0001437749-21-003648 | 10-K | XBRL Viewer

Basis of Presentation and Significant Accounting Policies [Text Block]

NOTE 1.

The Company and Summary of Significant Accounting Policies

Description of Business

Qualys, Inc. (the “Company”, "we", "us", "our") was incorporated in the state of Delaware on December 30, 1999. The Company is headquartered in Foster City, California and has wholly-owned subsidiaries throughout the world. The Company is a pioneer and leading provider of cloud-based IT, security and compliance solutions that enable organizations to identify security risks to their IT infrastructures, help protect their IT systems and applications from ever-evolving cyber-attacks and achieve compliance with internal policies and external regulations. The Company’s cloud solutions address the growing security and compliance complexities and risks that are amplified by the dissolving boundaries between internal and external IT infrastructures and web environments, the rapid adoption of cloud computing and the proliferation of geographically dispersed IT assets. Organizations can use the Company’s integrated suite of solutions delivered on its Qualys Cloud Platform to cost-effectively obtain a unified view of their security and compliance posture across globally-distributed IT infrastructures.

Basis of Presentation

The accompanying consolidated financial statements and footnotes have been prepared in accordance with U.S. GAAP as well as the instructions to Form 10-K and the rules and regulations of the SEC. In the opinion of management, the accompanying consolidated financial statements reflect all adjustments, which include only normal recurring adjustments, necessary for the fair presentation of the Company’s consolidated financial position, results of operations and cash flows for the periods presented. The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated upon consolidation.

Certain reclassifications have been made to the prior years' consolidated financial statements to conform to the current year presentation. The reclassifications did not have material effects on the prior year’s consolidated financial statements.

Risks and Uncertainties

In March 2020, the World Health Organization declared the outbreak of COVID-19 as a pandemic. As a result of COVID-19, the Company has modified certain aspects of its business, including restricting employee travel, requiring employees to work from home, and canceling certain events and meetings, among other modifications. The Company will continue to actively monitor the situation and may take further actions that alter its business operations as may be required by federal, state or local authorities or that the Company determines are in the best interests of its employees, customers, partners, suppliers and stockholders. COVID-19 has not had and is not expected to have a significant impact on the Company's business in 2021. However, while the Company has not incurred significant disruptions from the COVID-19 outbreak, the Company is unable to accurately predict the full impact that COVID-19 will have due to numerous uncertainties, including the duration of the outbreak, actions that may be taken by governmental authorities and the impact to the business of its customers and partners. The Company will continue to evaluate the nature and extent of the impact to its business, financial position, results of operations and cash flows.

Use of Estimates

The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of assets and liabilities at the date of the consolidated financial statements and the reported results of operations during the reporting period. The Company’s management regularly assesses these estimates, which primarily affect revenue recognition, the valuation of accounts receivable, goodwill and intangible assets, capitalization of internally developed software, stock-based compensation and the provision for income taxes. Actual results could differ from those estimates and such differences may be material to the accompanying consolidated financial statements.

Concentration of Credit Risk

The Company invests its cash and cash equivalents with major financial institutions. Cash balances with any one institution at times may be in excess of federally insured limits. Cash equivalents are invested in high-quality investment grade financial instruments and are diversified. The Company has not experienced any losses in such accounts and believes it is not exposed to any significant credit risk.

Credit risk with respect to accounts receivable is dispersed due to the large number of customers. Collateral is not required for accounts receivable. As of December 31, 2020 and 2019, no customer or channel partner accounted for more than 10% of the Company's revenues and accounts receivable balance.

Cash, Cash Equivalents, Restricted cash and Short-Term and Long-Term Marketable Securities

Cash and cash equivalents include cash held in banks, highly liquid money market funds and commercial paper, all with original maturities of three months or less when acquired. The Company’s short-term and long-term marketable securities consist of fixed-income U.S. and foreign government agency securities, corporate bonds, asset-backed securities and commercial paper. Management determines the appropriate classification of the Company's investments at the time of purchase and reevaluates such designation at each balance sheet date. The Company classifies its marketable securities as either short-term or long-term based on each instrument's underlying remaining contractual maturity date.

As of both December 31, 2020 and 2019, the Company has a restricted cash balance of $1.2 million in the form of a letter of credit issued to the landlord of the Company's California headquarter office lease as security deposit.

Cash equivalents are stated at cost, which approximates fair market value. Short-term and long-term marketable securities are classified as available-for-sale debt securities (AFS debt securities) and are carried at fair value. Unrealized gains and losses in fair value of the AFS debt securities are reported in other comprehensive income (loss). When the AFS debt securities are sold, cost is based on the specific identification method, and the realized gains and losses are included in other income (expense), net in the consolidated statements of operations. AFS debt securities are reviewed quarterly for impairment. An investment is considered impaired when its fair value is below its amortized cost. Declines in fair value from amortized cost for AFS debt securities that the company intends to sell or will more likely than not be required to sell before the expected recovery of the amortized cost basis are charged to other income (expense), net in the period in which the loss occurs. Otherwise, the credit loss component of the impairment is recorded as allowance for credit losses with an offsetting entry charged to other income (expense), net, while the remaining loss is recognized in other comprehensive income (loss).

Accounts Receivable

Accounts receivable are recorded at the invoiced amount and do not bear interest. The allowance for credit losses is determined on a collective basis where similar risk characteristics exist and on an individual basis when we identify significant customers or invoices with collectability issues. The estimate for credit losses considers historical write-offs by aging category, that are adjusted for current conditions and reasonable and supportable forecasts of future losses. Any change in the assumptions used in analyzing credit losses may result in additional allowances being recognized in the period in which the change occurs. When the Company ultimately concludes that a receivable is uncollectible, the balance is written off against the allowance for credit losses. Payments subsequently received on such receivables are recognized in the period received. The allowance for credit losses recognized and write-offs charged against the allowance were not significant for the years ended December 31, 2020 and 2019.

Non-marketable securities

During the fiscal year ended December 31, 2018, the Company invested $2.5 million in preferred stock of a privately-held company. The fair value of the investment is not readily available, and there are no quoted market prices for the investment. The Company elected the measurement alternative to account for the investment at cost less impairment and will measure the investment at fair value when the Company identifies observable price changes. The investment is assessed for impairment annually or whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. No impairment has been incurred related to the investment. The investment is included in other noncurrent assets on the consolidated balance sheets. The Company has not received any dividends from the investment.

Property and Equipment, net

Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which range from three to five years. Leasehold improvements are amortized on a straight-line basis over the lesser of the estimated useful life of the asset or the remaining lease term.

The Company purchases physical scanner appliances and other computer equipment that are provided to customers on a subscription basis. This equipment is recorded within property and equipment and the depreciation is recorded in cost of revenues over an estimated useful life of three years.

Upon retirement or disposal, the cost of assets and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is reflected in the consolidated statements of operations. Repairs and maintenance that do not extend the life of an asset are expensed as incurred and major improvements are capitalized as property and equipment.

Leases

The Company leases certain offices, computer equipment and its data center facilities under finance leases and non-cancelable operating leases. On January 1, 2019, the Company adopted ASC 842 Leases using the current period adjustment method with an effective date of January 1, 2019. For both operating and finance leases, we recognize a right-of-use asset, which represents our right to use the underlying asset for the lease term, and a lease liability, which represents the present value of our obligation to make payments arising over the lease term. Many of our leases include rental escalation clauses, renewal options and/or termination options that are factored into our determination of lease payments and lease terms when appropriate. The present value of the lease payments is calculated using the incremental borrowing rate of the underlying leases determined at lease commencement. As most of our leases do not provide a readily determinable implicit rate, the Company determines an incremental borrowing rate using a portfolio approach based on the rate of interest that the Company would have to pay to borrow an amount equal to the lease payments on a collateralized basis over a similar term as the leases.

Where the Company is the lessee, the Company elects to account for non-lease components associated with its leases (e.g., common area maintenance costs) and lease components separately for substantially all of its asset classes, except for data centers, for which the Company elected to combine lease and non-lease components. For leases with a term of one year or less, the Company has elected not to record the right-of-use asset or liability.

In arrangements where the Company is the lessor, the Company elected to apply the practical expedient to account for lease components (e.g., customer premise equipment) and non-lease components (e.g., service revenue) as combined components as revenue under ASC 606 as service revenues are the predominant components in the arrangements.

Impairment of Long-Lived Assets

The Company evaluates its long-lived assets, which consist of property and equipment, and intangible assets subject to amortization, for indicators of possible impairment when events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. Impairment exists if the carrying amounts of such assets exceed the estimates of future undiscounted cash flows expected to be generated by such assets. Should an impairment exist, the impairment loss would be measured based on the excess carrying value of the asset over the asset’s estimated fair value. In each of 2020, 2019 and 2018, the Company had no impairment of long-lived assets.

Goodwill and Intangible Assets

Goodwill represents the excess of the purchase price over the fair value of the net tangible and identifiable intangible assets acquired in a business combination and is not subject to amortization. Goodwill and other intangible assets with indefinite lives are not amortized, but tested for impairment at least annually or more frequently if certain circumstances indicate a possible impairment may exist. These tests are performed at the reporting unit level. The Company’s operations are organized as one reporting unit.

In testing for a potential impairment of goodwill, the Company first performs a qualitative assessment of its reporting unit to determine if it is more likely than not (a more than 50% likelihood) that the fair value of the reporting unit is less than its carrying amount. If the fair value is not considered to be less than the carrying amount, no further evaluation is necessary. The Company performed the annual assessment on December 1, 2020 and 2019 and concluded there was no potential impairment of goodwill.

In testing for a potential impairment of intangible assets with indefinite lives that are not subject to amortization, the Company first performs a qualitative assessment to determine if it is more likely than not (a more than 50% likelihood) that the fair value of the indefinite-lived intangible assets is less than the carrying amount. If the fair value is not considered to be less than the carrying amount, no further evaluation is necessary. The Company performs the annual qualitative assessment in the fourth quarter each fiscal year. There were no such impairment losses during 2020, 2019 and 2018.

If the qualitative assessment indicates there is more than a 50% likelihood that the fair value is less than the carrying amount of the reporting unit or the intangible asset, the Company would perform a quantitative test. Goodwill impairment is measured as the amount by which a reporting unit’s carrying value exceeds its fair value. For indefinite-lived intangible assets, the Company would perform the quantitative impairment test by comparing the fair value of the indefinite-lived intangible asset with its carrying value.

Internally Developed Software

Costs incurred in the development phase are capitalized and amortized over the product’s estimated useful life, which is three years. Capitalized costs include salaries, benefits and stock-based compensation charges for employees that are directly involved in developing its cloud security platform during the post planning and implementation phases. Capitalized costs related to internally developed software under development are treated as construction in progress until the program, feature or functionality is ready for its intended use, at which time amortization commences. These capitalized costs are included in other noncurrent assets on the consolidated balance sheets. For the fiscal years 2020, 2019 and 2018, the Company capitalized $1.0 million, $1.0 million and $1.3 million of costs related to internally developed software (of which $0.2 million, $0.2 million and $0.2 million, respectively, were stock-based compensation), respectively. As of December 31, 2020 and 2019, unamortized internally developed software costs totaled $2.6 million and $2.0 million, respectively. Amortization of internally developed software is recorded in cost of revenues. Costs associated with minor enhancements and maintenance are expensed as incurred. Management evaluates the useful lives of these assets on an annual basis and tests for impairment whenever events or changes in circumstances occur that could impact the recoverability of these assets.

Business Combinations

The Company applies the provisions of ASC 805, Business Combinations, in accounting for its acquisitions. It requires the Company to recognize separately from goodwill the assets acquired and the liabilities assumed at their acquisition date fair values. Goodwill as of the acquisition date is measured as the excess of consideration transferred over the net of the acquisition date fair values of the assets acquired and the liabilities assumed. While the Company uses its best estimates and assumptions to accurately value assets acquired and liabilities assumed at the acquisition date as well as any contingent consideration, where applicable, its estimates are inherently uncertain and subject to refinement. As a result, during the measurement period, which may be up to one year from the acquisition date, the Company records adjustments to the assets acquired and liabilities assumed with the corresponding offset to goodwill. Upon the conclusion of the measurement period or final determination of the values of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded to its consolidated statements of operations.

Derivative Financial Instruments

Derivative financial instruments are utilized by the Company to reduce foreign currency exchange risks. The Company uses foreign currency forward contracts, with maturities of 13 months or less, to mitigate the impact of foreign currency fluctuations of certain non-U.S. dollar denominated net asset positions, to date primarily cash, accounts receivable and operating lease liabilities, as well as to manage foreign currency fluctuation risk related to forecasted transactions. Open contracts are recorded within prepaid expenses and other current assets, other noncurrent assets, accrued liabilities or other noncurrent liabilities in the consolidated balance sheets. Gains and losses resulting from currency exchange rate movements on non-designated forward contracts are recognized in other income (expense), net. Any gains or losses from derivatives designated as cash flow hedges are first recorded within accumulated other comprehensive income ("AOCI") and then reclassified into revenue or operating expenses when the hedged item impacts the consolidated statements of operations. Cash flows related to these forward contracts are classified in our consolidated statements of cash flows in the same manner as the underlying hedged transaction within cash flows from operating activities.

Stock-Based Compensation

The Company recognizes the fair value of its employee stock options and restricted stock units (RSU) on a straight-line basis over the requisite service periods for those awards ultimately expected to vest. The fair value of each option is estimated on the date of grant using the Black-Scholes-Merton option pricing model and the fair value of each RSU is based on the price of the Company's stock on the date of grant. Forfeitures are estimated on the date of grant and revised if actual or expected forfeiture activity differs materially from original estimates.

For performance-based non-qualified stock options (PSO) and performance-based restricted stock units (PSU), we recognize compensation costs over the requisite service period when it is probable that the performance conditions will be met. We assess these conditions on a quarterly basis.

Revenue Recognition

The Company derives revenues from subscriptions that require customers to pay a fee in order to access the Company’s cloud solutions. Contract period with customers generally ranges from less than a year to five years. The subscription fee entitles the customer to an unlimited number of scans for a specified number of networked devices or web applications and, if requested by a customer as part of their subscription, a specified number of physical or virtual scanner appliances. The Company’s physical and virtual scanner appliances are requested by certain customers as part of their subscriptions in order to scan IT infrastructures within their firewalls and do not function without, and are not sold separately from, subscriptions for the Company’s solutions. In some limited cases, the Company also provides certain computer equipment used to extend its Qualys Cloud Platform into its customers’ private cloud environment. Customers are required to return physical scanner appliances and computer equipment if they do not renew their subscriptions.

The Company determines revenue recognition through the following steps:

•

Identification of the contract, or contracts, with a customer;

•

Identification of the performance obligations in the contract;

•

Determination of the transaction price

•

Allocation of the transaction price to the performance obligations in the contract; and

•

Recognition of revenue when, or as, the Company satisfies a performance obligation.

At the inception of a customer contract, the Company makes an assessment as to that customer's ability to pay for the services provided. The Company assesses collectability based on a number of factors, including credit worthiness of the customer along with past transaction history. In addition, the Company performs periodic evaluations of its customers’ financial condition.

The vast majority of the Company’s revenue contracts are subscription based and contain a single performance obligation. In the rare case that multiple performance obligations exist, the Company determines the standalone selling prices ("SSP") of each performance obligation at contract inception, using information that may include market conditions and other observable inputs. As the Company, in general, does not offer rights of return, performance bonuses, customer loyalty programs, payments via non-cash methods, refunds, volume rebates, incentive payments, penalties, price concessions or payments or discounts contingent on future events, the contract prices are generally composed of fixed amount consideration for a specific period of time and typically do not include variable consideration. The subscription contracts typically do not confer to the customers any future rights that would constitute material rights under ASC 606.

Revenue is recognized when control of the subscription service is transferred to its customers in an amount that reflects the consideration the Company expects to be entitled to in exchange for those services. The Company's subscription services are typically satisfied ratably over the subscription term as its cloud-based offerings are delivered to customers electronically and over time. In addition, the Company recognizes revenues for certain limited scan arrangements on an as-used basis. The Company recognizes revenue related to professional services based on time and materials or completion of milestones stated in the contracts. When physical equipment are provided to the customers as part of the subscription service contract, the Company applies the practical expedient allowed under ASC 842 Leases to combine lease and nonlease components as a combined component to be accounted for under ASC 606, as the Company determined that the software subscription is the predominant component of the combined components. Therefore, the Company recognizes revenue for the physical equipment ratably over the related subscription period.

Deferred revenues consist of customer contracts billed or cash received that will be recognized in the future under subscriptions existing at the balance sheet date. The current portion of deferred revenues represents amounts that are expected to be recognized within one year of the balance sheet date.

Costs of shipping and handling charges incurred by the Company associated with physical scanner appliances and other computer equipment are included in cost of revenues. Sales taxes and other taxes collected from customers to be remitted to government authorities are excluded from revenues.

Incremental direct costs of obtaining a contract, which consist of sales commissions primarily for new business and upsells, are deferred and amortized over the estimated life of the customer relationship if renewals are expected and the renewal commission is not commensurate with the initial commission. The Company elected the practical expedient to expense commissions on renewals where the specific anticipated contract term amortization period is one year or less. The Company amortizes the capitalized commission cost as a selling expense on a straight-line basis over a period of five years. The Company classifies deferred commissions as current or noncurrent based on the timing of when it expects to recognize the expense. The current and noncurrent portions of deferred commissions are included in prepaid expenses and other current assets and other noncurrent assets, respectively, in its consolidated balance sheets.

Advertising Expenses

Advertising costs are expensed as incurred and include costs of advertising and promotional materials. The Company incurred advertising costs of $207 thousand, $74 thousand and $87 thousand for 2020, 2019 and 2018, respectively.

Income Taxes

The Company provides for the effect of income taxes in its consolidated financial statements using the asset and liability method which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, net operating loss carryovers, and tax credit carry forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the period that includes the enactment date.

Income tax expense or benefit is recognized for the amount of taxes payable or refundable for the current year and for deferred tax assets and liabilities for the tax consequences of events that have been recognized in an entity’s financial statements or tax returns. The Company must make significant assumptions, judgments and estimates to determine its current provision for (benefit from) income taxes, its deferred tax assets and liabilities, and any valuation allowance to be recorded against its deferred tax assets. The Company's judgments, assumptions and estimates relating to the current provision for (benefit from) income taxes include the geographic mix and amount of income (loss), its interpretation of current tax laws, and possible outcomes of current and future audits conducted by foreign and domestic tax authorities. The Company's judgments also include anticipating the tax positions the Company will record in the consolidated financial statements before actually preparing and filing the tax returns. The Company's estimates and assumptions may differ from the actual results as reflected on its income tax returns and will record the required adjustments when they are identified or resolved. Changes in the Company's business, tax laws or its interpretation of tax laws, and developments in current and future tax audits, could significantly impact the amounts provided for income taxes in the Company's results of operations, financial position, or cash flows.

Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to tax benefit carry-forwards and to differences between the financial statement amounts of assets and liabilities and their respective tax basis. The Company regularly reviews its deferred tax assets for recoverability and establishes a valuation allowance if it is more likely than not that some portion or all of the deferred tax assets will not be realized. To make this assessment, the Company takes into account predictions of the amount and category of taxable income from various sources and all available positive and negative evidence about these possible sources of taxable income. The weight given to the potential effect of negative and positive evidence is commensurate with the extent to which the strength of the evidence can be objectively verified.

