Varonis Systems (VRNS) 10-K 9 Feb 21 2020 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Feb. 05, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-36324
Entity Registrant Name	VARONIS SYSTEMS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	57-1222280
Entity Address, Address Line One	1250 Broadway, 29th Floor
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10001
City Area Code	877
Local Phone Number	292-8767
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	VRNS
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 2,730
Entity Common Stock, Shares Outstanding		31,832,751
Documents Incorporated by Reference	Portions of the Registrant’s Proxy Statement to be used in connection with the solicitation of proxies for the Registrant’s 2021 Annual Meeting of Stockholders are incorporated by reference in Part III of this Annual Report on Form 10-K.
Entity Central Index Key	0001361113
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 234,092	$ 68,929
Marketable securities	34,117	41,531
Short-term deposits	30,053	10,000
Trade receivables (net of allowance of $1,250 and $637 at December 31, 2020 and December 31, 2019, respectively)	94,229	75,050
Prepaid expenses and other current assets	27,357	19,366
Total current assets	419,848	214,876
Long-term assets:
Operating lease right-of-use asset	47,924	55,057
Property and equipment, net	37,163	36,338
Intangible assets, net	5,846	0
Goodwill	23,135	0
Other assets	21,566	12,041
Total long-term assets	135,634	103,436
Total assets	555,482	318,312
Current liabilities:
Trade payables	850	997
Accrued expenses and other short-term liabilities	83,198	62,607
Deferred revenues	98,588	95,975
Total current liabilities	182,636	159,579
Long-term liabilities:
Convertible senior notes, net	218,460	0
Operating lease liability	54,540	57,040
Deferred revenues	2,778	5,460
Other liabilities	2,997	2,701
Total long-term liabilities	278,775	65,201
Stockholders’ equity:
Common stock of $0.001 par value - Authorized: 200,000,000 shares at December 31, 2020 and December 31, 2019; Issued and outstanding: 31,818,954 shares at December 31, 2020 and 30,583,311 shares at December 31, 2019	32	31
Accumulated other comprehensive income (loss)	9,371	(449)
Additional paid-in capital	395,410	310,682
Accumulated deficit	(310,742)	(216,732)
Total stockholders’ equity	94,071	93,532
Total liabilities and stockholders’ equity	$ 555,482	$ 318,312

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 1,250	$ 637
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares, issued (in shares)	31,818,954	30,583,311
Common stock, shares, outstanding (in shares)	31,818,954	30,583,311

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Revenue	$ 292,689	$ 254,190	$ 270,288
Cost of revenues	44,261	35,144	27,683
Gross profit	248,428	219,046	242,605
Operating costs and expenses:
Research and development	99,363	80,764	69,971
Sales and marketing	179,902	169,898	168,309
General and administrative	47,578	44,371	33,460
Total operating expenses	326,843	295,033	271,740
Operating loss	(78,415)	(75,987)	(29,135)
Financial income (expenses), net	(7,483)	(389)	970
Loss before income taxes	(85,898)	(76,376)	(28,165)
Income taxes	(8,112)	(2,388)	(413)
Net loss	$ (94,010)	$ (78,764)	$ (28,578)
Net loss per share of common stock, basic and diluted (in USD per share)	$ (2.99)	$ (2.60)	$ (0.98)
Weighted average number of shares used in computing net loss per share of common stock, basic and diluted (in shares)	31,445,631	30,257,410	29,020,645
Subscriptions
Revenues:
Revenue	$ 161,188	$ 76,730	$ 8,750
Perpetual licenses
Revenues:
Revenue	1,473	42,093	139,578
Maintenance and services
Revenues:
Revenue	$ 130,028	$ 135,367	$ 121,960

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net loss	$ (94,010)	$ (78,764)	$ (28,578)
Other comprehensive income (loss):
Unrealized income (loss) on marketable securities, net of tax	(94)	21	48
Income (loss) on marketable securities reclassified into earnings, net of tax	76	5	(27)
Total	(18)	26	21
Unrealized income (loss) on derivative instruments, net of tax	4,043	3,510	(7,531)
Realized income on derivative instruments, net of tax	6,052	0	0
Loss (income) on derivative instruments reclassified into earnings, net of tax	(257)	(352)	3,741
Total	9,838	3,158	(3,790)
Total other comprehensive income (loss)	9,820	3,184	(3,769)
Comprehensive loss	$ (84,190)	$ (75,580)	$ (32,347)

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Accumulated other comprehensive income (loss)	Accumulated deficit
Balance (in shares) at Dec. 31, 2017		28,146,162
Balance at Dec. 31, 2017	$ 114,642	$ 28	$ 223,868	$ 136	$ (109,390)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	34,961		34,961
Common stock issued under employee stock plans, net (in shares)		1,430,718
Common stock issued under employee stock plans, net	8,114	$ 2	8,112
Realized and unrealized gains (losses) on derivative	(3,790)			(3,790)
Unrealized gains (losses) in available for sale securities	21			21
Net loss	(28,578)				(28,578)
Balance (in shares) at Dec. 31, 2018		29,576,880
Balance at Dec. 31, 2018	125,370	$ 30	266,941	(3,633)	(137,968)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	46,139		46,139
Common stock issued under employee stock plans, net (in shares)		1,006,431
Common stock issued under employee stock plans, net	(2,397)	$ 1	(2,398)
Realized and unrealized gains (losses) on derivative	3,158			3,158
Unrealized gains (losses) in available for sale securities	26			26
Net loss	(78,764)				(78,764)
Balance (in shares) at Dec. 31, 2019		30,583,311
Balance at Dec. 31, 2019	93,532	$ 31	310,682	(449)	(216,732)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	68,585		68,585
Common stock issued under employee stock plans, net (in shares)		1,200,001
Common stock issued under employee stock plans, net	9,791	$ 1	9,790
Issuance of common stock from acquisitions	4,198	$ 0	4,198
Issuance of common stock from acquisitions (in shares)		35,642
Fair value of replacement equity awards attributable to pre-acquisition service	709		709
Realized and unrealized gains (losses) on derivative	9,838			9,838
Unrealized gains (losses) in available for sale securities	(18)			(18)
Purchase of capped calls related to Convertible senior notes	(29,348)		(29,348)
Equity component of Convertible senior notes, net	30,794		30,794
Net loss	(94,010)				(94,010)
Balance (in shares) at Dec. 31, 2020		31,818,954
Balance at Dec. 31, 2020	$ 94,071	$ 32	$ 395,410	$ 9,371	$ (310,742)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net loss	$ (94,010)	$ (78,764)	$ (28,578)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation	9,903	6,321	4,156
Stock-based compensation	68,585	46,139	34,961
Amortization of deferred commissions	13,106	13,630	13,185
Noncash operating lease costs	8,737	9,023
Amortization of debt discount and issuance costs	4,096	0	0
Capital loss (gain) from sale of fixed assets	0	45	(27)
Changes in assets and liabilities:
Trade receivables	(19,075)	8,173	(7,627)
Prepaid expenses and other current assets	(543)	(1,225)	(1,932)
Deferred commissions	(19,131)	(19,132)	(15,308)
Other long-term assets	1,436	81	(270)
Trade payables	(328)	(1,623)	1,985
Accrued expenses and other short-term liabilities	16,058	(886)	9,910
Deferred revenues	(169)	7,219	14,115
Other long-term liabilities	5,493	316	(1,025)
Net cash provided by (used in) operating activities	(5,842)	(10,683)	23,545
Cash flows from investing activities:
Decrease (increase) in short-term deposits	(20,071)	60,466	(30,280)
Decrease (increase) in marketable securities	7,414	(1,761)	(39)
Increase in long-term deposits	(2,606)	(21)	(313)
Acquisition, net of cash acquired	(29,369)	0	0
Proceeds from sale of property and equipment	0	11	27
Purchases of property and equipment	(10,116)	(25,392)	(9,583)
Net cash provided by (used in) investing activities	(54,748)	33,303	(40,188)
Cash flows from financing activities:
Proceeds from issuance of convertible senior notes, net of issuance costs	245,308	0	0
Purchases of capped calls	(29,348)	0	0
Proceeds (withholdings) from employee stock plans, net	9,793		8,114
Proceeds (withholdings) from employee stock plans, net		(2,398)
Net cash provided by (used in) financing activities	225,753	(2,398)	8,114
Increase (decrease) in cash and cash equivalents	165,163	20,222	(8,529)
Cash and cash equivalents at beginning of period	68,929	48,707	57,236
Cash and cash equivalents at end of period	234,092	68,929	48,707
Supplemental disclosure of cash flow information:
Cash paid for income taxes	1,342	3,955	$ 710
Net lease liabilities arising from obtaining right-of-use assets	$ 6,256	$ 10,252

