement of Cash Flows for the three months ended March 31, 2018 that reflect the adoption of the new standard are as follows: (in thousands) Three months ended March 31, 2018 Statement of Cash Flows As reported Adjustments Balance without adoption of Topic 606 Net loss $ (9,781 ) $ (3,629 ) $ (13,410 ) Adjustments to reconcile net income (loss) to net cash provided by operating activities Amortization of deferred costs 1,041 (1,041 ) - Changes in operating assets and liabilities: Deferred costs (3,626 ) 3,626 - Deferred revenue 700 1,044 1,744 Net cash provided by operating activities $ 22,502 $ - $ 22,502 Disaggregation of Revenue The Company’s revenue was comprised of the following major product and service lines (in thousands): Three months ended March 31 2018 2017 Major product/service lines Products and licenses $ 20,512 $ 19,578 Services: Subscriptions 34,953 27,252 Maintenance and support 25,226 21,980 Professional services and training 3,553 3,498 Total services revenue 63,732 52,730 Total revenue $ 84,244 $ 72,308 The company’s revenue by geographic region based on the customer’s location is presented in footnote 10. The following table presents the Company’s revenue by timing of revenue recognition (in thousands): Three months ended March 31 2018 2017 Timing of revenue recognition Products and services transferred at a point in time $ 20,512 $ 19,578 Products and services transferred over time 63,732 52,730 Total revenue $ 84,244 $ 72,308 Deferred Revenue The following table provides information about deferred revenues from contracts with customers (in thousands). As of March 31, 2018 Deferred Revenue (current) $ 121,818 Deferred Revenue 34,575 Total Deferred Revenue $ 156,393 The deferred revenue balance includes customer deposits of $0.9 million, primarily related to cancellable professional services which were billed in advance. Standard payment terms to customers range from 30 to 90 days; however, payment terms and conditions in our customer contracts may vary. In some cases, customers prepay for products and services in advance of our delivery of the related products or services; in other cases, payment is due as services are performed or in arrears following the delivery of the related products or services. Unbilled revenues primarily relate to the Company’s rights to consideration for work completed but not billed at the reporting date and typically relate to professional services. The unbilled revenues are transferred to receivables when the rights become unconditional. Deferred revenue relates to the advance consideration received from customers, which precedes our performance to satisfy the associated performance obligation(s). The Company’s deferred revenue primarily result from customer payments received upfront for subscription, maintenance and support on software licenses and certain fixed fee professional services because these performance obligations are satisfied over time. $46.4 million of services revenue was recognized during the three months ended March 31, 2018 that was included in the deferred revenue balances at the beginning of the period. Transaction Price Allocated to the Remaining Performance Obligations The following table includes estimated revenue expected to be recognized over time related to performance obligations that are unsatisfied (or partially unsatisfied) as of March 31, 2018 (in thousands). Remainder of 2018 2019 2020 2021 Thereafter Performance obligations transferred over time $ 109,260 $ 31,104 $ 12,816 $ 2,019 $ 1,194 Total net revenue $ 109,260 $ 31,104 $ 12,816 $ 2,019 $ 1,194 Amortization of Deferred Costs Deferred costs primarily consist of capitalized incremental contract origination costs and were $18,495 and $15,911 as of March 31, 2018 and January 1, 2018 respectively. For the three months ended March 31, 2018, amortization costs of $1,041 were recorded, and there were no impairments of deferred costs.

Basis of Presentation and Sum23

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2018
Summary of Change in Cash Flows As Reported and As Previously Reported Prior to Adoption of Standards	The following table summarizes the change in cash flows as reported and as previously reported prior to the adoption of these standards (in thousands): Quarter Ended March 31, 2018 March 31, 2017 As Reported As Reported As previously Reported Change in restricted cash - - $ (18 ) Net cash provided by (used in) investing activities (343 ) $ 10,457 10,439 NET INCREASE (DECREASE) 21,783 28,993 28,975 Balance at beginning of period* 194,874 109,295 107,343 Balance at end of period* 216,657 138,288 136,318 *: Amounts in As Reported column include cash, cash equivalents and restricted cash as required. Amounts in the As Previously Reported column reflect only cash and cash equivalents.
Summary of Revenue Comprised of Major Product and Service Lines	The Company’s revenue was comprised of the following major product and service lines (in thousands): Three months ended March 31 2018 2017 Major product/service lines Products and licenses $ 20,512 $ 19,578 Services: Subscriptions 34,953 27,252 Maintenance and support 25,226 21,980 Professional services and training 3,553 3,498 Total services revenue 63,732 52,730 Total revenue $ 84,244 $ 72,308
Summary of Revenue by Timing of Revenue Recognition	The following table presents the Company’s revenue by timing of revenue recognition (in thousands): Three months ended March 31 2018 2017 Timing of revenue recognition Products and services transferred at a point in time $ 20,512 $ 19,578 Products and services transferred over time 63,732 52,730 Total revenue $ 84,244 $ 72,308
Summary of Deferred Revenues from Contracts with Customers	The following table provides information about deferred revenues from contracts with customers (in thousands). As of March 31, 2018 Deferred Revenue (current) $ 121,818 Deferred Revenue 34,575 Total Deferred Revenue $ 156,393
Summary of Estimated Revenue Expected to be Recognized Over Time Related to Performance Obligations	The following table includes estimated revenue expected to be recognized over time related to performance obligations that are unsatisfied (or partially unsatisfied) as of March 31, 2018 (in thousands). Remainder of 2018 2019 2020 2021 Thereafter Performance obligations transferred over time $ 109,260 $ 31,104 $ 12,816 $ 2,019 $ 1,194 Total net revenue $ 109,260 $ 31,104 $ 12,816 $ 2,019 $ 1,194
Topic 606 [Member]
Summary of Impacts of Adopting the New Standard on Financial Statements	The following tables summarize the impacts of adopting the new standard on the Company’s condensed consolidated financial statements as of adoption on January 1, 2018. Select condensed consolidated balance sheet line items that reflect the adoption of the new standard are as follows (in thousands): As reported on December 31, 2017 Impact of adoption As adjusted on January 1, 2018 ASSETS Deferred costs, current - $ 3,755 $ 3,755 Other assets including non-current deferred cost 1,593 12,156 13,749 LIABILITIES Deferred revenue, current 126,174 (4,159 ) 122,015 Deferred revenue 33,081 597 33,678 STOCKHOLDERS' EQUITY Accumulated deficit $ (256,537 ) $ 19,473 $ (237,064 ) The following tables summarize the impacts of adopting the new standard on the Company’s condensed consolidated financial statements for the three months ended March 31, 2018. Select consolidated balance sheet line items that reflect the adoption of the new standard are as follows: March 31, 2018 As reported Adjustments Balances without adoption of Topic 606 ASSETS Deferred cost, current $ 4,452 $ (4,452 ) - Other assets including non-current deferred cost 15,455 (14,043 ) 1,412 LIABILITIES AND STOCKHOLDERS' EQUITY Deferred revenue, current 121,818 4,402 126,220 Deferred revenue 34,575 204 34,779 STOCKHOLDERS' EQUITY Accumulated deficit $ (246,845 ) $ (23,101 ) $ (269,946 ) Select Condensed Consolidated Statement of operations line items for the three months ended March 31, 2018 that reflect the adoption of the new standard are as follows: Three months ended March 31, 2018 As reported Adjustments Balances without adoption of Topic 606 Net revenue: Products and license $ 20,512 $ (234 ) $ 20,278 Services: Subscriptions 34,953 86 35,039 Maintenance and Support 25,226 (958 ) 24,268 Professional services and training 3,553 62 3,615 Total services 63,732 (810 ) 62,922 Total net revenue 84,244 (1,044 ) 83,200 Operating expenses: Sales and marketing 39,531 2,585 42,116 Loss from operations (11,237 ) (3,629 ) (14,866 ) Net loss (9,781 ) (3,629 ) (13,410 ) Net loss per share of common stock stockholders, basic and diluted $ (0.28 ) $ (0.11 ) $ (0.39 ) Select Condensed Consolidated Statement of Cash Flows for the three months ended March 31, 2018 that reflect the adoption of the new standard are as follows: (in thousands) Three months ended March 31, 2018 Statement of Cash Flows As reported Adjustments Balance without adoption of Topic 606 Net loss $ (9,781 ) $ (3,629 ) $ (13,410 ) Adjustments to reconcile net income (loss) to net cash provided by operating activities Amortization of deferred costs 1,041 (1,041 ) - Changes in operating assets and liabilities: Deferred costs (3,626 ) 3,626 - Deferred revenue 700 1,044 1,744 Net cash provided by operating activities $ 22,502 $ - $ 22,502