The Company applies a two-step approach to determining the financial statement recognition and measurement of uncertain tax positions. The Company only recognizes an income tax expense or benefit with respect to uncertain tax positions in its financial statements that the Company judges is more likely than not to be sustained solely on its technical merits in a tax audit, including resolution of any related appeals or litigation processes. To make this judgment, the Company must interpret complex and sometimes ambiguous tax laws, regulations and administrative practices. If an income tax position meets the more likely than not recognition threshold, then the Company must measure the amount of the tax benefit to be recognized by determining the largest amount of tax benefit that has a greater than a 50% likelihood of being realized upon effective settlement with a taxing authority that has full knowledge of all of the relevant facts. It is inherently difficult and subjective to estimate such amounts, as this requires the Company to determine the probability of various possible settlement outcomes. To determine if a tax position is effectively settled after a tax examination has been completed, the Company must also estimate the likelihood that another taxing authority could review the respective tax position. The Company must also determine when it is reasonably possible that the amount of unrecognized tax benefits will significantly increase or decrease in the 12 months after each fiscal year-end. These judgments are difficult because a taxing authority may change its behavior as a result of the Company's disclosures in its financial statements. The Company must reevaluate its income tax positions on a quarterly basis to consider factors such as changes in facts or circumstances, changes in tax law, effectively settled issues under audit, and new audit activity. Such a change in recognition or measurement would result in recognition of a tax benefit or an additional charge to the tax provision. The Company's policy is to recognize interest and penalties related to unrecognized tax benefits as a component of the provision for income taxes.

Comprehensive Income (Loss)

Other comprehensive income (loss) consists of unrealized gains (losses) on marketable securities, net of tax, and derivative financial instruments designated as cash flow hedges which are not included in the Company’s net income. Total comprehensive income includes net income and other comprehensive income (loss) and is included in the consolidated statements of comprehensive income.

Foreign Currency Transactions

The Company’s operations are conducted in various countries around the world and the financial statements of its foreign subsidiaries are reported in the U.S. dollar as their respective functional currency. Monetary assets and liabilities denominated in foreign currencies have been re-measured into U.S. dollars using the exchange rates in effect at the balance sheet date, and income and expenses are re-measured at average exchange rates during the period. Foreign currency re-measurement gains and losses and foreign currency transaction gains and losses are recognized in other income (expense), net. The Company recorded total foreign currency transaction gain of $0.3 million and losses of $0.4 million and $0.6 million during 2020, 2019 and 2018, respectively.

Net Income Per Share

Basic net income per share is computed by dividing net income by the weighted-average number of common shares outstanding during the period. All participating securities are excluded from basic weighted average common shares outstanding. Diluted net income per share is computed by dividing net income by the weighted-average number of shares of common stock outstanding during the period, adjusted for the effects of potentially dilutive common shares, which are comprised of outstanding stock options and RSUs. The dilutive potential common shares are computed using the treasury stock method or the as-if converted method, as applicable. The outstanding stock options and RSUs which would be anti-dilutive are excluded from the computation of diluted net income per common share.

Recently Adopted Accounting Pronouncements

In August 2018, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("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. This ASU aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs related to internal-use software. It also requires the Company to expense the capitalized implementation costs of a hosting arrangement that is a service contract over the term of the hosting arrangement. The Company adopted this ASU prospectively to applicable implementation costs incurred since January 1, 2020. The adoption did not have a material impact on the Company's consolidated financial statements.

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326) as modified by subsequently issued ASU No. 2018-19, 2019-04, 2019-05 and 2019-11, which introduces a new accounting model, Current Expected Credit Losses ("CECL"). CECL requires earlier recognition of credit losses, while also providing additional transparency about credit risk. CECL utilizes a lifetime expected credit loss measurement objective for the recognition of credit losses at the time the financial asset is originated or acquired. The expected credit losses are adjusted each period for changes in expected lifetime credit losses. The Company adopted this ASU on January 1, 2020, using a modified retrospective transition method, which requires a cumulative-effect adjustment, if any, to the opening balance of retained earnings to be recognized on the date of adoption with prior periods not restated. The adoption did not have a material impact on the Company's consolidated financial statements.

Recently Issued Accounting Pronouncements Not Yet Adopted

In December 2019, the FASB issued ASU No. 2019-12, Simplifying the Accounting for Income Taxes (ASU 2019-12), which simplifies the accounting for income taxes, eliminates certain exceptions within ASC 740, Income Taxes, and clarifies certain aspects of the current guidance to promote consistency among reporting entities. ASU 2019-12 is effective for the Company for fiscal years beginning after December 15, 2020. Most amendments within the standard are required to be applied on a prospective basis, while certain amendments must be applied on a retrospective or modified retrospective basis. The adoption of this ASU is not expected to have a material impact on the Company's consolidated financial statements.

Note 2 - Fair Value of Financial Instruments

12 Months Ended

Dec. 31, 2020

Fair Value Disclosures [Text Block]

NOTE 2.

Fair Value of Financial Instruments

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. For certain of the Company’s financial instruments, including certain cash equivalents, accounts receivable, accounts payable and accrued liabilities, the carrying amounts approximate their fair values due to the relatively short maturity of these balances.

The Company measures and reports certain cash equivalents, marketable securities, derivative foreign currency forward contracts at fair value in accordance with the provisions of the authoritative accounting guidance that addresses fair value measurements. This guidance establishes a hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available. The hierarchy is broken down into three levels based on the reliability of inputs as follows:

Level 1-Valuations based on quoted prices in active markets for identical assets or liabilities.

Level 2-Valuations based on other than quoted prices in active markets for identical assets and liabilities, including quoted prices for identical assets or liabilities in less active or inactive markets, quoted prices for similar assets or liabilities in active markets, or inputs other than quoted prices that are observable for substantially the full term of the assets or liabilities.

Level 3-Valuations based on inputs that are generally unobservable and typically reflect management’s estimates of assumptions that market participants would use in pricing the asset or liability.

The Company's financial instruments consist of assets and liabilities measured using Level 1 and 2 inputs. Level 1 assets include a highly liquid money market fund, which is valued using unadjusted quoted prices that are available in an active market for an identical asset. Level 2 assets include fixed-income U.S. and foreign government agency securities, commercial paper, corporate bonds, asset-backed securities and derivative financial instruments consisting of foreign currency forward contracts. The securities, bonds and commercial paper are valued using prices from independent pricing services based on quoted prices of identical instruments in less active or inactive market, quoted prices of similar instruments in active market or industry models using data inputs such as interest rates and prices that can be directly observed or corroborated in active markets. The foreign currency forward contracts are valued using observable inputs, such as quotations on forward foreign exchange points and foreign interest rates.

The Company's cash and cash equivalents, short-term marketable securities, and long-term marketable securities consist of the following:

	*December 31, 2020*
	*Amortized Cost*		*Unrealized Gains*		*Unrealized Losses*			*Fair Value*
	(in thousands)
Cash and cash equivalents:
Cash	$	33,105	$	—	$	—		$	33,105
Money market funds		38,028		—		—			38,028
Commercial paper		2,999		—		—			2,999
Total		74,132		—		—			74,132
Short-term marketable securities:
Commercial paper		6,147		—		—			6,147
Corporate bonds		24,368		170		—			24,538
Asset-backed securities		6,263		18		—			6,281
U.S. government agencies		244,568		369		(11	)		244,926
Total		281,346		557		(11	)		281,892
Long-term marketable securities:
Asset-backed securities		38,456		160		(3	)		38,613
U.S. government agencies		6,884		17		—			6,901
Foreign government agencies		1,006		31		—			1,037
Corporate bonds		51,068		839		—			51,907
Total		97,414		1,047		(3	)		98,458
Total	$	452,892	$	1,604	$	(14	)	$	454,482

December 31, 2019

Amortized Cost

Unrealized Gains

Unrealized Losses

Fair Value

(in thousands)

Cash and cash equivalents:

Cash
$ 84,102 $ — $ — $ 84,102

Money market funds
58 — — 58

Commercial paper 3,399 — — 3,399

Total
87,559 — — 87,559

Short-term marketable securities:

Commercial paper
2,239 — — 2,239

Corporate bonds
33,048 51 (1 ) 33,098

Asset-backed securities
2,438 11 — 2,449

U.S. government agencies
173,364 184 (3 ) 173,545

Total
211,089 246 (4 ) 211,331

Long-term marketable securities:

Asset-backed securities
40,001 193 (1 ) 40,193

U.S. government agencies
46,447 370 — 46,817

Corporate bonds
32,236 262 — 32,498

Total
118,684 825 (1 ) 119,508

Total
$ 417,332 $ 1,071 $ (5 ) $ 418,398

As of December 31, 2020 and 2019, there were no marketable securities that had been in a continuous unrealized loss position for 12 months or longer. The Company had the ability and intent to hold all marketable securities that were in an unrealized loss position until recovery of the amortized cost basis. The Company considered the extent to which fair value was less than amortized cost basis and conditions related to security’s industry and geography and changes to the ratings, if any, and concluded the decline in fair value compared to carrying value was not related to credit loss.

The following table sets forth by level within the fair value hierarchy the fair value of the Company's cash equivalents and marketable securities measured on a recurring basis:

	*December 31, 2020*
	*Level 1*		*Level 2*		*Fair Value*
	(in thousands)
Money market funds	$	38,028	$	—	$	38,028
Commercial paper		—		9,146		9,146
U.S. government agencies		—		251,827		251,827
Foreign government agencies		—		1,037		1,037
Corporate bonds		—		76,445		76,445
Asset-backed securities		—		44,894		44,894
Total	$	38,028	$	383,349	$	421,377

	*December 31, 2019*
	*Level 1*		*Level 2*		*Fair Value*
	(in thousands)
Money market funds	$	58	$	—	$	58
Commercial paper		—		5,638		5,638
U.S. government agencies		—		220,362		220,362
Corporate bonds		—		65,596		65,596
Asset-backed securities		—		42,642		42,642
Total	$	58	$	334,238	$	334,296

As of December 31, 2020 and 2019, the Company had no investments utilizing level 3 inputs.

The following summarizes the fair value of marketable securities classified as AFS debt securities by contractual maturity:

	*December 31, 2020*
	*Mature within One Year*		*After One Year through Two Years*		*Over Two Years*		*Fair Value*
	(in thousands)
Commercial paper	$	9,146	$	—	$	—	$	9,146
U.S. government agencies		244,925		6,715		187		251,827
Foreign government agencies		—		—		1,037		1,037
Corporate bonds		24,538		31,983		19,924		76,445
Asset-backed securities		6,282		18,642		19,970		44,894
Total	$	284,891	$	57,340	$	41,118	$	383,349

Derivative Financial Instruments

Designated cash flow hedges

The Company uses a hedging strategy to reduce its exposure to foreign currency exchange rate fluctuations for forecasted subscription renewals and new orders in both GBP and Euro. The Company uses forward currency contracts accounted for as cash flow hedges against a designated portion of forecasted subscription renewals and new orders. Unrealized foreign exchange gains or losses related to those designated cash flow hedge contracts are recorded in AOCI and will be reclassified into revenues in the same periods when the hedged contracts are recognized into revenues.

In addition, the Company uses a hedging strategy to reduce its exposure associated with costs incurred in INR. Unrealized foreign exchange gains or losses related to those designated cash flow hedge contracts are recorded in AOCI and will be reclassified into operating expenses when the associated hedged expenses are incurred.

At December 31, 2020, the Company had 39 open designated cash flow hedge forward contracts with notional amounts of €25.9 million, £8.7 million and Rs. 1,933.5 million. At December 31, 2019, the Company had 26 open cash flow hedge contracts with notional amount of €24.2 million and £9.7 million.

At December 31, 2020 and 2019, a net amount of unrealized losses of $1.8 million before tax and unrealized gains of $0.7 million before tax, respectively, on the foreign currency forward contracts for GBP and Euro reported in AOCI is expected to be reclassified into revenue within the next 12 months. At December 31, 2020, a net amount of unrealized gains of $1.5 million before tax on the foreign currency forward contracts for INR reported in AOCI is expected to be reclassified into operating expenses within the next 12 months.

Non-designated forward contracts

At December 31, 2020, the Company had 24 outstanding non-designated forward contracts with notional amounts of €17.7 million, £6.5 million and ₨. 32.8 million which will mature at various dates through January 2022. At December 31, 2019, the Company had 15 outstanding non-designated forward contracts with notional amounts of €20.0 million, £5.6 million and Rs. 756.0 million.

The following summarizes derivative financial instruments as of December 31, 2020 and 2019:

	*December 31,*
	*2020*			*2019*
	(in thousands)
Assets:
Foreign currency forward contracts designated as cash flow hedge	$	511		$	427
Foreign currency forward contracts not designated as hedging instruments		27			515
Total	$	538		$	942
Liabilities:
Foreign currency forward contracts designated as cash flow hedge	$	(2,200	)	$	(524	)
Foreign currency forward contracts not designated as hedging instruments		(1,677	)		(550	)
Total	$	(3,877	)	$	(1,074	)

All foreign currency forward contracts were valued at fair value using level 2 inputs.

The following summarizes the gains (losses) recognized from forward contracts and other foreign currency transactions in other income (expense), net on the consolidated statements of operations:

	*Year Ended December 31,*
	*2020*			*2019*			*2018*
	(in thousands)
Net gains (losses) from forward contracts	$	(1,634	)	$	438		$	543
Other foreign currency transaction gains (losses)		1,894			(792	)		(1,120	)
Total foreign exchange gains (losses), net		260			(354	)		(577	)
Other expenses		(253	)		(253	)		(224	)
Other income (expense), net	$	7		$	(607	)	$	(801	)

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

Note 3 - Accumulated Other Comprehensive Income

12 Months Ended

Dec. 31, 2020

Accumulated Other Comprehensive Income Disclosure [Text Block]

NOTE 3.

Accumulated Other Comprehensive Income

The components of AOCI were as follows:

	*December 31,*
	*2020*			*2019*
	(in thousands)
Unrealized gains (losses) on AFS debt securities	$	1,224		$	822
Unrealized gains (losses) on cash flow hedges		(1,708	)		340
Total accumulated other comprehensive income	$	(484	)	$	1,162

The effects on income before income taxes of amounts reclassified from AOCI to the consolidated statements of operations were as follows:

	*Year Ended December 31,*
	*2020*			*2019*		*2018*
	(in thousands)
Reclassification of AOCI - AFS debt securities
Other income (expense), net	$	25		$	—	$	(289	)

Reclassification of AOCI - cashflow hedges
Revenue	$	960		$	134	$	—
Cost of revenues		(76	)		—		—
Research and development expenses		(264	)		—		—
Sales and marketing expenses		(20	)		—		—
General and administrative expenses		(36	)		—		—
Total	$	564		$	134	$	—

Note 4 - Property and Equipment, Net

12 Months Ended

Dec. 31, 2020

Property, Plant and Equipment Disclosure [Text Block]

NOTE 4.

Property and Equipment, Net

Property and equipment, net, which includes assets under finance lease, consists of the following:

	*December 31,*
	*2020*			*2019*
	(in thousands)
Computer equipment	$	136,286		$	112,599
Computer software		26,164			26,137
Scanner appliances		16,749			15,864
Furniture, fixtures and equipment		6,599			6,973
Equipment under capital lease		3,503			3,503
Leasehold improvements		21,107			18,817
Total property and equipment		210,408			183,893
Less: accumulated depreciation and amortization		(145,558	)		(123,314	)
Property and equipment, net	$	64,850		$	60,579

Physical scanner appliances and other computer equipment that are or will be subject to leases by customers have a net carrying value of $7.5 million and $4.9 million, respectively, including assets that have not been placed in service of $1.9 million and $0.9 million, respectively, as of December 31, 2020 and 2019. Depreciation and amortization expenses relating to property and equipment were $26.1 million, $24.9 million and $25.1 million for 2020, 2019 and 2018, respectively.

Note 5 - Revenue from Contracts with Customers

12 Months Ended

Dec. 31, 2020

Revenue from Contract with Customer [Text Block]

NOTE 5.

Revenue from Contracts with Customers

The Company records deferred revenue when cash payments are received or due in advance of its performance offset by revenue recognized in the period. Revenues of $188.6 million and $160.8 million were recognized during the years ended December 31, 2020 and December 31, 2019, respectively, which amounts were included in the deferred revenue balances as of December 31, 2019 and December 31, 2018, respectively.

The Company's payment terms vary by the type and location of its customers and the products or services offered. The term between invoicing and when payment is due is not significant. For certain products or services and customer types, the Company requires payment before the products or services are delivered to the customer.

The following table sets forth the expected revenue from all remaining performance obligations as of December 31, 2020:

	(in thousands)
2021	$	103,165
2022		70,381
2023		35,304
2024		1,363
2025		401
2026 and thereafter		168
Total	$	210,782

Revenues allocated to remaining performance obligations represents the transaction price of noncancelable orders for which service has not been performed, which include deferred revenue and the amounts that will be invoiced and recognized as revenues in future periods from open contracts and excludes unexercised renewals. The Company applied the short-term contract exemption to exclude the remaining performance obligations that are part of a contract that has an original expected duration of one year or less.

From time to time, the Company enters into contracts with customers that extend beyond one year, with certain of its customers electing to pay for more than one year of services upon contract execution. For any discounts associated with these multiple year contracts, the Company concluded its contracts did not contain a financing component.

Revenues by sales channel are as follows:

	*Year Ended December 31,*
	*2020*		*2019*			*2018*
	(in thousands)
Direct	$	212,296	$	186,130	$	164,084
Partner		150,667		135,477		114,805
Total	$	362,963	$	321,607	$	278,889

The Company utilizes partners to enable and accelerate the adoption of its cloud platform by increasing its distribution capabilities and market awareness of its cloud platform as well as by targeting geographic regions outside the reach of its direct sales force. The Company's channel partners maintain relationships with their customers throughout the territories in which they operate and provide their customers with services and third-party solutions to help meet those customers’ evolving security and compliance requirements. As such, these partners may offer the Company's IT security and compliance solutions in conjunction with one or more of their own products or services and act as a conduit through which the Company can connect with these prospective customers to offer its solutions. For sales involving a channel partner, the channel partner engages with the prospective customer directly and involves the Company's sales team as needed to assist in developing and closing an order. When a channel partner secures a sale, the Company sells the associated subscription to the channel partner who in turn resells the subscription to the customer. Sales to channel partners are made at a discount and revenues are recorded at this discounted price over the subscription terms. The Company does not have any influence or specific knowledge of its partners' selling terms with their customers. See Note 13, "Segment Information and Information about Geographic Area" for disaggregation of revenue by geographic area.

Capitalized costs to obtain contracts, current and noncurrent are as follows:

	*December 31, 2020*		*December 31, 2019*
	(in thousands)
Commission asset, current	$	3,459	$	2,568
Commission asset, noncurrent	$	6,906	$	6,454

For the years ended December 31, 2020, 2019,and 2018, the Company recognized $3.0 million, $2.0 million and $1.2 million of commission expense from amortization of its commission assets, respectively. During the same periods, there was no impairment loss related to the capitalized costs.

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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Note 6 - Acquisitions

12 Months Ended

Dec. 31, 2020

Business Combination Disclosure [Text Block]

NOTE 6.

Acquisitions

The following table summarizes the purchase price allocation of business and asset acquisitions during the fiscal years 2020, 2019 and 2018 based on estimated fair values of the acquired assets as of the acquisition date:

Acquiree	*Acquisition Date*	*Purchase Consideration*		*Net Tangible Assets Acquired/ (liabilities assumed)*			*Purchased Intangible Assets*		*Goodwill*		*Deferred Tax Liability*
		(in thousands)
Spell security	July 24, 2020	$	1,500	$	—		$	1,500	$	—	$	—
Adya	January 10, 2019	$	1,000	$	—		$	900	$	100	$	—
Layered Insight	October 16, 2018	$	13,434	$	(80	)	$	9,600	$	5,498	$	(1,500	)
1Mobility	April 1, 2018	$	4,000	$	—		$	3,700	$	300	$	—

On July 24, 2020, the Company acquired certain intangible assets of Spell Security, a privately held company incorporated in India. Spell Security’s technology expands the Company's endpoint behavior detection, threat hunting, malware research and multi-layered response capabilities for its EDR application. The purchase consideration related to the acquisition was $1.5 million in cash, including $0.2 million of deferred consideration due 15 months from the closing date of the acquisition, subject to potential adjustment from possible indemnity claims. The Company accounted for this transaction as an asset purchase. The Company recognized intangible assets of $1.0 million for developed technology and $0.5 million for non-compete agreements, which will be amortized over four and two years, respectively.