General

General	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	GENERAL Varonis Systems, Inc. ("VSI" and together with its subsidiaries, collectively, the “Company”) was incorporated under the laws of the State of Delaware on November 3, 2004, commenced operations on January 1, 2005 and has twelve wholly-owned subsidiaries.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Significant Accounting Policies	SIGNIFICANT ACCOUNTING POLICIES The consolidated financial statements are prepared according to United States generally accepted accounting principles (“U.S. GAAP”), applied on a consistent basis, as follows: a. Use of Estimates: The preparation of the consolidated financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates, judgments and assumptions. The Company’s management believes that the estimates, judgments and assumptions used are reasonable based upon information available at the time they are made. These estimates, judgments and assumptions can affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the dates of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. On an ongoing basis, the Company’s management evaluates estimates, including those related to accounts receivable and sales allowances, fair values of stock-based awards, deferred taxes and income tax uncertainties, and contingent liabilities. Such estimates are based on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. b. Financial Statements in U.S. Dollars: Most of the Company's revenues and costs are denominated in United States dollars (“dollars”). Some of the subsidiaries’ revenues and costs are primarily incurred in Euros, the Pound Sterling, Canadian dollars, Australian dollars and New Israeli Shekels ("NIS"); however, the Company’s management believes that the dollar is the primary currency of the economic environment in which it and each of its subsidiaries operate. Thus, the dollar is the Company’s functional and reporting currency. Accordingly, transactions denominated in currencies other than the functional currency are remeasured to the functional currency in accordance with ASC No. 830, “Foreign Currency Matters” at the exchange rate at the date of the transaction or the average exchange rate in the quarter. At the end of each reporting period, financial assets and liabilities are remeasured to the functional currency using exchange rates in effect at the balance sheet date. Non-financial assets and liabilities are remeasured at historical exchange rates. Gains and losses related to remeasurement are recorded as financial income (expense) in the consolidated statements of operations as appropriate. c. Principles of Consolidation: The consolidated financial statements include the accounts of VSI and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated upon consolidation. d. Cash, Cash Equivalents, Marketable Securities and Short-Term Investments: The Company accounts for investments in marketable securities in accordance with ASC No. 320, “Investments—Debt and Equity Securities” and ASC No. 326, “Financial Instruments—Credit Losses”. 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 money market funds and various deposit accounts. The Company considers all high quality investments purchased with original maturities at the date of purchase greater than three but less than twelve months to be short-term deposits. Cash equivalents, marketable securities and short-term deposits are classified as available for sale and are, therefore, recorded at fair value on the consolidated balance sheet, with any unrealized gains and losses reported in accumulated other comprehensive income (loss), which is reflected as a separate component of stockholders’ equity in the Company’s 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 financial income (expenses), net in the consolidated statement of operations. Cash, cash equivalents, marketable securities and short-term deposits consist of the following (in thousands): As of December 31, 2020 Amortized Gross Gross Fair Cash and cash equivalents Money market funds $ 10,712 $ — $ — $ 10,712 Total $ 10,712 $ — $ — $ 10,712 Marketable securities US Treasury securities $ 34,113 $ 4 *) $ 34,117 Total $ 34,113 $ 4 *) $ 34,117 Short-term deposits Term bank deposits $ 30,053 $ — $ — $ 30,053 Total $ 30,053 $ — $ — $ 30,053 *) Represents an amount lower than $1. As of December 31, 2019 Amortized Gross Gross Fair Cash and cash equivalents Money market funds $ 4,789 $ — $ — $ 4,789 Total $ 4,789 $ — $ — $ 4,789 Marketable securities US Treasury securities $ 41,510 $ 23 $ (2) $ 41,531 Total $ 41,510 $ 23 $ (2) $ 41,531 Short-term deposits Term bank deposits $ 10,000 $ — $ — $ 10,000 Total $ 10,000 $ — $ — $ 10,000 All the US Treasury securities in marketable securities have a stated effective maturity of less than 12 months as of December 31, 2020 and 2019. The gross unrealized gains and losses related to these short-term investments was due primarily to changes in interest rates. Available for sale debt securities with an amortized cost basis in excess of estimated fair value are assessed using the Current Expected Credit losses ("CECL") model to determine what portion of that difference, if any, is caused by expected credit losses. Expected credit losses on available for sale debt securities are recognized in financial income (expenses), net on the consolidated statements of operations. During the year ended December 31, 2020 and 2019, the Company did not recognize an allowance for credit losses on available for sale marketable securities as any expected credit losses are not material to the consolidated financial statements. A short-term bank deposit is a deposit with a maturity of more than three months but less than one year. Deposits in U.S. dollars bore interest at rates ranging from 0.10% - 0.16%, per annum, as of December 31, 2020 and a rate of 1.71%, per annum, as of December 31, 2019. Short-term deposits are presented at cost which approximates market value due to their short maturities. e. Property and Equipment: Property and equipment are stated at cost, net of accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets at the following annual rates: % Computer equipment 33% Office furniture and equipment 14% — 15% Leasehold improvements Over the shorter of the expected lease f. Goodwill and Other Long-Lived Assets, including Acquired Intangible Assets and Right-of-Use-Asset: Goodwill represents the excess of the fair value of purchase consideration in a business combination over the fair value of net tangible and intangible assets acquired. Goodwill amounts are not amortized, but rather tested for impairment at least annually or more often if circumstances indicate that the carrying value may not be recoverable. No indications of impairment of goodwill were noted during the periods presented. Acquired intangible assets consist of identifiable intangible assets, including developed technology and trademarks, resulting from business combinations. Acquired finite-lived intangible assets are initially recorded at fair value and are amortized on a straight-line basis over their estimated useful lives. Amortization expense of developed technology and trademarks are recorded within cost of revenues and sales and marketing, respectively, in the consolidated statements of operations. The Company’s long-lived assets are reviewed for impairment in accordance with ASC No. 360 “Property, Plant and Equipment” whenever events or changes in circumstances indicate that the carrying amount of an asset (or asset group) may not be recoverable. Recoverability of assets (or asset group) to be held and used is measured by a comparison of the carrying amount of an asset to the future undiscounted cash flows expected to be generated by the assets. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the fair value of the assets. During the year ended December 31, 2020, the Company updated its accounting estimates and recognized an impairment of $3,149 related to the carrying value of certain right-of-use assets as, due to COVID-19, the Company reduced and expects to reduce the use of certain leases as employees work remotely. During the years ended December 31, 2019 and 2018, no impairment losses have been recorded. g. Long-Term Lease Deposits: Long-term lease deposits include long-term deposits for offices. h. Revenue Recognition: The Company generates revenues in the form of software license fees and related maintenance and services fees. Subscription revenues are comprised of time-based licenses whereby customers use the Company's software with related maintenance (including support and unspecified upgrades and enhancements when and if they are available) for a specified period. Subscriptions are sold on premises and are recognized from sales of subscription licenses to new and existing customers. When products are purchased as a subscription, the associated maintenance is included as part of the subscription revenues. Perpetual licenses have the same functionality as subscriptions and perpetual license revenues consist of the revenues recognized from sales of perpetual licenses to new and existing customers. Maintenance and services primarily consist of fees for maintenance services of perpetual license sales (including support and unspecified upgrades and enhancements when and if they are available) and to a lesser extent professional services which focus on both operationalizing the software and training the Company’s customers to fully leverage the use of its products although the user can benefit from the software without the Company's assistance. The Company sells its products worldwide directly to a network of distributors and VARs, and payment is typically due within 30 to 60 calendar days of the invoice date. The Company recognizes revenues in accordance with ASC No. 606, “Revenue from Contracts with Customers”. As such, the Company identifies a contract with a customer, identifies the performance obligations in the contract, determines the transaction price, allocates the transaction price to each performance obligation in the contract and recognizes revenues when (or as) the Company satisfies a performance obligation. Subscription software and perpetual license revenues are recognized at the point of time when the software license has been delivered and the benefit of the asset has transferred. Maintenance associated with subscription licenses is recognized ratably over the term of the agreement and is included as part of the subscription revenues line item. The Company recognizes revenues from maintenance of perpetual license sales ratably over the term of the underlying maintenance contract. The term of the maintenance contract is usually one year. Renewals of maintenance contracts create new performance obligations that are satisfied over the new term with the revenues recognized ratably over the period. Revenues from professional services consist mostly of time and material services. The performance obligations are satisfied, and revenues are recognized, when the services are provided or once the service term has expired. The Company enters into contracts that can include combinations of products and services, which are generally capable of being distinct and accounted for as separate performance obligations. The license is distinct upon delivery as the customer can derive the economic benefit of the software without any professional services, updates or technical support. The Company allocates the transaction price to each performance obligation based on its relative standalone selling price out of the total consideration of the contract. For maintenance, the Company determines the standalone selling prices based on the price at which the Company separately sells a renewal contract. For professional services, the Company determines the standalone selling prices based on the price at which the Company separately sells those services. For software licenses, the Company uses the residual approach to determine the standalone selling prices due to the lack of history of selling software license on a standalone basis and the highly variable sales price. Trade and other receivables are primarily comprised of trade receivables that are recorded at the invoice amount mostly for a one year period, net of an allowance for doubtful accounts. Deferred revenues represent mostly unrecognized fees billed or collected for maintenance and professional services. Deferred revenues are recognized as (or when) the Company performs under the contract. Pursuant to these contracts, customers are not invoiced for subsequent years until the annual renewal occurs. The amount of revenues recognized in the period that was included in the opening deferred revenues balance was $96,535 for the year ended December 31, 2020. The Company does not grant a right of return to its customers, except for one of its resellers. During the years ended December 31, 2020, 2019 and 2018, there were no returns from this reseller. For information regarding disaggregated revenues, please refer to Note 14. i. Contract Costs: The Company pays sales commissions to sales and marketing and certain management personnel based on their attainment of certain predetermined sales goals. Sales commissions earned by its employees are considered incremental and recoverable costs of obtaining a contract with a customer. Sales commissions paid for initial contracts, which are not commensurate with sales commissions paid for renewal contracts, are capitalized and amortized over an expected period of benefit. Based on its technology, customer contracts and other factors, the Company has determined the expected period of benefit to be approximately four years. Sales commissions for renewal contracts are capitalized and then amortized on a straight-line basis. Amortization expenses related to these costs are mostly included in sales and marketing expenses in the accompanying consolidated statements of operations. j. Cost of Revenues: Cost of revenues consists of the cost of maintenance and services, resulting from costs associated with support, customer success and professional services. k. Accounting for Stock-Based Compensation: The Company accounts for stock-based compensation in accordance with ASC No. 718, “Compensation-Stock Compensation.” ASC No. 718 requires companies to estimate the fair value of equity-based payment awards on the date of grant using an Option-Pricing Model. The Company recognizes compensation expenses for the value of its equity awards granted based on the straight-line method over the requisite service period of each of the awards. Upon adoption of ASU 2016-09, the Company elected to change its accounting policy to account for forfeitures as they occur. The non-cash compensation expenses related to employees and consultants for the years ended December 31, 2020, 2019 and 2018 amounted to $68,585, $46,139 and $34,961, respectively. l. Business Combinations: The Company accounts for its business combinations using the acquisition method of accounting, which requires, among other things, allocation of the fair value of purchase consideration to the tangible and intangible assets acquired and liabilities assumed at their estimated fair values on the acquisition date. The excess of the fair value of purchase consideration over the values of these identifiable assets and liabilities is recorded as goodwill. When determining the fair value of assets acquired and liabilities assumed, the Company makes estimates and assumptions, especially with respect to intangible assets. The Company's estimates of fair value are based upon assumptions believed to be reasonable, but which are inherently uncertain and unpredictable and, as a result, actual results may differ from estimates. During the measurement period, not to exceed one year from the date of acquisition, the Company may record adjustments to the assets acquired and liabilities assumed, with a corresponding offset to goodwill if new information is obtained related to facts and circumstances that existed as of the acquisition date. After the measurement period, any subsequent adjustments are reflected in the consolidated statements of operations. Acquisition costs, such as legal and consulting fees, are expensed as incurred. m. Research and Development Costs: Research and development costs are charged to the statement of operations as incurred. ASC No. 985-20, “Software-Costs of Software to Be Sold, Leased, or Marketed,” requires capitalization of certain software development costs subsequent to the establishment of technological feasibility. Based on the Company’s product development process, technological feasibility is established upon the completion of a working model. The Company does not incur material costs between the completion of the working model and the point at which the product is ready for general release. Therefore, research and development costs are charged to the statement of operations as incurred. n. Income Taxes: The Company accounts for income taxes in accordance with ASC No. 740, using the asset and liability method whereby deferred tax assets and liability account balances are determined based on the differences between financial reporting and the tax basis for assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The Company provides a valuation allowance, if necessary, to reduce deferred tax assets to the amounts that are more likely-than-not to be realized. ASC 740 contains a two-step approach to recognizing and measuring a liability for uncertain tax positions. The first step is to evaluate the tax position taken or expected to be taken in a tax return by determining if the weight of available evidence indicates that it is more likely than not that, on an evaluation of the technical merits, the tax position will be sustained on audit, including resolution of any related appeals or litigation processes. The second step is to measure the tax benefit as the largest amount that is more than 50% likely to be realized upon ultimate settlement. The Company accrues interest and penalties related to unrecognized tax provisions in its taxes on income. o. 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 forecasted to be incurred in currencies other than the U.S. dollar. The majority of the Company’s revenues and operating expenditures are transacted in U.S. dollars. However, certain operating expenditures are incurred in or exposed to other currencies, primarily the NIS. 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. In addition, the Company enters into forward contracts to hedge a portion of its monetary items in the balance sheet, such as trade receivables and payables, denominated in Pound Sterling and Euro for short-term periods (the “Fair Value Hedging Program”). The purpose of the Fair Value Hedging Program is to protect the fair value of the monetary assets from foreign exchange rate fluctuations. Gains and losses from derivatives related to the Fair Value Hedging Program are not designated as hedging instruments. The Company does not enter into derivative financial instruments for trading purposes. Derivative instruments measured at fair value and their classification on the consolidated balance sheets are presented in the following table (in thousands): Assets as of Assets (liabilities) as of December 31, 2020 December 31, 2019 Notional Fair Notional Fair Foreign exchange forward contract derivatives in cash flow hedging relationships included in prepaid expenses and other current assets and accrued expenses and other short-term liabilities $ 90,452 $ 3,315 $ 84,968 $ (470) Foreign exchange forward contract derivatives for monetary items included in prepaid expenses and other current assets $ 33,977 $ 17 $ 26,995 $ 5 For the years ended December 31, 2020 and 2019, the consolidated statements of operations reflect a gain of $257 and $352, respectively, related to the effective portion of foreign currency forward contracts. For the years ended December 31, 2020, the realized gains from these derivatives were $6,052. The cash flows associated with these derivatives are reflected as cash flows from operating activities in the consolidated statements of cash flows. Effective with our January 1, 2019 adoption of ASU No. 2017-12, ineffectiveness of cash flow hedges is no longer recognized in financial income (expenses), net in the consolidated statement of operations. No material ineffective hedges were recognized for the years ended December 31, 2020 and 2019 in operating expenses in the consolidated statement of operations. For the years ended December 31, 2020 and 2019, the consolidated statements of operations reflect a loss of $1,144 and a gain of $683, respectively, in financial income (expenses), net, related to the Fair Value Hedging Program. p. Concentrations of Credit Risks: Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash, cash equivalents, marketable securities, short-term deposits and trade receivables. The Company’s cash, cash equivalents, marketable securities and short-term deposits are invested in major banks mainly in the United States but also in Israel, France, Canada, the United Kingdom, Germany, the Netherlands, Ireland, Luxembourg and Australia. Such deposits in the United States may be in excess of insured limits and are not insured in other jurisdictions. The Company maintains cash and cash equivalents with diverse financial institutions and monitors the amount of credit exposure to each financial institution. The Company’s trade receivables are geographically diversified and derived primarily from sales to a network of distributors and VARs mainly in the United States and Europe. Concentration of credit risk with respect to trade receivables is limited by credit limits, ongoing credit evaluation and account monitoring procedures. The Company performs ongoing credit evaluations of its channel partners and establishes an allowance for doubtful accounts based upon a specific review of all significant outstanding invoices. The Company writes off receivables when they are deemed uncollectible and having exhausted all collection efforts. q. Retirement and Severance Pay: VSI and Varonis U.S. Public Sector LLC ("VPS") make available to its employees a retirement plan (the “U.S. Plan”) that qualifies as a deferred salary arrangement under Section 401(k) of the Internal Revenue Code of 1986, as amended (the "Code"). Participants in the U.S. Plan may elect to defer a portion of their pre-tax earnings, up to the Internal Revenue Service annual contribution limit. VSI and VPS match 100% of each participant’s contributions up to a maximum of 3% of the participant’s total pay and 50% of each participant’s contributions on contributions between 3% and 5% of the participant’s total pay. Each participant may contribute up to 80% of total remuneration up to the Internal Revenue Service’s annual contribution limit. Contributions to the U.S. Plan are recorded during the year contributed as an expense in the consolidated statements of income. Varonis Systems Ltd ("VSL") makes available to its employees, pursuant to Israel’s Severance Pay Law, severance pay equal to one month’s salary for each year of employment, or a portion thereof. The employees of the Israeli subsidiary elected to be included under section 14 of the Severance Pay Law, 1963 (“section 14”). According to this section, these employees are entitled only to monthly deposits, at a rate of 8.33% of their monthly salary, made in their name with insurance companies. Payments in accordance with section 14 release the Company from any future severance payments (under the above Israeli Severance Pay Law) in respect of those employees; therefore, related assets and liabilities are not presented in the balance sheet. The Company’s liability for severance pay for the employees of its French subsidiary is calculated pursuant to French law, according to which French employees are entitled to an indemnity (a statutory redundancy). The law provides for the payment of severance payment to any employee working for the French subsidiary for at least a year. Varonis (UK) Limited ("VSUK") makes available to certain eligible employees a pension plan whereby participants in the plan may elect to defer a portion of their earnings. VSUK matches 100% of each participant’s contributions up to a maximum of 3% of the participant’s eligible wages. Varonis Systems (Ireland) Limited makes available to its employees a pension plan matching 100% of each participant’s elected deferred earnings contributions up to a maximum of 3% and 50% of the participant's contributions on contributions between 3% and 5% of the participant’s eligible wages. Varonis Systems (Netherlands) B.V. makes available to all its employees a pension plan whereby the Company contributes 7.7% of the participant’s eligible wages. Varonis Systems (Australia) Pty Ltd contributes 9.5% of eligible wages to employee retirement plans. Total expenses related to retirement and severance pay amounted to $7,169, $6,390 and $6,765 for the years ended December 31, 2020, 2019 and 2018, respectively. The amount of severance payable included in other liabilities as of December 31, 2020 and 2019 is $2,727 and $2,554, respectively. r. Fair Value of Financial Instruments: Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. A three tier fair value hierarchy is established as a basis for considering such assumptions and for inputs used in the valuation methodologies in measuring fair value: • Level 1: Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets. • Level 2: Observable inputs that reflect quoted prices for identical assets or liabilities in markets that are not active; quoted prices for similar assets or liabilities in active markets; inputs other than quoted prices that are observable for the assets or liabilities; or inputs that are derived principally from or corroborated by observable market data by correlation or other means. • Level 3: Unobservable inputs reflecting the Company's own assumptions incorporated in valuation techniques used to determine fair value. These assumptions are required to be consistent with market participant assumptions that are reasonably available. The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The carrying amounts of cash and cash equivalents, marketable securities, trade receivables, short-term deposits and trade payables approximate their fair value due to the short-term maturity of such instruments. s. Basic and Diluted Net Loss Per Share: Basic net loss per share is computed by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by giving effect to all potentially dilutive securities, including stock options, restricted stock unit and the impact of the conversion spread of the 1.25% Convertible Senior Notes issued by the Company on May 11, 2020 and due August 2025 in an aggregate principal amount of $253,000 (the "2025 Notes"), to the extent dilutive. Basic and diluted net loss per share was the same for each period presented as the inclusion of all potential shares of common stock outstanding would have been anti-dilutive. There were 3,148,442 and 3,033,718 potentially dilutive shares from the conversion of outstanding stock options and restricted stock units that were not included in the calculation of diluted net loss per share as of December 31, 2020 and 2019, respectively. Additionally, 2,746,418 shares underlying the conversion option of the 2025 Notes are not considered in the calculation of diluted net income per share as the effect would be anti-dilutive. The Company intends to settle the principal amount of the 2025 Notes in cash and therefore will use the treasury stock method for calculating any potential dilutive effect on diluted net income per share, if applicable. The conversion will have a dilutive impact on diluted net income per share when the average market price of a common stock for a given period exceeds the conversion price of $92.12 per share. t. Contingent Liabilities: The Company accounts for its contingent liabilities in accordance with ASC No. 450 “Contingencies”. A provision is recorded when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. With respect to legal matters, provisions are reviewed and adjusted to reflect the impact of negotiations, estimated settlements, legal rulings, advice of legal counsel and other information and events pertaining to a particular matter. As of December 31, 2020 and 2019, the Company was not a party to any litigation that could have a material adverse effect on the Company’s business, financial position, results of operations or cash flows. u. Basis of Presentation: Certain amounts in prior years' financial statements have been recast and reclassified to conform to the current year's presentation. v. Revolving Credit Facility: On August 21, 2020, the Company entered into a credit and security agreement with KeyBank National Association and other parties thereto ( the "Credit and Security Agreement"), for a three-year secured revolving credit facility of $70,000, with a letter of credit sublimit of $15,000 and an accordion feature under which the Company can increase the credit facility to up to $90,000 (the "Credit Facility"). Borrowings and repayments under the Credit Facility may occur from time to time in the Company’s ordinary course of business through the maturity date, which is the earlier of August 21, 2023 or 90 days prior to the scheduled maturity of any Convertible Debt Securities (including the 2025 Notes), at which time any amounts outstanding are to be paid in full. The fees incurred in connection with entering into the Credit and Security Agreement were recorded in prepaid expenses and other current assets on the consolidated balance sheet and are amortized on a straight-line basis over the contractual term of the arrangement. Ongoing fees and interest paid on the used and unused portions of the Credit Facility are expensed as incurred and included within financial income (expenses), net on the consolidated statement of operations. The Credit Facility is secured by a first priority perfected security interest in substantially all tangible and intangible assets (excluding real property and other customary exceptions) of the Company and its domestic subsidiaries and a first priority perfected lien on the capital stock of domestic entities within the Company, and 65% of the voting capital stock of the foreign subsidiaries of the Company. The Credit and Security Agreement contains customary covenants, including a requirement of quarterly minimum recurring revenues and a minimum available liquidity of at least $25,000 at all times, and customary events

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2020
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid Expenses and Other Current Assets	PREPAID EXPENSES AND OTHER CURRENT ASSETS December 31, 2020 2019 Deferred commission $ 14,144 $ 10,044 Prepaid expenses 7,938 7,648 Foreign currency forward contracts derivatives 3,332 — Government institutions & other receivables 1,586 1,357 Short-term deposits & other 357 317 Prepaid expenses and other current assets $ 27,357 $ 19,366

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	PROPERTY AND EQUIPMENT, NET December 31, 2020 2019 Cost: Computer equipment $ 18,848 $ 16,546 Office furniture and equipment 5,735 4,910 Leasehold improvements 37,391 31,291 61,974 52,747 Accumulated depreciation 24,811 16,409 Property and equipment, net $ 37,163 $ 36,338 Depreciation expenses for the years ended December 31, 2020, 2019 and 2018 were $9,903, $6,321 and $4,156, respectively.

Accrued Expenses and Other Shor

Accrued Expenses and Other Short Term Liabilities	12 Months Ended
	Dec. 31, 2020
Accrued Liabilities and Other Liabilities [Abstract]
Accrued Expenses And Other Short Term Liabilities	ACCRUED EXPENSES AND OTHER SHORT-TERM LIABILITIES December 31, 2020 2019 Government authorities and other $ 37,268 $ 24,689 Employees 32,593 23,479 Accrued expenses 13,337 13,766 Foreign exchange forward contract derivatives — 470 Other short-term liabilities — 203 Accrued expenses and other short-term liabilities $ 83,198 $ 62,607

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	LEASES In February 2016, the FASB issued ASU 2016-02, “Leases”, on the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e., lessees and lessors). The new standard requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase by the lessee. This classification will determine whether lease expense is recognized based on an effective interest method or on a straight-line basis over the term of the lease, respectively. A lessee is also required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification. The Company has elected the short-term lease exception for leases with a term of 12 months or less. As part of this election it does not recognize right-of-use assets and lease liabilities on the balance sheet for leases with terms less than 12 months. The Company also elected the practical expedient to not separate lease and non-lease components for all its leases. This results in the initial and subsequent measurement of the balances of the right-of-use asset and lease liability being greater than if the policy election was not applied. Some leases include one or more options to renew. The exercise of lease renewal options is typically at the Company's sole discretion; therefore, the majority of renewals to extend the lease terms are not included in our right-of-use assets and lease liabilities as they are not reasonably certain of exercise. The Company regularly evaluates the renewal options, and, when it is reasonably certain of exercise, it will include the renewal period in its lease term. New lease modifications result in remeasurement of the right-of-use asset and lease liability. The right-of-use asset and lease liability are initially measured at the present value of the lease payments, discounted using the interest rate implicit in the lease or, if that rate cannot be readily determined, the Company's incremental borrowing rate based on the information available at the date of adoption in determining the present value of the lease payments. The Company's incremental borrowing rate is estimated to approximate the interest rate on similar terms and payments and in economic environments where the leased asset is located. Some of the real estate leases contain variable lease payments, including payments based on a Consumer Price Index ("CPI"). Variable lease payments based on a CPI are initially measured using the index in effect at lease adoption. Additional payments based on the change in a CPI are recorded as a period expense when incurred. The Company has liens granted to a financial institution mainly to secure various operating lease agreements in connection with its office space. The Company has various operating leases for office space, vehicles and office equipment that expire through 2030. Its lease agreements generally do not contain any material residual value guarantees or material restrictive covenants. Below is a summary of its operating right-of-use assets and operating lease liabilities as of December 31, 2020: December 31, 2020 Operating right-of-use assets $ 47,924 Operating lease liabilities, current $ 8,700 Operating lease liabilities long-term 54,540 Total operating lease liabilities $ 63,240 Operating lease liabilities, current are included within accrued expenses and other short-term liabilities Minimum lease payments for the Company's right-of-use assets over the remaining lease periods as of December 31, 2020, are as follows: December 31, 2020 2021 $ 10,694 2022 14,509 2023 7,596 2024 6,726 2025 6,764 Thereafter 25,751 Total undiscounted lease payments $ 72,040 Less: Imputed interest (8,800) Present value of lease liabilities $ 63,240 In the third quarter of 2020, the Company reassessed the lease term of certain office space and related discount rate which resulted in changes to the right-of-use asset and the lease liability. Furthermore, as of December 31, 2020, the Company had additional operating leases that had not yet commenced of $997 and $6,344. These operating leases are expected to commence in the first quarter of 2021 with lease terms through 2024 and 2030, respectively. The weighted average remaining lease terms and discount rates for all of operating leases were as follows as of December 31, 2020: Remaining lease term and discount rate: Weighted average remaining lease term (years) 7.49 Weighted average discount rate 3.32 % Total rent expenses for the years ended December 31, 2020, 2019 and 2018 were $12,151, $8,912 and $6,570, respectively.