Cash, Cash Equivalents, Restr24

Cash, Cash Equivalents, Restricted Cash and Short-Term Investments (Tables)	3 Months Ended
	Mar. 31, 2018
Cash And Cash Equivalents [Abstract]
Summary of Cash, Cash Equivalents, and Restricted Cash	The following table provides a summary of cash, cash equivalents, and restricted cash reported within the Condensed Consolidated Balance Sheets that reconciles to the corresponding amount in the Condensed Consolidated Statements of Cash Flows (in thousands): As of March 31, 2018 As of December 31, 2017 As of March 31, 2017 As of December 31, 2016 Cash and cash equivalents $ 214,274 $ 192,538 $ 136,318 $ 107,343 Restricted cash included in Current assets 51 52 72 68 Restricted cash included in Non-current assets 2,332 2,284 1,898 1,884 Total cash, cash equivalents, and restricted cash shown in the Statements of Cash Flows $ 216,657 $ 194,874 $ 138,288 $ 109,295
Summary of Cash, Cash Equivalents and Short-Term Investments	Cash, cash equivalents and short-term investments consist of the following (in thousands): As of March 31, 2018 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value Cash and cash equivalents: Cash $ 110,746 - - $ 110,746 Commercial paper 3,995 - 2 3,993 Money market funds 84,081 - - 84,081 US government and US government agencies 15,455 - 1 15,454 Total $ 214,277 - $ 3 $ 214,274 Short-term investments: Commercial paper - - - - Corporate debt obligations 118,628 - 799 117,829 US government and US government agencies 46,426 - 199 46,227 Bank deposits 480 - 1 479 Total $ 165,534 - $ 999 $ 164,535 As of December 31, 2017 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value Cash and cash equivalents: Cash $ 92,030 - - $ 92,030 Commercial paper - - - - Money market funds 84,144 - - 84,144 US government and US government agencies 16,367 - 3 16,364 Total $ 192,541 - $ 3 $ 192,538 Short-term investments: Commercial paper $ 699 - - $ 699 Corporate debt obligations 123,320 - 488 122,832 US government and US government agencies 43,097 - 114 42,983 Bank deposits 480 - 1 479 Total $ 167,596 - $ 603 $ 166,993
Summary of Cost and Estimated Fair Value of Short-Term Investments	The following table summarizes the cost and estimated fair value of short-term investments based on stated effective maturities as of March 31, 2018 (in thousands): As of March 31, 2018 Estimated Amortized Fair Cost Value Short-term investments: Due within one year $ 110,202 $ 109,734 Due within two years 55,332 54,801 Total $ 165,534 $ 164,535
Schedule of Short-Term Investments at Fair Value and Length of Continuous Unrealized Loss Position	The following tables show the short-term investments in an unrealized loss position and the related gross unrealized losses and fair value and length of time that the short-term investments have been in a continuous unrealized loss position (in thousands): As of March 31, 2018 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Commercial paper $ - $ - $ - $ - Corporate debt obligations 47,967 492 69,863 307 117,830 799 US government and US government agencies 34,753 173 11,473 26 46,226 199 Bank deposits 479 1 479 1 $ 82,720 $ 665 $ 81,815 $ 334 $ 164,535 $ 999 As of December 31, 2017 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Commercial paper $ 699 $ - $ - $ - $ 699 $ - Corporate debt obligations 77,715 377 45,117 111 122,832 488 US government and US government agencies 29,093 76 11,461 38 40,554 114 Bank deposits - - 479 1 479 1 $ 107,507 $ 453 $ 57,057 $ 150 $ 164,564 $ 603

Fair Value of Financial Instr25

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Assets and Liabilities Subject to Fair Value Measurements on Recurring Basis	The following table sets forth the Company’s assets and liabilities that were measured at fair value as of March 31, 2018 and December 31, 2017, by level within the fair value hierarchy (in thousands): As of March 31, 2018 Level I Level II Level III Fair Financial Assets: Cash equivalents: Money market funds $ 84,081 - - $ 84,081 Commercial paper - 3,993 - 3,993 US government and US government agencies - 15,454 - 15,454 Short-term investments: Commercial paper - - - - Corporate debt obligations - 117,829 - 117,829 US government and US government agencies - 46,227 - 46,227 Bank deposits - 479 - 479 Prepaid expenses and other current assets - Forward foreign exchange contracts - 175 - 175 Total financial assets $ 84,081 $ 184,157 - $ 268,238 As of December 31, 2017 Level I Level II Level III Fair Value Financial Assets: Cash equivalents: Money market funds $ 84,144 $ - $ - $ 84,144 US government and US government agencies 16,364 16,364 Short-term investments: Commercial paper - 699 - 699 Corporate debt obligations - 122,832 - 122,832 US government and US government agencies - 42,983 - 42,983 Bank deposits - 479 - 479 Prepaid expenses and other current assets - Forward foreign exchange contracts - 551 - 551 Total financial assets $ 84,144 $ 183,908 $ - $ 268,052

Derivative Instruments (Tables)

Derivative Instruments (Tables)	3 Months Ended
	Mar. 31, 2018
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Instruments Measured at Fair Value and Classification on Condensed Consolidated Balance Sheets	Derivative instruments measured at fair value and their classification on the condensed consolidated balance sheets are presented in the following tables (in thousands): As of March 31, 2018 As of December 31, 2017 Notional Amount Fair Value Notional Amount Fair Value Foreign exchange forward contract derivatives in cash flow hedging relationships - included in prepaid expenses and other current assets $ 48,495 $ 175 $ 66,560 $ 551
Gains (Losses) on Derivative Instruments and Classification on Condensed Consolidated Statement of Operations	Gains (losses) on derivative instruments and their classification on the condensed consolidated statement of operations are presented in the following table (in thousands): For the three months ended March 31 2018 2017 Foreign Exchange Forward Contract Derivatives in cash flow hedging relationships: Gains recognized in OCI (a) $ 356 $ 2,887 Losses recognized in OCI (a) $ (510 ) - Gains recognized from accumulated OCI into net income (b) $ 257 $ 206 Losses recognized from accumulated OCI into net income (b) $ - $ (5 ) (a) Net change in the fair value of the effective portion classified in other comprehensive income (loss) (“OCI”). (b) Effective portion of cash flow hedges reclassified from accumulated other comprehensive income (loss) into net income, of which $84 and $173 were recognized within cost of sales and operating expenses, respectively, for the three months ended March 31, 2018; $14 and $187 were recognized within cost of sales and operating expenses, respectively, for the three months ended March 31, 2017. All amounts are reflected within the respective condensed consolidated statement of operations.

Goodwill and Acquired Intangi27

Goodwill and Acquired Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Changes in the Carrying Amount of Goodwill	The changes in the carrying amount of goodwill for the period ended March 31, 2018 were as follows (in thousands): Balance as of January 1 $ 36,389 Changes during the three month period - Balance as of March 31 $ 36,389
Summary of Acquired Intangible Assets Subject to Amortization	Acquired intangible assets subject to amortization are presented as follows (in thousands): As of March 31, 2018 Weighted Average Remaining Useful life (years) Gross Carrying Amount Accumulated Amortization Net Book Value Acquired technology 5.8 $ 3,753 $ (1,321 ) $ 2,432 Customer relationships 5.7 480 (90 ) 390 Trade name and other 5.7 280 (50 ) 230 Total acquired intangibles 5.7 $ 4,513 $ (1,461 ) $ 3,052 As of December 31, 2017 Weighted Average Remaining Useful life (years) Gross Carrying Amount Accumulated Amortization Net Book Value Acquired technology 6.0 $ 3,753 $ (1,216 ) $ 2,537 Customer relationships 6.0 480 (71 ) 409 Trade name and other 6.0 280 (42 ) 238 Total acquired intangibles 6.0 $ 4,513 $ (1,329 ) $ 3,184
Schedule of Expected Amortization Expense in Future Periods	As of March 31, 2018, the amortization expense in future periods is expected to be as follows (in thousands): Acquired Fiscal Year Technology 2018 (remaining 9 months) 397 2019 529 2020 529 2021 529 Thereafter 1,068 Total expected amortization expense $ 3,052