On January 10, 2019, the Company acquired the assets of Adya, an India-based company. The acquisition included a cloud application management platform, which enables security and compliance audits of SaaS applications. Total purchase consideration included $0.2 million of deferred consideration due 18 months from the closing date of the acquisition, subject to potential adjustment from possible indemnity claims, which was fully paid to Adya during the fiscal year ended December 31, 2020. The acquired intangible assets relating to Adya's developed technology are being amortized over the estimated useful lives of approximately four years. Goodwill arising from the Adya acquisition is deductible for tax purposes over 15 years.

On October 16, 2018, the Company completed the acquisition of Layered Insight, a pioneer and global leader in container native application protection, providing accurate insight into container images, adaptive analysis of running containers, and automated enforcement of the container environment. Of the total consideration, $1.6 million was paid during the fiscal year ended December 31, 2019 based on the terms and conditions of the purchase agreement. All consideration was paid in cash. The Company also paid additional $4.0 million as the acquired business had achieved certain integration milestones for the annual period ending December 31, 2019. In addition, the Company initially recorded $1.5 million of the contingent consideration related to revenue milestone payments in accrued liabilities of the consolidated balance sheet as of December 31, 2018, which was reversed during the fiscal year 2019 as the revenue milestone was not met. The acquired intangible asset relating to Layered Insight's developed technology is amortized over the estimated useful life of approximately four years. Goodwill arising from the Layered Insight acquisition is not deductible for tax purposes.

On April 1, 2018, the Company acquired the assets of 1Mobility, a Singapore-based company. The acquisition allowed the Company to provide enterprises of all sizes with the ability to create and continuously update an inventory of mobile devices on all versions of Android, iOS and Windows Mobile in their environment; and to continuously assess their security and compliance posture, while quarantining devices that were compromised or out-of-compliance. Of the total purchase consideration, $0.6 million was paid during the fiscal year ended December 31, 2019 based on the terms and conditions of the purchase agreement. The acquired intangible assets relating to 1Mobility's developed technology is being amortized over the estimated useful lives of approximately four years. Goodwill arising from the 1Mobility acquisition is deductible for tax purposes over 15 years.

Pro forma financial information for these acquisitions in the fiscal years 2020, 2019 and 2018 was not presented because the acquisitions were not material to the Company's consolidated financial statements, either individually or in aggregate.

Changes in the carrying amount of goodwill for the years ended December 31, 2020, 2019 and 2018 were as follows:

	(in thousands)
Balance as of December 31, 2018	$	7,225
Goodwill acquired		100
Adjustment		122
Balance as of December 31, 2019 and 2020	$	7,447

Note 7 - Intangible Assets, Net

12 Months Ended

Dec. 31, 2020

Intangible Assets Disclosure [Text Block]

NOTE 7.

Intangible Assets, Net

Intangible assets consist primarily of developed technology and patent licenses acquired from business or asset acquisitions. Acquired intangibles are amortized on a straight-line basis over the respective estimated useful lives of the assets.

The carrying values of intangible assets are as follows:

					*December 31, 2020*
	*Weighted Average Lives (Years)*		*Weighted Average Remaining Lives (Years)*		*Cost*		*Accumulated Amortization*			*Net Book Value*
					(in thousands)
Developed technology		4.4		1.8	$	27,356	$	(16,152	)	$	11,204
Patent licenses		14.0		3.7		1,387		(1,021	)		366
Non-compete agreements		2.0		1.6		500		(104	)		396
Total intangibles subject to amortization					$	29,243	$	(17,277	)		11,966
Intangible assets not subject to amortization											40
Total intangible assets, net										$	12,006

						*December 31, 2019*
	*Weighted Average Lives (Years)*		*Weighted Average Remaining Lives (Years)*		*Cost*		*Accumulated Amortization*			*Net Book Value*
						(in thousands)
Developed technology		4.6		2.7	$	26,356	$	(10,066	)	$	16,290
Patent licenses		14.0		4.7		1,387		(922	)		465
Total intangibles subject to amortization					$	27,743	$	(10,988	)		16,755
Intangible assets not subject to amortization											40
Total intangible assets, net										$	16,795

Intangible assets amortization expenses were $6.3 million, $6.1 million and $3.7 million for 2020, 2019 and 2018 respectively, which were recorded in cost of revenues in the consolidated statements of operations.

As of December 31, 2020, the Company expects amortization expense in future periods to be as follows:

		(in thousands)
2021	$	6,581
2022		4,823
2023		350
2024		212
Total expected future amortization expense	$	11,966

Note 8 - Leases

12 Months Ended

Dec. 31, 2020

Lessee, Operating Leases and Finance Lease [Text Block]

NOTE 8.

Leases

The following table presents the lease-related assets and liabilities recorded on the balance sheet:

Classification on the Balance Sheet	*Classification of Lease*	*December 31,*
		*2020*		*2019*
Assets		*(in thousands)*
Operating lease - right of use asset	Operating leases	$	44,838	$	40,551
Property and equipment, net	Finance leases		131		1,299
Total lease assets		$	44,969	$	41,850

Liabilities
Current
Operating lease liabilities, current	Operating leases	$	11,672	$	7,663
Accrued liabilities	Finance leases		64		124
Noncurrent
Operating lease liabilities, noncurrent	Operating leases		45,700		44,015
Other noncurrent liabilities	Finance leases		—		54
*Total lease liabilities*		$	57,436	$	51,856

The Company leases certain offices, computer equipment and its data center facilities under non-cancelable operating leases for varying periods through 2029. While under our lease agreements we have options to extend our leases up to four years, we have not included renewal options in determining the lease terms for calculating our lease liabilities, as these options have not been reasonably certain of exercise.

Leases expense was $16.7 million, $13.9 million and $9.9 million for 2020, 2019 and 2018, respectively.

Supplemental cash flow information related to operating leases was as follows:

	*Year Ended December 31,*
	*2020*		*2019*
	(in thousands)
Operating cash flows included in the measurement of lease liabilities		13,403		9,372
Lease liabilities arising from obtaining right of use assets		15,837		17,359

Maturities of the Company's operating lease liabilities at December 31, 2020 are as follows:

		(in thousands)
2021	$	14,186
2022		13,316
2023		11,297
2024		10,010
2025		6,407
2026 and thereafter		10,317
Total minimum lease payments		65,533
Less: amount representing interest		(8,161	)
Present value of minimum payments		57,372
Less: lease obligations, current		(11,672	)
Lease obligations, noncurrent	$	45,700

The weighted average remaining lease term and the weighted average discount rate of the Company's leases were as follows:

	*December 31,*
	*2020*			*2019*
Weighted average remaining lease term (years)
Operating leases		4.1			6.5
Finance leases		0.1			1.3
Weighted average discount rates
Operating leases		4.8	%		5.0	%
Finance leases		5.0	%		5.0	%

Note 9 - Commitment and Contingencies

12 Months Ended

Dec. 31, 2020

Commitments and Contingencies Disclosure [Text Block]

NOTE 9.

Commitment and Contingencies

Purchase Obligation

The Company has entered into agreements to purchase goods and services in the ordinary course of business. As of December 31, 2020, these remaining purchase commitments for future periods are as follows:

	(in thousands)
2021	$	20,131
2022		6,528
2023		6,924
2024		7,780
2025		1,873
Total purchase commitment	$	43,236

Indemnifications

The Company from time to time enters into certain types of contracts that contingently require it to indemnify various parties against claims from third parties. These contracts primarily relate to (i) the Company's by-laws, under which it must indemnify directors and executive officers, and may indemnify other officers and employees, for liabilities arising out of their relationship, (ii) contracts under which the Company must indemnify directors and certain officers for liabilities arising out of their relationship, and (iii) contracts under which the Company may be required to indemnify customers or resellers from certain liabilities arising from potential infringement of intellectual property rights, as well as potential damages caused by limited product defects. To date, the Company has not incurred and has not recorded any liability in connection with such indemnifications.

The Company maintains director and officer insurance, which may cover certain liabilities arising from its obligation to indemnify its directors.

Legal Proceedings

From time to time the Company may become involved in legal proceedings or be subject to claims arising in the ordinary course of our business. The Company records a provision for a liability when it is both probable that a liability has been incurred and the amount can be reasonably estimated. The Company provides disclosure if it is reasonably possible that a loss has been incurred and a range of loss or possible loss can be reasonably estimated. Significant judgment is required to determine both probability and the estimated amount. The Company reviews these provisions at least quarterly and adjust these provisions to reflect the impact of negotiations, settlements, rulings, advice of legal counsel, and updated information.

As of December 31, 2020, there has not been at least a reasonable possibility that the Company has incurred a material loss from any ongoing legal proceedings, individually or taken together. However, litigation is inherently unpredictable and is subject to significant uncertainties, some of which are beyond the Company's control. Should any of these estimates and assumptions change or prove to have been incorrect, the Company could incur significant charges related to legal matters which could have a material impact on its results of operations, financial position and cash flows.

Note 10 - Stockholders' Equity and Stock-based Compensation

12 Months Ended

Dec. 31, 2020

Shareholders' Equity and Share-based Payments [Text Block]

NOTE 10.

Stockholders' Equity and Stock-based Compensation

Common Stock

The Company had reserved shares of common stock for future issuance as of December 31, 2020 as follows:

Options and RSUs outstanding under equity incentive plans
2000 Equity Incentive Plan			102,087
2012 Equity Incentive Plan			3,160,057
Shares available for future grants under an equity incentive plan
2012 Equity Incentive Plan			6,628,383
Total shares reserved for future issuance			9,890,527

Preferred Stock

Effective October 3, 2012, the Company is authorized to issue 20,000,000 shares of undesignated preferred stock with a par value of $0.001 per share. Each series of preferred stock will have such rights and preferences including dividend rights, dividend rate, conversion rights, voting rights, rights and terms of redemption (including sinking fund provisions), redemption price, and liquidation preferences as determined by the Board. As of December 31, 2020, and 2019, there were no issued or outstanding shares of preferred stock.

Equity Incentive Plan

2012 Equity Incentive Plan

The 2012 Equity Incentive Plan was adopted and approved in September 2012 and became effective on September 26, 2012. Under the 2012 Plan, the Company is authorized to grant to eligible participant's incentive stock options (ISOs), non-statutory stock options (NSOs), stock appreciation rights (SARs), restricted stock awards (RSAs), RSUs, performance units and performance shares equivalent to up to 15,699,245 shares of common stock as of December 31, 2020. The number of shares of common stock available for issuance under the 2012 Plan includes an annual increase on January 1 of each year by an amount equal to the least of 3,050,000 shares; 5% of the outstanding shares of stock as of the last day of the immediately preceding fiscal year; or an amount determined by the Board of Directors. Options may be granted with an exercise price that is at least equal to the fair market value of the Company's stock at the date of grant and are exercisable when vested. Options and RSU's granted generally vest over a period of up to four years. ISOs may only be granted to employees and any subsidiary corporations' employees. All other awards may be granted to employees, directors and consultants and subsidiary corporations' employees and consultants. Options, SARs, RSUs, performance units and performance awards may be granted with vesting terms as determined by the Board of Directors and expire no more than ten years after the date of grant or earlier if employment or service is terminated.

2000 Equity Incentive Plan

Under the 2000 Equity Incentive Plan (2000 Plan), the Company was authorized to grant to eligible participants either ISOs or NSOs. The ISOs were granted at a price per share not less than the fair market value at the date of grant. The NSOs were granted at a price per share not less than 85% of the fair market value at the date of grant. Options granted generally vest over a period of up to four years, with a maximum term of ten years. The 2000 Plan was terminated in connection with the closing of the Company's initial public offering, and accordingly, no shares are currently available for grant under the 2000 Plan. The 2000 Plan continues to govern outstanding awards granted thereunder.

Options granted under the 2000 Plan were immediately exercisable, and unvested shares are subject to repurchase by the Company. Upon termination of employment of an option holder, the Company has the right to repurchase at the original purchase price any issued but unvested common shares. The amounts paid for shares purchased under an early exercise of stock options and subject to repurchase by the Company are not reported as a component of stockholders’ equity until those shares vest. The amounts received in exchange for these shares are recorded as an accrued liability in the accompanying consolidated balance sheets and will be reclassified to common stock and additional paid-in capital as the shares vest.

Stock-based Compensation Expenses

The following table shows a summary of the stock-based compensation expense included in the consolidated statements of operations for the fiscal years ended December 31, 2020, 2019 and 2018:

	*Year Ended December 31,*
	*2020*		*2019*		*2018*
	(in thousands)
Cost of revenues	$	2,767	$	2,262	$	2,489
Research and development		13,502		11,151		7,961
Sales and marketing		5,785		4,984		4,650
General and administrative		17,981		16,495		14,990
Total stock-based employee compensation	$	40,035	$	34,892	$	30,090

The income tax benefit related to the stock-based compensation expenses was $5.5 million, $5.5 million and $4.8 million for the years ended December 31, 2020, 2019 and 2018, respectively. As of December 31, 2020, the Company had $21.8 million of unrecognized employee compensation cost related to unvested stock options and $71.3 million of unrecognized compensation cost related to unvested RSU's that it expects to recognize over a weighted-average period of 2.7 years and 2.6 years, respectively.

The fair value of each option granted to employees is estimated on the date of grant using the Black-Scholes-Merton option-pricing model based on the following assumptions:

Year Ended December 31,

2020

2019

2018

Expected term (in years)

4.5 to 5.5

4.4 to 6.6

4.5 to 5.0

Volatility

38% to 43%

40% to 46%

45% to 47%

Risk-free interest rate

0.3% to 1.4%

1.5% to 2.4%

2.5% to 3.0%

Dividend yield

—

The expected term of the options is based on evaluations of historical and expected future employee exercise behavior. The risk-free interest rate is based on the U.S. Treasury rates at the date of grant with maturity dates approximately equal to the expected term at the grant date. The volatility was estimated using the historical volatility derived from the Company's common stock. The Company has not historically declared any dividends and does not expect to in the future.

Stock Option Plan Activity

A summary of the Company’s stock option activity is as follows:

	*Outstanding Shares*			*Weighted Average Exercise Price Per Share*		*Weighted Average Remaining Contractual Life (Years)*		*Aggregate Intrinsic Value*
								(in thousands)
Balance as of December 31, 2017		4,495,891		$	25.29		6.6	$	153,129
Granted		366,786		$	79.79
Exercised		(1,183,235	)	$	20.33
Canceled		(250,133	)	$	39.61
Balance as of December 31, 2018		3,429,309		$	31.79		6.4	$	149,935
Granted		496,145		$	87.10
Exercised		(901,290	)	$	27.55
Canceled		(157,489	)	$	71.04
Balance as of December 31, 2019		2,866,675		$	40.54		6.0	$	125,647
Granted		593,694		$	99.77
Exercised		(1,129,845	)	$	30.50
Canceled		(115,082	)	$	87.91
Balance as of December 31, 2020		2,215,442		$	59.07		6.5	$	139,121
Vested and expected to vest—December 31, 2020		2,071,441		$	56.39		6.3	$	135,647
Exercisable—December 31, 2020		1,290,452		$	34.69		4.7	$	112,502

The following table summarizes the outstanding and vested stock options at December 31, 2020:

	Outstanding						Exercisable
Exercise Price	Number of Shares		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Life (Years)		Number of Shares		Weighted Average Exercise Price Per Share
4.4 - 20.8		266,447	$	13.25		2.1		266,447	$	13.25
22.31 - 25.17		130,550	$	24.16		4.3		130,550	$	24.16
25.56 - 25.56		264,824	$	25.56		5.3		264,824	$	25.56
26.86 - 34.97		227,072	$	30.72		3.9		227,072	$	30.72
36.25 - 52.6		232,792	$	40.24		5.4		215,601	$	39.80
59.95 - 86.35		307,387	$	80.11		8.3		77,644	$	74.90
87.26 - 89.55		189,217	$	88.48		8.6		52,147	$	88.42
93.08 - 93.08		223,744	$	93.08		9.9		—	$	—
94.45 - 104.8		273,709	$	97.76		8.8		56,167	$	94.91
121.65 - 121.65		99,700	$	121.65		9.6		—	$	—
		2,215,442	$	59.07		6.5		1,290,452	$	34.69

The weighted-average grant date fair value of the Company’s stock options granted during 2020, 2019 and 2018 was $35.49, $34.02 and $33.05, respectively. The total intrinsic value of options exercised during 2020, 2019 and 2018 was $77.5 million, $52.1 million and $71.7 million, respectively. Intrinsic value of an option is the difference between the fair value of the Company’s common stock at the time of exercise and the exercise price paid.

Restricted Stock Unit Activity

A summary of the Company’s RSU activity is as follows:

	*Number of Shares*			*Weighted-Average Grant Date Fair Value Per Share*
Balance as of December 31, 2017		1,410,588		$	40.34
Granted		548,245		$	75.44
Vested		(525,375	)	$	39.87
Cancelled		(206,575	)	$	43.43
Balance as of December 31, 2018		1,226,883		$	55.71
Granted		595,985		$	81.59
Vested		(438,892	)	$	53.17
Cancelled		(169,158	)	$	65.51
Balance as of December 31, 2019		1,214,818		$	67.99
Granted		531,146		$	99.96
Vested		(475,853	)	$	62.57
Cancelled		(223,409	)	$	77.37
Balance as of December 31, 2020		1,046,702		$	86.78
Expected to vest as of December 31, 2020		961,926		$	86.02

The aggregate vesting date fair value of RSUs vested during 2020, 2019 and 2018 was $46.5 million, $37.9 million and $38.9 million, respectively.

Performance-Based Stock Options and Restricted Stock Units

On December 10, 2020, the compensation committee of the Company's board of directors (Compensation Committee) granted the equity award for 2021 to the Company’s Chairman and Chief Executive Officer, Philippe Courtot (Mr. Courtot). The first portion of the award consists of 69,401 RSUs that will vest in 16 quarterly installments beginning on November 1, 2020. The second portion of the award consists of a target number of 223,744 PSO, which will vest at the end of the three-year performance period from January 2021 through December 2023. The actual number of PSOs eligible to vest range from 0% to 200% of the target number, depending on the level of achievement of goals related to revenue growth and free cash flow per share growth during the performance period.

On November 2, 2019, the Compensation Committee granted the equity award for 2020 to Mr. Courtot. The first portion of the award consists of 48,683 RSUs that will vest in 16 quarterly installments beginning on December 1, 2019. The second portion of the award consists of a target number of 123,856 PSOs, which will vest at the end of the three-year performance period from January 2020 through December 2022. The actual number of PSOs eligible to vest range from 0% to 200% of the target number, depending on the level of achievement of goals related to revenue growth and free cash flow per share growth during the performance period.

On December 21, 2018, the Compensation Committee granted the equity award for 2019 to Mr. Courtot. The first portion of the award consists of 56,250 RSUs that will vest in 16 quarterly increments beginning on January 1, 2019. The second portion of the award consists of a target number of 33,089 PSU, which will vest at the end of the three-year performance period from January 2019 through December 2021. The actual number of PSUs eligible to vest range from 0% to 200% of the target number, depending on the level of achievement of goals related to revenue growth during the three-year performance period from January 2019 through December 2021 and Adjusted EBITDA margin for the fiscal year of 2021. The third portion of the award consists of a target number of 33,088 PSUs, one third of which (11,030 target PSUs) will vest at the end of each fiscal year of 2019, 2020 and 2021. The actual number of PSUs eligible to vest at each vesting date range from 0% to 200% of the target number, depending on the level of achievement of goals related to revenue growth and Adjusted EBITDA margin for each of those years.