Convertible Senior Notes and Ca

Convertible Senior Notes and Capped Call Transactions	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Convertible Senior Notes and Capped Call Transactions	CONVERTIBLE SENIOR NOTES AND CAPPED CALL TRANSACTIONS On May 11, 2020, the Company issued the 2025 Notes pursuant to an Indenture dated May 11, 2020 (the “Indenture”), between the Company and U.S. Bank National Association, as trustee. The offering consisted of $220,000 aggregate principal amount plus the full exercise of the initial purchasers’ option to purchase up to an additional $33,000 aggregate principal amount. The net proceeds to the Company after the initial purchaser discount and issuance costs were approximately $245,158. The Company used $29,348 of the net proceeds from the offering to pay the cost of the capped call transactions described below. The Company expects to use the remaining net proceeds for working capital and general corporate purposes, which may include research and development, capital expenditures and other general corporate purposes. The 2025 Notes will mature on August 15, 2025, unless earlier converted, redeemed or repurchased. Interest will be payable semi-annually in arrears on February 15 and August 15 of each year, beginning on August 15, 2020, at a rate of 1.25% per year. The initial conversion rate for the 2025 Notes is 10.8556 shares of the Company’s common stock for each $1,000 principal amount of the 2025 Notes which is equivalent to an initial conversion price of approximately $92.12 per share. The conversion rate is subject to adjustment in specified events. The 2025 Notes are convertible into shares of the Company’s common stock, par value $0.001 per share (the “common stock”), at the option of a holder, prior to the close of business on the business day immediately preceding February 15, 2025, only under the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on September 30, 2020 (and only during such calendar quarter), if the last reported sale price of the common stock for at least 20 trading days (whether or not consecutive) during the 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; (2) during the five consecutive business day period immediately after any five consecutive trading day period (the “measurement period”) in which the “trading price” (as defined in the Indenture) per $1,000 principal amount of the 2025 Notes, as determined following a request by a holder of the 2025 Notes in the manner described in the Indenture, for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on each such trading day; (3) if the Company calls any or all of the 2025 Notes for redemption, at any time prior to the close of business on the scheduled trading day immediately preceding the redemption date; or (4) upon the occurrence of certain corporate events specified in the Indenture. In addition, regardless of the foregoing circumstances, on or after February 15, 2025 until the close of business on the second scheduled trading day immediately preceding the maturity date, a holder may convert all or any portion of its 2025 Notes at any time. Upon conversion, the 2025 Notes may be settled, at the Company’s election, in cash, shares of the Company’s common stock, or a combination of cash and shares of the Company’s common stock in the manner and subject to the terms and conditions provided in the Indenture. The 2025 Notes are not redeemable at the Company’s option prior to August 20, 2023. The Company may redeem the 2025 Notes for cash, at its option, on a redemption date occurring on or after August 20, 2023, and on or prior to the 41st scheduled trading day immediately preceding the maturity date, if the last reported sale price of the Company’s common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive), including the trading day immediately preceding the date on which the Company provides notice of redemption, during any 30 consecutive trading day period ending on and including the trading day immediately preceding the date on which the Company provides notice of redemption at a redemption price equal to 100% of the principal amount of the 2025 Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. If the Company undergoes a “fundamental change” (as defined in the Indenture), subject to certain conditions, holders may require the Company to repurchase for cash all or part of their 2025 Notes at a fundamental change repurchase price equal to 100% of the principal amount of the 2025 Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. The Indenture includes customary terms, including certain events of default after which the 2025 Notes may be due and payable immediately. The 2025 Notes are the Company’s unsecured obligations and rank senior in right of payment to all of the Company’s indebtedness that is expressly subordinated in right of payment to the 2025 Notes. The Company accounted for its convertible senior notes in accordance with ASC 470-20 "Debt with Conversion and Other Options" and separated the Notes into liability and equity components. The carrying amounts of the liability components of the Notes were calculated by measuring the fair value of similar debt instruments that do not have an associated convertible feature. The carrying amounts of the equity components, representing the conversion option, were determined by deducting the fair value of the liability components from the par value of the 2025 Notes. This difference represents the debt discount that is amortized to interest expense over the terms of the 2025 Notes using the effective interest rate method. The carrying amount of the equity components representing the conversion option was approximately $31,779 for the 2025 Notes and is recorded in additional paid-in capital and are not remeasured as long as they continue to meet the conditions for equity classification. The Company allocates transaction costs related to the issuance of the 2025 Notes to the liability and equity components using the same proportions as the initial carrying value of the Notes. Transaction costs attributable to the liability component were approximately $6,857 and are being amortized to interest expense at an effective interest method rate of 4.51% over the term of the 2025 Notes. Transaction costs attributable to the equity component were approximately $985 and are netted with the equity component of the 2025 Notes in additional paid-in capital. The net carrying amount of the liability and equity components of the 2025 Notes as of December 31, 2020 was as follows: As of December 31, 2020 (in thousands) Liability component Principal $ 253,000 Unamortized discount (28,410) Unamortized issuance costs (6,130) Net carrying amount $ 218,460 Equity component, net of discount and issuance costs $ 30,794 The interest expense recognized related to the 2025 Notes for the year ended December 31, 2020 was as follows: December 31, 2020 Contractual interest expense $ 2,012 Amortization of debt discount 3,369 Amortization of debt issuance costs 727 Total $ 6,108 As of December 31, 2020, the total estimated fair value of the 2025 Notes was approximately $481,725. The fair value was determined based on the closing trading price per $100 of the 2025 Notes as of the last day of trading for the period. The fair value of the 2025 Notes is primarily affected by the trading price of our common stock and market interest rates. The fair value of the 2025 Notes is considered a Level 2 within the fair value hierarchy and was determined based on inputs that are observable in the market or that could be derived from, or corroborated with, observable market data, quoted price of the 2025 Notes in an over-the-counter market. Capped Call Transactions On May 6, 2020, in connection with the pricing of the 2025 Notes, the Company entered into privately negotiated capped call transactions (the “Initial Capped Call Transactions”). In addition, in connection with initial purchasers’ exercise in full of their option to purchase additional 2025 Notes, on May 8, 2020, the Company entered into additional privately negotiated capped call transactions (the “Additional Capped Call Transactions,” and, together with the Initial Capped Call Transactions, the “Capped Call Transactions”) with the initial purchasers or their respective affiliates and other financial institutions. The capped call transactions are generally expected to reduce the potential dilution to the Company’s common stock upon any conversion of the 2025 Notes and/or offset any cash payments the Company is required to make in excess of the principal amount of converted 2025 Notes, as the case may be, with such reduction and/or offset subject to a cap price initially equal to $141.72 (the "Cap Price") which represents a premium of 100% over the last reported sale price of the Company’s common stock on May 6, 2020, subject to certain adjustments. The Capped Call Transactions are separate transactions, in each case, entered into by the Company with the Option Counterparties, and are not part of the terms of the 2025 Notes and will not change the holders’ rights under the 2025 Notes. As the Capped Call Transactions are considered indexed to the Company's stock and are considered equity classified, they are recorded in stockholders’ equity on the consolidated balance sheet and are not accounted for as derivatives. The cost of the Capped Call Transactions was approximately $29,348 and was recorded as a reduction to additional paid-in capital. Based on our Common Stock price as of December 31, 2020, the Cap Price under the Capped Call Transactions was exceeded, hence as of December 31, 2020, and as long as our Common Stock price shall be higher than $141.72, the incremental amount by which the stock price exceeds the Cap Price is not protected under the Capped Call Transactions.

Business Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Business Combinations	BUSINESS COMBINATIONS On October 29, 2020, the Company completed the acquisition of all the share capital of Polyrize Security Ltd. ("Polyrize"), a provider of software that maps and analyzes relationships between users and data across a number of cloud applications and services. The deal was for $39,380 and comprised of the total fair value of consideration of $29,620 (the "Purchase Price") and an aggregate conditional retention consideration of $9,760 to be paid to its founders over three years subject to their continued employment with the Company. The Purchase Price consisted of $24,713 in cash, $4,198 for the fair value of 35,642 shares of our common stock issued and $709 in fair value of replacement equity awards attributable to pre-acquisition service. The conditional retention consideration expenses related to the founders will be recorded as compensation expenses in the statement of operations over the period. The following table summarizes the allocation of the purchase price to the fair value of the tangible and intangible assets acquired and liabilities assumed as of the acquisition date: Purchase Price Allocation Estimated Useful Life Net tangible assets acquired $ 375 Intangible assets: Developed technology & trademarks 6,110 4 Goodwill 23,135 Total purchase price $ 29,620 The excess of purchase consideration over the fair value of net tangible and identifiable intangible assets acquired was recorded as goodwill. The Company believes the goodwill represents the synergies expected from expanded market opportunities when integrating Polyrize with our offerings. Acquisition-related costs of $325 are included in general and administrative expenses on our consolidated statements of comprehensive loss. As part of the acquisition and consideration described above, the Company assumed a certain portion of the vested and unvested options held by Polyrize’ employees and consultants (“Polyrize Options”). The portion of the fair value of the assumed equity awards associated with pre-acquisition service of these employees and consultants represented a component of the total purchase consideration, as discussed above. The remaining fair value of these issued awards, which are subject to the recipients’ continued service with the Company and thus excluded from the Purchase Price, will be recognized ratably as stock-based compensation expense over the required service period. Pro forma results of operations related to this acquisition have not been prepared as they are immaterial to the Company's consolidated financial statements.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	GOODWILL AND INTANGIBLE ASSETS Goodwill Goodwill represents the excess of the purchase price over the identifiable tangible and intangible assets acquired less liabilities assumed arising from business combinations. The changes in the carrying amounts of goodwill for the year ended December 31, 2020 is due to the acquisition of Polyrize. For additional information regarding the acquisition, see Note 8. The following table reflects goodwill activity for the year ended December 31, 2020: Amount Balance at December 31, 2019 $ — Goodwill acquired 23,135 Balance at December 31, 2020 $ 23,135 All goodwill balances are subject to annual goodwill impairment testing. As of December 31, 2020, the Company performed a qualitative analysis and concluded that no impairment for goodwill, including intangibles, was required. Intangible Assets Total cost and amortization of intangible assets comprised of the following: Intangible assets, net Estimated Useful Life December 31, 2020 Developed technology & trademarks 4 $ 6,110 Total intangible assets 6,110 Less: Accumulated amortization 264 Total intangible assets, net $ 5,846 Intangible assets are expensed on a straight-line basis over the useful life of the asset. The Company recorded amortization expense of $264 for the year ended December 31, 2020. The following table summarizes estimated future amortization expense of our intangible assets as of December 31, 2020 (in thousands): Years ending December 31, Amount 2021 $ 1,533 2022 1,525 2023 1,525 2024 1,263 Total future amortization expense $ 5,846

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The following table sets forth the Company’s assets and liabilities that were measured at fair value as of December 31, 2020 and 2019 by level within the fair value hierarchy (in thousands): As of December 31, 2020 As of December 31, 2019 Level I Level Level Fair Level I Level Level Fair Financial assets: Cash equivalents: Money market funds $ 10,712 $ — $ — $ 10,712 $ 4,789 $ — $ — $ 4,789 Marketable securities: US Treasury securities 34,117 — — 34,117 41,531 — — 41,531 Prepaid expenses and other current assets: Forward foreign exchange contracts — 3,332 — 3,332 — 5 — 5 Financial liabilities: Accrued expenses and other short-term liabilities: Forward foreign exchange contracts — — — — — (470) — (470) Total financial assets (liabilities) $ 44,829 $ 3,332 $ — $ 48,161 $ 46,320 $ (465) $ — $ 45,855 See Note 7 “Convertible Senior Notes and Capped Call Transactions” for the carrying amount and estimated fair value of the Company's convertible senior notes as of December 31, 2020.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Stockholders' Equity	STOCKHOLDERS’ EQUITY a. Composition of common stock capital: Authorized Issued and outstanding Number of shares December 31, December 31, 2020 2019 2020 2019 Stock of $0.001 par value: Common stock 200,000,000 200,000,000 31,818,954 30,583,311 b. Common stock rights: The Company’s Amended and Restated Certificate of Incorporation authorizes the Company to issue 200,000,000 shares of common stock, par value $0.001 per share. The common stock confers upon its holders the right to participate in the general meetings of the Company, to vote at such meetings (each share represents one vote), to elect board members and to participate in any distribution of dividends or any other distribution of the Company’s property, including the distribution of surplus assets upon liquidation. On February 8, 2021, the Company announced a three-for-one split of its common stock to stockholders of record as of the close of business on March 12, 2021. Trading of the Company’s common stock will begin on a split-adjusted basis on March 15, 2021. Common stock and per share data in this Annual Report on Form 10-K have not been adjusted for the impact of the split. c. Stock option plans: On December 30, 2005, the Company’s board of directors adopted the Varonis Systems, Inc. 2005 Stock Plan (the “2005 Stock Plan”). As of December 31, 2013, the Company had reserved 4,713,319 shares of common stock available for issuance to employees, directors, officers and consultants of the Company and its subsidiaries. The options generally vest over four years. No awards were granted under the 2005 Stock Plan subsequent to December 31, 2013, and no further awards will be granted under the 2005 Stock Plan. On November 14, 2013, the Company’s board of directors adopted the Varonis Systems, Inc. 2013 Omnibus Equity Incentive Plan (the “2013 Plan”) which was subsequently approved by the Company’s stockholders. The Company initially reserved 1,904,633 shares of common stock for issuance under the 2013 Plan to employees, directors, officers and consultants of the Company and its subsidiaries. The number of shares of common stock available for issuance under the 2013 Plan was increased on January 1, 2016 and has been, and will be, increased on each January 1 thereafter by four percent (4%) of the number of shares of common stock issued and outstanding on each December 31 immediately prior to the date of increase (rounded down to the nearest whole share), but the amount of each increase will be limited to the number of shares of common stock necessary to bring the total number of shares of Common Stock available for grant and issuance under the 2013 Plan to five percent (5%) of the number of shares of common stock issued and outstanding on each December 31. Since January 1, 2016, the share reserve under the 2013 Plan has been automatically increased by an aggregate of 6,796,150 shares. Awards granted under the 2013 Plan generally vest over four years. Any award that is forfeited or canceled before expiration becomes available for future grants under the 2013 Plan. On October 22, 2020, and as part of the acquisition, the Company’s board of directors approved the assumption of a certain portion of Polyrize Options pursuant to the terms and conditions of Polyrize 2019 Share Incentive (“Polyrize Plan”) as part of the acquisition. The number of shares of Common Stock of the Company issuable pursuant to such assumed options is 13,427. A summary of employees’ stock options activities during the year ended December 31, 2020 is as follows: Year ended December 31, 2020 Number Weighted Aggregate Weighted Options outstanding at the beginning of the year 454,348 $ 20.628 $ 25,935 4.343 Granted 10,933 $ 17.045 Exercised (123,751) $ 20.503 Forfeited (609) $ 11.618 Options outstanding at the end of the period 340,921 $ 20.586 $ 48,760 3.604 Options exercisable at the end of the period 331,759 $ 20.684 $ 47,417 3.452 There were no options granted in 2020 pursuant to our 2005 Stock Plan and 2013 Plan. Under the Polyrize Plan, 10,933 options were granted in 2020. The aggregate intrinsic value in the table above represents the total intrinsic value that would have been received by the option holders had all option holders exercised their options on the last date of the period. Total intrinsic value of options exercised for the years ended December 31, 2020, 2019 and 2018 was $9,922, $12,453 and $40,610, respectively. As of December 31, 2020 and 2019, there was $810 and $9, respectively, of total unrecognized compensation cost related to non-vested share-based compensation arrangements granted under the 2005 Stock Plan, 2013 Plan and Polyrize Plan. This cost is expected to be recognized over a period of approximately 2.721 and 0.132 years, respectively. The options outstanding as of December 31, 2020 have been separated into ranges of exercise price as follows: Range of exercise price Options Weighted Weighted Options Weighted Weighted $ 6.230 — 8.800 10,356 1.104 $ 8.289 10,356 1.104 $ 8.289 $ 12.470 — 17.045 100,758 3.769 $ 14.639 91,596 3.235 $ 14.346 $ 19.510 — 24.230 173,685 3.534 $ 21.440 173,685 3.534 $ 21.440 $ 29.880 46,548 4.142 $ 29.880 46,548 4.142 $ 29.880 $ 39.860 9,574 3.222 $ 39.860 9,574 3.222 $ 39.860 340,921 3.604 $ 20.586 331,759 3.452 $ 20.684 d. Options issued to consultants: The Company’s outstanding options granted to consultants for services as of December 31, 2020 were as follows: Issuance date Options for Exercise price Options Exercisable (number) (number) August 2013 2,500 $ 21.140 2,500 August 2023 March 2014 1,650 $ 39.860 1,650 March 2024 May 2014 2,000 $ 22.010 2,000 May 2024 November 2014 3,445 $ 21.660 3,445 November 2024 February 2016 1,000 $ 16.870 1,000 February 2026 October 2019 393 $ 17.045 393 October 2029 May 2020 212 $ 17.045 212 May 2030 11,200 11,200 There were no options granted in 2020 pursuant to our 2005 Stock Plan and 2013 Plan. In 2020, 2,494 options were assumed under the Polyrize Plan, of which 605 options remained outstanding as of December 31, 2020. e. Restricted stock units: The following provides a summary of the restricted stock unit activity for the Company for the year ended December 31, 2020: Number of Weighted- Outstanding as of January 1, 2020 2,559,083 $ 49.58 Granted 1,395,697 $ 87.03 Vested (950,323) $ 44.63 Forfeited (208,136) $ 62.40 Unvested as of December 31, 2020 2,796,321 $ 69.01 As of December 31, 2020, there was $141,408 of total unrecognized compensation cost related to employees and non-employees unvested restricted stock units which is expected to be recognized over a period of 2.120 years. f. 2015 Employee Stock Purchase Plan On May 5, 2015, the Company’s stockholders approved the Varonis Systems, Inc. 2015 Employee Stock Purchase Plan (the “ESPP”), which the Company’s board of directors had adopted on March 19, 2015. The ESPP became effective as of June 30, 2015. The ESPP allows eligible employees to purchase shares of the Company’s common stock at a discount through payroll deductions of up to 15% of their eligible compensation, at not less than 85% of the fair market value of the Company’s common stock on the first day or last trading day in the offering period, subject to any plan limitations. The Company initially reserved 500,000 shares of common stock for issuance under the ESPP. The number of shares available for issuance under the ESPP was increased on January 1, 2016 and has been, and will be, increased each January 1 thereafter, by an amount equal to the lesser of (i) one percent (1%) of the number of shares of common stock issued and outstanding on each December 31 immediately prior to the date of increase, except that the amount of each such increase will be limited to the number of shares of common stock necessary to bring the total number of shares of common stock available for issuance under the ESPP to two percent (2%) of the number of shares of common stock issued and outstanding on each such December 31, or (ii) 400,000 shares of common stock. Since January 1, 2016, the share reserve under the ESPP has been automatically increased by an aggregate of 846,618 shares. The ESPP will continue in effect until the earlier of (i) the date when no shares of common stock are available for issuance thereunder or (ii) June 30, 2025; unless terminated prior thereto by the Company’s board of directors or compensation committee, each of which has the right to terminate the ESPP at any time. g. Stock-based compensation expense for employees and consultants: The Company recognized non-cash stock-based compensation expense in the consolidated statements of operations as follows (in thousands): Year ended December 31, 2020 2019 2018 Cost of revenues $ 5,013 $ 2,561 $ 1,757 Research and development 21,979 13,188 9,645 Sales and marketing 25,578 14,782 16,081 General and administrative 16,015 15,608 7,478 Total $ 68,585 $ 46,139 $ 34,961