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Future Minimum Payments Under Operating Leases and Minimum Rentals to be Received Under Non-Cancellable Subleases	Future minimum payments under these facility operating leases and minimum rentals to be received under non-cancellable subleases are as follows as of March 31, 2018 (in thousands): Operating Leases Estimated Sublease Income Period Ending March 31: 2018 (remaining 9 months) 4,350 515 2019 5,003 - 2020 4,714 - 2021 557 - Thereafter 396 - Total $ 15,020 $ 515

Stockholders_ Equity and Empl29

Stockholders’ Equity and Employee Stock Plans (Tables)	3 Months Ended
	Mar. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Option Activity under Plans and Related Information	The following table summarizes option activity under the Plans and related information: Options Outstanding Weighted- Average Remaining Number of Shares Weighted Average Exercis e Contractual Term (in years) Aggregate Intrinsic Value (i n Balances - January 1, 2018 997,674 $ 41.87 5.72 $ 5,689 Granted - - Exercised (168,408 ) $ 31.43 Cancelled or forfeited (93,193 ) $ 48.28 Balances - March 31, 2018 736,073 $ 43.45 5.27 $ 4,823 Vested and expected to vest - March 31, 2018 736,073 $ 43.45 5.27 $ 4,823 Exercisable - March 31, 2018 640,637 $ 42.38 5.00 $ 4,727 (1) The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying awards and the closing stock price of $43.30 of the Company’s common stock on March 31, 2018.
Summary of RSU Activity Outstanding and Weighted Average Grant Date Fair Value	The following table summarizes RSU activity under the Plans and related information: Number of Restricted Stock Units Outstanding Weighted- Average Grant Date Fair Value Unvested - January 1, 2018 2,353,315 $ 47.42 Granted 785,400 $ 43.31 Granted, performance RSUs 438,980 $ 44.48 Released (407,535 ) $ 41.49 Cancelled or forfeited (504,423 ) $ 43.74 Unvested - March 31, 2018 2,665,737 $ 47.33
Stock-Based Compensation Expense	The Company recognized stock-based compensation expense under the 2003 Plan, 2011 Plan, ESPP, Inducement Option and RSU Plans, the Incapsula 2010 Share Incentive Plan and the 2015 Plan in the condensed consolidated statements of operations as follows (in thousands): For the three months ended March 31 2018 2017 Cost of revenue $ 1,321 $ 1,269 Research and development 2,445 4,768 Sales and marketing 3,314 3,466 General and administrative 7,557 3,432 Restructuring charges - 675 Total stock-based compensation expense $ 14,637 $ 13,610

Accumulated Other Comprehensi30

Accumulated Other Comprehensive Income (Loss) (Tables)	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Changes in Balances of Accumulated Other Comprehensive Income (Loss)	The changes in the balances of accumulated other comprehensive income (loss) by component are as follows (in thousands): For the three months ended March 31, 2018 For the three months ended March 31, 2017 Unrealized gain (loss) on cash flow hedges Unrealized gain (loss) on investments Total Unrealized gain (loss) on cash flow hedges Unrealized gain (loss) on investments Total Balance at January 1 $ 160 $ (615 ) $ (455 ) $ (1,065 ) $ (413 ) $ (1,478 ) Other comprehensive income (loss) before reclassifications (154 ) (396 ) (550 ) 1,930 28 1,958 Amounts reclassified to net income (loss) (257 ) - (257 ) (201 ) - (201 ) Change in other comprehensive income (loss) (411 ) (396 ) (807 ) 1,729 28 1,757 Balance at March 31 $ (251 ) $ (1,011 ) $ (1,262 ) $ 664 $ (385 ) $ 279
Summary of Reclassifications Out of Accumulated Other Comprehensive Income (Loss)	The following is a summary of reclassifications out of accumulated other comprehensive income (loss) for the three months ended March 31, 2018 and 2017 (in thousands): For the three months ended March 31, 2018 For the three months ended March 31, 2017 Pre-Tax Amount Tax (Expense) Benefit After-Tax Amount Pre-Tax Amount Tax (Expense) Benefit After-Tax Amount Unrealized gains (losses) on cash flow hedges: Current period unrealized gain (loss) $ (154 ) $ - $ (154 ) $ 2,887 (957 ) $ 1,930 Reclassification adjustments 1 (257 ) - (257 ) (201 ) - (201 ) Unrealized gains (losses) on cash flow hedges, net (411 ) — (411 ) 2,686 (957 ) 1,729 Unrealized gains (losses) on investments: Current period unrealized gain (loss) $ (396 ) — (396 ) $ 44 (16 ) 28 Unrealized gains (losses) on investments: (396 ) — (396 ) 44 (16 ) 28 Other comprehensive income (loss) $ (807 ) $ — $ (807 ) $ 2,730 $ (973 ) $ 1,757 1

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Company's Revenue by Geographic Region, Based on Customer's Location	The Company’s net revenue by geographic region, based on the customer’s location, is summarized as follows (in thousands): Three months ended March 31 2018 2017 Primary geographical markets Americas United States $ 36,404 $ 37,645 Other 9,478 7,177 Americas sub-total $ 45,882 $ 44,822 EMEA 17,124 13,780 APAC 21,238 13,706 Total revenue $ 84,244 $ 72,308
Long-Lived Assets by Location	The following table presents long-lived assets by location (in thousands): As of March 31, As of December 31, 2018 2017 United States $ 21,615 $ 23,697 Israel 4,882 4,640 Rest of world 248 254 Total long-lived assets $ 26,745 $ 28,591

Restructuring Charges (Tables)

Restructuring Charges (Tables)	3 Months Ended
	Mar. 31, 2018
Restructuring Charges [Abstract]
Summary of Restructuring Activity	The Company’s restructuring activity is summarized as follows: Balance as of December 31, 2017 Additions Adjustments Cash payments Balance as of March 31, 2018 Severance and termination-related costs - 2,451 - (2,361 ) 90 Legal and other exit costs - 100 - (100 ) - Total $ - $ 2,551 $ - $ (2,461 ) $ 90 Balance as of December 31, 2016 Additions Adjustments* Cash payments Balance as of March 31, 2017 Severance and termination-related costs 1,132 667 (797 ) (1,002 ) — Legal and other exit costs - - - - - Total $ 1,132 $ 667 $ (797 ) $ (1,002 ) $ -

Net Income (Loss) per Share (Ta

Net Income (Loss) per Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Reconciliation of Basic and Diluted Shares	The table below shows the reconciliation of the basic and diluted shares for the three months ended March 31, 2018, in thousands: For the three months ended March 31, 2018 2017 Weighted average number of shares outstanding: Basic 34,457 33,207 Dilutive effects of: Employee stock options, RSU’s and share based payment awards issued to employees - 564 Diluted 34,457 33,771
Antidilutive Securities Excluded from Computation of Diluted Net Income (Loss) Per Share of Common Stock	The following outstanding shares of common stock and potential common shares were excluded from the computation of diluted net income (loss) per share of common stock for the three months ended March 31, 2018 and 2017 because the impact of them would have been antidilutive: For the three months ended March 31, 2018 2017 Stock options to purchase common stock 736,073 761,710 Restricted stock units for common stock 2,665,737 598,503 Employee share purchase plan 111,357 -

Disposition of Business (Tables

Disposition of Business (Tables)	3 Months Ended
	Mar. 31, 2018
Discontinued Operations And Disposal Groups [Abstract]
Schedule of Carrying Amounts Immediately Preceding Disposition and Consolidated Results of Operations Through Disposal	The following table presents the carrying amounts of Skyfence immediately preceding the disposition on February 23, 2017: (dollars Assets Prepaid and other current assets $ 46 Property and equipment, net 219 Goodwill 1,058 Acquired intangible assets, net 4,496 Total assets $ 5,819 Liabilities Accounts payable $ 104 Accrued and other current liabilities 117 Deferred revenue 1,454 Total liabilities $ 1,675 The following table presents certain amounts related to Skyfence in our consolidated results of operations through its disposal on February 23, 2017: For March 31, 2018 2017 (dollars in thousands) Operating loss - $ (3,567 ) Loss before taxes - (3,648 ) Net loss - (3,659 )