The Compensation Committee, in consultation with its independent compensation consultant, designed these awards so that in each year greater than 50% of the compensation was based on the achievement of performance goals linked to metrics designed to drive the creation of shareholder value. The vesting of these awards is conditioned on Mr. Courtot’s continued service through the vesting dates or, for PSOs and PSUs, the dates that performance is certified in addition to the achievement of performance goals. If Mr. Courtot’s employment is terminated (a) by reason of death or disability or (b) by the Company for reasons other than cause or good reason within 12 months following a change in control, then 100% of any unvested portions of these awards will vest, with any vesting in connection with change in control terminations conditioned upon the effectiveness of a release of claims in favor of the Company .

During the year ended December 31, 2020, 14,864 PSUs, which represent 135% of the target, vested as a result of the Company achieving the corresponding level of performance goals for the fiscal year of 2019.

On June 10, 2020, the board of directors approved changes in the performance targets for certain previously granted PSO and PSU. Based on the projected performance levels expected to be achieved for those awards as of June 10, 2020, the modification resulted in an incremental expense of $7.5 million, which is expected to be recognized over 12 quarters beginning with the quarter ended June 30, 2020. This amount may change based upon actual performance achieved and updates to estimates of future performance during the remainder of the performance periods. During the year ended December 31, 2020, $0.9 million of incremental expenses due to the modification were recognized.

During the year ended December 31, 2020, stock-based compensation expense of $0.2 million and $2.8 million, including changes due to modifications, were recognized for PSOs and PSUs. During the year ended December 31, 2019, stock-based compensation expense of $0.3 million and $0.9 million were recognized for PSOs and PSUs, respectively.

Share Repurchase Program

On February 5, 2018, the Company's board of directors authorized a $100.0 million two-year share repurchase program, which was announced on February 12, 2018. On each of October 30, 2018, October 30, 2019 and May 7, 2020, the Company announced that its board of directors had authorized an increase of $100.0 million to the share repurchase program, resulting in an aggregate authorization of $400.0 million. Shares may be repurchased from time to time on the open market in accordance with Rule 10b-18 of the Exchange Act of 1934, including pursuant to a pre-set trading plan adopted in accordance with Rule 10b5-1 under the Exchange Act, until February 14, 2022.

Repurchased shares are retired and reclassified as authorized and unissued shares of common stock. On retirement of the repurchased shares, common stock is reduced by an amount equal to the number of shares being retired multiplied by the par value. The excess amount that is retired over its par value is first allocated as a reduction to additional paid-in capital based on the initial public offering price of the stock, with the remaining excess to retained earnings.

During the year ended December 31, 2020 and 2019, the Company repurchased 1,292,750 and 1,026,455 shares of its common stock for approximately $126.7 million and $86.4 million, respectively. All share repurchases were made using cash resources. As of December 31, 2020 and 2019, approximately $101.8 million and $128.5 remained available for share repurchases pursuant to the Company's share repurchase program.

On February 10, 2021, the Company announced that its Board of Directors authorized an additional $100.0 million to the original share repurchase program authorization, increasing the total amount of authorized repurchase to $500.0 million.

Note 11 - Employee Benefits Plan

12 Months Ended

Dec. 31, 2020

Compensation and Employee Benefit Plans [Text Block]

NOTE 11.

Employee Benefits Plan

The Company’s 401(k) Plan was established in 2000 to provide retirement and incidental benefits for its employees. As allowed under section 401(k) of the Internal Revenue Code, the 401(k) Plan provides tax-deferred salary deductions for eligible employees. Contributions to the 401(k) Plan are limited to a maximum amount as set periodically by the Internal Revenue Service. During the fiscal years ended December 31, 2020, 2019 and 2018, the Company made contributions to the 401(k) Plan of $1.3 million, $1.3 million and $1.2 million, respectively.

The Company contributes to a Provident Fund Plan for its employees in India, which is a defined contribution plan set up in accordance with local labor and tax laws. Gratuity is also paid by the Company to eligible employees in India in accordance with Payment of Gratuity Act, 1972. During the fiscal years ended December 31, 2020, 2019 and 2018, the Company contributed $1.4 million, $1.1 million and $0.7 million, respectively, to those plans.

Qualys, Inc.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

Note 12 - Income Taxes

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Text Block]

NOTE 12.

Income Taxes

The Company’s geographical breakdown of income before income taxes is as follows:

	*Year Ended December 31,*
	*2020*		*2019*		*2018*
	(in thousands)
Domestic	$	94,099	$	72,124	$	50,010
Foreign		7,938		7,859		5,458
Income before income taxes	$	102,037	$	79,983	$	55,468

The provision for (benefit from) income taxes consists of the following:

	*Year Ended December 31,*
	*2020*			*2019*			*2018*
	(in thousands)
Current
Federal	$	1,944		$	(90	)	$	(90	)
State		1,438			646			62
Foreign		3,571			3,000			1,988
Total current provision		6,953			3,556			1,960
Deferred
Federal		4,239			7,085			(3,449	)
State		26			447			21
Foreign		(753	)		(441	)		(368	)
Total deferred (benefit) provision		3,512			7,091			(3,796	)
Total provision for (benefit from) provision for income taxes	$	10,465		$	10,647		$	(1,836	)

The reconciliation of the statutory federal income tax rate to the Company’s effective tax rate is as follows:

	*Year Ended December 31,*
	*2020*			*2019*			*2018*
Federal statutory rate		21.0	%		21.0	%		21.0	%
State taxes		1.6			1.5			(1.9	)
Stock-based compensation		4.8			4.0			5.8
Excess tax benefits related to stock-based compensation		(13.8	)		(11.2	)		(26.2	)
Foreign source income		0.2			0.1			(0.2	)
Change in valuation allowance		0.8			1.1			4.4
Foreign-derived intangible income deduction		(1.7	)		—			—
Federal and state research and development credit		(2.6	)		(3.7	)		(6.7	)
Other		—			0.4			0.5
Provision for (benefit from) income taxes		10.3	%		13.2	%		(3.3	)%

Deferred Income Taxes

Deferred income taxes reflect the 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 components of the Company’s deferred tax assets and liabilities are as follows:

	*December 31,*
	*2020*			*2019*
	(in thousands)
Deferred tax assets
Net operating loss carryforwards	$	290		$	1,325
Research and development credit carryforwards		16,965			20,182
Foreign tax credit carryforwards		3,497			2,586
Accrued liabilities		2,019			1,109
Deferred revenues		5,123			4,843
Operating lease liabilities		15,924			13,187
Intangible assets		1,397			327
Stock-based compensation		3,907			5,942
Other		430			158
Gross deferred tax assets		49,552			49,659
Valuation allowance		(11,188	)		(10,094	)
Net deferred tax assets		38,364			39,565
Deferred tax liabilities
Fixed assets		(7,017	)		(8,097	)
Operating leases - right of use asset		(13,054	)		(10,496	)
Deferred commissions		(2,482	)		(2,142	)
Total deferred tax liabilities		(22,553	)		(20,735	)
Net deferred tax assets	$	15,811		$	18,830

The realization of deferred tax assets is dependent upon the generation of sufficient taxable income of the appropriate character in future periods. The Company regularly assesses the ability to realize its deferred tax assets and establishes a valuation allowance if it is more-likely than-not that some portion, or all, of the deferred tax assets will not be realized. The Company weighs all available positive and negative evidence, including its earnings history and results of recent operations, scheduled reversals of deferred tax liabilities, projected future taxable income, and tax planning strategies. Due to the weight of objectively verifiable negative evidence, it is more-likely-than-not that its California deferred tax assets will not be realized as of December 31, 2020. Additionally, due to a lack of sufficient future income of the appropriate character, certain U.S. federal and state deferred tax assets are not more-likely-than-not to be realized. Accordingly, the Company has recorded a valuation allowance of $11.2 million and $10.1 million against such deferred tax assets as of December 31, 2020 and 2019, respectively. The increase in valuation allowance was mainly associated with the California research and development credit generated during the year ended December 31, 2020 that will not likely be realized for the foreseeable future.

At December 31, 2020, the Company had federal and state net operating loss carryforwards of approximately $1.4 million and $0.1 million, respectively, available to reduce federal and state taxable income. The federal net operating losses begin to expire in 2022 and the state net operating losses begin to expire in 2037. Utilization of the Company’s net operating loss carryforwards may be subject to an annual limitation due to the ownership change limitations provided by the Internal Revenue Code and similar state provisions. Such an annual limitation could result in the expiration of the net operating loss carryforwards before utilization. As of December 31, 2020, the Company had $10.7 million of federal and $15.0 million of state research and development credit carryforwards, respectively. Federal research and development credits begin to expire in 2035. State research and development credits do not expire. As of December 31, 2020, the Company had foreign tax credit carryforwards of $3.5 million which begin to expire in 2024.

The following table summarizes the activity related to the Company’s unrecognized tax benefits:

	*Year Ended December 31,*
	*2020*			*2019*			*2018*
	(in thousands)
Unrecognized tax benefits beginning balance	$	7,778		$	6,406		$	5,112
Gross increase for tax positions of prior years		4			—			279
Gross decrease for tax positions of prior years		—			(12	)		(227	)
Gross increase for tax positions of current year		1,258			1,384			1,399
Lapse of statute of limitations		(185	)		—			(157	)
Total unrecognized tax benefits	$	8,855		$	7,778		$	6,406

The unrecognized tax benefits, if recognized, would impact the income tax provision by $4.6 million, $4.2 million and $3.5 million as of December 31, 2020, 2019 and 2018, respectively. The remaining amount would result in the recognition of a corresponding deferred tax asset that is then offset by a full valuation allowance. As of December 31, 2020, the Company does not believe that its estimates, as otherwise provided for, on such tax positions will significantly increase or decrease within the next twelve months. The Company has elected to include interest and penalties as a component of income tax expense. The amounts were not material for 2020, 2019 and 2018.

The Company files income tax returns in the United States, including various state jurisdictions. The Company’s subsidiaries file tax returns in various foreign jurisdictions. The tax years 2001 through 2019 remain open to examination by the major taxing jurisdictions in which the Company is subject to tax. The Company is also currently subject to tax audits in various jurisdictions. The Company believes that an adequate provision has been made for any adjustments that may result from tax examinations. However, the outcome of tax audits cannot be predicted with certainty. If any issues addressed in the Company's tax audits are resolved in a manner inconsistent with its expectations, the Company could be required to adjust its provision for income taxes in the period such resolution occurs.

U.S. income tax has not been recognized on the excess of the amount for financial reporting over the tax basis of investments in foreign subsidiaries that is indefinitely reinvested outside the United States. A determination of the unrecognized deferred tax liability related to this basis difference is not practicable because of the complexities of the calculation.

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

Note 13 - Segment Information and Information about Geographic Area

12 Months Ended

Dec. 31, 2020

Segment Reporting Disclosure [Text Block]

NOTE 13.

Segment Information and Information about Geographic Area

Under ASC 280 Segment Reporting, Operating segments are defined as components of an entity about which separate financial information is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company operates in one segment and has only one reportable segment. The Company’s chief operating decision maker is the Chairman and Chief Executive Officer, who makes operating decisions, assesses performance and allocates resources on a consolidated basis. All of the Company’s principal operations and decision-making functions are located in the United States.

Revenue by geographic area, based on the customers billing address, is as follows:

	*Year Ended December 31,*
	*2020*		*2019*		*2018*
	(in thousands)
United States	$	230,444	$	206,555	$	185,887
Foreign		132,519		115,052		93,002
Total revenues	$	362,963	$	321,607	$	278,889

Property and equipment, net, by geographic area, is as follows:

	*December 31,*
	*2020*		*2019*
	(in thousands)
United States	$	43,791	$	46,100
India		12,465		9,221
Rest of world		8,594		5,258
Total property and equipment, net	$	64,850	$	60,579

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

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-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8657-108599

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8721-108599

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-URI http://asc.fasb.org/topic&trid=2134510

Note 14 - Net Income Per Share

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Text Block]

NOTE 14.

Net Income Per Share

The computations for basic and diluted net income per share are as follows:

	*Year Ended December 31,*
	*2020*		*2019*		*2018*
	(in thousands, except per share data)
Numerator:
Net income	$	91,572	$	69,336	$	57,304

Denominator:
Weighted-average shares used in computing net income per share - basic		39,167		39,075		38,876
Effect of potentially dilutive securities:
Common stock options		1,267		1,807		2,401
Restricted stock units		389		463		620
Weighted-average shares used in computing net income per share - diluted	$	40,823	$	41,345	$	41,897
Net income per share:
Basic	$	2.34	$	1.77	$	1.47
Diluted	$	2.24	$	1.68	$	1.37

Potentially dilutive securities not included in the calculation of diluted net income per share because doing so would be anti-dilutive are as follows:

	*Year Ended December 31,*
	*2020*		*2019*		*2018*
	(in thousands)
Common stock options		620		461		177
Restricted stock units		80		26		22
Total anti-dilutive shares		700		487		199

Note 15 - Selected Quarterly Financial Information (Unaudited)

12 Months Ended

Dec. 31, 2020

Quarterly Financial Information [Text Block]

NOTE 15.

Selected Quarterly Financial Information (Unaudited)

The following table shows a summary of the Company's quarterly financial information for each of the quarters in the two-year period ended December 31, 2020:

	*Three Months Ended*
	*December 31, 2020*		*September 30, 2020*		*June 30, 2020*		*March 31, 2020*		*December 31, 2019*		*September 30, 2019*		*June 30, 2019*		*March 31, 2019*
	(unaudited)
	(in thousands, except per share data)
Revenues	$	94,801	$	93,069	$	88,830	$	86,263	$	84,664	$	82,671	$	78,929	$	75,343
Income from operations		24,412		26,303		25,508		20,431		19,545		22,549		16,108		14,051
Other income (expense), net		680		1,331		1,586		1,786		1,757		1,786		2,401		1,786
Income before income taxes		25,092		27,634		27,094		22,217		21,302		24,335		18,509		15,837
Net income	$	23,816	$	22,743	$	26,319	$	18,694	$	20,664	$	19,174	$	16,232	$	13,266
Net income per share:
Basic	$	0.61	$	0.58	$	0.67	$	0.48	$	0.53	$	0.49	$	0.41	$	0.34
Diluted	$	0.59	$	0.56	$	0.64	$	0.46	$	0.50	$	0.47	$	0.39	$	0.32

Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2020

Accounting Policies [Abstract]

Description Of Business Policy [Policy Text Block]

Description of Business

Qualys, Inc. (the “Company”, "we", "us", "our") was incorporated in the state of Delaware on December 30, 1999. The Company is headquartered in Foster City, California and has wholly-owned subsidiaries throughout the world. The Company is a pioneer and leading provider of cloud-based IT, security and compliance solutions that enable organizations to identify security risks to their IT infrastructures, help protect their IT systems and applications from ever-evolving cyber-attacks and achieve compliance with internal policies and external regulations. The Company’s cloud solutions address the growing security and compliance complexities and risks that are amplified by the dissolving boundaries between internal and external IT infrastructures and web environments, the rapid adoption of cloud computing and the proliferation of geographically dispersed IT assets. Organizations can use the Company’s integrated suite of solutions delivered on its Qualys Cloud Platform to cost-effectively obtain a unified view of their security and compliance posture across globally-distributed IT infrastructures.

Basis of Accounting, Policy [Policy Text Block]

Basis of Presentation

The accompanying consolidated financial statements and footnotes have been prepared in accordance with U.S. GAAP as well as the instructions to Form 10-K and the rules and regulations of the SEC. In the opinion of management, the accompanying consolidated financial statements reflect all adjustments, which include only normal recurring adjustments, necessary for the fair presentation of the Company’s consolidated financial position, results of operations and cash flows for the periods presented. The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated upon consolidation.

Certain reclassifications have been made to the prior years' consolidated financial statements to conform to the current year presentation. The reclassifications did not have material effects on the prior year’s consolidated financial statements.

Risk and Uncertainties, Policy [Policy Text Block]

Risks and Uncertainties

In March 2020, the World Health Organization declared the outbreak of COVID-19 as a pandemic. As a result of COVID-19, the Company has modified certain aspects of its business, including restricting employee travel, requiring employees to work from home, and canceling certain events and meetings, among other modifications. The Company will continue to actively monitor the situation and may take further actions that alter its business operations as may be required by federal, state or local authorities or that the Company determines are in the best interests of its employees, customers, partners, suppliers and stockholders. COVID-19 has not had and is not expected to have a significant impact on the Company's business in 2021. However, while the Company has not incurred significant disruptions from the COVID-19 outbreak, the Company is unable to accurately predict the full impact that COVID-19 will have due to numerous uncertainties, including the duration of the outbreak, actions that may be taken by governmental authorities and the impact to the business of its customers and partners. The Company will continue to evaluate the nature and extent of the impact to its business, financial position, results of operations and cash flows.

Use of Estimates, Policy [Policy Text Block]

Use of Estimates

The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of assets and liabilities at the date of the consolidated financial statements and the reported results of operations during the reporting period. The Company’s management regularly assesses these estimates, which primarily affect revenue recognition, the valuation of accounts receivable, goodwill and intangible assets, capitalization of internally developed software, stock-based compensation and the provision for income taxes. Actual results could differ from those estimates and such differences may be material to the accompanying consolidated financial statements.

Concentration Risk, Credit Risk, Policy [Policy Text Block]

Concentration of Credit Risk

The Company invests its cash and cash equivalents with major financial institutions. Cash balances with any one institution at times may be in excess of federally insured limits. Cash equivalents are invested in high-quality investment grade financial instruments and are diversified. The Company has not experienced any losses in such accounts and believes it is not exposed to any significant credit risk.

Credit risk with respect to accounts receivable is dispersed due to the large number of customers. Collateral is not required for accounts receivable. As of December 31, 2020 and 2019, no customer or channel partner accounted for more than 10% of the Company's revenues and accounts receivable balance.

Cash, Cash Equivalents and Short-Term and Long-Term Investments Policy [Policy Text Block]

Cash, Cash Equivalents, Restricted cash and Short-Term and Long-Term Marketable Securities

Cash and cash equivalents include cash held in banks, highly liquid money market funds and commercial paper, all with original maturities of three months or less when acquired. The Company’s short-term and long-term marketable securities consist of fixed-income U.S. and foreign government agency securities, corporate bonds, asset-backed securities and commercial paper. Management determines the appropriate classification of the Company's investments at the time of purchase and reevaluates such designation at each balance sheet date. The Company classifies its marketable securities as either short-term or long-term based on each instrument's underlying remaining contractual maturity date.

As of both December 31, 2020 and 2019, the Company has a restricted cash balance of $1.2 million in the form of a letter of credit issued to the landlord of the Company's California headquarter office lease as security deposit.

Cash equivalents are stated at cost, which approximates fair market value. Short-term and long-term marketable securities are classified as available-for-sale debt securities (AFS debt securities) and are carried at fair value. Unrealized gains and losses in fair value of the AFS debt securities are reported in other comprehensive income (loss). When the AFS debt securities are sold, cost is based on the specific identification method, and the realized gains and losses are included in other income (expense), net in the consolidated statements of operations. AFS debt securities are reviewed quarterly for impairment. An investment is considered impaired when its fair value is below its amortized cost. Declines in fair value from amortized cost for AFS debt securities that the company intends to sell or will more likely than not be required to sell before the expected recovery of the amortized cost basis are charged to other income (expense), net in the period in which the loss occurs. Otherwise, the credit loss component of the impairment is recorded as allowance for credit losses with an offsetting entry charged to other income (expense), net, while the remaining loss is recognized in other comprehensive income (loss).

Accounts Receivable [Policy Text Block]

Accounts Receivable

Accounts receivable are recorded at the invoiced amount and do not bear interest. The allowance for credit losses is determined on a collective basis where similar risk characteristics exist and on an individual basis when we identify significant customers or invoices with collectability issues. The estimate for credit losses considers historical write-offs by aging category, that are adjusted for current conditions and reasonable and supportable forecasts of future losses. Any change in the assumptions used in analyzing credit losses may result in additional allowances being recognized in the period in which the change occurs. When the Company ultimately concludes that a receivable is uncollectible, the balance is written off against the allowance for credit losses. Payments subsequently received on such receivables are recognized in the period received. The allowance for credit losses recognized and write-offs charged against the allowance were not significant for the years ended December 31, 2020 and 2019.