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES a. Tax Reform: On December 22, 2017, the Tax Cuts and Jobs Act (the "TCJA") was signed into law. The TCJA makes broad and complex changes to the Code that impact the Company's provision for income taxes. The changes include, but are not limited to: • Decreasing the corporate income tax rate from 35% to 21% effective for tax years beginning after December 31, 2017 (“Rate Reduction”); • The Deemed Repatriation Transition Tax; and • Taxation of GILTI earned by foreign subsidiaries beginning after December 31, 2017. The GILTI tax imposes a tax on foreign income in excess of a deemed return on tangible assets of foreign corporations. Deemed Repatriation Transition Tax The Deemed Repatriation Transition Tax is a tax on previously untaxed accumulated and current earnings and profits (“E&P”) of certain of our foreign subsidiaries in November 2, 2017 or December 31, 2017. Because the Company has a net cumulative deficit on the E&P of its foreign subsidiaries in both applicable dates in 2017, it should not be subject to the Deemed Repatriation Transition Tax. GILTI Tax Certain income (i.e., GILTI) earned by controlled foreign corporations (“CFCs”) must be included currently in the gross income of the CFCs’ U.S. shareholder. GILTI is the excess of the shareholder’s “net CFC tested income” over the net deemed tangible income return, which is the excess of (1) 10 percent of the aggregate of the U.S. shareholder’s pro rata share of the qualified business asset investment of each CFC with respect to which it is a U.S. shareholder, over (2) the amount of certain interest expense taken into account in the determination of net CFC-tested income. For 2020, the Company is not subject to tax on account of GILTI as it has net CFC tested loss on an aggregated basis. Accounting for the TCJA In January 2018, the FASB issued Staff Q&A Topic 740, No. 5, “Accounting for Global Intangible Low Taxed Income.” Pursuant to that guidance the Company is permitted to make an accounting policy election to either treat taxes due on future inclusions in U.S. taxable income related to GILTI as a component of current income tax expense when incurred or to factor such amounts into the Company’s measurement of its deferred tax expense. The Company has made an accounting policy election to treat GILTI as a component of current income tax expense. As of December 31, 2018, the Company's analysis for the Transition Tax has been filed with its December 31, 2017 tax return, and the Company considered its accounting for this area of the TCJA to be complete as of such date and did not make any measurement-period adjustments related to it. In addition, the Company recognizes its accounting for changes in the US federal rate and deferred tax impact for the rate change to be complete. The Company also accounted for the tax impact related to other areas of the TCJA and believe its analysis to be completed. The Company recognizes that the IRS is continuing to publish and finalize ongoing guidance which may modify accounting interpretation for the TCJA, the Company would look to account for these impacts in the period of such change is enacted. b. The Company: The Company is taxed in accordance with U.S. tax laws. As of December 31, 2020, the Company had federal net operating loss ("NOL") carry-forwards of approximately $207,768, of which approximately $22,907 expire starting in 2032 and the remainder do not expire and can only be used to offset 80% of taxable income. As of December 31, 2020, the Company had NOL carry-forwards for state and foreign income tax purposes of approximately $146,121 and $1,321, respectively. State NOL carry-forwards of $129,143 expire starting 2027 and the remainder do not expire. Foreign NOL carry-forwards do not expire. In addition, as of December 31, 2020, the Company had federal research credit, retention credit, foreign tax credit and Ireland Employment credit carryforwards of approximately $1,412, $24, $190 and $16, respectively. If not utilized, the federal tax carryforwards will begin to expire in 2033, 2032 and 2026, respectively. Ireland has no expiration on the employment credit. A U.S. corporation's ability to utilize its federal and state NOL and tax credit carryforwards to offset its taxable income is limited under Section 382 of the Code if the corporation undergoes an ownership change (within the meaning of Code Section 382). In general, an “ownership change” occurs whenever the percentage of the stock of a corporation owned by “5-percent shareholders” (within the meaning of Code Section 382) increases by more than 50 percentage points over the lowest percentage of the stock of such corporation owned by such “5-percent shareholders” at any time over the testing period. An ownership change under Code Section 382 would establish an annual limitation to the amount of NOL and tax credit carryforwards the Company could utilize to offset its taxable income or income tax in any single year. The annual limitation may result in the expiration of net operating losses and credits before utilization and in the event we have a change of ownership, utilization of the carryforwards could be restricted. c. Loss before taxes on income is comprised as follows: Year ended December 31, 2020 2019 2018 Domestic $ (80,086) $ (82,007) $ (25,557) Foreign (5,812) 5,631 (2,608) $ (85,898) $ (76,376) $ (28,165) d. Taxes on income (loss) are comprised as follows: Year ended December 31, 2020 2019 2018 Current: Domestic: Federal $ 90 $ 665 $ — State 128 13 169 Foreign 8,854 1,619 1,498 Total current income tax $ 9,072 $ 2,297 $ 1,667 Deferred: Federal $ 8 $ — $ — State 1 — — Foreign (969) 91 (1,254) Total deferred income tax $ (960) $ 91 $ (1,254) Income tax expense $ 8,112 $ 2,388 $ 413 e. Deferred income taxes: Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The Company’s deferred tax assets are derived from its U.S. NOL carry-forwards and other temporary differences. ASC 740 requires an assessment of both positive and negative evidence concerning the realizability of our deferred tax assets in each jurisdiction. After considering evidence such as current and cumulative financial reporting incomes, the expected sources of future taxable income and tax planning strategies, the Company’s management concluded that a valuation allowance is required for US, state and Israel deferred tax assets; however, for foreign jurisdictions, a net deferred tax asset of $1,131 is recorded as of December 31, 2020. Future changes in these factors, including the Company’s anticipated results, could have a significant impact on the realization of the deferred tax assets which would result in an increase or decrease to the valuation allowance and a corresponding charge to income tax expense. The Company reevaluates the judgements surrounding its estimates and makes adjustments as appropriate each reporting period. Significant components of our deferred tax assets and liabilities as of December 31, 2020 and 2019 are as follows: December 31, 2020 2019 Deferred tax assets: Carry forward losses and credits $ 53,221 $ 36,092 Deferred revenues 13,054 13,953 Accrued payroll, commissions, vacation 3,808 2,666 Equity compensation 10,348 6,220 Allowance for doubtful accounts 1,287 978 Accrued severance pay 312 340 Operating lease liability 11,302 12,244 Other 963 532 Deferred tax assets before valuation allowance 94,295 73,025 Valuation allowance (77,542) (62,379) Deferred tax assets $ 16,753 $ 10,646 Deferred tax liability: Accrued compensation and other accrued expense $ (48) $ (187) Operating lease right-of-use asset (8,780) (10,291) Convertible senior notes, net (6,797) — Deferred tax liability $ (15,625) $ (10,478) Net deferred tax asset $ 1,128 $ 168 The change in the valuation allowance was approximately an increase of $14,943 and $22,818 during 2020 and 2019, respectively. f. Reconciliation of the theoretical tax expenses: A reconciliation between the theoretical tax expense, assuming all income is taxed at the statutory tax rate applicable to income of the Company, and the actual tax expense as reported in the consolidated statements of operations is as follows: Year ended December 31, 2020 2019 2018 Loss before taxes, as reported in the consolidated statements of operations $ (85,898) $ (76,376) $ (28,165) Statutory tax rate 21 % 21 % 21 % Theoretical tax benefits on the above amount at the US statutory tax rate $ (18,039) $ (16,039) $ (5,915) Income tax at rate other than the U.S. statutory tax rate 4,845 (2,508) 692 Tax advances and non-deductible expenses including equity based compensation expenses 934 (115) (7,623) Operating losses and other temporary differences for which valuation allowance was provided 22,189 22,818 15,826 State tax (2,872) (3,436) (1,221) Impact of rate change — 401 — Change in tax reserve for uncertain tax positions 1,489 1,247 (1,728) Other individually immaterial income tax items (434) 20 382 Actual tax expense $ 8,112 $ 2,388 $ 413 g. A reconciliation of the beginning and ending amounts of unrecognized tax benefits in the years ended December 31, 2020 and 2019 are as follows: Gross unrecognized tax benefits as of January 1, 2019 $ 1,954 Increase in tax position for current year 1,545 Increase in tax position for prior years 387 Decrease for lapse of statute of limitations/settlements (685) Gross unrecognized tax benefits as of December 31, 2019 $ 3,201 Increase in tax position for current year 1,787 Increase in tax position for prior years 979 Decrease in tax position for prior years (171) Decrease for lapse of statute of limitations/settlements (1,106) Gross unrecognized tax benefits as of December 31, 2020 $ 4,690 There was $4,690 of unrecognized income tax benefits that, if recognized, approximately $4,407 would impact the effective tax rate in the period in which each of the benefits is recognized. The Company includes interest and penalties related to unrecognized tax benefits within the provision for income taxes on the consolidated statements of operations. The total amount of penalties and interest is approximately $538 as of December 31, 2020. h. Foreign taxation: 1. Israeli tax benefits under the Law for the Encouragement of Capital Investments, 1959 (the “Investment Law”): VSL has benefited from a status of a "Beneficiary Enterprise" under the Investment Law. The benefits available to a Beneficiary Enterprise relate only to taxable income attributable to the specific investment program and are conditioned upon meeting the terms stipulated in the Investment Law, the related regulations and the applicable certificate of approval (for a Beneficiary Enterprise). If VSL does not fulfill these conditions, in whole or in part, the benefits will most likely be cancelled, and VSL may be required to refund the benefits, in an amount linked to the Israeli consumer price index plus interest. If cash dividends are distributed out of tax exempt profits in a manner other than upon complete liquidation, VSL will then become liable for tax at the rate of 10%-25% (depending on the level of foreign investments in VSL) in respect of the amount distributed. 2. Undistributed earnings of foreign subsidiaries: In general, it is the Company’s practice and intention to reinvest the earnings of its non-U.S. subsidiaries in those operations. Undistributed earnings, if any, of foreign subsidiaries are immaterial for all periods presented. Because the Company’s non-U.S. subsidiary earnings have previously been included in the computation of the one-time Transition Tax on foreign earnings required by the TCJA and throughout the years have been included in the GILTI computations, any additional taxes due with respect to such earnings or the excess of the amount for financial reporting over the tax basis of its foreign investments would generally be limited to foreign withholding taxes and/or U.S. state income taxes. i. Tax assessments: The Company was audited by the Internal Revenue Service for tax year 2016. As of December 31, 2020, the Company's federal returns for the years ended 2010 through the current period and most state returns for the years ended 2009 through the current period are still open to examination due to the Company's net carry-over unused operating losses and tax credit attributable to those years. During 2019, the Israeli Tax Authority initiated a withholding tax audit on VSL for the years 2015-2017. During 2020, the Israeli Tax Authority initiated an income tax audit on VSL for the tax years 2016-2018. The Company believes it has valid arguments to support its positions and intends to defend against any tax assessment. The Company has recorded a provision with respect to its uncertain tax positions in accordance with ASC 740. The Company has final income tax assessments for VSL in Israel through 2015, VSUK in UK through 2016 and Varonis France SAS in France through 2018. All other foreign subsidiaries do not have final tax assessments since their respective inceptions.

Financial Income (Expenses), Ne

Financial Income (Expenses), Net	12 Months Ended
	Dec. 31, 2020
Financial Income (Expenses), Net [Abstract]
Financial Income (Expenses), Net	FINANCIAL INCOME (EXPENSES), NET Year ended December 31, 2020 2019 2018 Financial income: Interest on bank deposits & other $ 674 $ 2,041 $ 1,741 674 2,041 1,741 Financial expenses: Amortization of issuance costs 4,096 — — Interest expenses, principally from convertible note 2,017 — — Foreign currency transaction losses, net 1,726 2,225 574 Bank and other charges 318 205 197 (8,157) (2,430) (771) Financial income (expense), net $ (7,483) $ (389) $ 970

Geographic Information and Majo

Geographic Information and Major Customer and Product Data	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Geographic Information and Major Customer and Product Data	GEOGRAPHIC INFORMATION AND MAJOR CUSTOMER AND PRODUCT DATA Summary information about geographic areas: ASC 280, “Segment Reporting,” establishes standards for reporting information about operating segments. Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company manages its business on the basis of one reportable segment and derives revenues from licensing of software and sales of professional services, maintenance and technical support (see Note 1 above for a brief description of the Company’s business). The following is a summary of revenues within geographic areas: Year ended December 31, 2020 2019 2018 Revenues based on customer’s location: North America $ 207,488 $ 174,607 $ 167,361 EMEA (*) 77,093 70,208 93,816 Rest of the World 8,108 9,375 9,111 Total revenues $ 292,689 $ 254,190 $ 270,288 (*) Sales to customers in France accounted for $30,937 and $31,532 of the Company’s revenues for the years ended December 31, 2020 and 2018, respectively. Sales to customers in France did not exceed 10% of total revenues for the year ended December 31, 2019. During the years ended December 31, 2020, 2019 and 2018, there were no sales to a single customer exceeding 10% of the Company’s revenues. The following is a summary of long-lived assets, including property and equipment, net and operating lease right-of-use assets, within geographic areas: December 31, 2020 2019 Long-lived assets by geographic region: Israel $ 42,471 $ 45,382 United States 30,938 42,590 Ireland 9,684 597 Other 1,994 2,826 $ 85,087 $ 91,395