Basis of Presentation and Sum35

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail)	3 Months Ended		12 Months Ended
	Mar. 31, 2018USD ($)Customer	Mar. 31, 2017Customer	Dec. 31, 2017Customer	Jan. 01, 2018USD ($)
Revenue, Major Customer [Line Items]
Period to complete Professional service arrangements	90 days
Deferred costs amortization period	5 years
Customer deposits	$ 900,000
Services revenue recognized	46,400,000
Capitalized incremental contract origination costs included in deferred costs	18,495			$ 15,911
Amortization costs	1,041
Impairments of deferred costs	$ 0
Minimum [Member]
Revenue, Major Customer [Line Items]
Standard payment terms to customers range	30 days
Maximum [Member]
Revenue, Major Customer [Line Items]
Deferred costs expected amortization period	1 year
Standard payment terms to customers range	90 days
Subscription Services [Member] | Minimum [Member]
Revenue, Major Customer [Line Items]
Performance obligation service revenue satisfaction period	1 year
Subscription Services [Member] | Maximum [Member]
Revenue, Major Customer [Line Items]
Performance obligation service revenue satisfaction period	3 years
Maintenance and Support Services [Member] | Minimum [Member]
Revenue, Major Customer [Line Items]
Performance obligation service revenue satisfaction period	1 year
Maintenance and Support Services [Member] | Maximum [Member]
Revenue, Major Customer [Line Items]
Performance obligation service revenue satisfaction period	3 years
Credit Concentration Risk [Member]
Revenue, Major Customer [Line Items]
Number of customers representing 10% or more of gross accounts receivable | Customer	0		1
Number of customers representing 18% or more of gross accounts receivable | Customer			1
Revenue [Member] | Customer Concentration Risk [Member]
Revenue, Major Customer [Line Items]
Number of customers representing 10% or more of revenue | Customer	0	1
Minimum percentage of revenue or gross accounts receivable balance		11.00%
Accounts Receivable [Member] | Credit Concentration Risk [Member]
Revenue, Major Customer [Line Items]
Minimum percentage of revenue or gross accounts receivable balance			18.00%

Basis of Presentation and Sum36

Basis of Presentation and Summary of Significant Accounting Policies - Summary of Change in Cash Flows As Reported and As Previously Reported Prior to Adoption (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Cash And Cash Equivalents [Line Items]
Change in restricted cash		$ 0	$ 0
Net cash provided by (used in) investing activities		(343)	10,457
NET INCREASE (DECREASE)		21,783	28,993
CASH, CASH EQUIVALENTS AND RESTRICTED CASH - Beginning of period	[1]	194,874	109,295
CASH, CASH EQUIVALENTS AND RESTRICTED CASH - End of period	[1]	$ 216,657	138,288
As previously Reported [Member]
Cash And Cash Equivalents [Line Items]
Change in restricted cash			(18)
Net cash provided by (used in) investing activities			10,439
NET INCREASE (DECREASE)			28,975
CASH, CASH EQUIVALENTS AND RESTRICTED CASH - Beginning of period	[1]		107,343
CASH, CASH EQUIVALENTS AND RESTRICTED CASH - End of period	[1]		$ 136,318
[1]	Amounts in As Reported column include cash, cash equivalents and restricted cash as required. Amounts in the As Previously Reported column reflect only cash and cash equivalents.

Basis of Presentation and Sum37

Basis of Presentation and Summary of Significant Accounting Policies - Summary of Impacts of Adopting the New Standard on Balance Sheet for Adoption Date (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
ASSETS
Deferred costs, current	$ 4,452		$ 0
Other assets including non-current deferred cost	15,455		1,593
LIABILITIES
Deferred revenue, current	121,818		126,174
Deferred revenue	34,575		33,081
STOCKHOLDERS' EQUITY:
Accumulated deficit	(246,845)		$ (256,537)
Topic 606 [Member]
ASSETS
Deferred costs, current		$ 3,755
Other assets including non-current deferred cost		13,749
LIABILITIES
Deferred revenue, current		122,015
Deferred revenue		33,678
STOCKHOLDERS' EQUITY:
Accumulated deficit		(237,064)
Impact of Adoption [Member] | Topic 606 [Member]
ASSETS
Deferred costs, current	(4,452)	3,755
Other assets including non-current deferred cost	(14,043)	12,156
LIABILITIES
Deferred revenue, current	4,402	(4,159)
Deferred revenue	204	597
STOCKHOLDERS' EQUITY:
Accumulated deficit	$ (23,101)	$ 19,473

Basis of Presentation and Sum38

Basis of Presentation and Summary of Significant Accounting Policies - Summary of Impacts of Adopting the New Standard on Balance Sheet for Current Period (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
ASSETS
Deferred costs, current	$ 4,452		$ 0
Other assets including non-current deferred cost	15,455		1,593
LIABILITIES AND STOCKHOLDERS' EQUITY
Deferred revenue, current	121,818		126,174
Deferred revenue	34,575		33,081
STOCKHOLDERS' EQUITY:
Accumulated deficit	(246,845)		$ (256,537)
Topic 606 [Member]
ASSETS
Deferred costs, current		$ 3,755
Other assets including non-current deferred cost		13,749
LIABILITIES AND STOCKHOLDERS' EQUITY
Deferred revenue, current		122,015
Deferred revenue		33,678
STOCKHOLDERS' EQUITY:
Accumulated deficit		(237,064)
Adjustments [Member] | Topic 606 [Member]
ASSETS
Deferred costs, current	(4,452)	3,755
Other assets including non-current deferred cost	(14,043)	12,156
LIABILITIES AND STOCKHOLDERS' EQUITY
Deferred revenue, current	4,402	(4,159)
Deferred revenue	204	597
STOCKHOLDERS' EQUITY:
Accumulated deficit	(23,101)	$ 19,473
Balances Without Adoption of Topic 606 [Member] | Topic 606 [Member]
ASSETS
Other assets including non-current deferred cost	1,412
LIABILITIES AND STOCKHOLDERS' EQUITY
Deferred revenue, current	126,220
Deferred revenue	34,779
STOCKHOLDERS' EQUITY:
Accumulated deficit	$ (269,946)

Basis of Presentation and Sum39

Basis of Presentation and Summary of Significant Accounting Policies - Summary of Impacts of Adopting the New Standard on Statement of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net revenue:
Products and license	$ 20,512	$ 19,578
Services:
Subscriptions	34,953
Maintenance and Support	25,226
Professional services and training	3,553
Total services	63,732	52,730
Total net revenue	84,244	72,308
Operating expenses:
Sales and marketing	39,531	37,124
Loss from operations	(11,237)	(11,738)
Net (loss) income	$ (9,781)	$ 23,083
Net loss per share of common stock stockholders, basic and diluted	$ (0.28)
Adjustments [Member] | Topic 606 [Member]
Net revenue:
Products and license	$ (234)
Services:
Subscriptions	86
Maintenance and Support	(958)
Professional services and training	62
Total services	(810)
Total net revenue	(1,044)
Operating expenses:
Sales and marketing	2,585
Loss from operations	(3,629)
Net (loss) income	$ (3,629)
Net loss per share of common stock stockholders, basic and diluted	$ (0.11)
Balances Without Adoption of Topic 606 [Member] | Topic 606 [Member]
Net revenue:
Products and license	$ 20,278
Services:
Subscriptions	35,039
Maintenance and Support	24,268
Professional services and training	3,615
Total services	62,922
Total net revenue	83,200
Operating expenses:
Sales and marketing	42,116
Loss from operations	(14,866)
Net (loss) income	$ (13,410)
Net loss per share of common stock stockholders, basic and diluted	$ (0.39)

Basis of Presentation and Sum40

Basis of Presentation and Summary of Significant Accounting Policies - Summary of Impacts of Adopting the New Standard on Statement of Cash Flows (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue, Major Customer [Line Items]
Net (loss) income	$ (9,781)	$ 23,083
Adjustments to reconcile net income (loss) to net cash provided by operating activities
Amortization of deferred costs	1,041	0
Changes in operating assets and liabilities:
Deferred costs	(3,626)	0
Deferred revenue	700	(3,869)
Net cash provided by operating activities	22,502	$ 18,496
Adjustments [Member] | Topic 606 [Member]
Revenue, Major Customer [Line Items]
Net (loss) income	(3,629)
Adjustments to reconcile net income (loss) to net cash provided by operating activities
Amortization of deferred costs	(1,041)
Changes in operating assets and liabilities:
Deferred costs	3,626
Deferred revenue	1,044
Balances Without Adoption of Topic 606 [Member] | Topic 606 [Member]
Revenue, Major Customer [Line Items]
Net (loss) income	(13,410)
Changes in operating assets and liabilities:
Deferred revenue	1,744
Net cash provided by operating activities	$ 22,502