Securities Owned Not Readily Marketable, Policy [Policy Text Block]

Non-marketable securities

During the fiscal year ended December 31, 2018, the Company invested $2.5 million in preferred stock of a privately-held company. The fair value of the investment is not readily available, and there are no quoted market prices for the investment. The Company elected the measurement alternative to account for the investment at cost less impairment and will measure the investment at fair value when the Company identifies observable price changes. The investment is assessed for impairment annually or whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. No impairment has been incurred related to the investment. The investment is included in other noncurrent assets on the consolidated balance sheets. The Company has not received any dividends from the investment.

Property, Plant and Equipment, Policy [Policy Text Block]

Property and Equipment, net

Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which range from three to five years. Leasehold improvements are amortized on a straight-line basis over the lesser of the estimated useful life of the asset or the remaining lease term.

The Company purchases physical scanner appliances and other computer equipment that are provided to customers on a subscription basis. This equipment is recorded within property and equipment and the depreciation is recorded in cost of revenues over an estimated useful life of three years.

Upon retirement or disposal, the cost of assets and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is reflected in the consolidated statements of operations. Repairs and maintenance that do not extend the life of an asset are expensed as incurred and major improvements are capitalized as property and equipment.

Lessee, Leases [Policy Text Block]

Leases

The Company leases certain offices, computer equipment and its data center facilities under finance leases and non-cancelable operating leases. On January 1, 2019, the Company adopted ASC 842 Leases using the current period adjustment method with an effective date of January 1, 2019. For both operating and finance leases, we recognize a right-of-use asset, which represents our right to use the underlying asset for the lease term, and a lease liability, which represents the present value of our obligation to make payments arising over the lease term. Many of our leases include rental escalation clauses, renewal options and/or termination options that are factored into our determination of lease payments and lease terms when appropriate. The present value of the lease payments is calculated using the incremental borrowing rate of the underlying leases determined at lease commencement. As most of our leases do not provide a readily determinable implicit rate, the Company determines an incremental borrowing rate using a portfolio approach based on the rate of interest that the Company would have to pay to borrow an amount equal to the lease payments on a collateralized basis over a similar term as the leases.

Where the Company is the lessee, the Company elects to account for non-lease components associated with its leases (e.g., common area maintenance costs) and lease components separately for substantially all of its asset classes, except for data centers, for which the Company elected to combine lease and non-lease components. For leases with a term of one year or less, the Company has elected not to record the right-of-use asset or liability.

In arrangements where the Company is the lessor, the Company elected to apply the practical expedient to account for lease components (e.g., customer premise equipment) and non-lease components (e.g., service revenue) as combined components as revenue under ASC 606 as service revenues are the predominant components in the arrangements.

Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]

Impairment of Long-Lived Assets

The Company evaluates its long-lived assets, which consist of property and equipment, and intangible assets subject to amortization, for indicators of possible impairment when events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. Impairment exists if the carrying amounts of such assets exceed the estimates of future undiscounted cash flows expected to be generated by such assets. Should an impairment exist, the impairment loss would be measured based on the excess carrying value of the asset over the asset’s estimated fair value. In each of 2020, 2019 and 2018, the Company had no impairment of long-lived assets.

Goodwill and Intangible Assets, Policy [Policy Text Block]

Goodwill and Intangible Assets

Goodwill represents the excess of the purchase price over the fair value of the net tangible and identifiable intangible assets acquired in a business combination and is not subject to amortization. Goodwill and other intangible assets with indefinite lives are not amortized, but tested for impairment at least annually or more frequently if certain circumstances indicate a possible impairment may exist. These tests are performed at the reporting unit level. The Company’s operations are organized as one reporting unit.

In testing for a potential impairment of goodwill, the Company first performs a qualitative assessment of its reporting unit to determine if it is more likely than not (a more than 50% likelihood) that the fair value of the reporting unit is less than its carrying amount. If the fair value is not considered to be less than the carrying amount, no further evaluation is necessary. The Company performed the annual assessment on December 1, 2020 and 2019 and concluded there was no potential impairment of goodwill.

In testing for a potential impairment of intangible assets with indefinite lives that are not subject to amortization, the Company first performs a qualitative assessment to determine if it is more likely than not (a more than 50% likelihood) that the fair value of the indefinite-lived intangible assets is less than the carrying amount. If the fair value is not considered to be less than the carrying amount, no further evaluation is necessary. The Company performs the annual qualitative assessment in the fourth quarter each fiscal year. There were no such impairment losses during 2020, 2019 and 2018.

If the qualitative assessment indicates there is more than a 50% likelihood that the fair value is less than the carrying amount of the reporting unit or the intangible asset, the Company would perform a quantitative test. Goodwill impairment is measured as the amount by which a reporting unit’s carrying value exceeds its fair value. For indefinite-lived intangible assets, the Company would perform the quantitative impairment test by comparing the fair value of the indefinite-lived intangible asset with its carrying value.

Research, Development, and Computer Software, Policy [Policy Text Block]

Internally Developed Software

Costs incurred in the development phase are capitalized and amortized over the product’s estimated useful life, which is three years. Capitalized costs include salaries, benefits and stock-based compensation charges for employees that are directly involved in developing its cloud security platform during the post planning and implementation phases. Capitalized costs related to internally developed software under development are treated as construction in progress until the program, feature or functionality is ready for its intended use, at which time amortization commences. These capitalized costs are included in other noncurrent assets on the consolidated balance sheets. For the fiscal years 2020, 2019 and 2018, the Company capitalized $1.0 million, $1.0 million and $1.3 million of costs related to internally developed software (of which $0.2 million, $0.2 million and $0.2 million, respectively, were stock-based compensation), respectively. As of December 31, 2020 and 2019, unamortized internally developed software costs totaled $2.6 million and $2.0 million, respectively. Amortization of internally developed software is recorded in cost of revenues. Costs associated with minor enhancements and maintenance are expensed as incurred. Management evaluates the useful lives of these assets on an annual basis and tests for impairment whenever events or changes in circumstances occur that could impact the recoverability of these assets.

Business Combinations Policy [Policy Text Block]

Business Combinations

The Company applies the provisions of ASC 805, Business Combinations, in accounting for its acquisitions. It requires the Company to recognize separately from goodwill the assets acquired and the liabilities assumed at their acquisition date fair values. Goodwill as of the acquisition date is measured as the excess of consideration transferred over the net of the acquisition date fair values of the assets acquired and the liabilities assumed. While the Company uses its best estimates and assumptions to accurately value assets acquired and liabilities assumed at the acquisition date as well as any contingent consideration, where applicable, its estimates are inherently uncertain and subject to refinement. As a result, during the measurement period, which may be up to one year from the acquisition date, the Company records adjustments to the assets acquired and liabilities assumed with the corresponding offset to goodwill. Upon the conclusion of the measurement period or final determination of the values of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded to its consolidated statements of operations.

Derivatives, Reporting of Derivative Activity [Policy Text Block]

Derivative Financial Instruments

Derivative financial instruments are utilized by the Company to reduce foreign currency exchange risks. The Company uses foreign currency forward contracts, with maturities of 13 months or less, to mitigate the impact of foreign currency fluctuations of certain non-U.S. dollar denominated net asset positions, to date primarily cash, accounts receivable and operating lease liabilities, as well as to manage foreign currency fluctuation risk related to forecasted transactions. Open contracts are recorded within prepaid expenses and other current assets, other noncurrent assets, accrued liabilities or other noncurrent liabilities in the consolidated balance sheets. Gains and losses resulting from currency exchange rate movements on non-designated forward contracts are recognized in other income (expense), net. Any gains or losses from derivatives designated as cash flow hedges are first recorded within accumulated other comprehensive income ("AOCI") and then reclassified into revenue or operating expenses when the hedged item impacts the consolidated statements of operations. Cash flows related to these forward contracts are classified in our consolidated statements of cash flows in the same manner as the underlying hedged transaction within cash flows from operating activities.

Share-based Payment Arrangement [Policy Text Block]

Stock-Based Compensation

The Company recognizes the fair value of its employee stock options and restricted stock units (RSU) on a straight-line basis over the requisite service periods for those awards ultimately expected to vest. The fair value of each option is estimated on the date of grant using the Black-Scholes-Merton option pricing model and the fair value of each RSU is based on the price of the Company's stock on the date of grant. Forfeitures are estimated on the date of grant and revised if actual or expected forfeiture activity differs materially from original estimates.

For performance-based non-qualified stock options (PSO) and performance-based restricted stock units (PSU), we recognize compensation costs over the requisite service period when it is probable that the performance conditions will be met. We assess these conditions on a quarterly basis.

Revenue [Policy Text Block]

Revenue Recognition

The Company derives revenues from subscriptions that require customers to pay a fee in order to access the Company’s cloud solutions. Contract period with customers generally ranges from less than a year to five years. The subscription fee entitles the customer to an unlimited number of scans for a specified number of networked devices or web applications and, if requested by a customer as part of their subscription, a specified number of physical or virtual scanner appliances. The Company’s physical and virtual scanner appliances are requested by certain customers as part of their subscriptions in order to scan IT infrastructures within their firewalls and do not function without, and are not sold separately from, subscriptions for the Company’s solutions. In some limited cases, the Company also provides certain computer equipment used to extend its Qualys Cloud Platform into its customers’ private cloud environment. Customers are required to return physical scanner appliances and computer equipment if they do not renew their subscriptions.

The Company determines revenue recognition through the following steps:

•

Identification of the contract, or contracts, with a customer;

•

Identification of the performance obligations in the contract;

•

Determination of the transaction price

•

Allocation of the transaction price to the performance obligations in the contract; and

•

Recognition of revenue when, or as, the Company satisfies a performance obligation.

At the inception of a customer contract, the Company makes an assessment as to that customer's ability to pay for the services provided. The Company assesses collectability based on a number of factors, including credit worthiness of the customer along with past transaction history. In addition, the Company performs periodic evaluations of its customers’ financial condition.

The vast majority of the Company’s revenue contracts are subscription based and contain a single performance obligation. In the rare case that multiple performance obligations exist, the Company determines the standalone selling prices ("SSP") of each performance obligation at contract inception, using information that may include market conditions and other observable inputs. As the Company, in general, does not offer rights of return, performance bonuses, customer loyalty programs, payments via non-cash methods, refunds, volume rebates, incentive payments, penalties, price concessions or payments or discounts contingent on future events, the contract prices are generally composed of fixed amount consideration for a specific period of time and typically do not include variable consideration. The subscription contracts typically do not confer to the customers any future rights that would constitute material rights under ASC 606.

Revenue is recognized when control of the subscription service is transferred to its customers in an amount that reflects the consideration the Company expects to be entitled to in exchange for those services. The Company's subscription services are typically satisfied ratably over the subscription term as its cloud-based offerings are delivered to customers electronically and over time. In addition, the Company recognizes revenues for certain limited scan arrangements on an as-used basis. The Company recognizes revenue related to professional services based on time and materials or completion of milestones stated in the contracts. When physical equipment are provided to the customers as part of the subscription service contract, the Company applies the practical expedient allowed under ASC 842 Leases to combine lease and nonlease components as a combined component to be accounted for under ASC 606, as the Company determined that the software subscription is the predominant component of the combined components. Therefore, the Company recognizes revenue for the physical equipment ratably over the related subscription period.

Deferred revenues consist of customer contracts billed or cash received that will be recognized in the future under subscriptions existing at the balance sheet date. The current portion of deferred revenues represents amounts that are expected to be recognized within one year of the balance sheet date.

Costs of shipping and handling charges incurred by the Company associated with physical scanner appliances and other computer equipment are included in cost of revenues. Sales taxes and other taxes collected from customers to be remitted to government authorities are excluded from revenues.

Incremental direct costs of obtaining a contract, which consist of sales commissions primarily for new business and upsells, are deferred and amortized over the estimated life of the customer relationship if renewals are expected and the renewal commission is not commensurate with the initial commission. The Company elected the practical expedient to expense commissions on renewals where the specific anticipated contract term amortization period is one year or less. The Company amortizes the capitalized commission cost as a selling expense on a straight-line basis over a period of five years. The Company classifies deferred commissions as current or noncurrent based on the timing of when it expects to recognize the expense. The current and noncurrent portions of deferred commissions are included in prepaid expenses and other current assets and other noncurrent assets, respectively, in its consolidated balance sheets.

Advertising Cost [Policy Text Block]

Advertising Expenses

Advertising costs are expensed as incurred and include costs of advertising and promotional materials. The Company incurred advertising costs of $207 thousand, $74 thousand and $87 thousand for 2020, 2019 and 2018, respectively.

Income Tax, Policy [Policy Text Block]

Income Taxes

The Company provides for the effect of income taxes in its consolidated financial statements using the asset and liability method which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, net operating loss carryovers, and tax credit carry forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the period that includes the enactment date.

Income tax expense or benefit is recognized for the amount of taxes payable or refundable for the current year and for deferred tax assets and liabilities for the tax consequences of events that have been recognized in an entity’s financial statements or tax returns. The Company must make significant assumptions, judgments and estimates to determine its current provision for (benefit from) income taxes, its deferred tax assets and liabilities, and any valuation allowance to be recorded against its deferred tax assets. The Company's judgments, assumptions and estimates relating to the current provision for (benefit from) income taxes include the geographic mix and amount of income (loss), its interpretation of current tax laws, and possible outcomes of current and future audits conducted by foreign and domestic tax authorities. The Company's judgments also include anticipating the tax positions the Company will record in the consolidated financial statements before actually preparing and filing the tax returns. The Company's estimates and assumptions may differ from the actual results as reflected on its income tax returns and will record the required adjustments when they are identified or resolved. Changes in the Company's business, tax laws or its interpretation of tax laws, and developments in current and future tax audits, could significantly impact the amounts provided for income taxes in the Company's results of operations, financial position, or cash flows.

Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to tax benefit carry-forwards and to differences between the financial statement amounts of assets and liabilities and their respective tax basis. The Company regularly reviews its deferred tax assets for recoverability and establishes a valuation allowance if it is more likely than not that some portion or all of the deferred tax assets will not be realized. To make this assessment, the Company takes into account predictions of the amount and category of taxable income from various sources and all available positive and negative evidence about these possible sources of taxable income. The weight given to the potential effect of negative and positive evidence is commensurate with the extent to which the strength of the evidence can be objectively verified.

The Company applies a two-step approach to determining the financial statement recognition and measurement of uncertain tax positions. The Company only recognizes an income tax expense or benefit with respect to uncertain tax positions in its financial statements that the Company judges is more likely than not to be sustained solely on its technical merits in a tax audit, including resolution of any related appeals or litigation processes. To make this judgment, the Company must interpret complex and sometimes ambiguous tax laws, regulations and administrative practices. If an income tax position meets the more likely than not recognition threshold, then the Company must measure the amount of the tax benefit to be recognized by determining the largest amount of tax benefit that has a greater than a 50% likelihood of being realized upon effective settlement with a taxing authority that has full knowledge of all of the relevant facts. It is inherently difficult and subjective to estimate such amounts, as this requires the Company to determine the probability of various possible settlement outcomes. To determine if a tax position is effectively settled after a tax examination has been completed, the Company must also estimate the likelihood that another taxing authority could review the respective tax position. The Company must also determine when it is reasonably possible that the amount of unrecognized tax benefits will significantly increase or decrease in the 12 months after each fiscal year-end. These judgments are difficult because a taxing authority may change its behavior as a result of the Company's disclosures in its financial statements. The Company must reevaluate its income tax positions on a quarterly basis to consider factors such as changes in facts or circumstances, changes in tax law, effectively settled issues under audit, and new audit activity. Such a change in recognition or measurement would result in recognition of a tax benefit or an additional charge to the tax provision. The Company's policy is to recognize interest and penalties related to unrecognized tax benefits as a component of the provision for income taxes.

Comprehensive Income, Policy [Policy Text Block]

Comprehensive Income (Loss)

Other comprehensive income (loss) consists of unrealized gains (losses) on marketable securities, net of tax, and derivative financial instruments designated as cash flow hedges which are not included in the Company’s net income. Total comprehensive income includes net income and other comprehensive income (loss) and is included in the consolidated statements of comprehensive income.

Foreign Currency Transactions and Translations Policy [Policy Text Block]

Foreign Currency Transactions

The Company’s operations are conducted in various countries around the world and the financial statements of its foreign subsidiaries are reported in the U.S. dollar as their respective functional currency. Monetary assets and liabilities denominated in foreign currencies have been re-measured into U.S. dollars using the exchange rates in effect at the balance sheet date, and income and expenses are re-measured at average exchange rates during the period. Foreign currency re-measurement gains and losses and foreign currency transaction gains and losses are recognized in other income (expense), net. The Company recorded total foreign currency transaction gain of $0.3 million and losses of $0.4 million and $0.6 million during 2020, 2019 and 2018, respectively.

Earnings Per Share, Policy [Policy Text Block]

Net Income Per Share

Basic net income per share is computed by dividing net income by the weighted-average number of common shares outstanding during the period. All participating securities are excluded from basic weighted average common shares outstanding. Diluted net income per share is computed by dividing net income by the weighted-average number of shares of common stock outstanding during the period, adjusted for the effects of potentially dilutive common shares, which are comprised of outstanding stock options and RSUs. The dilutive potential common shares are computed using the treasury stock method or the as-if converted method, as applicable. The outstanding stock options and RSUs which would be anti-dilutive are excluded from the computation of diluted net income per common share.

New Accounting Pronouncements, Policy [Policy Text Block]

Recently Adopted Accounting Pronouncements

In August 2018, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("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. This ASU aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs related to internal-use software. It also requires the Company to expense the capitalized implementation costs of a hosting arrangement that is a service contract over the term of the hosting arrangement. The Company adopted this ASU prospectively to applicable implementation costs incurred since January 1, 2020. The adoption did not have a material impact on the Company's consolidated financial statements.

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326) as modified by subsequently issued ASU No. 2018-19, 2019-04, 2019-05 and 2019-11, which introduces a new accounting model, Current Expected Credit Losses ("CECL"). CECL requires earlier recognition of credit losses, while also providing additional transparency about credit risk. CECL utilizes a lifetime expected credit loss measurement objective for the recognition of credit losses at the time the financial asset is originated or acquired. The expected credit losses are adjusted each period for changes in expected lifetime credit losses. The Company adopted this ASU on January 1, 2020, using a modified retrospective transition method, which requires a cumulative-effect adjustment, if any, to the opening balance of retained earnings to be recognized on the date of adoption with prior periods not restated. The adoption did not have a material impact on the Company's consolidated financial statements.

Recently Issued Accounting Pronouncements Not Yet Adopted

In December 2019, the FASB issued ASU No. 2019-12, Simplifying the Accounting for Income Taxes (ASU 2019-12), which simplifies the accounting for income taxes, eliminates certain exceptions within ASC 740, Income Taxes, and clarifies certain aspects of the current guidance to promote consistency among reporting entities. ASU 2019-12 is effective for the Company for fiscal years beginning after December 15, 2020. Most amendments within the standard are required to be applied on a prospective basis, while certain amendments must be applied on a retrospective or modified retrospective basis. The adoption of this ASU is not expected to have a material impact on the Company's consolidated financial statements.