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Use of Estimates	a. Use of Estimates: The preparation of the consolidated financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates, judgments and assumptions. The Company’s management believes that the estimates, judgments and assumptions used are reasonable based upon information available at the time they are made. These estimates, judgments and assumptions can affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the dates of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. On an ongoing basis, the Company’s management evaluates estimates, including those related to accounts receivable and sales allowances, fair values of stock-based awards, deferred taxes and income tax uncertainties, and contingent liabilities. Such estimates are based on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities.
Financial Statements U.S. Dollars	b. Financial Statements in U.S. Dollars: Most of the Company's revenues and costs are denominated in United States dollars (“dollars”). Some of the subsidiaries’ revenues and costs are primarily incurred in Euros, the Pound Sterling, Canadian dollars, Australian dollars and New Israeli Shekels ("NIS"); however, the Company’s management believes that the dollar is the primary currency of the economic environment in which it and each of its subsidiaries operate. Thus, the dollar is the Company’s functional and reporting currency. Accordingly, transactions denominated in currencies other than the functional currency are remeasured to the functional currency in accordance with ASC No. 830, “Foreign Currency Matters” at the exchange rate at the date of the transaction or the average exchange rate in the quarter. At the end of each reporting period, financial assets and liabilities are remeasured to the functional currency using exchange rates in effect at the balance sheet date. Non-financial assets and liabilities are remeasured at historical exchange rates. Gains and losses related to remeasurement are recorded as financial income (expense) in the consolidated statements of operations as appropriate.
Principles of Consolidation	c. Principles of Consolidation:
Cash, Cash Equivalents, Marketable Securities and Short-Term Deposits	d. Cash, Cash Equivalents, Marketable Securities and Short-Term Investments: The Company accounts for investments in marketable securities in accordance with ASC No. 320, “Investments—Debt and Equity Securities” and ASC No. 326, “Financial Instruments—Credit Losses”. 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 money market funds and various deposit accounts. All the US Treasury securities in marketable securities have a stated effective maturity of less than 12 months as of December 31, 2020 and 2019. The gross unrealized gains and losses related to these short-term investments was due primarily to changes in interest rates. Available for sale debt securities with an amortized cost basis in excess of estimated fair value are assessed using the Current Expected Credit losses ("CECL") model to determine what portion of that difference, if any, is caused by expected credit losses. Expected credit losses on available for sale debt securities are recognized in financial income (expenses), net on the consolidated statements of operations. During the year ended December 31, 2020 and 2019, the Company did not recognize an allowance for credit losses on available for sale marketable securities as any expected credit losses are not material to the consolidated financial statements. A short-term bank deposit is a deposit with a maturity of more than three months but less than one year. Deposits in U.S. dollars bore interest at rates ranging from 0.10% - 0.16%, per annum, as of December 31, 2020 and a rate of 1.71%, per annum, as of December 31, 2019. Short-term deposits are presented at cost which approximates market value due to their short maturities.
Property and Equipment	e. Property and Equipment: Property and equipment are stated at cost, net of accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets at the following annual rates: % Computer equipment 33% Office furniture and equipment 14% — 15% Leasehold improvements Over the shorter of the expected lease
Goodwill and Other Long-Lived Assets, including Acquired Intangible Assets and Right-of-Use-Asset	f. Goodwill and Other Long-Lived Assets, including Acquired Intangible Assets and Right-of-Use-Asset: Goodwill represents the excess of the fair value of purchase consideration in a business combination over the fair value of net tangible and intangible assets acquired. Goodwill amounts are not amortized, but rather tested for impairment at least annually or more often if circumstances indicate that the carrying value may not be recoverable. No indications of impairment of goodwill were noted during the periods presented. Acquired intangible assets consist of identifiable intangible assets, including developed technology and trademarks, resulting from business combinations. Acquired finite-lived intangible assets are initially recorded at fair value and are amortized on a straight-line basis over their estimated useful lives. Amortization expense of developed technology and trademarks are recorded within cost of revenues and sales and marketing, respectively, in the consolidated statements of operations. The Company’s long-lived assets are reviewed for impairment in accordance with ASC No. 360 “Property, Plant and Equipment” whenever events or changes in circumstances indicate that the carrying amount of an asset (or asset group) may not be recoverable. Recoverability of assets (or asset group) to be held and used is measured by a comparison of the carrying amount of an asset to the future undiscounted cash flows expected to be generated by the assets. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the fair value of the assets. During the year ended December 31, 2020, the Company updated its accounting estimates and recognized an impairment of $3,149 related to the carrying value of certain right-of-use assets as, due to COVID-19, the Company reduced and expects to reduce the use of certain leases as employees work remotely. During the years ended December 31, 2019 and 2018, no impairment losses have been recorded.
Long-Term Lease Deposits	g. Long-Term Lease Deposits: Long-term lease deposits include long-term deposits for offices.
Revenue Recognition	h. Revenue Recognition: The Company generates revenues in the form of software license fees and related maintenance and services fees. Subscription revenues are comprised of time-based licenses whereby customers use the Company's software with related maintenance (including support and unspecified upgrades and enhancements when and if they are available) for a specified period. Subscriptions are sold on premises and are recognized from sales of subscription licenses to new and existing customers. When products are purchased as a subscription, the associated maintenance is included as part of the subscription revenues. Perpetual licenses have the same functionality as subscriptions and perpetual license revenues consist of the revenues recognized from sales of perpetual licenses to new and existing customers. Maintenance and services primarily consist of fees for maintenance services of perpetual license sales (including support and unspecified upgrades and enhancements when and if they are available) and to a lesser extent professional services which focus on both operationalizing the software and training the Company’s customers to fully leverage the use of its products although the user can benefit from the software without the Company's assistance. The Company sells its products worldwide directly to a network of distributors and VARs, and payment is typically due within 30 to 60 calendar days of the invoice date. The Company recognizes revenues in accordance with ASC No. 606, “Revenue from Contracts with Customers”. As such, the Company identifies a contract with a customer, identifies the performance obligations in the contract, determines the transaction price, allocates the transaction price to each performance obligation in the contract and recognizes revenues when (or as) the Company satisfies a performance obligation. Subscription software and perpetual license revenues are recognized at the point of time when the software license has been delivered and the benefit of the asset has transferred. Maintenance associated with subscription licenses is recognized ratably over the term of the agreement and is included as part of the subscription revenues line item. The Company recognizes revenues from maintenance of perpetual license sales ratably over the term of the underlying maintenance contract. The term of the maintenance contract is usually one year. Renewals of maintenance contracts create new performance obligations that are satisfied over the new term with the revenues recognized ratably over the period. Revenues from professional services consist mostly of time and material services. The performance obligations are satisfied, and revenues are recognized, when the services are provided or once the service term has expired. The Company enters into contracts that can include combinations of products and services, which are generally capable of being distinct and accounted for as separate performance obligations. The license is distinct upon delivery as the customer can derive the economic benefit of the software without any professional services, updates or technical support. The Company allocates the transaction price to each performance obligation based on its relative standalone selling price out of the total consideration of the contract. For maintenance, the Company determines the standalone selling prices based on the price at which the Company separately sells a renewal contract. For professional services, the Company determines the standalone selling prices based on the price at which the Company separately sells those services. For software licenses, the Company uses the residual approach to determine the standalone selling prices due to the lack of history of selling software license on a standalone basis and the highly variable sales price. Trade and other receivables are primarily comprised of trade receivables that are recorded at the invoice amount mostly for a one year period, net of an allowance for doubtful accounts. Deferred revenues represent mostly unrecognized fees billed or collected for maintenance and professional services. Deferred revenues are recognized as (or when) the Company performs under the contract. Pursuant to these contracts, customers are not invoiced for subsequent years until the annual renewal occurs. The amount of revenues recognized in the period that was included in the opening deferred revenues balance was $96,535 for the year ended December 31, 2020. The Company does not grant a right of return to its customers, except for one of its resellers. During the years ended December 31, 2020, 2019 and 2018, there were no returns from this reseller. For information regarding disaggregated revenues, please refer to Note 14. i. Contract Costs:
Cost of Revenues	j. Cost of Revenues: Cost of revenues consists of the cost of maintenance and services, resulting from costs associated with support, customer success and professional services.
Accounting for Stock-Based Compensation	k. Accounting for Stock-Based Compensation: The Company accounts for stock-based compensation in accordance with ASC No. 718, “Compensation-Stock Compensation.” ASC No. 718 requires companies to estimate the fair value of equity-based payment awards on the date of grant using an Option-Pricing Model. The Company recognizes compensation expenses for the value of its equity awards granted based on the straight-line method over the requisite service period of each of the awards. Upon adoption of ASU 2016-09, the Company elected to change its accounting policy to account for forfeitures as they occur. The non-cash compensation expenses related to employees and consultants for the years ended December 31, 2020, 2019 and 2018 amounted to $68,585, $46,139 and $34,961, respectively.
Business Combinations	l. Business Combinations: The Company accounts for its business combinations using the acquisition method of accounting, which requires, among other things, allocation of the fair value of purchase consideration to the tangible and intangible assets acquired and liabilities assumed at their estimated fair values on the acquisition date. The excess of the fair value of purchase consideration over the values of these identifiable assets and liabilities is recorded as goodwill. When determining the fair value of assets acquired and liabilities assumed, the Company makes estimates and assumptions, especially with respect to intangible assets. The Company's estimates of fair value are based upon assumptions believed to be reasonable, but which are inherently uncertain and unpredictable and, as a result, actual results may differ from estimates. During the measurement period, not to exceed one year from the date of acquisition, the Company may record adjustments to the assets acquired and liabilities assumed, with a corresponding offset to goodwill if new information is obtained related to facts and circumstances that existed as of the acquisition date. After the measurement period, any subsequent adjustments are reflected in the consolidated statements of operations. Acquisition costs, such as legal and consulting fees, are expensed as incurred.
Research and Development Costs	m. Research and Development Costs: Research and development costs are charged to the statement of operations as incurred. ASC No. 985-20, “Software-Costs of Software to Be Sold, Leased, or Marketed,” requires capitalization of certain software development costs subsequent to the establishment of technological feasibility. Based on the Company’s product development process, technological feasibility is established upon the completion of a working model. The Company does not incur material costs between the completion of the working model and the point at which the product is ready for general release. Therefore, research and development costs are charged to the statement of operations as incurred.
Income Taxes	n. Income Taxes: The Company accounts for income taxes in accordance with ASC No. 740, using the asset and liability method whereby deferred tax assets and liability account balances are determined based on the differences between financial reporting and the tax basis for assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The Company provides a valuation allowance, if necessary, to reduce deferred tax assets to the amounts that are more likely-than-not to be realized. ASC 740 contains a two-step approach to recognizing and measuring a liability for uncertain tax positions. The first step is to evaluate the tax position taken or expected to be taken in a tax return by determining if the weight of available evidence indicates that it is more likely than not that, on an evaluation of the technical merits, the tax position will be sustained on audit, including resolution of any related appeals or litigation processes. The second step is to measure the tax benefit as the largest amount that is more than 50% likely to be realized upon ultimate settlement. The Company accrues interest and penalties related to unrecognized tax provisions in its taxes on income.
Derivative Instruments	o. 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 forecasted to be incurred in currencies other than the U.S. dollar. The majority of the Company’s revenues and operating expenditures are transacted in U.S. dollars. However, certain operating expenditures are incurred in or exposed to other currencies, primarily the NIS. 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. In addition, the Company enters into forward contracts to hedge a portion of its monetary items in the balance sheet, such as trade receivables and payables, denominated in Pound Sterling and Euro for short-term periods (the “Fair Value Hedging Program”). The purpose of the Fair Value Hedging Program is to protect the fair value of the monetary assets from foreign exchange rate fluctuations. Gains and losses from derivatives related to the Fair Value Hedging Program are not designated as hedging instruments. The Company does not enter into derivative financial instruments for trading purposes.
Concentrations of Credit Risks	p. Concentrations of Credit Risks: Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash, cash equivalents, marketable securities, short-term deposits and trade receivables. The Company’s cash, cash equivalents, marketable securities and short-term deposits are invested in major banks mainly in the United States but also in Israel, France, Canada, the United Kingdom, Germany, the Netherlands, Ireland, Luxembourg and Australia. Such deposits in the United States may be in excess of insured limits and are not insured in other jurisdictions. The Company maintains cash and cash equivalents with diverse financial institutions and monitors the amount of credit exposure to each financial institution. The Company’s trade receivables are geographically diversified and derived primarily from sales to a network of distributors and VARs mainly in the United States and Europe. Concentration of credit risk with respect to trade receivables is limited by credit limits, ongoing credit evaluation and account monitoring procedures. The Company performs ongoing credit evaluations of its channel partners and establishes an allowance for doubtful accounts based upon a specific review of all significant outstanding invoices. The Company writes off receivables when they are deemed uncollectible and having exhausted all collection efforts.
Retirement and Severance Pay	q. Retirement and Severance Pay: VSI and Varonis U.S. Public Sector LLC ("VPS") make available to its employees a retirement plan (the “U.S. Plan”) that qualifies as a deferred salary arrangement under Section 401(k) of the Internal Revenue Code of 1986, as amended (the "Code"). Participants in the U.S. Plan may elect to defer a portion of their pre-tax earnings, up to the Internal Revenue Service annual contribution limit. VSI and VPS match 100% of each participant’s contributions up to a maximum of 3% of the participant’s total pay and 50% of each participant’s contributions on contributions between 3% and 5% of the participant’s total pay. Each participant may contribute up to 80% of total remuneration up to the Internal Revenue Service’s annual contribution limit. Contributions to the U.S. Plan are recorded during the year contributed as an expense in the consolidated statements of income. Varonis Systems Ltd ("VSL") makes available to its employees, pursuant to Israel’s Severance Pay Law, severance pay equal to one month’s salary for each year of employment, or a portion thereof. The employees of the Israeli subsidiary elected to be included under section 14 of the Severance Pay Law, 1963 (“section 14”). According to this section, these employees are entitled only to monthly deposits, at a rate of 8.33% of their monthly salary, made in their name with insurance companies. Payments in accordance with section 14 release the Company from any future severance payments (under the above Israeli Severance Pay Law) in respect of those employees; therefore, related assets and liabilities are not presented in the balance sheet. The Company’s liability for severance pay for the employees of its French subsidiary is calculated pursuant to French law, according to which French employees are entitled to an indemnity (a statutory redundancy). The law provides for the payment of severance payment to any employee working for the French subsidiary for at least a year. Varonis (UK) Limited ("VSUK") makes available to certain eligible employees a pension plan whereby participants in the plan may elect to defer a portion of their earnings. VSUK matches 100% of each participant’s contributions up to a maximum of 3% of the participant’s eligible wages. Varonis Systems (Ireland) Limited makes available to its employees a pension plan matching 100% of each participant’s elected deferred earnings contributions up to a maximum of 3% and 50% of the participant's contributions on contributions between 3% and 5% of the participant’s eligible wages. Varonis Systems (Netherlands) B.V. makes available to all its employees a pension plan whereby the Company contributes 7.7% of the participant’s eligible wages. Varonis Systems (Australia) Pty Ltd contributes 9.5% of eligible wages to employee retirement plans.
Fair Value of Financial Instruments	r. Fair Value of Financial Instruments: Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. A three tier fair value hierarchy is established as a basis for considering such assumptions and for inputs used in the valuation methodologies in measuring fair value: • Level 1: Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets. • Level 2: Observable inputs that reflect quoted prices for identical assets or liabilities in markets that are not active; quoted prices for similar assets or liabilities in active markets; inputs other than quoted prices that are observable for the assets or liabilities; or inputs that are derived principally from or corroborated by observable market data by correlation or other means. • Level 3: Unobservable inputs reflecting the Company's own assumptions incorporated in valuation techniques used to determine fair value. These assumptions are required to be consistent with market participant assumptions that are reasonably available. The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The carrying amounts of cash and cash equivalents, marketable securities, trade receivables, short-term deposits and trade payables approximate their fair value due to the short-term maturity of such instruments.
Basic and Diluted Net Loss Per Share	s. Basic and Diluted Net Loss Per Share: Basic net loss per share is computed by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by giving effect to all potentially dilutive securities, including stock options, restricted stock unit and the impact of the conversion spread of the 1.25% Convertible Senior Notes issued by the Company on May 11, 2020 and due August 2025 in an aggregate principal amount of $253,000 (the "2025 Notes"), to the extent dilutive. Basic and diluted net loss per share was the same for each period presented as the inclusion of all potential shares of common stock outstanding would have been anti-dilutive. There were 3,148,442 and 3,033,718 potentially dilutive shares from the conversion of outstanding stock options and restricted stock units that were not included in the calculation of diluted net loss per share as of December 31, 2020 and 2019, respectively. Additionally, 2,746,418 shares underlying the conversion option of the 2025 Notes are not considered in the calculation of diluted net income per share as the effect would be anti-dilutive. The Company intends to settle the principal amount of the 2025 Notes in cash and therefore will use the treasury stock method for calculating any potential dilutive effect on diluted net income per share, if applicable. The conversion will have a dilutive impact on diluted net income per share when the average market price of a common stock for a given period exceeds the conversion price of $92.12 per share.
Contingent Liabilities	t. Contingent Liabilities: The Company accounts for its contingent liabilities in accordance with ASC No. 450 “Contingencies”. A provision is recorded when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated.
Basis of Presentation	u. Basis of Presentation: Certain amounts in prior years' financial statements have been recast and reclassified to conform to the current year's presentation.
Revolving Credit Facility	v. Revolving Credit Facility: On August 21, 2020, the Company entered into a credit and security agreement with KeyBank National Association and other parties thereto ( the "Credit and Security Agreement"), for a three-year secured revolving credit facility of $70,000, with a letter of credit sublimit of $15,000 and an accordion feature under which the Company can increase the credit facility to up to $90,000 (the "Credit Facility"). Borrowings and repayments under the Credit Facility may occur from time to time in the Company’s ordinary course of business through the maturity date, which is the earlier of August 21, 2023 or 90 days prior to the scheduled maturity of any Convertible Debt Securities (including the 2025 Notes), at which time any amounts outstanding are to be paid in full. The fees incurred in connection with entering into the Credit and Security Agreement were recorded in prepaid expenses and other current assets on the consolidated balance sheet and are amortized on a straight-line basis over the contractual term of the arrangement. Ongoing fees and interest paid on the used and unused portions of the Credit Facility are expensed as incurred and included within financial income (expenses), net on the consolidated statement of operations. The Credit Facility is secured by a first priority perfected security interest in substantially all tangible and intangible assets (excluding real property and other customary exceptions) of the Company and its domestic subsidiaries and a first priority perfected lien on the capital stock of domestic entities within the Company, and 65% of the voting capital stock of the foreign subsidiaries of the Company. The Credit and Security Agreement contains customary covenants, including a requirement of quarterly minimum recurring revenues and a minimum available liquidity of at least $25,000 at all times, and customary events of default provisions. The Company may borrow under the Credit and Security Agreement at an interest rate equal to the London Interbank Offered Rate ("LIBOR") (subject to a 1.00% floor), plus an applicable margin equal to 3.00% per annum or the alternate base rate plus an applicable margin equal to 0.5% per annum. As of December 31, 2020, the Company had no balance outstanding on the Credit Facility and was in compliance with all financial covenants and non-financial covenants.
Recently Issued Accounting Pronouncements	w. Recently Adopted Accounting Pronouncements: In August 2018, the FASB issued ASU 2018-15, “Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract,” which aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The new standard requires capitalized costs to be amortized on a straight-line basis generally over the term of the arrangement, and the financial statement presentation for these capitalized costs would be the same as that of the fees related to the hosting arrangements. The new standard was adopted for interim and annual periods beginning January 1, 2020 using the prospective adoption approach. Adoption of this standard did not have a material impact on the Company's consolidated financial statements. In January 2016, the FASB issued ASU 2016-13, “Financial Instruments – Credit Losses on Financial Instruments”, which requires that expected credit losses relating to financial assets measured on an amortized cost basis and available for sale debt securities be recorded through an allowance for credit losses. This standard requires entities to estimate an expected lifetime credit loss on financial assets ranging from short-term trade accounts receivable to long-term financings and report credit losses using an expected losses model rather than the incurred losses model that was previously used, and establishes additional disclosures related to credit risks. For available for sale debt securities with unrealized losses, the standard eliminates the concept of other-than-temporary impairments and requires allowances to be recorded instead of reducing the amortized cost of the investment. ASU 2016-13 also limits the amount of credit losses to be recognized for available for sale debt securities to the amount by which carrying value exceeds fair value and also requires the reversal of previously recognized credit losses if fair value increases. The new standard was adopted for interim and annual periods beginning after January 1, 2020. Adoption of this standard did not have a material impact on the Company's consolidated financial statements. x. Recently Issued Accounting Pronouncements Not Yet Adopted: In August 2020, the FASB issued ASU 2020-06, ASC Subtopic 470-20 “Debt—Debt with “Conversion and Other Options” and ASC subtopic 815-40 “Hedging—Contracts in Entity’s Own Equity”. The standard reduced the number of accounting models for convertible debt instruments and convertible preferred stock. Convertible instruments that continue to be subject to separation models are (1) those with embedded conversion features that are not clearly and closely related to the host contract, that meet the definition of a derivative, and that do not qualify for a scope exception from derivative accounting and (2) convertible debt instruments issued with substantial premiums for which the premiums are recorded as paid-in capital. The amendments in this update are effective for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years. Early adoption is permitted, but no earlier than fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. The Company is currently assessing the impact of the adoption of this standard on its consolidated financial statements.