Basis of Presentation and Sum41

Basis of Presentation and Summary of Significant Accounting Policies - Summary of Revenue Comprised of Major Product and Service Lines (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation Of Revenue [Line Items]
Products and license	$ 20,512	$ 19,578
Services:
Subscriptions	34,953
Maintenance and Support	25,226
Professional services and training	3,553
Services	63,732	52,730
Total net revenue	84,244	72,308
Major Product and Service Lines [Member]
Disaggregation Of Revenue [Line Items]
Products and license	20,512	19,578
Services:
Subscriptions	34,953	27,252
Maintenance and Support	25,226	21,980
Professional services and training	3,553	3,498
Services	63,732	52,730
Total net revenue	$ 84,244	$ 72,308

Basis of Presentation and Sum42

Basis of Presentation and Summary of Significant Accounting Policies - Summary of Revenue by Timing of Revenue Recognition (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation Of Revenue [Line Items]
Total revenue	$ 84,244	$ 72,308
Products and Services Transferred at a Point in Time [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	20,512	19,578
Products and Services Transferred Over Time [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	$ 63,732	$ 52,730

Basis of Presentation and Sum43

Basis of Presentation and Summary of Significant Accounting Policies - Summary of Deferred Revenues from Contracts with Customers (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Revenue From Contract With Customer [Abstract]
Deferred Revenue (current)	$ 121,818	$ 126,174
Deferred Revenue	34,575	$ 33,081
Total Deferred Revenue	$ 156,393

Basis of Presentation and Sum44

Basis of Presentation and Summary of Significant Accounting Policies - Summary of Estimated Revenue Expected to be Recognized Over Time Related to Performance Obligations (Detail) $ in Thousands	Mar. 31, 2018USD ($)
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue remaining performance obligation, remainder of 2018	$ 109,260
Revenue remaining performance obligation, 2019	31,104
Revenue remaining performance obligation, 2020	12,816
Revenue remaining performance obligation, 2021	2,019
Revenue remaining performance obligation, Thereafter	1,194
Performance Obligations Transferred Over Time [Member]
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue remaining performance obligation, remainder of 2018	109,260
Revenue remaining performance obligation, 2019	31,104
Revenue remaining performance obligation, 2020	12,816
Revenue remaining performance obligation, 2021	2,019
Revenue remaining performance obligation, Thereafter	$ 1,194

Cash, Cash Equivalents, Restr45

Cash, Cash Equivalents, Restricted Cash and Short-Term Investments - Summary of Cash, Cash Equivalents, and Restricted Cash (Detail) - USD ($) $ in Thousands		Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents [Abstract]
Cash and cash equivalents		$ 214,274	$ 192,538	$ 136,318	$ 107,343
Restricted cash included in Current assets		51	52	72	68
Restricted cash included in Non-current assets		2,332	2,284	1,898	1,884
Total cash, cash equivalents, and restricted cash shown in the Statements of Cash Flows	[1]	$ 216,657	$ 194,874	$ 138,288	$ 109,295
[1]	Amounts in As Reported column include cash, cash equivalents and restricted cash as required. Amounts in the As Previously Reported column reflect only cash and cash equivalents.

Cash, Cash Equivalents, Restr46

Cash, Cash Equivalents, Restricted Cash and Short-Term Investments - Summary of Cash, Cash Equivalents and Short-Term Investments (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Schedule of Investments [Line Items]
Cash and cash equivalents, Amortized Cost	$ 214,277	$ 192,541
Cash and cash equivalents, Gross Unrealized Gains	0	0
Cash and cash equivalents, Gross Unrealized Losses	3	3
Cash and cash equivalents, Fair Value	214,274	192,538
Short-term investments, Amortized Cost	165,534	167,596	$ 165,534
Short-term investments, Gross Unrealized Gains	0	0
Short-term investments, Gross Unrealized Losses	999	603
Short-term investments, Estimated Fair Value	164,535	166,993	$ 164,535
Cash [Member]
Schedule of Investments [Line Items]
Cash and cash equivalents, Amortized Cost	110,746	92,030
Cash and cash equivalents, Gross Unrealized Gains	0	0
Cash and cash equivalents, Gross Unrealized Losses	0	0
Cash and cash equivalents, Fair Value	110,746	92,030
Commercial Paper [Member]
Schedule of Investments [Line Items]
Cash and cash equivalents, Amortized Cost	3,995	0
Cash and cash equivalents, Gross Unrealized Gains	0	0
Cash and cash equivalents, Gross Unrealized Losses	2	0
Cash and cash equivalents, Fair Value	3,993	0
Short-term investments, Amortized Cost		699
Short-term investments, Gross Unrealized Gains	0	0
Short-term investments, Gross Unrealized Losses	0	0
Short-term investments, Estimated Fair Value	0	699
Money Market Funds [Member]
Schedule of Investments [Line Items]
Cash and cash equivalents, Amortized Cost	84,081	84,144
Cash and cash equivalents, Gross Unrealized Gains	0	0
Cash and cash equivalents, Gross Unrealized Losses		0
Cash and cash equivalents, Fair Value	84,081	84,144
US Government and US Government Agencies [Member]
Schedule of Investments [Line Items]
Cash and cash equivalents, Amortized Cost	15,455	16,367
Cash and cash equivalents, Gross Unrealized Gains	0	0
Cash and cash equivalents, Gross Unrealized Losses	1	3
Cash and cash equivalents, Fair Value	15,454	16,364
Short-term investments, Amortized Cost	46,426	43,097
Short-term investments, Gross Unrealized Gains	0	0
Short-term investments, Gross Unrealized Losses	199	114
Short-term investments, Estimated Fair Value	46,227	42,983
Corporate Debt Obligations [Member]
Schedule of Investments [Line Items]
Short-term investments, Amortized Cost	118,628	123,320
Short-term investments, Gross Unrealized Gains	0	0
Short-term investments, Gross Unrealized Losses	799	488
Short-term investments, Estimated Fair Value	117,829	122,832
Bank Deposits [Member]
Schedule of Investments [Line Items]
Short-term investments, Amortized Cost	480	480
Short-term investments, Gross Unrealized Gains	0	0
Short-term investments, Gross Unrealized Losses	1	1
Short-term investments, Estimated Fair Value	$ 479	$ 479

Cash, Cash Equivalents, Restr47

Cash, Cash Equivalents, Restricted Cash and Short-Term Investments - Summary of Cost and Estimated Fair Value of Short-Term Investments (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Short Term Investments [Abstract]
Amortized Cost of short-term investments, Due within one year			$ 110,202
Amortized Cost of short-term investments, Due within two years			55,332
Short-term investments, Amortized Cost	$ 165,534	$ 167,596	165,534
Estimated fair value of short-term investments, Due within one year			109,734
Estimated fair value of short-term investments, Due within two years			54,801
Short-term investments, Estimated Fair Value	$ 164,535	$ 166,993	$ 164,535

Cash, Cash Equivalents, Restr48

Cash, Cash Equivalents, Restricted Cash and Short-Term Investments - Schedule of Short-Term Investments at Fair Value and Length of Continuous Unrealized Loss Position (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	$ 82,720	$ 107,507
Less than 12 Months, Unrealized Losses	665	453
12 Months or Greater, Fair Value	81,815	57,057
12 Months or Greater, Unrealized Losses	334	150
Total, Fair Value	164,535	164,564
Total, Unrealized Losses	999	603
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value		699
Less than 12 Months, Unrealized Losses		0
12 Months or Greater, Fair Value	0	0
12 Months or Greater, Unrealized Losses	0	0
Total, Fair Value	0	699
Total, Unrealized Losses	0	0
Corporate Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	47,967	77,715
Less than 12 Months, Unrealized Losses	492	377
12 Months or Greater, Fair Value	69,863	45,117
12 Months or Greater, Unrealized Losses	307	111
Total, Fair Value	117,830	122,832
Total, Unrealized Losses	799	488
US Government and US Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	34,753	29,093
Less than 12 Months, Unrealized Losses	173	76
12 Months or Greater, Fair Value	11,473	11,461
12 Months or Greater, Unrealized Losses	26	38
Total, Fair Value	46,226	40,554
Total, Unrealized Losses	199	114
Bank Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value		0
Less than 12 Months, Unrealized Losses	0	0
12 Months or Greater, Fair Value	479	479
12 Months or Greater, Unrealized Losses	1	1
Total, Fair Value	479	479
Total, Unrealized Losses	$ 1	$ 1