Note 2 - Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2020

Cash and Cash Equivalents and Debt Securities, Available-for-sale, Amortized Cost to Fair Value [Table Text Block]

	*December 31, 2020*
	*Amortized Cost*		*Unrealized Gains*		*Unrealized Losses*			*Fair Value*
	(in thousands)
Cash and cash equivalents:
Cash	$	33,105	$	—	$	—		$	33,105
Money market funds		38,028		—		—			38,028
Commercial paper		2,999		—		—			2,999
Total		74,132		—		—			74,132
Short-term marketable securities:
Commercial paper		6,147		—		—			6,147
Corporate bonds		24,368		170		—			24,538
Asset-backed securities		6,263		18		—			6,281
U.S. government agencies		244,568		369		(11	)		244,926
Total		281,346		557		(11	)		281,892
Long-term marketable securities:
Asset-backed securities		38,456		160		(3	)		38,613
U.S. government agencies		6,884		17		—			6,901
Foreign government agencies		1,006		31		—			1,037
Corporate bonds		51,068		839		—			51,907
Total		97,414		1,047		(3	)		98,458
Total	$	452,892	$	1,604	$	(14	)	$	454,482

	*December 31, 2019*
	*Amortized Cost*		*Unrealized Gains*		*Unrealized Losses*			*Fair Value*
	(in thousands)
Cash and cash equivalents:
Cash	$	84,102	$	—	$	—		$	84,102
Money market funds		58		—		—			58
Commercial paper		3,399		—		—			3,399
Total		87,559		—		—			87,559
Short-term marketable securities:
Commercial paper		2,239		—		—			2,239
Corporate bonds		33,048		51		(1	)		33,098
Asset-backed securities		2,438		11		—			2,449
U.S. government agencies		173,364		184		(3	)		173,545
Total		211,089		246		(4	)		211,331
Long-term marketable securities:
Asset-backed securities		40,001		193		(1	)		40,193
U.S. government agencies		46,447		370		—			46,817
Corporate bonds		32,236		262		—			32,498
Total		118,684		825		(1	)		119,508
Total	$	417,332	$	1,071	$	(5	)	$	418,398

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

	*December 31, 2020*
	*Level 1*		*Level 2*		*Fair Value*
	(in thousands)
Money market funds	$	38,028	$	—	$	38,028
Commercial paper		—		9,146		9,146
U.S. government agencies		—		251,827		251,827
Foreign government agencies		—		1,037		1,037
Corporate bonds		—		76,445		76,445
Asset-backed securities		—		44,894		44,894
Total	$	38,028	$	383,349	$	421,377

	*December 31, 2019*
	*Level 1*		*Level 2*		*Fair Value*
	(in thousands)
Money market funds	$	58	$	—	$	58
Commercial paper		—		5,638		5,638
U.S. government agencies		—		220,362		220,362
Corporate bonds		—		65,596		65,596
Asset-backed securities		—		42,642		42,642
Total	$	58	$	334,238	$	334,296

Investments Classified by Contractual Maturity Date [Table Text Block]

	*December 31, 2020*
	*Mature within One Year*		*After One Year through Two Years*		*Over Two Years*		*Fair Value*
	(in thousands)
Commercial paper	$	9,146	$	—	$	—	$	9,146
U.S. government agencies		244,925		6,715		187		251,827
Foreign government agencies		—		—		1,037		1,037
Corporate bonds		24,538		31,983		19,924		76,445
Asset-backed securities		6,282		18,642		19,970		44,894
Total	$	284,891	$	57,340	$	41,118	$	383,349

Schedule of Derivative Instruments [Table Text Block]

	*December 31,*
	*2020*			*2019*
	(in thousands)
Assets:
Foreign currency forward contracts designated as cash flow hedge	$	511		$	427
Foreign currency forward contracts not designated as hedging instruments		27			515
Total	$	538		$	942
Liabilities:
Foreign currency forward contracts designated as cash flow hedge	$	(2,200	)	$	(524	)
Foreign currency forward contracts not designated as hedging instruments		(1,677	)		(550	)
Total	$	(3,877	)	$	(1,074	)

Derivative Instruments, Gain (Loss) [Table Text Block]

	*Year Ended December 31,*
	*2020*			*2019*			*2018*
	(in thousands)
Net gains (losses) from forward contracts	$	(1,634	)	$	438		$	543
Other foreign currency transaction gains (losses)		1,894			(792	)		(1,120	)
Total foreign exchange gains (losses), net		260			(354	)		(577	)
Other expenses		(253	)		(253	)		(224	)
Other income (expense), net	$	7		$	(607	)	$	(801	)

Tabular disclosure of pertinent information about a derivative or group of derivatives on a disaggregated basis, such as for individual instruments, or small groups of similar instruments. May include a combination of the type of instrument, risks being hedged, notional amount, hedge designation, related hedged item, inception date, maturity date, or other relevant item.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
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Note 3 - Accumulated Other Comprehensive Income (Tables)

12 Months Ended

Dec. 31, 2020

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

	*December 31,*
	*2020*			*2019*
	(in thousands)
Unrealized gains (losses) on AFS debt securities	$	1,224		$	822
Unrealized gains (losses) on cash flow hedges		(1,708	)		340
Total accumulated other comprehensive income	$	(484	)	$	1,162

Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]

	*Year Ended December 31,*
	*2020*			*2019*		*2018*
	(in thousands)
Reclassification of AOCI - AFS debt securities
Other income (expense), net	$	25		$	—	$	(289	)

Reclassification of AOCI - cashflow hedges
Revenue	$	960		$	134	$	—
Cost of revenues		(76	)		—		—
Research and development expenses		(264	)		—		—
Sales and marketing expenses		(20	)		—		—
General and administrative expenses		(36	)		—		—
Total	$	564		$	134	$	—

Note 4 - Property and Equipment, Net (Tables)

12 Months Ended

Dec. 31, 2020

Property, Plant and Equipment [Table Text Block]

	*December 31,*
	*2020*			*2019*
	(in thousands)
Computer equipment	$	136,286		$	112,599
Computer software		26,164			26,137
Scanner appliances		16,749			15,864
Furniture, fixtures and equipment		6,599			6,973
Equipment under capital lease		3,503			3,503
Leasehold improvements		21,107			18,817
Total property and equipment		210,408			183,893
Less: accumulated depreciation and amortization		(145,558	)		(123,314	)
Property and equipment, net	$	64,850		$	60,579

Note 5 - Revenue from Contracts with Customers (Tables)

12 Months Ended

Dec. 31, 2020

Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block]

	(in thousands)
2021	$	103,165
2022		70,381
2023		35,304
2024		1,363
2025		401
2026 and thereafter		168
Total	$	210,782

Disaggregation of Revenue [Table Text Block]

	*Year Ended December 31,*
	*2020*		*2019*			*2018*
	(in thousands)
Direct	$	212,296	$	186,130	$	164,084
Partner		150,667		135,477		114,805
Total	$	362,963	$	321,607	$	278,889

Contract With Customer, Commission Asset Balances [Table Text Block]

	*December 31, 2020*		*December 31, 2019*
	(in thousands)
Commission asset, current	$	3,459	$	2,568
Commission asset, noncurrent	$	6,906	$	6,454

Note 6 - Acquisitions (Tables)

12 Months Ended

Dec. 31, 2020

Schedule of Business Acquisitions, by Acquisition [Table Text Block]

Acquiree	*Acquisition Date*	*Purchase Consideration*		*Net Tangible Assets Acquired/ (liabilities assumed)*			*Purchased Intangible Assets*		*Goodwill*		*Deferred Tax Liability*
		(in thousands)
Spell security	July 24, 2020	$	1,500	$	—		$	1,500	$	—	$	—
Adya	January 10, 2019	$	1,000	$	—		$	900	$	100	$	—
Layered Insight	October 16, 2018	$	13,434	$	(80	)	$	9,600	$	5,498	$	(1,500	)
1Mobility	April 1, 2018	$	4,000	$	—		$	3,700	$	300	$	—

Schedule of Goodwill [Table Text Block]

	(in thousands)
Balance as of December 31, 2018	$	7,225
Goodwill acquired		100
Adjustment		122
Balance as of December 31, 2019 and 2020	$	7,447

Note 7 - Intangible Assets, Net (Tables)

12 Months Ended

Dec. 31, 2020

Schedule of Acquired Finite-Lived Intangible Assets by Major Class [Table Text Block]

					*December 31, 2020*
	*Weighted Average Lives (Years)*		*Weighted Average Remaining Lives (Years)*		*Cost*		*Accumulated Amortization*			*Net Book Value*
					(in thousands)
Developed technology		4.4		1.8	$	27,356	$	(16,152	)	$	11,204
Patent licenses		14.0		3.7		1,387		(1,021	)		366
Non-compete agreements		2.0		1.6		500		(104	)		396
Total intangibles subject to amortization					$	29,243	$	(17,277	)		11,966
Intangible assets not subject to amortization											40
Total intangible assets, net										$	12,006

						*December 31, 2019*
	*Weighted Average Lives (Years)*		*Weighted Average Remaining Lives (Years)*		*Cost*		*Accumulated Amortization*			*Net Book Value*
						(in thousands)
Developed technology		4.6		2.7	$	26,356	$	(10,066	)	$	16,290
Patent licenses		14.0		4.7		1,387		(922	)		465
Total intangibles subject to amortization					$	27,743	$	(10,988	)		16,755
Intangible assets not subject to amortization											40
Total intangible assets, net										$	16,795

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

		(in thousands)
2021	$	6,581
2022		4,823
2023		350
2024		212
Total expected future amortization expense	$	11,966

Note 8 - Leases (Tables)

12 Months Ended

Dec. 31, 2020

Assets and Liabilities, Lease [Table Text Block]

Classification on the Balance Sheet	*Classification of Lease*	*December 31,*
		*2020*		*2019*
Assets		*(in thousands)*
Operating lease - right of use asset	Operating leases	$	44,838	$	40,551
Property and equipment, net	Finance leases		131		1,299
Total lease assets		$	44,969	$	41,850

Liabilities
Current
Operating lease liabilities, current	Operating leases	$	11,672	$	7,663
Accrued liabilities	Finance leases		64		124
Noncurrent
Operating lease liabilities, noncurrent	Operating leases		45,700		44,015
Other noncurrent liabilities	Finance leases		—		54
*Total lease liabilities*		$	57,436	$	51,856

Lessee, Operating Lease, Supplemental Cash Flow Disclosure [Table Text Block]

	*Year Ended December 31,*
	*2020*		*2019*
	(in thousands)
Operating cash flows included in the measurement of lease liabilities		13,403		9,372
Lease liabilities arising from obtaining right of use assets		15,837		17,359

Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]

		(in thousands)
2021	$	14,186
2022		13,316
2023		11,297
2024		10,010
2025		6,407
2026 and thereafter		10,317
Total minimum lease payments		65,533
Less: amount representing interest		(8,161	)
Present value of minimum payments		57,372
Less: lease obligations, current		(11,672	)
Lease obligations, noncurrent	$	45,700

Lessee, Weighted Average Remaining Lease Term and Weighted Average Discount Rate [Table Text Block]

	*December 31,*
	*2020*			*2019*
Weighted average remaining lease term (years)
Operating leases		4.1			6.5
Finance leases		0.1			1.3
Weighted average discount rates
Operating leases		4.8	%		5.0	%
Finance leases		5.0	%		5.0	%

Note 9 - Commitment and Contingencies (Tables)

12 Months Ended

Dec. 31, 2020

Contractual Obligation, Fiscal Year Maturity [Table Text Block]

	(in thousands)
2021	$	20,131
2022		6,528
2023		6,924
2024		7,780
2025		1,873
Total purchase commitment	$	43,236

Note 10 - Stockholders' Equity and Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2020

Schedule of Shares Reserved for Future Issuance [Table Text Block]

Options and RSUs outstanding under equity incentive plans
2000 Equity Incentive Plan			102,087
2012 Equity Incentive Plan			3,160,057
Shares available for future grants under an equity incentive plan
2012 Equity Incentive Plan			6,628,383
Total shares reserved for future issuance			9,890,527

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	*Year Ended December 31,*
	*2020*		*2019*		*2018*
	(in thousands)
Cost of revenues	$	2,767	$	2,262	$	2,489
Research and development		13,502		11,151		7,961
Sales and marketing		5,785		4,984		4,650
General and administrative		17,981		16,495		14,990
Total stock-based employee compensation	$	40,035	$	34,892	$	30,090

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

Year Ended December 31,

2020

2019

2018

Expected term (in years)

4.5 to 5.5

4.4 to 6.6

4.5 to 5.0

Volatility

38% to 43%

40% to 46%

45% to 47%

Risk-free interest rate

0.3% to 1.4%

1.5% to 2.4%

2.5% to 3.0%

Dividend yield

—

Share-based Payment Arrangement, Option, Activity [Table Text Block]

	*Outstanding Shares*			*Weighted Average Exercise Price Per Share*		*Weighted Average Remaining Contractual Life (Years)*		*Aggregate Intrinsic Value*
								(in thousands)
Balance as of December 31, 2017		4,495,891		$	25.29		6.6	$	153,129
Granted		366,786		$	79.79
Exercised		(1,183,235	)	$	20.33
Canceled		(250,133	)	$	39.61
Balance as of December 31, 2018		3,429,309		$	31.79		6.4	$	149,935
Granted		496,145		$	87.10
Exercised		(901,290	)	$	27.55
Canceled		(157,489	)	$	71.04
Balance as of December 31, 2019		2,866,675		$	40.54		6.0	$	125,647
Granted		593,694		$	99.77
Exercised		(1,129,845	)	$	30.50
Canceled		(115,082	)	$	87.91
Balance as of December 31, 2020		2,215,442		$	59.07		6.5	$	139,121
Vested and expected to vest—December 31, 2020		2,071,441		$	56.39		6.3	$	135,647
Exercisable—December 31, 2020		1,290,452		$	34.69		4.7	$	112,502

Share-based Payment Arrangement, Option, Exercise Price Range [Table Text Block]

	Outstanding						Exercisable
Exercise Price	Number of Shares		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Life (Years)		Number of Shares		Weighted Average Exercise Price Per Share
4.4 - 20.8		266,447	$	13.25		2.1		266,447	$	13.25
22.31 - 25.17		130,550	$	24.16		4.3		130,550	$	24.16
25.56 - 25.56		264,824	$	25.56		5.3		264,824	$	25.56
26.86 - 34.97		227,072	$	30.72		3.9		227,072	$	30.72
36.25 - 52.6		232,792	$	40.24		5.4		215,601	$	39.80
59.95 - 86.35		307,387	$	80.11		8.3		77,644	$	74.90
87.26 - 89.55		189,217	$	88.48		8.6		52,147	$	88.42
93.08 - 93.08		223,744	$	93.08		9.9		—	$	—
94.45 - 104.8		273,709	$	97.76		8.8		56,167	$	94.91
121.65 - 121.65		99,700	$	121.65		9.6		—	$	—
		2,215,442	$	59.07		6.5		1,290,452	$	34.69

Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]

	*Number of Shares*			*Weighted-Average Grant Date Fair Value Per Share*
Balance as of December 31, 2017		1,410,588		$	40.34
Granted		548,245		$	75.44
Vested		(525,375	)	$	39.87
Cancelled		(206,575	)	$	43.43
Balance as of December 31, 2018		1,226,883		$	55.71
Granted		595,985		$	81.59
Vested		(438,892	)	$	53.17
Cancelled		(169,158	)	$	65.51
Balance as of December 31, 2019		1,214,818		$	67.99
Granted		531,146		$	99.96
Vested		(475,853	)	$	62.57
Cancelled		(223,409	)	$	77.37
Balance as of December 31, 2020		1,046,702		$	86.78
Expected to vest as of December 31, 2020		961,926		$	86.02

Note 12 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]

	*Year Ended December 31,*
	*2020*		*2019*		*2018*
	(in thousands)
Domestic	$	94,099	$	72,124	$	50,010
Foreign		7,938		7,859		5,458
Income before income taxes	$	102,037	$	79,983	$	55,468

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

	*Year Ended December 31,*
	*2020*			*2019*			*2018*
	(in thousands)
Current
Federal	$	1,944		$	(90	)	$	(90	)
State		1,438			646			62
Foreign		3,571			3,000			1,988
Total current provision		6,953			3,556			1,960
Deferred
Federal		4,239			7,085			(3,449	)
State		26			447			21
Foreign		(753	)		(441	)		(368	)
Total deferred (benefit) provision		3,512			7,091			(3,796	)
Total provision for (benefit from) provision for income taxes	$	10,465		$	10,647		$	(1,836	)

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	*Year Ended December 31,*
	*2020*			*2019*			*2018*
Federal statutory rate		21.0	%		21.0	%		21.0	%
State taxes		1.6			1.5			(1.9	)
Stock-based compensation		4.8			4.0			5.8
Excess tax benefits related to stock-based compensation		(13.8	)		(11.2	)		(26.2	)
Foreign source income		0.2			0.1			(0.2	)
Change in valuation allowance		0.8			1.1			4.4
Foreign-derived intangible income deduction		(1.7	)		—			—
Federal and state research and development credit		(2.6	)		(3.7	)		(6.7	)
Other		—			0.4			0.5
Provision for (benefit from) income taxes		10.3	%		13.2	%		(3.3	)%

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	*December 31,*
	*2020*			*2019*
	(in thousands)
Deferred tax assets
Net operating loss carryforwards	$	290		$	1,325
Research and development credit carryforwards		16,965			20,182
Foreign tax credit carryforwards		3,497			2,586
Accrued liabilities		2,019			1,109
Deferred revenues		5,123			4,843
Operating lease liabilities		15,924			13,187
Intangible assets		1,397			327
Stock-based compensation		3,907			5,942
Other		430			158
Gross deferred tax assets		49,552			49,659
Valuation allowance		(11,188	)		(10,094	)
Net deferred tax assets		38,364			39,565
Deferred tax liabilities
Fixed assets		(7,017	)		(8,097	)
Operating leases - right of use asset		(13,054	)		(10,496	)
Deferred commissions		(2,482	)		(2,142	)
Total deferred tax liabilities		(22,553	)		(20,735	)
Net deferred tax assets	$	15,811		$	18,830

Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]

	*Year Ended December 31,*
	*2020*			*2019*			*2018*
	(in thousands)
Unrecognized tax benefits beginning balance	$	7,778		$	6,406		$	5,112
Gross increase for tax positions of prior years		4			—			279
Gross decrease for tax positions of prior years		—			(12	)		(227	)
Gross increase for tax positions of current year		1,258			1,384			1,399
Lapse of statute of limitations		(185	)		—			(157	)
Total unrecognized tax benefits	$	8,855		$	7,778		$	6,406

Note 13 - Segment Information and Information about Geographic Area (Tables)

12 Months Ended

Dec. 31, 2020

Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block]

	*Year Ended December 31,*
	*2020*		*2019*		*2018*
	(in thousands)
United States	$	230,444	$	206,555	$	185,887
Foreign		132,519		115,052		93,002
Total revenues	$	362,963	$	321,607	$	278,889

	*December 31,*
	*2020*		*2019*
	(in thousands)
United States	$	43,791	$	46,100
India		12,465		9,221
Rest of world		8,594		5,258
Total property and equipment, net	$	64,850	$	60,579

Note 14 - Net Income Per Share (Tables)

12 Months Ended

Dec. 31, 2020

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	*Year Ended December 31,*
	*2020*		*2019*		*2018*
	(in thousands, except per share data)
Numerator:
Net income	$	91,572	$	69,336	$	57,304

Denominator:
Weighted-average shares used in computing net income per share - basic		39,167		39,075		38,876
Effect of potentially dilutive securities:
Common stock options		1,267		1,807		2,401
Restricted stock units		389		463		620
Weighted-average shares used in computing net income per share - diluted	$	40,823	$	41,345	$	41,897
Net income per share:
Basic	$	2.34	$	1.77	$	1.47
Diluted	$	2.24	$	1.68	$	1.37

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	*Year Ended December 31,*
	*2020*		*2019*		*2018*
	(in thousands)
Common stock options		620		461		177
Restricted stock units		80		26		22
Total anti-dilutive shares		700		487		199

Note 15 - Selected Quarterly Financial Information (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2020

Quarterly Financial Information [Table Text Block]