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Cash, Cash Equivalents and Investments	Cash, cash equivalents, marketable securities and short-term deposits consist of the following (in thousands): As of December 31, 2020 Amortized Gross Gross Fair Cash and cash equivalents Money market funds $ 10,712 $ — $ — $ 10,712 Total $ 10,712 $ — $ — $ 10,712 Marketable securities US Treasury securities $ 34,113 $ 4 *) $ 34,117 Total $ 34,113 $ 4 *) $ 34,117 Short-term deposits Term bank deposits $ 30,053 $ — $ — $ 30,053 Total $ 30,053 $ — $ — $ 30,053 *) Represents an amount lower than $1. As of December 31, 2019 Amortized Gross Gross Fair Cash and cash equivalents Money market funds $ 4,789 $ — $ — $ 4,789 Total $ 4,789 $ — $ — $ 4,789 Marketable securities US Treasury securities $ 41,510 $ 23 $ (2) $ 41,531 Total $ 41,510 $ 23 $ (2) $ 41,531 Short-term deposits Term bank deposits $ 10,000 $ — $ — $ 10,000 Total $ 10,000 $ — $ — $ 10,000
Property, Plant and Equipment Estimated Useful Life	Depreciation is calculated using the straight-line method over the estimated useful lives of the assets at the following annual rates: % Computer equipment 33% Office furniture and equipment 14% — 15% Leasehold improvements Over the shorter of the expected lease
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	Derivative instruments measured at fair value and their classification on the consolidated balance sheets are presented in the following table (in thousands): Assets as of Assets (liabilities) as of December 31, 2020 December 31, 2019 Notional Fair Notional Fair Foreign exchange forward contract derivatives in cash flow hedging relationships included in prepaid expenses and other current assets and accrued expenses and other short-term liabilities $ 90,452 $ 3,315 $ 84,968 $ (470) Foreign exchange forward contract derivatives for monetary items included in prepaid expenses and other current assets $ 33,977 $ 17 $ 26,995 $ 5

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Prepaid Expense and Other Assets, Current [Abstract]
Schedule of prepaid expenses and other current assets	December 31, 2020 2019 Deferred commission $ 14,144 $ 10,044 Prepaid expenses 7,938 7,648 Foreign currency forward contracts derivatives 3,332 — Government institutions & other receivables 1,586 1,357 Short-term deposits & other 357 317 Prepaid expenses and other current assets $ 27,357 $ 19,366

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	December 31, 2020 2019 Cost: Computer equipment $ 18,848 $ 16,546 Office furniture and equipment 5,735 4,910 Leasehold improvements 37,391 31,291 61,974 52,747 Accumulated depreciation 24,811 16,409 Property and equipment, net $ 37,163 $ 36,338

Accrued Expenses and Other Sh_2

Accrued Expenses and Other Short Term Liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Accrued Liabilities and Other Liabilities [Abstract]
Schedule of Accounts Expense and Other Liabilities	December 31, 2020 2019 Government authorities and other $ 37,268 $ 24,689 Employees 32,593 23,479 Accrued expenses 13,337 13,766 Foreign exchange forward contract derivatives — 470 Other short-term liabilities — 203 Accrued expenses and other short-term liabilities $ 83,198 $ 62,607

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Summary of Right-of-Use Assets and Lease Liabilities	Below is a summary of its operating right-of-use assets and operating lease liabilities as of December 31, 2020: December 31, 2020 Operating right-of-use assets $ 47,924 Operating lease liabilities, current $ 8,700 Operating lease liabilities long-term 54,540 Total operating lease liabilities $ 63,240
Lessee, Operating Lease, Liability, Maturity	Minimum lease payments for the Company's right-of-use assets over the remaining lease periods as of December 31, 2020, are as follows: December 31, 2020 2021 $ 10,694 2022 14,509 2023 7,596 2024 6,726 2025 6,764 Thereafter 25,751 Total undiscounted lease payments $ 72,040 Less: Imputed interest (8,800) Present value of lease liabilities $ 63,240
Summary of Weighted Average Remaining Lease Terms and Discount Rates	The weighted average remaining lease terms and discount rates for all of operating leases were as follows as of December 31, 2020: Remaining lease term and discount rate: Weighted average remaining lease term (years) 7.49 Weighted average discount rate 3.32 %

Convertible Senior Notes and _2

Convertible Senior Notes and Capped Call Transactions (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of Net Carrying Amount of Liability and Equity Components of Convertible Notes	The net carrying amount of the liability and equity components of the 2025 Notes as of December 31, 2020 was as follows: As of December 31, 2020 (in thousands) Liability component Principal $ 253,000 Unamortized discount (28,410) Unamortized issuance costs (6,130) Net carrying amount $ 218,460 Equity component, net of discount and issuance costs $ 30,794
Schedule of Interest Expense	The interest expense recognized related to the 2025 Notes for the year ended December 31, 2020 was as follows: December 31, 2020 Contractual interest expense $ 2,012 Amortization of debt discount 3,369 Amortization of debt issuance costs 727 Total $ 6,108

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The following table summarizes the allocation of the purchase price to the fair value of the tangible and intangible assets acquired and liabilities assumed as of the acquisition date: Purchase Price Allocation Estimated Useful Life Net tangible assets acquired $ 375 Intangible assets: Developed technology & trademarks 6,110 4 Goodwill 23,135 Total purchase price $ 29,620

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following table reflects goodwill activity for the year ended December 31, 2020: Amount Balance at December 31, 2019 $ — Goodwill acquired 23,135 Balance at December 31, 2020 $ 23,135
Schedule of Finite-Lived Intangible Assets	Total cost and amortization of intangible assets comprised of the following: Intangible assets, net Estimated Useful Life December 31, 2020 Developed technology & trademarks 4 $ 6,110 Total intangible assets 6,110 Less: Accumulated amortization 264 Total intangible assets, net $ 5,846
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The following table summarizes estimated future amortization expense of our intangible assets as of December 31, 2020 (in thousands): Years ending December 31, Amount 2021 $ 1,533 2022 1,525 2023 1,525 2024 1,263 Total future amortization expense $ 5,846

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table sets forth the Company’s assets and liabilities that were measured at fair value as of December 31, 2020 and 2019 by level within the fair value hierarchy (in thousands): As of December 31, 2020 As of December 31, 2019 Level I Level Level Fair Level I Level Level Fair Financial assets: Cash equivalents: Money market funds $ 10,712 $ — $ — $ 10,712 $ 4,789 $ — $ — $ 4,789 Marketable securities: US Treasury securities 34,117 — — 34,117 41,531 — — 41,531 Prepaid expenses and other current assets: Forward foreign exchange contracts — 3,332 — 3,332 — 5 — 5 Financial liabilities: Accrued expenses and other short-term liabilities: Forward foreign exchange contracts — — — — — (470) — (470) Total financial assets (liabilities) $ 44,829 $ 3,332 $ — $ 48,161 $ 46,320 $ (465) $ — $ 45,855

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Schedule of Stock by Class	Authorized Issued and outstanding Number of shares December 31, December 31, 2020 2019 2020 2019 Stock of $0.001 par value: Common stock 200,000,000 200,000,000 31,818,954 30,583,311
Share-based Compensation, Stock Options, Activity	A summary of employees’ stock options activities during the year ended December 31, 2020 is as follows: Year ended December 31, 2020 Number Weighted Aggregate Weighted Options outstanding at the beginning of the year 454,348 $ 20.628 $ 25,935 4.343 Granted 10,933 $ 17.045 Exercised (123,751) $ 20.503 Forfeited (609) $ 11.618 Options outstanding at the end of the period 340,921 $ 20.586 $ 48,760 3.604 Options exercisable at the end of the period 331,759 $ 20.684 $ 47,417 3.452
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range	The options outstanding as of December 31, 2020 have been separated into ranges of exercise price as follows: Range of exercise price Options Weighted Weighted Options Weighted Weighted $ 6.230 — 8.800 10,356 1.104 $ 8.289 10,356 1.104 $ 8.289 $ 12.470 — 17.045 100,758 3.769 $ 14.639 91,596 3.235 $ 14.346 $ 19.510 — 24.230 173,685 3.534 $ 21.440 173,685 3.534 $ 21.440 $ 29.880 46,548 4.142 $ 29.880 46,548 4.142 $ 29.880 $ 39.860 9,574 3.222 $ 39.860 9,574 3.222 $ 39.860 340,921 3.604 $ 20.586 331,759 3.452 $ 20.684
Schedule of Stockholders' Equity Note, Warrants or Rights	The Company’s outstanding options granted to consultants for services as of December 31, 2020 were as follows: Issuance date Options for Exercise price Options Exercisable (number) (number) August 2013 2,500 $ 21.140 2,500 August 2023 March 2014 1,650 $ 39.860 1,650 March 2024 May 2014 2,000 $ 22.010 2,000 May 2024 November 2014 3,445 $ 21.660 3,445 November 2024 February 2016 1,000 $ 16.870 1,000 February 2026 October 2019 393 $ 17.045 393 October 2029 May 2020 212 $ 17.045 212 May 2030 11,200 11,200
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	The following provides a summary of the restricted stock unit activity for the Company for the year ended December 31, 2020: Number of Weighted- Outstanding as of January 1, 2020 2,559,083 $ 49.58 Granted 1,395,697 $ 87.03 Vested (950,323) $ 44.63 Forfeited (208,136) $ 62.40 Unvested as of December 31, 2020 2,796,321 $ 69.01
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs	The Company recognized non-cash stock-based compensation expense in the consolidated statements of operations as follows (in thousands): Year ended December 31, 2020 2019 2018 Cost of revenues $ 5,013 $ 2,561 $ 1,757 Research and development 21,979 13,188 9,645 Sales and marketing 25,578 14,782 16,081 General and administrative 16,015 15,608 7,478 Total $ 68,585 $ 46,139 $ 34,961

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	c. Loss before taxes on income is comprised as follows: Year ended December 31, 2020 2019 2018 Domestic $ (80,086) $ (82,007) $ (25,557) Foreign (5,812) 5,631 (2,608) $ (85,898) $ (76,376) $ (28,165)
Schedule of Components of Income Tax Expense (Benefit)	d. Taxes on income (loss) are comprised as follows: Year ended December 31, 2020 2019 2018 Current: Domestic: Federal $ 90 $ 665 $ — State 128 13 169 Foreign 8,854 1,619 1,498 Total current income tax $ 9,072 $ 2,297 $ 1,667 Deferred: Federal $ 8 $ — $ — State 1 — — Foreign (969) 91 (1,254) Total deferred income tax $ (960) $ 91 $ (1,254) Income tax expense $ 8,112 $ 2,388 $ 413
Schedule of Deferred Tax Assets and Liabilities	Significant components of our deferred tax assets and liabilities as of December 31, 2020 and 2019 are as follows: December 31, 2020 2019 Deferred tax assets: Carry forward losses and credits $ 53,221 $ 36,092 Deferred revenues 13,054 13,953 Accrued payroll, commissions, vacation 3,808 2,666 Equity compensation 10,348 6,220 Allowance for doubtful accounts 1,287 978 Accrued severance pay 312 340 Operating lease liability 11,302 12,244 Other 963 532 Deferred tax assets before valuation allowance 94,295 73,025 Valuation allowance (77,542) (62,379) Deferred tax assets $ 16,753 $ 10,646 Deferred tax liability: Accrued compensation and other accrued expense $ (48) $ (187) Operating lease right-of-use asset (8,780) (10,291) Convertible senior notes, net (6,797) — Deferred tax liability $ (15,625) $ (10,478) Net deferred tax asset $ 1,128 $ 168
Schedule of Effective Income Tax Rate Reconciliation	A reconciliation between the theoretical tax expense, assuming all income is taxed at the statutory tax rate applicable to income of the Company, and the actual tax expense as reported in the consolidated statements of operations is as follows: Year ended December 31, 2020 2019 2018 Loss before taxes, as reported in the consolidated statements of operations $ (85,898) $ (76,376) $ (28,165) Statutory tax rate 21 % 21 % 21 % Theoretical tax benefits on the above amount at the US statutory tax rate $ (18,039) $ (16,039) $ (5,915) Income tax at rate other than the U.S. statutory tax rate 4,845 (2,508) 692 Tax advances and non-deductible expenses including equity based compensation expenses 934 (115) (7,623) Operating losses and other temporary differences for which valuation allowance was provided 22,189 22,818 15,826 State tax (2,872) (3,436) (1,221) Impact of rate change — 401 — Change in tax reserve for uncertain tax positions 1,489 1,247 (1,728) Other individually immaterial income tax items (434) 20 382 Actual tax expense $ 8,112 $ 2,388 $ 413
Schedule of Unrecognized Tax Benefits Roll Forward	g. A reconciliation of the beginning and ending amounts of unrecognized tax benefits in the years ended December 31, 2020 and 2019 are as follows: Gross unrecognized tax benefits as of January 1, 2019 $ 1,954 Increase in tax position for current year 1,545 Increase in tax position for prior years 387 Decrease for lapse of statute of limitations/settlements (685) Gross unrecognized tax benefits as of December 31, 2019 $ 3,201 Increase in tax position for current year 1,787 Increase in tax position for prior years 979 Decrease in tax position for prior years (171) Decrease for lapse of statute of limitations/settlements (1,106) Gross unrecognized tax benefits as of December 31, 2020 $ 4,690

Financial Income (Expenses), _2

Financial Income (Expenses), Net (Tables)	12 Months Ended
	Dec. 31, 2020
Financial Income (Expenses), Net [Abstract]
Schedule Of Nonoperating Income, by Component	Year ended December 31, 2020 2019 2018 Financial income: Interest on bank deposits & other $ 674 $ 2,041 $ 1,741 674 2,041 1,741 Financial expenses: Amortization of issuance costs 4,096 — — Interest expenses, principally from convertible note 2,017 — — Foreign currency transaction losses, net 1,726 2,225 574 Bank and other charges 318 205 197 (8,157) (2,430) (771) Financial income (expense), net $ (7,483) $ (389) $ 970

Geographic Information and Ma_2

Geographic Information and Major Customer and Product Data (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Revenue from External Customers by Geographic Areas	The following is a summary of revenues within geographic areas: Year ended December 31, 2020 2019 2018 Revenues based on customer’s location: North America $ 207,488 $ 174,607 $ 167,361 EMEA (*) 77,093 70,208 93,816 Rest of the World 8,108 9,375 9,111 Total revenues $ 292,689 $ 254,190 $ 270,288 (*) Sales to customers in France accounted for $30,937 and $31,532 of the Company’s revenues for the years ended December 31, 2020 and 2018, respectively. Sales to customers in France did not exceed 10% of total revenues for the year ended December 31, 2019.
Long-lived Assets by Geographic Areas	December 31, 2020 2019 Long-lived assets by geographic region: Israel $ 42,471 $ 45,382 United States 30,938 42,590 Ireland 9,684 597 Other 1,994 2,826 $ 85,087 $ 91,395

General (Details Textual)

General (Details Textual)	Dec. 31, 2020subsidiary
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Subsidiary or equity method investee, number	12

Significant Accounting Polici_4

Significant Accounting Policies - Cash, Cash Equivalents and Short-term Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Cash and Cash Equivalents
Significant Accounting Policies [Line Items]
Amortized Cost	$ 10,712	$ 4,789
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	10,712	4,789
Cash and Cash Equivalents | Money Market Funds
Significant Accounting Policies [Line Items]
Amortized Cost	10,712	4,789
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	10,712	4,789
Marketable Securities
Significant Accounting Policies [Line Items]
Amortized Cost	34,113	41,510
Gross Unrealized Gains	4	23
Gross Unrealized Losses		(2)
Fair Value	34,117	41,531
Marketable Securities | US Treasury securities
Significant Accounting Policies [Line Items]
Amortized Cost	34,113	41,510
Gross Unrealized Gains	4	23
Gross Unrealized Losses		(2)
Fair Value	34,117	41,531
Short-term Deposits
Significant Accounting Policies [Line Items]
Amortized Cost	30,053	10,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	30,053	10,000
Short-term Deposits | Term Bank Deposits
Significant Accounting Policies [Line Items]
Amortized Cost	30,053	10,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$ 30,053	$ 10,000

Significant Accounting Polici_5

Significant Accounting Policies (Details Textual) - USD ($)	Aug. 21, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	May 11, 2020
Significant Accounting Policies [Line Items]
Operating lease, impairment loss		$ 3,149,000	$ 0	$ 0
Contract with customer, liability, revenue recognized		96,535,000
Sales returns		$ 0	0	0
Capitalized contract cost, amortization period (years)		4 years
Granted (in shares)		10,933
Stock-based compensation		$ 68,585,000	46,139,000	34,961,000
Gain (loss) on derivative instruments reclassified into earnings, net of tax		257,000	352,000	(3,741,000)
Realized income on derivative instruments, net of tax		6,052,000	0	0
Derivative instruments not designated as hedging instruments, gain (loss), net		(1,144,000)	683,000
Severance and retirement costs		$ 7,169,000	$ 6,390,000	$ 6,765,000
Restricted Stock Units and Stock Options
Significant Accounting Policies [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares		3,148,442	3,033,718
Credit and Security Agreement | London Interbank Offered Rate (LIBOR)
Significant Accounting Policies [Line Items]
Basis spread on variable rate	3.00%
Credit and Security Agreement | Base Rate
Significant Accounting Policies [Line Items]
Basis spread on variable rate	0.50%
2025 Senior Notes
Significant Accounting Policies [Line Items]
Debt instrument, face amount		$ 253,000,000
2025 Senior Notes | Convertible Debt Securities
Significant Accounting Policies [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares		2,746,418
Line of Credit | Revolving Credit Facility
Significant Accounting Policies [Line Items]
Debt instrument, term	3 years
Maximum borrowing capacity	$ 70,000,000
Line of credit facility, accordion feature, increase limit	$ 90,000,000
First priority perfected lien on voting capital stock, percent	65.00%
Debt instrument, covenant, minimum available liquidity	$ 25,000,000
Line of Credit | Letter of Credit
Significant Accounting Policies [Line Items]
Maximum borrowing capacity	$ 15,000,000
Convertible Debt | 2025 Senior Notes
Significant Accounting Policies [Line Items]
Interest rate, stated percentage					1.25%
Initial conversion price (in dollars per share)		$ 92.12
Debt instrument, face amount					$ 253,000,000
Other Noncurrent Liabilities
Significant Accounting Policies [Line Items]
Restructuring reserve		$ 2,727,000	$ 2,554,000
Israel | VSUK Plan
Significant Accounting Policies [Line Items]
Defined contribution plan, maximum annual contributions per employee, percent		8.33%
Israel | VSIR Plan
Significant Accounting Policies [Line Items]
Defined contribution plan, employer matching contribution, percent of match		100.00%
United Kingdom | VSUK Plan
Significant Accounting Policies [Line Items]
Defined contribution plan, employer matching contribution, percent of match		100.00%
Defined contribution plan, employer matching contribution, percent of base pay		3.00%
Australia | VAUS Plan
Significant Accounting Policies [Line Items]
Defined contribution plan, employer matching contribution, percent of employees' eligible wages		9.50%
Deferred Salary Arrangement | United States
Significant Accounting Policies [Line Items]
Defined contribution plan, employer matching contribution, percent of match		100.00%
Defined contribution plan, employer matching contribution, percent of participants contribution		50.00%
Foreign Exchange Contract
Significant Accounting Policies [Line Items]
Gain (loss) on derivative instruments reclassified into earnings, net of tax		$ 257,000	$ 352,000
Realized income on derivative instruments, net of tax		$ 6,052,000
United States of America, Dollars
Significant Accounting Policies [Line Items]
Investment interest rate			1.71%
Minimum | Credit and Security Agreement | London Interbank Offered Rate (LIBOR)
Significant Accounting Policies [Line Items]
Basis spread on variable rate	1.00%
Minimum | Israel | VSIR Plan
Significant Accounting Policies [Line Items]
Defined contribution plan, employer matching contribution, percent of base pay		3.00%
Defined contribution plan, employer matching contribution, percent of participants contribution		3.00%
Minimum | Deferred Salary Arrangement | United States
Significant Accounting Policies [Line Items]
Defined contribution plan, contributions, percentage of participants base pay		3.00%
Minimum | United States of America, Dollars
Significant Accounting Policies [Line Items]
Investment interest rate		0.10%
Maximum | Israel | VSIR Plan
Significant Accounting Policies [Line Items]
Defined contribution plan, employer matching contribution, percent of base pay		5.00%
Defined contribution plan, employer matching contribution, percent of participants contribution		50.00%
Maximum | Netherlands | VNL Plan
Significant Accounting Policies [Line Items]
Defined contribution plan, employer matching contribution, percent of base pay		7.70%
Maximum | Deferred Salary Arrangement | United States
Significant Accounting Policies [Line Items]
Defined contribution plan, employer matching contribution, percent of base pay		3.00%
Defined contribution plan, contributions, percentage of participants base pay		5.00%
Participant matching contribution percentage of base remuneration		80.00%
Maximum | United States of America, Dollars
Significant Accounting Policies [Line Items]
Investment interest rate		0.16%
Maintenance and services
Significant Accounting Policies [Line Items]
Revenue, performance obligation, description of timing		one year