Fair Value of Financial Instr49

Fair Value of Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value transfers between level 1 to level 2	$ 0
Fair value transfers between level 2 to level 1	0
Fair value transfers into level 3	0
Fair value transfers out of level 3	0
Level II [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Severance pay assets	$ 6,400,000	$ 6,600,000

Fair Value of Financial Instr50

Fair Value of Financial Instruments - Assets and Liabilities Subject to Fair Value Measurements on Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 214,274	$ 192,538
Short-term investments	164,535	166,993	$ 164,535
Commercial Paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	3,993	0
Short-term investments	0	699
Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	84,081	84,144
US Government and US Government Agencies [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	15,454	16,364
Short-term investments	46,227	42,983
Corporate Debt Obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	117,829	122,832
Bank Deposits [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	479	479
Fair Value, Measurements, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	268,238	268,052
Fair Value, Measurements, Recurring [Member] | Commercial Paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	3,993
Short-term investments	0	699
Fair Value, Measurements, Recurring [Member] | Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	84,081	84,144
Fair Value, Measurements, Recurring [Member] | US Government and US Government Agencies [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	15,454	16,364
Short-term investments	46,227	42,983
Fair Value, Measurements, Recurring [Member] | Corporate Debt Obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	117,829	122,832
Fair Value, Measurements, Recurring [Member] | Bank Deposits [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	479	479
Fair Value, Measurements, Recurring [Member] | Level I [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	84,081	84,144
Fair Value, Measurements, Recurring [Member] | Level I [Member] | Commercial Paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	0
Short-term investments	0	0
Fair Value, Measurements, Recurring [Member] | Level I [Member] | Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	84,081	84,144
Fair Value, Measurements, Recurring [Member] | Level I [Member] | US Government and US Government Agencies [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Short-term investments	0	0
Fair Value, Measurements, Recurring [Member] | Level I [Member] | Corporate Debt Obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	0	0
Fair Value, Measurements, Recurring [Member] | Level I [Member] | Bank Deposits [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	0	0
Fair Value, Measurements, Recurring [Member] | Level II [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	184,157	183,908
Fair Value, Measurements, Recurring [Member] | Level II [Member] | Commercial Paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	3,993
Short-term investments	0	699
Fair Value, Measurements, Recurring [Member] | Level II [Member] | Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Fair Value, Measurements, Recurring [Member] | Level II [Member] | US Government and US Government Agencies [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	15,454	16,364
Short-term investments	46,227	42,983
Fair Value, Measurements, Recurring [Member] | Level II [Member] | Corporate Debt Obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	117,829	122,832
Fair Value, Measurements, Recurring [Member] | Level II [Member] | Bank Deposits [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	479	479
Fair Value, Measurements, Recurring [Member] | Level III [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	0	0
Fair Value, Measurements, Recurring [Member] | Level III [Member] | Commercial Paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	0
Short-term investments	0	0
Fair Value, Measurements, Recurring [Member] | Level III [Member] | Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Fair Value, Measurements, Recurring [Member] | Level III [Member] | US Government and US Government Agencies [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Short-term investments	0	0
Fair Value, Measurements, Recurring [Member] | Level III [Member] | Corporate Debt Obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	0	0
Fair Value, Measurements, Recurring [Member] | Level III [Member] | Bank Deposits [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments	0	0
Fair Value, Measurements, Recurring [Member] | Forward Foreign Exchange Contracts [Member] | Prepaid Expenses and Other Current Assets [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Prepaid expenses and other current assets - Forward foreign exchange contracts	175	551
Fair Value, Measurements, Recurring [Member] | Forward Foreign Exchange Contracts [Member] | Level I [Member] | Prepaid Expenses and Other Current Assets [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Prepaid expenses and other current assets - Forward foreign exchange contracts	0	0
Fair Value, Measurements, Recurring [Member] | Forward Foreign Exchange Contracts [Member] | Level II [Member] | Prepaid Expenses and Other Current Assets [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Prepaid expenses and other current assets - Forward foreign exchange contracts	175	551
Fair Value, Measurements, Recurring [Member] | Forward Foreign Exchange Contracts [Member] | Level III [Member] | Prepaid Expenses and Other Current Assets [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Prepaid expenses and other current assets - Forward foreign exchange contracts	$ 0	$ 0

Derivative Instruments - Additi

Derivative Instruments - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2018
Forward Foreign Exchange Contracts [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative contracts maturity	12 months

Derivative Instruments - Deriva

Derivative Instruments - Derivative Instruments Measured at Fair Value and Classification on Condensed Consolidated Balance Sheets (Detail) - Forward Foreign Exchange Contracts [Member] - Designated As Hedging Instrument [Member] - Prepaid Expenses and Other Current Assets [Member] - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Derivative Notional Amount	$ 48,495,000	$ 66,560,000
Derivative Fair Value	$ 175,000	$ 551,000

Derivative Instruments - Gains

Derivative Instruments - Gains (Losses) on Derivative Instruments and Classification on Condensed Consolidated Statement of Operations (Detail) - Designated As Hedging Instrument [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivatives, Fair Value [Line Items]
Gains recognized in OCI	$ 356	$ 2,887
Losses recognized in OCI	(510)	0
Gains recognized from accumulated OCI into net income	257	206
Losses recognized from accumulated OCI into net income	$ 0	$ (5)

Derivative Instruments - Gain54

Derivative Instruments - Gains (Losses) on Derivative Instruments and Classification on Condensed Consolidated Statement of Operations (Parenthetical) (Detail) - Designated As Hedging Instrument [Member] - Unrealized Gain (Loss) on Cash Flow Hedges [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cost of Sales [Member]
Derivatives, Fair Value [Line Items]
Cash flow hedge Gain (loss) reclassified	$ 84	$ 14
Operating Expenses [Member]
Derivatives, Fair Value [Line Items]
Cash flow hedge Gain (loss) reclassified	$ 173	$ 187

Goodwill and Acquired Intangi55

Goodwill and Acquired Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Finite Lived Intangible Assets [Line Items]
Goodwill impairments	$ 0	$ 0
Impairment of intangible assets	$ 0	$ 0
Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Estimated useful life	7 years
Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Estimated useful life	10 years

Goodwill and Acquired Intangi56

Goodwill and Acquired Intangible Assets - Changes in the Carrying Amount of Goodwill (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
Balance as of January 1	$ 36,389
Changes during the three month period	0
Balance as of March 31	$ 36,389

Goodwill and Acquired Intangi57

Goodwill and Acquired Intangible Assets - Summary of Acquired Intangible Assets Subject to Amortization (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Finite Lived Intangible Assets [Line Items]
Weighted Average Remaining Useful life (years)	5 years 8 months 12 days	6 years
Gross Carrying Amount	$ 4,513	$ 4,513
Accumulated Amortization	(1,461)	(1,329)
Net Book Value	$ 3,052	$ 3,184
Acquired Technology [Member]
Finite Lived Intangible Assets [Line Items]
Weighted Average Remaining Useful life (years)	5 years 9 months 18 days	6 years
Gross Carrying Amount	$ 3,753	$ 3,753
Accumulated Amortization	(1,321)	(1,216)
Net Book Value	$ 2,432	$ 2,537
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Weighted Average Remaining Useful life (years)	5 years 8 months 12 days	6 years
Gross Carrying Amount	$ 480	$ 480
Accumulated Amortization	(90)	(71)
Net Book Value	$ 390	$ 409
Trade Name and Other [Member]
Finite Lived Intangible Assets [Line Items]
Weighted Average Remaining Useful life (years)	5 years 8 months 12 days	6 years
Gross Carrying Amount	$ 280	$ 280
Accumulated Amortization	(50)	(42)
Net Book Value	$ 230	$ 238

Goodwill and Acquired Intangi58

Goodwill and Acquired Intangible Assets - Schedule of Expected Amortization Expense in Future Periods (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
2018 (remaining 9 months)	$ 397
2,019	529
2,020	529
2,021	529
Thereafter	1,068
Net Book Value	$ 3,052	$ 3,184