	*Three Months Ended*
	*December 31, 2020*		*September 30, 2020*		*June 30, 2020*		*March 31, 2020*		*December 31, 2019*		*September 30, 2019*		*June 30, 2019*		*March 31, 2019*
	(unaudited)
	(in thousands, except per share data)
Revenues	$	94,801	$	93,069	$	88,830	$	86,263	$	84,664	$	82,671	$	78,929	$	75,343
Income from operations		24,412		26,303		25,508		20,431		19,545		22,549		16,108		14,051
Other income (expense), net		680		1,331		1,586		1,786		1,757		1,786		2,401		1,786
Income before income taxes		25,092		27,634		27,094		22,217		21,302		24,335		18,509		15,837
Net income	$	23,816	$	22,743	$	26,319	$	18,694	$	20,664	$	19,174	$	16,232	$	13,266
Net income per share:
Basic	$	0.61	$	0.58	$	0.67	$	0.48	$	0.53	$	0.49	$	0.41	$	0.34
Diluted	$	0.59	$	0.56	$	0.64	$	0.46	$	0.50	$	0.47	$	0.39	$	0.32

Note 1 - The Company and Summary of Significant Accounting Policies (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Restricted Cash, Total	$ 1,200	$ 1,200
Proceeds from Dividends Received	0
Impairment of Long-Lived Assets Held-for-use	$ 0	0	$ 0
Number of Reporting Units	1
Goodwill, Impairment Loss	$ 0	0
Impairment of Intangible Assets (Excluding Goodwill), Total	0	0	0
Capitalized Computer Software, Gross	1,000	1,000	1,300
Capitalized Computer Software, Unamortized	$ 2,600	2,000
Capitalized Contract Cost, Amortization Period (Year)	5 years
Advertising Expense	$ 207	74	87
Foreign Currency Transaction Gain, before Tax	300
Foreign Currency Transaction Loss, before Tax		400	600
Deferred Compensation, Share-based Payments [Member]
Capitalized Computer Software, Gross	$ 200	$ 200	200
Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Asset, Useful Life (Year)	3 years
Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)	3 years
Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)	5 years
Contract with Customer, Period (Year)	5 years
Preferred Stock [Member]
Investments, Total			2,500
Other than Temporary Impairment Losses, Investments, Total			$ 0

Note 2 - Fair Value of Financial Instruments (Details Textual) $ in Thousands, € in Millions, ₨ in Millions, £ in Millions	Dec. 31, 2020 USD ($)	Dec. 31, 2020 EUR (€)	Dec. 31, 2020 GBP (£)	Dec. 31, 2020 INR (₨)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 EUR (€)	Dec. 31, 2019 GBP (£)	Dec. 31, 2019 INR (₨)
Marketable Securities In Unrealized Loss Positions, More Than 12 Months Qualitative Disclosure, Number Of Positions	0	0	0	0	0	0	0	0
Foreign Exchange Contract [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member]
Derivative, Number of Instruments Held, Total	39	39	39	39	26	26	26	26
Derivative, Notional Amount		€ 25.9	£ 8.7	₨ 1,933.5		€ 24.2	£ 9.7
Foreign Exchange Contract [Member] \| Not Designated as Hedging Instrument [Member]
Derivative, Number of Instruments Held, Total	24	24	24	24	15	15	15	15
Derivative, Notional Amount		€ 17.7	£ 6.5	₨ 32.8		€ 20.0	£ 5.6	₨ 756.0
Foreign Exchange Contracts for GBP and Euro [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member]
Foreign Currency Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months	$ (1,800)				$ 700
Foreign Exchange Contracts for INR [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member]
Foreign Currency Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months	1,500
Fair Value, Inputs, Level 3 [Member]
Investments, Fair Value Disclosure, Total	$ 0				$ 0

Note 2 - Fair Value of Financial Instruments - Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Cash and cash equivalents	$ 74,132	$ 87,559
Short-term marketable securities, amortization cost	281,346	211,089
Unrealized gains, short-term securities	557	246
Short-term marketable securities, unrealized loss	(11)	(4)
Short-term marketable securities	281,892	211,331
Long-term marketable securities, amortization cost	97,414	118,684
Unrealized gains, long-term securities	1,047	825
Long-term marketable securities, unrealized loss	(3)	(1)
Long-term marketable securities	98,458	119,508
Cash and cash equivalents and marketable securities, amortization cost	452,892	417,332
Unrealized gains, securities	1,604	1,071
Unrealized loss, securities	(14)	(5)
Cash and cash equivalents and short-term and long-term Marketable Securities, fair value	454,482	418,398
Commercial Paper, Not Included with Cash and Cash Equivalents [Member]
Short-term marketable securities, amortization cost	6,147	2,239
Unrealized gains, short-term securities	0	0
Short-term marketable securities, unrealized loss	0	0
Short-term marketable securities	6,147	2,239
Corporate Debt Securities [Member]
Short-term marketable securities, amortization cost	24,368	33,048
Unrealized gains, short-term securities	170	51
Short-term marketable securities, unrealized loss	0	(1)
Short-term marketable securities	24,538	33,098
Long-term marketable securities, amortization cost	51,068	32,236
Unrealized gains, long-term securities	839	262
Long-term marketable securities, unrealized loss	0	0
Long-term marketable securities	51,907	32,498
Asset-backed Securities [Member]
Short-term marketable securities, amortization cost	6,263	2,438
Unrealized gains, short-term securities	18	11
Short-term marketable securities, unrealized loss	0	0
Short-term marketable securities	6,281	2,449
Long-term marketable securities, amortization cost	38,456	40,001
Unrealized gains, long-term securities	160	193
Long-term marketable securities, unrealized loss	(3)	(1)
Long-term marketable securities	38,613	40,193
US Government Agencies Debt Securities [Member]
Short-term marketable securities, amortization cost	244,568	173,364
Unrealized gains, short-term securities	369	184
Short-term marketable securities, unrealized loss	(11)	(3)
Short-term marketable securities	244,926	173,545
Long-term marketable securities, amortization cost	6,884	46,447
Unrealized gains, long-term securities	17	370
Long-term marketable securities, unrealized loss	0	0
Long-term marketable securities	6,901	46,817
Foreign Government Agencies [Member]
Long-term marketable securities, amortization cost	1,006
Unrealized gains, long-term securities	31
Long-term marketable securities, unrealized loss	0
Long-term marketable securities	1,037
Cash [Member]
Cash and cash equivalents	33,105	84,102
Money Market Funds [Member]
Cash and cash equivalents	38,028	58
Commercial Paper [Member]
Cash and cash equivalents	$ 2,999	$ 3,399

Note 2 - Fair Value of Financial Instruments - Fair Value Hierarchy (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Money market funds	$ 38,028	$ 58
Commercial paper	9,146	5,638
U.S. government agencies	251,827	220,362
Foreign government agencies	1,037
Corporate bonds	76,445	65,596
Asset-backed securities	44,894	42,642
Total	421,377	334,296
Fair Value, Inputs, Level 1 [Member]
Money market funds	38,028	58
Commercial paper	0	0
U.S. government agencies	0	0
Foreign government agencies	0
Corporate bonds	0	0
Asset-backed securities	0	0
Total	38,028	58
Fair Value, Inputs, Level 2 [Member]
Money market funds	0	0
Commercial paper	9,146	5,638
U.S. government agencies	251,827	220,362
Foreign government agencies	1,037
Corporate bonds	76,445	65,596
Asset-backed securities	44,894	42,642
Total	$ 383,349	$ 334,238

Note 2 - Fair Value of Financial Instruments - Summary of the Fair Value of Marketable Securities (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Available-for-sale Securities, Debt and Equity Maturities, Next Twelve Months, Fair Value	$ 284,891
Available-for-sale Securities, Debt and Equity Maturities, Year One through Two, Fair Value	57,340
Available-for-sale Securities, Debt and Equity Maturities, Year over two years, Fair Value	41,118
Debt Securities, Available-for-sale	383,349
Commercial Paper [Member]
Available-for-sale Securities, Debt and Equity Maturities, Next Twelve Months, Fair Value	9,146
Available-for-sale Securities, Debt and Equity Maturities, Year One through Two, Fair Value	0
Available-for-sale Securities, Debt and Equity Maturities, Year over two years, Fair Value	0
Debt Securities, Available-for-sale	9,146
US Government Agencies Debt Securities [Member]
Available-for-sale Securities, Debt and Equity Maturities, Next Twelve Months, Fair Value	244,925
Available-for-sale Securities, Debt and Equity Maturities, Year One through Two, Fair Value	6,715
Available-for-sale Securities, Debt and Equity Maturities, Year over two years, Fair Value	187
Debt Securities, Available-for-sale	251,827
Foreign Government Agencies [Member]
Available-for-sale Securities, Debt and Equity Maturities, Next Twelve Months, Fair Value	0
Available-for-sale Securities, Debt and Equity Maturities, Year One through Two, Fair Value	0
Available-for-sale Securities, Debt and Equity Maturities, Year over two years, Fair Value	1,037
Debt Securities, Available-for-sale	1,037
Corporate Bond Securities [Member]
Available-for-sale Securities, Debt and Equity Maturities, Next Twelve Months, Fair Value	24,538
Available-for-sale Securities, Debt and Equity Maturities, Year One through Two, Fair Value	31,983
Available-for-sale Securities, Debt and Equity Maturities, Year over two years, Fair Value	19,924
Debt Securities, Available-for-sale	76,445
Asset-backed Securities [Member]
Available-for-sale Securities, Debt and Equity Maturities, Next Twelve Months, Fair Value	6,282
Available-for-sale Securities, Debt and Equity Maturities, Year One through Two, Fair Value	18,642
Available-for-sale Securities, Debt and Equity Maturities, Year over two years, Fair Value	19,970
Debt Securities, Available-for-sale	$ 44,894

Note 2 - Fair Value of Financial Instruments - Summary of Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Foreign currency forward contracts	$ 538	$ 942
Foreign currency forward contracts	(3,877)	(1,074)
Designated as Hedging Instrument [Member]
Foreign currency forward contracts	511	427
Foreign currency forward contracts	(2,200)	(524)
Not Designated as Hedging Instrument [Member]
Foreign currency forward contracts	27	515
Foreign currency forward contracts	$ (1,677)	$ (550)

Note 2 - Fair Value of Financial Instruments - Amounts Recognized In Statement Of Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net gains (losses) from forward contracts	$ (1,634)	$ 438	$ 543
Other foreign currency transaction gains (losses)	1,894	(792)	(1,120)
Total foreign exchange gains (losses), net	260	(354)	(577)
Other expenses	(253)	(253)	(224)
Other income (expense), net	$ 7	$ (607)	$ (801)

Note 3 - Accumulated Other Comprehensive Income - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated other comprehensive income (loss)	$ 404,482	$ 386,803	$ 357,989	$ 343,544
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Accumulated other comprehensive income (loss)	1,224	822
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Accumulated other comprehensive income (loss)	(1,708)	340
AOCI Attributable to Parent [Member]
Accumulated other comprehensive income (loss)	$ (484)	$ 1,162	$ (586)	$ (574)

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

Note 3 - Accumulated Other Comprehensive Income - Amounts Reclassified from AOCI (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other income (expense), net									$ (7)	$ 607	$ 801
Revenue									(362,963)	(321,607)	(278,889)
Cost of revenues									79,226	69,517	66,185
Research and development									72,548	68,239	53,255
Sales and marketing									67,965	70,833	70,039
General and administrative									46,570	40,765	39,049
Total	$ 25,092	$ 27,634	$ 27,094	$ 22,217	$ 21,302	$ 24,335	$ 18,509	$ 15,837	102,037	79,983	55,468
Reclassification out of Accumulated Other Comprehensive Income [Member] \| AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Other income (expense), net									25	0	(289)
Reclassification out of Accumulated Other Comprehensive Income [Member] \| Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Revenue									960	134	0
Cost of revenues									(76)	0	0
Research and development									(264)	0	0
Sales and marketing									(20)	0	0
General and administrative									(36)	0	0
Total									$ 564	$ 134	$ 0

Note 4 - 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, Net, Ending Balance	$ 64,850	$ 60,579
Depreciation, Depletion And Amortization, Excluding Intangible Asset Amortization	26,100	24,900	$ 25,100
Scanner Appliances and Other Computer Equipment Subject To Subscription [Member]
Property, Plant and Equipment, Net, Ending Balance	7,500	4,900
Scanner Appliances and Other Computer Equipment Not Placed In Service [Member]
Property, Plant and Equipment, Net, Ending Balance	$ 1,900	$ 900

Note 4 - Property and Equipment, Net - Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property and equipment	$ 210,408	$ 183,893
Less: accumulated depreciation and amortization	(145,558)	(123,314)
Property and equipment, net	64,850	60,579
Computer Equipment [Member]
Property and equipment	136,286	112,599
Computer Software, Intangible Asset [Member]
Property and equipment	26,164	26,137
Scanner Appliances [Member]
Property and equipment	16,749	15,864
Furniture and Fixtures [Member]
Property and equipment	6,599	6,973
Assets Held under Capital Leases [Member]
Property and equipment	3,503	3,503
Leasehold Improvements [Member]
Property and equipment	$ 21,107	$ 18,817

Note 5 - Revenue from Contracts with Customers (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Contract with Customer, Liability, Revenue Recognized	$ 188,600	$ 160,800
Amortization of Deferred Sales Commissions	3,000	2,000	$ 1,200
Capitalized Contract Cost, Impairment Loss	$ 0	$ 0	$ 0

Note 5 - Revenue from Contracts with Customers - Expected Revenue from All Remaining Performance Obligations (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Remaining performance obligations	$ 210,782

Note 5 - Revenue from Contracts with Customers - Expected Revenue from All Remaining Performance Obligations 2 (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Remaining performance obligations	$ 210,782
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Remaining performance obligations, period (Year)	1 year
Remaining performance obligations	$ 103,165
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Remaining performance obligations, period (Year)	1 year
Remaining performance obligations	$ 70,381
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Remaining performance obligations, period (Year)	1 year
Remaining performance obligations	$ 35,304
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Remaining performance obligations, period (Year)	1 year
Remaining performance obligations	$ 1,363
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Remaining performance obligations, period (Year)	1 year
Remaining performance obligations	$ 401
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Remaining performance obligations, period (Year)	1 year
Remaining performance obligations	$ 168

Note 5 - Revenue from Contracts with Customers - Revenue by Sales Channel (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues	$ 362,963	$ 321,607	$ 278,889
Sales Channel, Directly to Consumer [Member]
Revenues	212,296	186,130	164,084
Sales Channel, Through Intermediary [Member]
Revenues	$ 150,667	$ 135,477	$ 114,805

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Note 5 - Revenue from Contracts with Customers - Capitalized Cost to Obtain Contracts, Current and Noncurrent (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Commission asset, current	$ 3,459	$ 2,568
Commission asset, noncurrent	$ 6,906	$ 6,454

Note 6 - Acquisitions (Details Textual) - USD ($) $ in Thousands					12 Months Ended
	Jul. 24, 2020	Jan. 10, 2019	Oct. 16, 2018	Apr. 01, 2018	Dec. 31, 2020	Dec. 31, 2019
Developed Technology Rights [Member]
Finite-Lived Intangible Asset, Useful Life (Year)					4 years 4 months 24 days	4 years 7 months 6 days
Noncompete Agreements [Member]
Finite-Lived Intangible Asset, Useful Life (Year)					2 years
Spell Security [Member]
Business Combination, Consideration Transferred, Total	$ 1,500
Business Combination, Contingent Consideration, Liability, Total	200
Spell Security [Member] \| Developed Technology Rights [Member]
Finite-lived Intangible Assets Acquired	$ 1,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life (Year)	4 years
Spell Security [Member] \| Noncompete Agreements [Member]
Finite-lived Intangible Assets Acquired	$ 500
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life (Year)	2 years
Adya [Member]
Business Combination, Consideration Transferred, Total		$ 1,000
Payment for Contingent Consideration Liability, Investing Activities		$ 200
Goodwill, Deductible for Tax Purpose Period (Year)		15 years
Adya [Member] \| Developed Technology Rights [Member]
Finite-Lived Intangible Asset, Useful Life (Year)		4 years
Layered Insights [Member]
Business Combination, Consideration Transferred, Total			$ 13,434
Business Combination, Consideration Transferred, Other						$ 1,600
Business Combination, Additional Consideration						4,000
Business Combination, Earnout Milestone			$ 1,500
Layered Insights [Member] \| Developed Technology Rights [Member]
Finite-Lived Intangible Asset, Useful Life (Year)			4 years
The 1Mobility [Member]
Business Combination, Consideration Transferred, Total				$ 4,000
Goodwill, Deductible for Tax Purpose Period (Year)				15 years
Business Combination, Consideration Transferred, Other						$ 600
The 1Mobility [Member] \| Developed Technology Rights [Member]
Finite-Lived Intangible Asset, Useful Life (Year)				4 years

Note 6 - Acquisitions - Estimated Fair Values of the Acquired Assets (Details) - USD ($) $ in Thousands	Jul. 24, 2020	Jan. 10, 2019	Oct. 16, 2018	Apr. 01, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill					$ 7,447	$ 7,447	$ 7,225
Spell Security [Member]
Purchase Consideration	$ 1,500
Net Tangible Assets Acquired/ (liabilities assumed)	0
Purchased Intangible Assets	1,500
Goodwill	0
Deferred Tax Liability	$ 0
Adya [Member]
Purchase Consideration		$ 1,000
Net Tangible Assets Acquired/ (liabilities assumed)		0
Purchased Intangible Assets		900
Goodwill		100
Deferred Tax Liability		$ 0
Layered Insights [Member]
Purchase Consideration			$ 13,434
Net Tangible Assets Acquired/ (liabilities assumed)			(80)
Purchased Intangible Assets			9,600
Goodwill			5,498
Deferred Tax Liability			$ (1,500)
The 1Mobility [Member]
Purchase Consideration				$ 4,000
Net Tangible Assets Acquired/ (liabilities assumed)				0
Purchased Intangible Assets				3,700
Goodwill				300
Deferred Tax Liability				$ 0

Note 6 - Acquisitions - Changes in Carrying Amount of Goodwill (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Balance	$ 7,225
Goodwill acquired	100
Adjustment	122
Balance	$ 7,447

Note 7 - Intangible Assets, Net (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Amortization of Intangible Assets, Total	$ 6.3	$ 6.1	$ 3.7

Note 7 - Intangible Assets, Net - Carrying Value of Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cost	$ 29,243	$ 27,743
Amortization of intangible assets	(17,277)	(10,988)
Net Book Value	11,966	16,755
Intangible assets, net	12,006	16,795
Intangible Assets Not Subject to Amortization [Member]
Intangible assets not subject to amortization	$ 40	$ 40
Developed Technology Rights [Member]
Weighted Average Life (Year)	4 years 4 months 24 days	4 years 7 months 6 days
Weighted Average Remaining Life (Year)	1 year 9 months 18 days	2 years 8 months 12 days
Cost	$ 27,356	$ 26,356
Amortization of intangible assets	(16,152)	(10,066)
Net Book Value	$ 11,204	$ 16,290
Patents [Member]
Weighted Average Life (Year)	14 years	14 years
Weighted Average Remaining Life (Year)	3 years 8 months 12 days	4 years 8 months 12 days
Cost	$ 1,387	$ 1,387
Amortization of intangible assets	(1,021)	(922)
Net Book Value	$ 366	$ 465
Noncompete Agreements [Member]
Weighted Average Life (Year)	2 years
Weighted Average Remaining Life (Year)	1 year 7 months 6 days
Cost	$ 500
Amortization of intangible assets	(104)
Net Book Value	$ 396

Note 7 - Intangible Assets, Net - Expected Amortization Expense in Future Periods (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
2021	$ 6,581
2022	4,823
2023	350
2024	212
Total expected future amortization expense	$ 11,966	$ 16,755

Note 8 - Leases (Details Textual) - USD ($) $ in Millions	12 Months Ended
Note 8 - Leases (Details Textual) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Lessee, Operating Lease, Renewal Term (Year)	4 years
Operating Lease, Expense	$ 16.7	$ 13.9	$ 9.9

Note 8 - Leases - Lease-related Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Operating leases - right of use asset	$ 44,838	$ 40,551
Property and equipment, net	131	1,299
Total lease assets	44,969	41,850
Operating lease liabilities, current	11,672	7,663
Accrued liabilities	64	124
Lease obligations, noncurrent, operating leases	45,700	44,015
Other noncurrent liabilities	0	54
Total lease liabilities	$ 57,436	$ 51,856