Significant Accounting Polici_6

Significant Accounting Policies - Property and Equipment, Schedule of Depreciation Annual Rates and Estimated Useful Lives of Assets (Details)	12 Months Ended
	Dec. 31, 2020
Computer equipment
Significant Accounting Policies [Line Items]
Depreciation rate	33.00%
Office furniture and equipment | Minimum
Significant Accounting Policies [Line Items]
Depreciation rate	14.00%
Office furniture and equipment | Maximum
Significant Accounting Policies [Line Items]
Depreciation rate	15.00%
Leasehold improvements
Significant Accounting Policies [Line Items]
Leasehold improvements	Over the shorter of the expected leaseterm or estimated useful life

Significant Accounting Polici_7

Significant Accounting Policies - Derivative Instruments Measured at Fair Value (Details) - Foreign Exchange Contract - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Prepaid Expenses and Other Current Assets | Cash Flow Hedging
Derivative [Line Items]
Derivative Asset, Notional Amount	$ 90,452	$ 84,968
Derivative Asset, Fair Value	3,315
Prepaid Expenses and Other Current Assets | Fair Value Hedging
Derivative [Line Items]
Derivative Asset, Notional Amount	33,977	26,995
Derivative Asset, Fair Value	$ 17	5
Accrued Expenses And Other Short Term Liabilities | Cash Flow Hedging
Derivative [Line Items]
Derivative Liability, Fair Value		$ (470)

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Schedule Of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Prepaid Expense and Other Assets, Current [Abstract]
Deferred commission	$ 14,144	$ 10,044
Prepaid expenses	7,938	7,648
Foreign currency forward contracts derivatives	3,332	0
Government institutions & other receivables	1,586	1,357
Short-term deposits & other	357	317
Prepaid expenses and other current assets	$ 27,357	$ 19,366

Property and Equipment, Net - S

Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 61,974	$ 52,747
Accumulated depreciation	24,811	16,409
Property and equipment, net	37,163	36,338
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	18,848	16,546
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	5,735	4,910
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 37,391	$ 31,291

Property and Equipment, Net (De

Property and Equipment, Net (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Depreciation	$ 9,903	$ 6,321	$ 4,156

Accrued Expenses and Other Sh_3

Accrued Expenses and Other Short Term Liabilities - Schedule of Accrued Expenses and Other Short Term Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accrued Liabilities and Other Liabilities [Abstract]
Government authorities and other	$ 37,268	$ 24,689
Employees	32,593	23,479
Accrued expenses	13,337	13,766
Foreign exchange forward contract derivatives	0	470
Other short-term liabilities	0	203
Accrued expenses and other short-term liabilities	$ 83,198	$ 62,607

Leases - Summary of Right-of-Us

Leases - Summary of Right-of-Use Assets and Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating right-of-use assets	$ 47,924	$ 55,057
Operating lease liabilities, current	8,700
Operating lease liabilities long-term	54,540	$ 57,040
Total operating lease liabilities	$ 63,240

Leases - Minimum Lease Payments

Leases - Minimum Lease Payments for Right-of-Use Assets (Details) $ in Thousands	Dec. 31, 2020USD ($)
Leases [Abstract]
2021	$ 10,694
2022	14,509
2023	7,596
2024	6,726
2025	6,764
Thereafter	25,751
Total undiscounted lease payments	72,040
Less: Imputed interest	(8,800)
Present value of lease liabilities	$ 63,240

Leases - Summary of Weighted Av

Leases - Summary of Weighted Average Remaining Lease Terms and Discount Rates (Details)	Dec. 31, 2020
Leases [Abstract]
Weighted average remaining lease term (years)	7 years 5 months 26 days
Weighted average discount rate	3.32%

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Lessee, Lease, Description [Line Items]
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent	us-gaap:AccruedLiabilitiesAndOtherLiabilities
Operating leases, expense	$ 12,151	$ 8,912	$ 6,570
Lease terms through 2024
Lessee, Lease, Description [Line Items]
Operating lease, lease not yet commenced, amount	997
Lease terms through 2030
Lessee, Lease, Description [Line Items]
Operating lease, lease not yet commenced, amount	$ 6,344

Convertible Senior Notes and _3

Convertible Senior Notes and Capped Call Transactions - Narrative (Details)	May 11, 2020USD ($)$ / shares	Dec. 31, 2020USD ($)tradingDay$ / shares	Dec. 31, 2019USD ($)$ / shares	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Proceeds from issuance of convertible senior notes, net of issuance costs		$ 245,308,000	$ 0	$ 0
Payments for capped calls		$ 29,348,000	$ 0	$ 0
Common stock, par value (in usd per share) | $ / shares		$ 0.001	$ 0.001
Cap price | $ / shares		$ 141.72
Percentage premium over the last reported sale price of company common stock used to calculate cap price		100.00%
2025 Senior Notes
Debt Instrument [Line Items]
Equity component, net of discount and issuance costs		$ 30,794,000
Fair value of the notes		$ 481,725,000
Convertible Debt
Debt Instrument [Line Items]
Payments for capped calls	$ 29,348,000
Common stock, par value (in usd per share) | $ / shares	$ 0.001
Convertible Debt | 2025 Senior Notes
Debt Instrument [Line Items]
Principal amount excluding purchasers' option	$ 220,000,000
Additional amount included in principal from exercised options	33,000,000
Proceeds from issuance of convertible senior notes, net of issuance costs	$ 245,158,000
Interest rate, stated percentage	1.25%
Debt instrument, convertible, conversion ratio		10.8556
Initial conversion price (in dollars per share) | $ / shares		$ 92.12
Repurchase of notes percentage		100.00%
Equity component, net of discount and issuance costs		$ 31,779,000
Debt issuance costs of liability component		$ 6,857,000
Debt instrument, interest rate, effective percentage		4.51%
Convertible Debt | 2025 Senior Notes | Additional paid-in capital
Debt Instrument [Line Items]
Debt issuance costs of equity component		$ 985,000
Convertible Debt | 2025 Senior Notes | Debt Conversion, Option One
Debt Instrument [Line Items]
Threshold trading days | tradingDay		20
Threshold consecutive trading days | tradingDay		30
Threshold percentage of conversion price		130.00%
Convertible Debt | 2025 Senior Notes | Debt Conversion, Option Two
Debt Instrument [Line Items]
Threshold consecutive trading days | tradingDay		5
Threshold percentage of conversion price		98.00%
Threshold consecutive business days | tradingDay		5

Convertible Senior Notes and _4

Convertible Senior Notes and Capped Call Transactions - Schedule of Convertible Notes (Details) - 2025 Senior Notes $ in Thousands	Dec. 31, 2020USD ($)
Debt Instrument [Line Items]
Principal	$ 253,000
Unamortized discount	(28,410)
Unamortized issuance costs	(6,130)
Net carrying amount	218,460
Equity component, net of discount and issuance costs	$ 30,794

Convertible Senior Notes and _5

Convertible Senior Notes and Capped Call Transactions - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Amortization of issuance costs	$ 4,096	$ 0	$ 0
Interest Expense, Debt	2,017	$ 0	$ 0
2025 Senior Notes
Debt Instrument [Line Items]
Contractual interest expense	2,012
Amortization of debt discount	3,369
Amortization of issuance costs	727
Interest Expense, Debt	$ 6,108

Business Combinations - Narrati

Business Combinations - Narrative (Details) - Polyrize $ in Thousands	Oct. 29, 2020USD ($)shares
Business Acquisition [Line Items]
Total purchase price	$ 39,380
Fair value of consideration	29,620
Contingent consideration	$ 9,760
Contingent consideration period	3 years
Payments to acquire businesses, gross	$ 24,713
Fair value of common stock issued	$ 4,198
Equity interest issued or issuable, number of shares | shares	35,642
Fair value of replacement equity awards attributable to pre-acquisitions service	$ 709
Acquisition related costs	$ 325

Business Combinations - Purchas

Business Combinations - Purchase Price Allocation and Estimated Useful Life (Details) - USD ($) $ in Thousands	Oct. 29, 2020	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Goodwill		$ 23,135	$ 0
Polyrize
Business Acquisition [Line Items]
Net tangible assets acquired	$ 375
Goodwill	23,135
Total purchase price	29,620
Polyrize | Developed technology & trademarks
Business Acquisition [Line Items]
Intangible assets	$ 6,110
Estimated Useful Life (in years)	4 years

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Goodwill Rollforward (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Goodwill [Roll Forward]
Balance at December 31, 2019	$ 0
Goodwill acquired	23,135
Balance at December 31, 2020	$ 23,135

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Cost and Amortization of Intangible Assets (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Finite-Lived Intangible Assets [Line Items]
Total intangible assets	$ 6,110
Less: Accumulated amortization	264
Total intangible assets, net	$ 5,846
Developed technology & trademarks
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life (in years)	4 years
Total intangible assets	$ 6,110

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 264

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Estimated Future Amortization Expense (Details) $ in Thousands	Dec. 31, 2020USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2021	$ 1,533
2022	1,525
2023	1,525
2024	1,263
Total intangible assets, net	$ 5,846

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets (liabilities)	$ 48,161	$ 45,855
Foreign Exchange Forward
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	3,332	5
Derivative liabilities	0	(470)
Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	10,712	4,789
US Treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	34,117	41,531
Level I
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets (liabilities)	44,829	46,320
Level I | Foreign Exchange Forward
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0
Derivative liabilities	0	0
Level I | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	10,712	4,789
Level I | US Treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	34,117	41,531
Level II
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets (liabilities)	3,332	(465)
Level II | Foreign Exchange Forward
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	3,332	5
Derivative liabilities	0	(470)
Level II | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Level II | US Treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0	0
Level III
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets (liabilities)	0	0
Level III | Foreign Exchange Forward
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0
Derivative liabilities	0	0
Level III | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Level III | US Treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	$ 0	$ 0

Stockholders' Equity - Composit

Stockholders' Equity - Composition of Common Stock (Details) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Equity [Abstract]
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares, issued (in shares)	31,818,954	30,583,311
Common stock, shares, outstanding (in shares)	31,818,954	30,583,311

Stockholders' Equity (Details T

Stockholders' Equity (Details Textual) $ / shares in Units, $ in Thousands	Mar. 12, 2021	Oct. 22, 2020shares	Jun. 30, 2015shares	Nov. 14, 2013shares	Dec. 31, 2020USD ($)vote$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2013shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares authorized (in shares)					200,000,000	200,000,000		200,000,000	200,000,000
Common stock, par value (in usd per share) | $ / shares					$ 0.001	$ 0.001		$ 0.001	$ 0.001
Number of voting rights | vote					1
Granted (in shares)					10,933
Exercises in period, intrinsic value | $					$ 9,922	$ 12,453	$ 40,610
Compensation cost not yet recognized | $					$ 810	$ 9		$ 810	$ 810
Compensation cost not yet recognized, period for recognition					2 years 8 months 19 days	1 month 17 days
Stockholders' Equity					STOCKHOLDERS’ EQUITY a. Composition of common stock capital: Authorized Issued and outstanding Number of shares December 31, December 31, 2020 2019 2020 2019 Stock of $0.001 par value: Common stock 200,000,000 200,000,000 31,818,954 30,583,311 b. Common stock rights: The Company’s Amended and Restated Certificate of Incorporation authorizes the Company to issue 200,000,000 shares of common stock, par value $0.001 per share. The common stock confers upon its holders the right to participate in the general meetings of the Company, to vote at such meetings (each share represents one vote), to elect board members and to participate in any distribution of dividends or any other distribution of the Company’s property, including the distribution of surplus assets upon liquidation. On February 8, 2021, the Company announced a three-for-one split of its common stock to stockholders of record as of the close of business on March 12, 2021. Trading of the Company’s common stock will begin on a split-adjusted basis on March 15, 2021. Common stock and per share data in this Annual Report on Form 10-K have not been adjusted for the impact of the split. c. Stock option plans: On December 30, 2005, the Company’s board of directors adopted the Varonis Systems, Inc. 2005 Stock Plan (the “2005 Stock Plan”). As of December 31, 2013, the Company had reserved 4,713,319 shares of common stock available for issuance to employees, directors, officers and consultants of the Company and its subsidiaries. The options generally vest over four years. No awards were granted under the 2005 Stock Plan subsequent to December 31, 2013, and no further awards will be granted under the 2005 Stock Plan. On November 14, 2013, the Company’s board of directors adopted the Varonis Systems, Inc. 2013 Omnibus Equity Incentive Plan (the “2013 Plan”) which was subsequently approved by the Company’s stockholders. The Company initially reserved 1,904,633 shares of common stock for issuance under the 2013 Plan to employees, directors, officers and consultants of the Company and its subsidiaries. The number of shares of common stock available for issuance under the 2013 Plan was increased on January 1, 2016 and has been, and will be, increased on each January 1 thereafter by four percent (4%) of the number of shares of common stock issued and outstanding on each December 31 immediately prior to the date of increase (rounded down to the nearest whole share), but the amount of each increase will be limited to the number of shares of common stock necessary to bring the total number of shares of Common Stock available for grant and issuance under the 2013 Plan to five percent (5%) of the number of shares of common stock issued and outstanding on each December 31. Since January 1, 2016, the share reserve under the 2013 Plan has been automatically increased by an aggregate of 6,796,150 shares. Awards granted under the 2013 Plan generally vest over four years. Any award that is forfeited or canceled before expiration becomes available for future grants under the 2013 Plan. On October 22, 2020, and as part of the acquisition, the Company’s board of directors approved the assumption of a certain portion of Polyrize Options pursuant to the terms and conditions of Polyrize 2019 Share Incentive (“Polyrize Plan”) as part of the acquisition. The number of shares of Common Stock of the Company issuable pursuant to such assumed options is 13,427. A summary of employees’ stock options activities during the year ended December 31, 2020 is as follows: Year ended December 31, 2020 Number Weighted Aggregate Weighted Options outstanding at the beginning of the year 454,348 $ 20.628 $ 25,935 4.343 Granted 10,933 $ 17.045 Exercised (123,751) $ 20.503 Forfeited (609) $ 11.618 Options outstanding at the end of the period 340,921 $ 20.586 $ 48,760 3.604 Options exercisable at the end of the period 331,759 $ 20.684 $ 47,417 3.452 There were no options granted in 2020 pursuant to our 2005 Stock Plan and 2013 Plan. Under the Polyrize Plan, 10,933 options were granted in 2020. The aggregate intrinsic value in the table above represents the total intrinsic value that would have been received by the option holders had all option holders exercised their options on the last date of the period. Total intrinsic value of options exercised for the years ended December 31, 2020, 2019 and 2018 was $9,922, $12,453 and $40,610, respectively. As of December 31, 2020 and 2019, there was $810 and $9, respectively, of total unrecognized compensation cost related to non-vested share-based compensation arrangements granted under the 2005 Stock Plan, 2013 Plan and Polyrize Plan. This cost is expected to be recognized over a period of approximately 2.721 and 0.132 years, respectively. The options outstanding as of December 31, 2020 have been separated into ranges of exercise price as follows: Range of exercise price Options Weighted Weighted Options Weighted Weighted $ 6.230 — 8.800 10,356 1.104 $ 8.289 10,356 1.104 $ 8.289 $ 12.470 — 17.045 100,758 3.769 $ 14.639 91,596 3.235 $ 14.346 $ 19.510 — 24.230 173,685 3.534 $ 21.440 173,685 3.534 $ 21.440 $ 29.880 46,548 4.142 $ 29.880 46,548 4.142 $ 29.880 $ 39.860 9,574 3.222 $ 39.860 9,574 3.222 $ 39.860 340,921 3.604 $ 20.586 331,759 3.452 $ 20.684 d. Options issued to consultants: The Company’s outstanding options granted to consultants for services as of December 31, 2020 were as follows: Issuance date Options for Exercise price Options Exercisable (number) (number) August 2013 2,500 $ 21.140 2,500 August 2023 March 2014 1,650 $ 39.860 1,650 March 2024 May 2014 2,000 $ 22.010 2,000 May 2024 November 2014 3,445 $ 21.660 3,445 November 2024 February 2016 1,000 $ 16.870 1,000 February 2026 October 2019 393 $ 17.045 393 October 2029 May 2020 212 $ 17.045 212 May 2030 11,200 11,200 There were no options granted in 2020 pursuant to our 2005 Stock Plan and 2013 Plan. In 2020, 2,494 options were assumed under the Polyrize Plan, of which 605 options remained outstanding as of December 31, 2020. e. Restricted stock units: The following provides a summary of the restricted stock unit activity for the Company for the year ended December 31, 2020: Number of Weighted- Outstanding as of January 1, 2020 2,559,083 $ 49.58 Granted 1,395,697 $ 87.03 Vested (950,323) $ 44.63 Forfeited (208,136) $ 62.40 Unvested as of December 31, 2020 2,796,321 $ 69.01 As of December 31, 2020, there was $141,408 of total unrecognized compensation cost related to employees and non-employees unvested restricted stock units which is expected to be recognized over a period of 2.120 years. f. 2015 Employee Stock Purchase Plan On May 5, 2015, the Company’s stockholders approved the Varonis Systems, Inc. 2015 Employee Stock Purchase Plan (the “ESPP”), which the Company’s board of directors had adopted on March 19, 2015. The ESPP became effective as of June 30, 2015. The ESPP allows eligible employees to purchase shares of the Company’s common stock at a discount through payroll deductions of up to 15% of their eligible compensation, at not less than 85% of the fair market value of the Company’s common stock on the first day or last trading day in the offering period, subject to any plan limitations. The Company initially reserved 500,000 shares of common stock for issuance under the ESPP. The number of shares available for issuance under the ESPP was increased on January 1, 2016 and has been, and will be, increased each January 1 thereafter, by an amount equal to the lesser of (i) one percent (1%) of the number of shares of common stock issued and outstanding on each December 31 immediately prior to the date of increase, except that the amount of each such increase will be limited to the number of shares of common stock necessary to bring the total number of shares of common stock available for issuance under the ESPP to two percent (2%) of the number of shares of common stock issued and outstanding on each such December 31, or (ii) 400,000 shares of common stock. Since January 1, 2016, the share reserve under the ESPP has been automatically increased by an aggregate of 846,618 shares. The ESPP will continue in effect until the earlier of (i) the date when no shares of common stock are available for issuance thereunder or (ii) June 30, 2025; unless terminated prior thereto by the Company’s board of directors or compensation committee, each of which has the right to terminate the ESPP at any time. g. Stock-based compensation expense for employees and consultants: The Company recognized non-cash stock-based compensation expense in the consolidated statements of operations as follows (in thousands): Year ended December 31, 2020 2019 2018 Cost of revenues $ 5,013 $ 2,561 $ 1,757 Research and development 21,979 13,188 9,645 Sales and marketing 25,578 14,782 16,081 General and administrative 16,015 15,608 7,478 Total $ 68,585 $ 46,139 $ 34,961
Forecast | Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock split, conversion ratio	3
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost not yet recognized | $					$ 141,408			$ 141,408	$ 141,408
Compensation cost not yet recognized, period for recognition					2 years 1 month 13 days
The 2005 Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)										4,713,319
Vesting period (in years)					4 years
Granted (in shares)					0				0
Available for grant (in shares)					0			0	0
The 2005 Stock Plan | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)					0
The 2013 Omnibus Equity Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)				1,904,633
Vesting period (in years)					4 years
Granted (in shares)					0
Percentage of outstanding stock reserved for grant				4.00%
Percentage of outstanding stock maximum				5.00%
Capital shares reserved for future issuance, annual increase, maximum (in shares)					6,796,150			6,796,150	6,796,150
The 2013 Omnibus Equity Award Plan | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)					0
Polyrize Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)		13,427
Granted (in shares)					10,933
Polyrize Plan | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		2,494			605
2015 ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum employee subscription rate			15.00%
Purchase price of common stock, percent			85.00%
Number of shares authorized (in shares)			500,000
Percent of shares increase, employee stock purchase plan			1.00%
Common stock availability threshold, employee stock purchase plan			2.00%
Shares increase threshold, employee stock purchase plan (in shares)			400,000
Number of additional shares authorized (in shares)								846,618