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Loss Contingencies [Line Items]
Operating lease expiration year	2,023
Rent expense	$ 1,700,000	$ 1,600,000
Tenant improvement allowances	0	0
Restricted cash	2,332,000	1,898,000	$ 2,284,000	$ 1,884,000
Purchase commitments	$ 2,500,000		2,600,000
Period of purchase commitment of inventory from specified date	6 months
Loss contingency accrual	$ 0		$ 0
Cancelable Lease Agreement [Member]
Loss Contingencies [Line Items]
Motor vehicle lease expenses	1,200,000	$ 700,000
Maximum [Member] | Cancelable Lease Agreement [Member]
Loss Contingencies [Line Items]
Penalties	$ 100,000

Commitments and Contingencies60

Commitments and Contingencies - Future Minimum Payments Under Operating Leases and Minimum Rentals to be Received Under Non-Cancellable Subleases (Detail) $ in Thousands	Mar. 31, 2018USD ($)
Operating Leases
2018 (remaining 9 months)	$ 4,350
2,019	5,003
2,020	4,714
2,021	557
Thereafter	396
Total	15,020
Estimated Sublease Income
2018 (remaining 9 months)	515
2,019	0
2,020	0
2,021	0
Thereafter	0
Total	$ 515

Stockholders' Equity and Employ

Stockholders' Equity and Employee Stock Plans - Additional Information (Detail)	Jan. 01, 2018shares	Apr. 26, 2017shares	May 31, 2016shares	Oct. 31, 2015shares	Aug. 31, 2014shares	Jan. 31, 2012	Sep. 30, 2011Periodshares	Mar. 31, 2018USD ($)shares	Mar. 31, 2017USD ($)shares	Dec. 31, 2017shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock, shares authorized								5,000,000
Preferred stock, shares outstanding								0
Preferred stock, shares issued								0
Number of shares granted								785,400
Number of stock option outstanding, granted								0	0
Intrinsic value of options exercised | $								$ 2,600,000
Compensation cost related to unvested stock-based awards granted, but not yet recognized | $								$ 96,800,000
Nonvested awards, compensation cost not yet recognized, period for recognition								3 years
Capitalized stock-based compensation expense | $								$ 0	$ 0
2003 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserve of common stock for future issuance								955,568
2003 Stock Plan [Member] | Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage of fair value of common stock on grant date								85.00%
2003 Stock Plan [Member] | Stock options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period								10 years
2003 Stock Plan [Member] | Stock options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period								4 years
2003 Stock Plan [Member] | Stock options [Member] | Greater 10% Ownership [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage of fair value of common stock on grant date								110.00%
Minimum percentage of combined voting power								10.00%
2011 Stock Option and Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserve of common stock for future issuance							1,000,000
Increase percentage of common stock outstanding								4.00%
Increase in reserve share		850,000	1,300,000
2011 Stock Option and Incentive Plan [Member] | Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage of fair value of common stock on grant date								100.00%
Expiration period								10 years
2011 Stock Option and Incentive Plan [Member] | Restricted Stock Units for Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period								4 years
Description of vesting terms								The Company also grants RSUs. RSUs granted to new hires and merit grants to existing employees generally vest over a four-year period with 25% vesting at the end of one year and the remainder vesting quarterly thereafter.
2011 Stock Option and Incentive Plan [Member] | Restricted Stock Units for Common Stock [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage at the end of period								25.00%
2011 Stock Option and Incentive Plan [Member] | Performance-based RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period								3 years
Vesting performance period								1 year
Vesting service period								2 years
Description of vesting terms								The PRSUs provide for a target number of shares that generally vest over three years which includes a one-year performance period and two years of service-based vesting. The PRSUs vest contingent upon the Company’s achievement of annual revenue and annual operating margin targets for fiscal 2018 relative to the Company’s annual operating plan.
Vest contingent upon the company’s achievement of total operating expenses at the internal operating plan, percentage								110.00%
Award expiration date								Nov. 30, 2019
2011 Stock Option and Incentive Plan [Member] | Performance-based RSUs [Member] | Executives [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted								74,621
2011 Stock Option and Incentive Plan [Member] | Performance-based RSUs [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Earned percentage on target award amount, depending on level of achievement								200.00%
2011 Stock Option and Incentive Plan [Member] | Performance-based RSUs [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Earned percentage on target award amount, depending on level of achievement								0.00%
2011 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserve of common stock for future issuance							500,000
Increase percentage of common stock outstanding						1.00%
Increase in reserve share	342,338
Program effective date							Nov. 8, 2011
Percentage in payroll of deduction base salary to acquire shares of common stock							15.00%
Offering period							24 months
Percentage of fair value of common stock on offering period							85.00%
Number of years, shares reserved for issuance increase						8 years
Number of stock option outstanding, granted								0
2011 Employee Stock Purchase Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserve of common stock for future issuance							20,000,000
Number of purchase periods for offering | Period							5
Inducement Stock Option Plan And Agreement [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period					10 years
Description of vesting terms								In accordance with the terms of the Inducement Option Plans, the Company issued options to purchase an aggregate of 290,000 shares of the Company’s common stock at an exercise price equal to the fair market value of a share of the Company’s common stock on the dates of grant of the options. The options, which have a ten-year term, vest at the rate of 25% of the shares on each of the first anniversary of the vesting commencement date with an additional 6.25% of the shares subject to the option vesting each quarter thereafter so long as the participant has not been terminated.
Number of stock option outstanding, granted					290,000
Inducement Stock Option Plan And Agreement [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage at the end of period					25.00%
Inducement Stock Option Plan And Agreement [Member] | Quarterly Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage at the end of period					6.25%
Inducement Restricted Stock Unit Plan and Agreement [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Description of vesting terms								In accordance with the terms of the Inducement RSU Plans, the Company issued RSUs representing an aggregate of 290,000 shares of the Company’s common stock. The RSUs, which expire following settlement, vest at the rate of 25% of the shares on each of the first anniversary of the vesting commencement date with an additional 6.25% of the shares subject to the RSU vesting each quarter thereafter so long as the participant has not been terminated.
Shares available for grant					290,000
Inducement Restricted Stock Unit Plan and Agreement [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage at the end of period					25.00%
Inducement Restricted Stock Unit Plan and Agreement [Member] | Quarterly Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage at the end of period					6.25%
2015 Equity Inducement Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserve of common stock for future issuance				100,000
2015 Equity Inducement Plan [Member] | Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage of fair value of common stock on grant date				100.00%
Expiration period				10 years
Increase in reserve share										350,000
2015 Equity Inducement Plan [Member] | Restricted Stock Units for Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted								221,400		101,200

Stockholders' Equity and Empl62

Stockholders' Equity and Employee Stock Plans - Summary of Option Activity under Plans and Related Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Stock Options Outstanding, Beginning balance	997,674
Number of Stock Options Outstanding, Granted	0	0
Number of Stock Options Outstanding, Exercised	(168,408)
Number of Stock Options Outstanding, Cancelled or forfeited	(93,193)
Number of Stock Options Outstanding, Ending balance	736,073		997,674
Number of Shares, Vested and expected to vest	736,073
Number of Shares, Exercisable	640,637
Weighted Average Exercise Price of Stock Options Outstanding	$ 43.45		$ 41.87
Weighted Average Exercise Price, Exercised	31.43
Weighted Average Exercise Price, Cancelled or forfeited	48.28
Weighted Average Exercise Price, Vested and expected to vest	43.45
Weighted Average Exercise Price, Exercisable	$ 42.38
Weighted-Average Remaining Contractual Term (in years)	5 years 3 months 7 days		5 years 8 months 19 days
Weighted-Average Remaining Contractual Term (in years), Vested and expected to vest	5 years 3 months 7 days
Weighted-Average Remaining Contractual Term (in years), Exercisable	5 years
Aggregate Intrinsic Value	$ 4,823		$ 5,689
Aggregate Intrinsic Value, Vested and expected to vest	4,823
Aggregate Intrinsic Value, Exercisable	$ 4,727

Stockholders' Equity and Empl63

Stockholders' Equity and Employee Stock Plans - Summary of Option Activity under Plans and Related Information (Parenthetical) (Detail)	Mar. 31, 2018$ / shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Closing stock price	$ 43.30