Stockholders' Equity - Stock Op

Stockholders' Equity - Stock Options Activities (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares
Number
Options outstanding at the beginning of the year (in shares) | shares	454,348
Granted (in shares) | shares	10,933
Exercised (in shares) | shares	(123,751)
Forfeited (in shares) | shares	(609)
Options outstanding at the end of the period (in shares) | shares	340,921	454,348
Options exercisable at the end of the year (in shares) | shares	331,759
Weighted average exercise price
Options outstanding at the beginning of the year, weighted average exercise price (in dollars per share) | $ / shares	$ 20.628
Granted, weighted average exercise price (in dollars per share) | $ / shares	17.045
Exercised, weighted average exercise price (in dollars per share) | $ / shares	20.503
Forfeited, weighted average exercise price (in dollars per share) | $ / shares	11.618
Options outstanding at the end of the period, weighted average exercise price (in dollars per share) | $ / shares	20.586	$ 20.628
Options exercisable at the end of the year, weighted average exercise price (in dollars per share) | $ / shares	$ 20.684
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Options outstanding at the beginning of the year, aggregate intrinsic value | $	$ 48,760	$ 25,935
Options exercisable at the end of the year, aggregate intrinsic value | $	$ 47,417
Options outstanding at the beginning of the year, weighted average remaining contractual life (Year)	3 years 7 months 6 days	4 years 4 months 2 days
Options exercisable at the end of the year, weighted average remaining contractual life (Year)	3 years 5 months 12 days

Stockholders' Equity - Options

Stockholders' Equity - Options Outstanding Separated Into Range of Exercise Price (Details)	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Class of Stock [Line Items]
Exercise price range, number of outstanding options (in shares) | shares	340,921,000
Exercise price range, outstanding options, weighted average remaining contractual term (in years)	3 years 7 months 6 days
Exercise price range, outstanding options, weighted average exercise price (in usd per share)	$ 20.586
Exercise price range, number of exercisable options (in shares) | shares	331,759,000
Exercise price range, exercisable options, weighted average remaining contractual term (in years)	3 years 5 months 12 days
Exercise price range, exercisable options, weighted average exercise price (in usd per share)	$ 20.684
Range One
Class of Stock [Line Items]
Exercise price range, lower range limit (in usd per share)	6.230
Exercise price range, upper range limit (in usd per share)	$ 8.800
Exercise price range, number of outstanding options (in shares) | shares	10,356,000
Exercise price range, outstanding options, weighted average remaining contractual term (in years)	1 year 1 month 9 days
Exercise price range, outstanding options, weighted average exercise price (in usd per share)	$ 8.289
Exercise price range, number of exercisable options (in shares) | shares	10,356,000
Exercise price range, exercisable options, weighted average remaining contractual term (in years)	1 year 1 month 9 days
Exercise price range, exercisable options, weighted average exercise price (in usd per share)	$ 8.289
Range Two
Class of Stock [Line Items]
Exercise price range, lower range limit (in usd per share)	12.470
Exercise price range, upper range limit (in usd per share)	$ 17.045
Exercise price range, number of outstanding options (in shares) | shares	100,758,000
Exercise price range, outstanding options, weighted average remaining contractual term (in years)	3 years 9 months 7 days
Exercise price range, outstanding options, weighted average exercise price (in usd per share)	$ 14.639
Exercise price range, number of exercisable options (in shares) | shares	91,596,000
Exercise price range, exercisable options, weighted average remaining contractual term (in years)	3 years 2 months 26 days
Exercise price range, exercisable options, weighted average exercise price (in usd per share)	$ 14.346
Range Three
Class of Stock [Line Items]
Exercise price range, lower range limit (in usd per share)	19.510
Exercise price range, upper range limit (in usd per share)	$ 24.230
Exercise price range, number of outstanding options (in shares) | shares	173,685,000
Exercise price range, outstanding options, weighted average remaining contractual term (in years)	3 years 6 months 10 days
Exercise price range, outstanding options, weighted average exercise price (in usd per share)	$ 21.440
Exercise price range, number of exercisable options (in shares) | shares	173,685,000
Exercise price range, exercisable options, weighted average remaining contractual term (in years)	3 years 6 months 10 days
Exercise price range, exercisable options, weighted average exercise price (in usd per share)	$ 21.440
Range Four
Class of Stock [Line Items]
Exercise price range, number of outstanding options (in shares) | shares	46,548,000
Exercise price range, outstanding options, weighted average remaining contractual term (in years)	4 years 1 month 20 days
Exercise price range, outstanding options, weighted average exercise price (in usd per share)	$ 29.880
Exercise price range, number of exercisable options (in shares) | shares	46,548,000
Exercise price range, exercisable options, weighted average remaining contractual term (in years)	4 years 1 month 20 days
Exercise price range, exercisable options, weighted average exercise price (in usd per share)	$ 29.880
Range Five
Class of Stock [Line Items]
Exercise price range, number of outstanding options (in shares) | shares	9,574,000
Exercise price range, outstanding options, weighted average remaining contractual term (in years)	3 years 2 months 19 days
Exercise price range, outstanding options, weighted average exercise price (in usd per share)	$ 39.860
Exercise price range, number of exercisable options (in shares) | shares	9,574,000
Exercise price range, exercisable options, weighted average remaining contractual term (in years)	3 years 2 months 19 days
Exercise price range, exercisable options, weighted average exercise price (in usd per share)	$ 39.860

Stockholders' Equity - Outstand

Stockholders' Equity - Outstanding Options Granted to Consultants for Sales and Pre-marketing Services (Details) - $ / shares	Oct. 22, 2020	Dec. 31, 2020	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, weighted average exercise price (in dollars per share)		$ 17.045
Options exercisable at the end of the year (in shares)		331,759	331,759
Granted (in shares)		10,933
The 2005 Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		0	0
The 2013 Omnibus Equity Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		0
Polyrize Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		10,933
Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares)		11,200
Options exercisable at the end of the year (in shares)		11,200	11,200
Consultants | The 2005 Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		0
Consultants | The 2013 Omnibus Equity Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		0
Consultants | Polyrize Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	2,494	605
August 2013 | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares)		2,500
Granted, weighted average exercise price (in dollars per share)		$ 21.140
Options exercisable at the end of the year (in shares)		2,500	2,500
Exercisable through		August 2023
March 2014 | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares)		1,650
Granted, weighted average exercise price (in dollars per share)		$ 39.860
Options exercisable at the end of the year (in shares)		1,650	1,650
Exercisable through		March 2024
May 2014 | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares)		2,000
Granted, weighted average exercise price (in dollars per share)		$ 22.010
Options exercisable at the end of the year (in shares)		2,000	2,000
Exercisable through		May 2024
November 2014 | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares)		3,445
Granted, weighted average exercise price (in dollars per share)		$ 21.660
Options exercisable at the end of the year (in shares)		3,445	3,445
Exercisable through		November 2024
February 2016 | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares)		1,000
Granted, weighted average exercise price (in dollars per share)		$ 16.870
Options exercisable at the end of the year (in shares)		1,000	1,000
Exercisable through		February 2026
October 2019 | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares)		393
Granted, weighted average exercise price (in dollars per share)		$ 17.045
Options exercisable at the end of the year (in shares)		393	393
Exercisable through		October 2029
May 2020 | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares)		212
Granted, weighted average exercise price (in dollars per share)		$ 17.045
Options exercisable at the end of the year (in shares)		212	212
Exercisable through		May 2030

Stockholders' Equity - Restrict

Stockholders' Equity - Restricted Stock Unit Activity (Details) - Restricted Stock Units (RSUs)	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Number of Shares Underlying Outstanding Restricted Stock Units
Balance, restricted stock units (in shares) | shares	2,559,083
Granted, restricted stock units (in shares) | shares	1,395,697
Vested, restricted stock units (in shares) | shares	(950,323)
Forfeited, restricted stock units (in shares) | shares	(208,136)
Balance, restricted stock units (in shares) | shares	2,796,321
Weighted- Average Grant Date Fair Value
Balance, weighted average grant date fair value on restricted stock units (in dollars per share) | $ / shares	$ 49.58
Granted, weighted average grant date fair value on restricted stock units (in dollars per share) | $ / shares	87.03
Vested, weighted average grant date fair value on restricted stock units (in dollars per share) | $ / shares	44.63
Forfeited, weighted average grant date fair value on restricted stock units (in dollars per share) | $ / shares	62.40
Balance, weighted average grant date fair value on restricted stock units (in dollars per share) | $ / shares	$ 69.01

Stockholders' Equity - Non-cash

Stockholders' Equity - Non-cash Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 68,585	$ 46,139	$ 34,961
Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	5,013	2,561	1,757
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	21,979	13,188	9,645
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	25,578	14,782	16,081
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 16,015	$ 15,608	$ 7,478

Income Taxes (Details Textual)

Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Tax Credit Carryforward [Line Items]
Valuation allowance, deferred tax asset, increase (decrease), amount	$ 14,943	$ 22,818
Unrecognized tax benefits	4,690	$ 3,201	$ 1,954
Unrecognized tax benefits that would impact effective tax rate	4,407
Unrecognized tax benefits, income tax penalties and interest expense	538
Domestic Tax Authority
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	207,768
Operating loss carryforwards, subject to expiration	22,907
State and Local Jurisdiction
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	146,121
Operating loss carryforwards, subject to expiration	129,143
Foreign Tax Authority
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	1,321
Deferred income tax asset	$ 1,131
Israel Tax Authority | Foreign Tax Authority | VSL | Minimum
Tax Credit Carryforward [Line Items]
Tax rate for amount of dividends distributed, other than complete liquidation	10.00%
Israel Tax Authority | Foreign Tax Authority | VSL | Maximum
Tax Credit Carryforward [Line Items]
Tax rate for amount of dividends distributed, other than complete liquidation	25.00%
Research Tax Credit Carryforward | Domestic Tax Authority
Tax Credit Carryforward [Line Items]
Tax credit carryforward, amount	$ 1,412
Retention | Domestic Tax Authority
Tax Credit Carryforward [Line Items]
Tax credit carryforward, amount	24
Foreign Tax Credit | Domestic Tax Authority
Tax Credit Carryforward [Line Items]
Tax credit carryforward, amount	190
Ireland Employment | Domestic Tax Authority
Tax Credit Carryforward [Line Items]
Tax credit carryforward, amount	$ 16

Income Taxes - Schedule of Prof

Income Taxes - Schedule of Profit (Loss) Before Taxes on Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Domestic	$ (80,086)	$ (82,007)	$ (25,557)
Foreign	(5,812)	5,631	(2,608)
Loss before income taxes	$ (85,898)	$ (76,376)	$ (28,165)

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Taxes on Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ 90	$ 665	$ 0
State	128	13	169
Foreign	8,854	1,619	1,498
Total current income tax	9,072	2,297	1,667
Deferred:
Federal	8	0	0
State	1	0	0
Foreign	(969)	91	(1,254)
Total deferred income tax	(960)	91	(1,254)
Income tax expense	$ 8,112	$ 2,388	$ 413

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Deferred Tax Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Carry forward losses and credits	$ 53,221	$ 36,092
Deferred revenues	13,054	13,953
Accrued payroll, commissions, vacation	3,808	2,666
Equity compensation	10,348	6,220
Allowance for doubtful accounts	1,287	978
Accrued severance pay	312	340
Operating lease liability	11,302	12,244
Other	963	532
Deferred tax assets before valuation allowance	94,295	73,025
Valuation allowance	(77,542)	(62,379)
Deferred tax assets	16,753	10,646
Deferred tax liability:
Accrued compensation and other accrued expense	(48)	(187)
Operating lease right-of-use asset	(8,780)	(10,291)
Convertible senior notes, net	(6,797)	0
Deferred tax liability	(15,625)	(10,478)
Net deferred tax asset	$ 1,128	$ 168

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Theoretical Tax Expense and Actual Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Loss before taxes, as reported in the consolidated statements of operations	$ (85,898)	$ (76,376)	$ (28,165)
Statutory tax rate	21.00%	21.00%	21.00%
Theoretical tax benefits on the above amount at the US statutory tax rate	$ (18,039)	$ (16,039)	$ (5,915)
Income tax at rate other than the U.S. statutory tax rate	4,845	(2,508)	692
Tax advances and non-deductible expenses including equity based compensation expenses	934	(115)	(7,623)
Operating losses and other temporary differences for which valuation allowance was provided	22,189	22,818	15,826
State tax	(2,872)	(3,436)	(1,221)
Impact of rate change	0	401	0
Change in tax reserve for uncertain tax positions	1,489	1,247	(1,728)
Other individually immaterial income tax items	(434)	20	382
Income tax expense	$ 8,112	$ 2,388	$ 413

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross unrecognized tax benefits	$ 3,201	$ 1,954
Increase in tax position for current year	1,787	1,545
Increase in tax position for prior years	979	387
Decrease in tax position for prior years	(171)
Decrease for lapse of statute of limitations/settlements	(1,106)	(685)
Gross unrecognized tax benefits	$ 4,690	$ 3,201

Financial Income (Expenses), _3

Financial Income (Expenses), Net - Summary of Financial Income and Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financial Income (Expenses), Net [Abstract]
Interest on bank deposits & other	$ 674	$ 2,041	$ 1,741
Financial income	674	2,041	1,741
Amortization of issuance costs	4,096	0	0
Interest expenses, principally from convertible note	2,017	0	0
Foreign currency transaction losses, net	1,726	2,225	574
Bank and other charges	318	205	197
Financial expenses	(8,157)	(2,430)	(771)
Total	$ (7,483)	$ (389)	$ 970

Geographic Information and Ma_3

Geographic Information and Major Customer and Product Data (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)segment	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	1
Revenue	$ 292,689	$ 254,190	$ 270,288
France
Segment Reporting Information [Line Items]
Revenue	$ 30,937		$ 31,532

Geographic Information and Ma_4

Geographic Information and Major Customer and Product Data - Revenues Within Geographical Areas (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Revenue	$ 292,689	$ 254,190	$ 270,288
North America
Segment Reporting Information [Line Items]
Revenue	207,488	174,607	167,361
EMEA
Segment Reporting Information [Line Items]
Revenue	77,093	70,208	93,816
Rest of World
Segment Reporting Information [Line Items]
Revenue	$ 8,108	$ 9,375	$ 9,111

Geographic Information and Ma_5

Geographic Information and Major Customer and Product Data - Long-lived Assets by Geographic Region (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Long-lived assets	$ 85,087	$ 91,395
Israel
Segment Reporting Information [Line Items]
Long-lived assets	42,471	45,382
United States
Segment Reporting Information [Line Items]
Long-lived assets	30,938	42,590
Ireland
Segment Reporting Information [Line Items]
Long-lived assets	9,684	597
Other
Segment Reporting Information [Line Items]
Long-lived assets	$ 1,994	$ 2,826