Stockholders' Equity and Empl64

Stockholders' Equity and Employee Stock Plans - Summary of RSU Activity Outstanding and Weighted Average Grant Date Fair Value (Detail)	3 Months Ended
	Mar. 31, 2018$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Restricted Stock Units Outstanding, Unvested - Beginning Balance | shares	2,353,315
Number of Restricted Stock Units Outstanding, Granted | shares	785,400
Number of Restricted Stock Units Outstanding, Granted, performance RSUs | shares	438,980
Number of Restricted Stock Units Outstanding, Released | shares	(407,535)
Number of Restricted Stock Units Outstanding, Cancelled or forfeited | shares	(504,423)
Number of Restricted Stock Units Outstanding, Unvested - Ending Balance | shares	2,665,737
Weighted-Average Grant Date Fair Value, Unvested | $ / shares	$ 47.42
Weighted-Average Grant Date Fair Value, Granted | $ / shares	43.31
Weighted-Average Grant Date Fair Value, Granted, performance RSUs | $ / shares	44.48
Weighted-Average Grant Date Fair Value, Released | $ / shares	41.49
Weighted-Average Grant Date Fair Value, Cancelled or forfeited | $ / shares	43.74
Weighted-Average Grant Date Fair Value, Unvested | $ / shares	$ 47.33

Stockholders' Equity and Empl65

Stockholders' Equity and Employee Stock Plans - Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 14,637	$ 13,610
Cost of revenues [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	1,321	1,269
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	2,445	4,768
Sales and Marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	3,314	3,466
General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	7,557	3,432
Restructuring Charges [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 0	$ 675

Accumulated Other Comprehensi66

Accumulated Other Comprehensive Income (Loss) - Changes in Balances of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 315,117	$ 231,963
Other comprehensive income (loss) before reclassifications	(550)	1,958
Amounts reclassified to net income (loss)	(257)	(201)
Total other comprehensive (loss) income, net of tax	(807)	1,757
Ending balance	338,261	272,944
Unrealized Gain (Loss) on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	160	(1,065)
Other comprehensive income (loss) before reclassifications	(154)	1,930
Amounts reclassified to net income (loss)	(257)	(201)
Total other comprehensive (loss) income, net of tax	(411)	1,729
Ending balance	(251)	664
Unrealized Gain (Loss) on Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(615)	(413)
Other comprehensive income (loss) before reclassifications	(396)	28
Amounts reclassified to net income (loss)	0	0
Total other comprehensive (loss) income, net of tax	(396)	28
Ending balance	(1,011)	(385)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(455)	(1,478)
Ending balance	$ (1,262)	$ 279

Accumulated Other Comprehensi67

Accumulated Other Comprehensive Income (Loss) - Summary of Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), Pre-Tax Amount	$ (807)	$ 2,730
Other comprehensive income (loss), Tax (Expense) Benefit	0	(973)
Other comprehensive income (loss) before reclassification adjustments, After-Tax Amount	(550)	1,958
Other comprehensive income (loss), Reclassification adjustments, After-Tax Amount	(257)	(201)
Total other comprehensive (loss) income, net of tax	(807)	1,757
Unrealized Gains (Losses) on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassification adjustments, Pre-Tax Amount	(154)	2,887
Other comprehensive income (loss), Reclassification adjustments, Pre-Tax Amount	(257)	(201)
Other comprehensive income (loss), Pre-Tax Amount	(411)	2,686
Other comprehensive income (loss) before reclassification adjustments, Tax (Expense) Benefit	0	(957)
Other comprehensive income (loss), Reclassification adjustments, Tax (Expense) Benefit	0	0
Other comprehensive income (loss), Tax (Expense) Benefit	0	(957)
Other comprehensive income (loss) before reclassification adjustments, After-Tax Amount	(154)	1,930
Other comprehensive income (loss), Reclassification adjustments, After-Tax Amount	(257)	(201)
Total other comprehensive (loss) income, net of tax	(411)	1,729
Unrealized Gains (Losses) on Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassification adjustments, Pre-Tax Amount	(396)	44
Other comprehensive income (loss), Pre-Tax Amount	(396)	44
Other comprehensive income (loss) before reclassification adjustments, Tax (Expense) Benefit	0	(16)
Other comprehensive income (loss), Tax (Expense) Benefit	0	(16)
Other comprehensive income (loss) before reclassification adjustments, After-Tax Amount	(396)	28
Other comprehensive income (loss), Reclassification adjustments, After-Tax Amount	0	0
Total other comprehensive (loss) income, net of tax	$ (396)	$ 28

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Income tax (benefit) expense	$ (479)	$ 958

Segment Information - Additiona

Segment Information - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2018Segment
Segment Reporting [Abstract]
Number of operating segments	1

Segment Information - Company's

Segment Information - Company's Revenue by Geographic Region, Based on Customer's Location (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 84,244	$ 72,308
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	36,404	37,645
EMEA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	17,124	13,780
APAC [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	21,238	13,706
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	9,478	7,177
Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 45,882	$ 44,822

Segment Information - Long-Live

Segment Information - Long-Lived Assets by Location (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	$ 26,745	$ 28,591
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	21,615	23,697
Israel [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	4,882	4,640
Rest of World [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	$ 248	$ 254

Restructuring Charges - Additio

Restructuring Charges - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Restructuring And Related Activities [Abstract]
Restructuring charges	$ 2,551	$ 667

Restructuring Charges - Summary

Restructuring Charges - Summary of Restructuring Activity (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Restructuring Cost And Reserve [Line Items]
Beginning balance	$ 0	$ 1,132
Additions	2,551	667
Adjustments	0	(797)
Cash payments	(2,461)	(1,002)
Ending balance	90	0
Severance and Termination-Related Costs [Member]
Restructuring Cost And Reserve [Line Items]
Beginning balance	0	1,132
Additions	2,451	667
Adjustments	0	(797)
Cash payments	(2,361)	(1,002)
Ending balance	90	0
Legal and Other Exit Costs [Member]
Restructuring Cost And Reserve [Line Items]
Beginning balance	0	0
Additions	100	0
Adjustments	0	0
Cash payments	(100)	0
Ending balance	$ 0	$ 0

Net Income (Loss) per Share - R

Net Income (Loss) per Share - Reconciliation of Basic and Diluted Shares (Detail) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Weighted average number of shares outstanding:
Basic	34,457	33,207
Dilutive effects of:
Employee stock options, RSU’s and share based payment awards issued to employees	0	564
Diluted	34,457	33,771

Net Income (Loss) per Share - A

Net Income (Loss) per Share - Antidilutive Securities Excluded from Computation of Diluted Net Income (Loss) Per Share of Common Stock (Detail) - shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Stock options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share	736,073	761,710
Restricted Stock Units for Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share	2,665,737	598,503
Employee Share Purchase Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share	111,357	0

Disposition of Business - Addit

Disposition of Business - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Feb. 23, 2017
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Recognized gain on sale of Skyfence	$ 0	$ 35,871
Skyfence Cloud Access Security Broker Business [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Cash consideration on sale of assets			$ 40,000
Escrow to secure indemnification obligations			$ 5,000
Recognized gain on sale of Skyfence		$ 35,900

Disposition of Business - Sched

Disposition of Business - Schedule of Carrying Amounts Immediately Preceding Disposition (Detail) - Skyfence Networks Ltd. [Member] $ in Thousands	Feb. 23, 2017USD ($)
Assets
Prepaid and other current assets	$ 46
Property and equipment, net	219
Goodwill	1,058
Acquired intangible assets, net	4,496
Total assets	5,819
Liabilities
Accounts payable	104
Accrued and other current liabilities	117
Deferred revenue	1,454
Total liabilities	$ 1,675

Disposition of Business - Sch78

Disposition of Business - Schedule of Consolidated Results of Operations Through Disposal (Detail) - Skyfence Cloud Access Security Broker Business [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Operating loss	$ 0	$ (3,567)
Loss before taxes	0	(3,648)
Net loss	$ 0	$ (3,659)

Subsequent Event - Additional I

Subsequent Event - Additional Information (Detail) - Scenario Forecast [Member] - Israeli Tax Authorities [Member] $ in Millions	3 Months Ended
	Jun. 30, 2018USD ($)
Minimum [Member]
Subsequent Event [Line Items]
Adjustment to tax reserves	$ 18
Maximum [Member]
Subsequent Event [Line Items]
Adjustment to tax reserves	$ 21