Note 8 - Leases - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating cash flows included in the measurement of lease liabilities	$ 13,403	$ 9,372
Lease liabilities arising from obtaining right of use assets	$ 15,837	$ 17,359

Note 8 - Leases - Minimum Annual Lease Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
2021, operating leases	$ 14,186
2022, operating leases	13,316
2023, operating leases	11,297
2024, operating leases	10,010
2025, operating leases	6,407
2025 and thereafter, operating leases	10,317
Total minimum lease payments, operating leases	65,533
Less: amount representing interest, operating leases	(8,161)
Present value of minimum payments, operating leases	57,372
Less: lease obligations, current, operating leases	11,672	$ 7,663
Lease obligations, noncurrent, operating leases	$ 45,700	$ 44,015

Note 8 - Leases - Weighted Average Remaining Lease Term and Weighted Average Discount Rate (Details)	Dec. 31, 2020	Dec. 31, 2019
Operating leases, weighted average remaining lease term (Year)	4 years 1 month 6 days	6 years 6 months
Finance leases, weighted average remaining lease term (Year)	1 month 6 days	1 year 3 months 18 days
Operating leases, weighted average discount rates	4.80%	5.00%
Finance leases, weighted average discount rates	5.00%	5.00%

Note 9 - Commitment and Contingencies - Remaining Purchase Commitments (Details) $ in Thousands	Dec. 31, 2020 USD ($)
2021	$ 20,131
2022	6,528
2023	6,924
2024	7,780
2025	1,873
Total purchase commitment	$ 43,236

Note 10 - Stockholders' Equity and Stock-based Compensation (Details Textual) $ / shares in Units, $ in Thousands										12 Months Ended
	Feb. 10, 2021 USD ($)	Dec. 10, 2020 shares	Jun. 10, 2020 USD ($)	May 07, 2020 USD ($)	Nov. 02, 2019 shares	Oct. 30, 2019 USD ($)	Dec. 21, 2018 shares	Oct. 30, 2018 USD ($)	Feb. 05, 2018 USD ($)	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Oct. 03, 2012 $ / shares shares
Preferred Stock, Shares Authorized (in shares) \| shares										20,000,000	20,000,000		20,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share) \| $ / shares										$ 0.001	$ 0.001		$ 0.001
Preferred Stock, Shares Issued, Total (in shares) \| shares										0	0
Preferred Stock, Shares Outstanding, Ending Balance (in shares) \| shares										0	0
Share-based Payment Arrangement, Expense, Tax Benefit \| $										$ 5,500	$ 5,500	$ 4,800
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share) \| $ / shares										$ 35.49	$ 34.02	$ 33.05
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value \| $										$ 77,500	$ 52,100	$ 71,700
Share-Based Compensation, Percentage Of Awards Based On Achievement Of Performance Goals										50.00%
Share-based Payment Arrangement, Plan Modification, Incremental Cost \| $			$ 7,500
Share-based Payment Arrangement, Expense \| $										$ 40,035	34,892	30,090
Stock Repurchase Program, Authorized Amount \| $				$ 400,000					$ 100,000	$ 101,800	$ 128,500
Stock Repurchase Program, Period in Force (Year)									2 years
Stock Repurchase Program, Additional Authorized Amount \| $				$ 100,000		$ 100,000		$ 100,000
Stock Repurchased and Retired During Period, Shares (in shares) \| shares										1,292,750	1,026,455
Stock Repurchased and Retired During Period, Value \| $										$ 126,700	$ 86,400
Subsequent Event [Member]
Stock Repurchase Program, Authorized Amount \| $	$ 500,000
Stock Repurchase Program, Additional Authorized Amount \| $	$ 100,000
Share-based Payment Arrangement, Option [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total \| $										$ 21,800
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)										2 years 8 months 12 days
Share-based Payment Arrangement, Option [Member] \| Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) \| shares		223,744			123,856
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)		3 years
Share-based Payment Arrangement, Expense \| $										$ 200	300
Restricted Stock Units (RSUs) [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total \| $										$ 71,300
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)										2 years 7 months 6 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value \| $										$ 46,500	$ 37,900	$ 38,900
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period (in shares) \| shares										475,853	438,892	525,375
Restricted Stock Units (RSUs) [Member] \| Time based Shared Based Compensation [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) \| shares		69,401			48,683
Share based Compensation Arrangement by Share based Payment Award, Vesting Period, Number Of Quarterly Periods		16			16		16
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period (in shares) \| shares							56,250
Restricted Stock Units (RSUs) [Member] \| Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) \| shares							33,089			33,088
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)							3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period (in shares) \| shares										14,864
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage							33.33%
Share-Based Compensation Arrangement By Share-based Payment Award, Equity Instruments Other Than Options, Target Number Of Shares (in shares) \| shares							11,030
Share-based Compensation Termination Period Trigger (Month)										12 months
Share-Based Compensation, Percentage Of Shares That Will Vest Upon Trigger										100.00%
Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period As A Percentage Of Target										135.00%
Share-based Payment Arrangement, Expense \| $										$ 2,800	$ 900
Non-Qualified Stock Options (NSOs) and Restricted Stock Units (RSUs) [Member]
Share-based Payment Arrangement, Expense \| $										$ 900
Maximum [Member] \| Share-based Payment Arrangement, Option [Member] \| Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Target Percentage		200.00%			200.00%
Maximum [Member] \| Restricted Stock Units (RSUs) [Member] \| Performance Shares, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Target Percentage							200.00%
Maximum [Member] \| Restricted Stock Units (RSUs) [Member] \| Performance Shares, Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Target Percentage							200.00%
Minimum [Member] \| Share-based Payment Arrangement, Option [Member] \| Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Target Percentage		0.00%			0.00%
Minimum [Member] \| Restricted Stock Units (RSUs) [Member] \| Performance Shares, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Target Percentage							0.00%
Minimum [Member] \| Restricted Stock Units (RSUs) [Member] \| Performance Shares, Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Target Percentage							0.00%
The 2012 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) \| shares										15,699,245
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized, Annual Increase, Shares (in shares) \| shares										3,050,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized, Annual Increase, Percent of Shares Outstanding										5.00%
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)										10 years
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares) \| shares										6,628,383
The 2012 Equity Incentive Plan [Member] \| Maximum [Member] \| Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)										4 years
The 2000 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Strike Price as a Percentage of Market Value										85.00%
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares) \| shares										0
The 2000 Equity Incentive Plan [Member] \| Maximum [Member] \| Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)										4 years
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)										10 years

Note 10 - Stockholders' Equity and Stock-based Compensation - Reserved Shares of Common Stock for Future Issuance (Details) - shares	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity Incentive Plan (in shares)	2,215,442	2,866,675	3,429,309	4,495,891
Total shares reserved for future issuance (in shares)	9,890,527
The 2000 Equity Incentive Plan [Member]
Equity Incentive Plan (in shares)	102,087
Shares available for future grants under an equity incentive plan (in shares)	0
The 2012 Equity Incentive Plan [Member]
Equity Incentive Plan (in shares)	3,160,057
Shares available for future grants under an equity incentive plan (in shares)	6,628,383

Note 10 - Stockholders' Equity and Stock-based Compensation - Summary of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stock-based compensation	$ 40,035	$ 34,892	$ 30,090
Cost of Sales [Member]
Stock-based compensation	2,767	2,262	2,489
Research and Development Expense [Member]
Stock-based compensation	13,502	11,151	7,961
Selling and Marketing Expense [Member]
Stock-based compensation	5,785	4,984	4,650
General and Administrative Expense [Member]
Stock-based compensation	$ 17,981	$ 16,495	$ 14,990

Note 10 - Stockholders' Equity and Stock-based Compensation - Fair Value Assumptions, Stock Options (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Dividend yield	0.00%	0.00%	0.00%
Minimum [Member]
Expected term (in years) (Year)	4 years 6 months	4 years 4 months 24 days	4 years 6 months
Volatility	38.00%	40.00%	45.00%
Risk-free interest rate	0.30%	1.50%	2.50%
Maximum [Member]
Expected term (in years) (Year)	5 years 6 months	6 years 7 months 6 days	5 years
Volatility	43.00%	46.00%	47.00%
Risk-free interest rate	1.40%	2.40%	3.00%

Note 10 - Stockholders' Equity and Stock-based Compensation - Share-based Compensation and Stock Options Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Balance (in shares)	2,866,675	3,429,309	4,495,891
Weighted average exercise price, balance (in dollars per share)	$ 40.54	$ 31.79	$ 25.29
Weighted Average Remaining Contractual Life Balance (Year)	6 years 6 months	6 years	6 years 4 months 24 days	6 years 7 months 6 days
Aggregate intrinsic value	$ 139,121	$ 125,647	$ 149,935	$ 153,129
Granted (in shares)	593,694	496,145	366,786
Weighted average exercise price, granted (in dollars per share)	$ 99.77	$ 87.10	$ 79.79
Exercised (in shares)	(1,129,845)	(901,290)	(1,183,235)
Weighted average exercise price, exercised (in dollars per share)	$ 30.50	$ 27.55	$ 20.33
Canceled (in shares)	(115,082)	(157,489)	(250,133)
Weighted average exercise price, canceled (in dollars per share)	$ 87.91	$ 71.04	$ 39.61
Balance (in shares)	2,215,442	2,866,675	3,429,309	4,495,891
Weighted average exercise price, balance (in dollars per share)	$ 59.07	$ 40.54	$ 31.79	$ 25.29
Vested and expected to vest (in shares)	2,071,441
Vested and Expected to vest, weighted average exercise price (in dollars per share)	$ 56.39
Vested and Expected to vest, weighted average remaining contractual life (Year)	6 years 3 months 18 days
Vested and Expected to vest, aggregate intrinsic value	$ 135,647
Exercisable (in shares)	1,290,452
Exercisable, Weighted average exercise price (in dollars per share)	$ 34.69
Exercisable, weighted average remaining contractual life (Year)	4 years 8 months 12 days
Exercisable, aggregate intrinsic value	$ 112,502

Note 10 - Stockholders' Equity and Stock-based Compensation - Summarizes the Outstanding and Vested Stock Options (Details)	12 Months Ended
	Dec. 31, 2020 $ / shares shares
Number of shares, outstanding (in shares) \| shares	2,215,442
Weighted average exercise price per share, outstanding (in dollars per share)	$ 59.07
Weighted average remaining contractual life, outstanding 2 (Year)	6 years 6 months
Number of shares, exercisable (in shares) \| shares	1,290,452
Weighted average exercise price per share, exercisable (in dollars per share)	$ 34.69
Exercise Price Range One [Member]
Exercise price range, lower limit (in dollars per share)	4.4
Exercise price range, upper limit (in dollars per share)	$ 20.8
Number of shares, outstanding (in shares) \| shares	266,447
Weighted average exercise price per share, outstanding (in dollars per share)	$ 13.25
Weighted average remaining contractual life, outstanding 2 (Year)	2 years 1 month 6 days
Number of shares, exercisable (in shares) \| shares	266,447
Weighted average exercise price per share, exercisable (in dollars per share)	$ 13.25
Exercise Price Range Two [Member]
Exercise price range, lower limit (in dollars per share)	22.31
Exercise price range, upper limit (in dollars per share)	$ 25.17
Number of shares, outstanding (in shares) \| shares	130,550
Weighted average exercise price per share, outstanding (in dollars per share)	$ 24.16
Weighted average remaining contractual life, outstanding 2 (Year)	4 years 3 months 18 days
Number of shares, exercisable (in shares) \| shares	130,550
Weighted average exercise price per share, exercisable (in dollars per share)	$ 24.16
Exercise Price Range Three [Member]
Exercise price range, lower limit (in dollars per share)	25.56
Exercise price range, upper limit (in dollars per share)	$ 25.56
Number of shares, outstanding (in shares) \| shares	264,824
Weighted average exercise price per share, outstanding (in dollars per share)	$ 25.56
Weighted average remaining contractual life, outstanding 2 (Year)	5 years 3 months 18 days
Number of shares, exercisable (in shares) \| shares	264,824
Weighted average exercise price per share, exercisable (in dollars per share)	$ 25.56
Exercise Price Range Four [Member]
Exercise price range, lower limit (in dollars per share)	26.86
Exercise price range, upper limit (in dollars per share)	$ 34.97
Number of shares, outstanding (in shares) \| shares	227,072
Weighted average exercise price per share, outstanding (in dollars per share)	$ 30.72
Weighted average remaining contractual life, outstanding 2 (Year)	3 years 10 months 24 days
Number of shares, exercisable (in shares) \| shares	227,072
Weighted average exercise price per share, exercisable (in dollars per share)	$ 30.72
Exercise Price Range Five [Member]
Exercise price range, lower limit (in dollars per share)	36.25
Exercise price range, upper limit (in dollars per share)	$ 52.6
Number of shares, outstanding (in shares) \| shares	232,792
Weighted average exercise price per share, outstanding (in dollars per share)	$ 40.24
Weighted average remaining contractual life, outstanding 2 (Year)	5 years 4 months 24 days
Number of shares, exercisable (in shares) \| shares	215,601
Weighted average exercise price per share, exercisable (in dollars per share)	$ 39.80
Exercise Price Range Six[Member]
Exercise price range, lower limit (in dollars per share)	59.95
Exercise price range, upper limit (in dollars per share)	$ 86.35
Number of shares, outstanding (in shares) \| shares	307,387
Weighted average exercise price per share, outstanding (in dollars per share)	$ 80.11
Weighted average remaining contractual life, outstanding 2 (Year)	8 years 3 months 18 days
Number of shares, exercisable (in shares) \| shares	77,644
Weighted average exercise price per share, exercisable (in dollars per share)	$ 74.90
Exercise Price Range Seven [Member]
Exercise price range, lower limit (in dollars per share)	87.26
Exercise price range, upper limit (in dollars per share)	$ 89.55
Number of shares, outstanding (in shares) \| shares	189,217
Weighted average exercise price per share, outstanding (in dollars per share)	$ 88.48
Weighted average remaining contractual life, outstanding 2 (Year)	8 years 7 months 6 days
Number of shares, exercisable (in shares) \| shares	52,147
Weighted average exercise price per share, exercisable (in dollars per share)	$ 88.42
Exercise Price Range Eight [Member]
Exercise price range, lower limit (in dollars per share)	93.08
Exercise price range, upper limit (in dollars per share)	$ 93.08
Number of shares, outstanding (in shares) \| shares	223,744
Weighted average exercise price per share, outstanding (in dollars per share)	$ 93.08
Weighted average remaining contractual life, outstanding 2 (Year)	9 years 10 months 24 days
Number of shares, exercisable (in shares) \| shares	0
Weighted average exercise price per share, exercisable (in dollars per share)	$ 0
Exercise Price Range Nine [Member]
Exercise price range, lower limit (in dollars per share)	94.45
Exercise price range, upper limit (in dollars per share)	$ 104.8
Number of shares, outstanding (in shares) \| shares	273,709
Weighted average exercise price per share, outstanding (in dollars per share)	$ 97.76
Weighted average remaining contractual life, outstanding 2 (Year)	8 years 9 months 18 days
Number of shares, exercisable (in shares) \| shares	56,167
Weighted average exercise price per share, exercisable (in dollars per share)	$ 94.91
Exercise Price Range Ten [Member]
Exercise price range, lower limit (in dollars per share)	121.65
Exercise price range, upper limit (in dollars per share)	$ 121.65
Number of shares, outstanding (in shares) \| shares	99,700
Weighted average exercise price per share, outstanding (in dollars per share)	$ 121.65
Weighted average remaining contractual life, outstanding 2 (Year)	9 years 7 months 6 days
Number of shares, exercisable (in shares) \| shares	0
Weighted average exercise price per share, exercisable (in dollars per share)	$ 0

Note 10 - Stockholders' Equity and Stock-based Compensation - Share-based Compensation, Restricted Stock and Restricted Stock Units (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Balance, number of shares (in shares)	1,214,818	1,226,883	1,410,588
Balance, weighted average grant date fair value (in dollars per share)	$ 67.99	$ 55.71	$ 40.34
Granted, number of shares (in shares)	531,146	595,985	548,245
Granted, weighted average grant date fair value (in dollars per share)	$ 99.96	$ 81.59	$ 75.44
Vested, number of shares (in shares)	(475,853)	(438,892)	(525,375)
Vested, weighted average grant date fair value (in dollars per share)	$ 62.57	$ 53.17	$ 39.87
Cancelled, number of shares (in shares)	(223,409)	(169,158)	(206,575)
Cancelled, weighted average grant date fair value (in dollars per share)	$ 77.37	$ 65.51	$ 43.43
Balance, number of shares (in shares)	1,046,702	1,214,818	1,226,883
Balance, weighted average grant date fair value (in dollars per share)	$ 86.78	$ 67.99	$ 55.71
Expected to vest, number of shares (in shares)	961,926
Expected to vest, weighted average grant date fair value (in dollars per share)	$ 86.02

Note 11 - Employee Benefits Plan (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
401(k) Plan [Member]
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 1.3	$ 1.3	$ 1.2
Provident Fund Plan and Gratuity Plan [Member]
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 1.4	$ 1.1	$ 0.7

Note 12 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Tax Assets, Valuation Allowance, Total	$ 11,188	$ 10,094
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 4,600	$ 4,200	$ 3,500
Open Tax Year	2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
Domestic Tax Authority [Member]
Operating Loss Carryforwards, Total	$ 1,400
Domestic Tax Authority [Member] \| Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	10,700
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Total	100
State and Local Jurisdiction [Member] \| Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	15,000
Foreign Tax Authority [Member]
Tax Credit Carryforward, Amount	$ 3,500

Note 12 - Income Taxes - Schedule of Income before Income Tax, Domestic and Foreign (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Domestic									$ 94,099	$ 72,124	$ 50,010
Foreign									7,938	7,859	5,458
Income before income taxes	$ 25,092	$ 27,634	$ 27,094	$ 22,217	$ 21,302	$ 24,335	$ 18,509	$ 15,837	$ 102,037	$ 79,983	$ 55,468

Note 12 - Income Taxes - Schedule of Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Federal	$ 1,944	$ (90)	$ (90)
State	1,438	646	62
Foreign	3,571	3,000	1,988
Total current provision	6,953	3,556	1,960
Federal	4,239	7,085	(3,449)
State	26	447	21
Foreign	(753)	(441)	(368)
Total deferred (benefit) provision	3,512	7,091	(3,796)
Total provision for (benefit from) provision for income taxes	$ 10,465	$ 10,647	$ (1,836)

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

Note 12 - Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Federal statutory rate	21.00%	21.00%	21.00%
State taxes	1.60%	1.50%	(1.90%)
Stock-based compensation	4.80%	4.00%	5.80%
Excess tax benefits related to stock-based compensation	(13.80%)	(11.20%)	(26.20%)
Foreign source income	0.20%	0.10%	(0.20%)
Change in valuation allowance	0.80%	1.10%	4.40%
Foreign-derived intangible income deduction	(1.70%)	0.00%	0.00%
Federal and state research and development credit	(2.60%)	(3.70%)	(6.70%)
Other	0.00%	0.40%	0.50%
Provision for (benefit from) income taxes	10.30%	13.20%	(3.30%)

Note 12 - Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Net operating loss carryforwards	$ 290	$ 1,325
Research and development credit carryforwards	16,965	20,182
Foreign tax credit carryforwards	3,497	2,586
Accrued liabilities	2,019	1,109
Deferred revenues	5,123	4,843
Operating lease liabilities	15,924	13,187
Intangible assets	1,397	327
Stock-based compensation	3,907	5,942
Other	430	158
Gross deferred tax assets	49,552	49,659
Valuation allowance	(11,188)	(10,094)
Net deferred tax assets	38,364	39,565
Fixed assets	(7,017)	(8,097)
Operating leases - right of use asset	(13,054)	(10,496)
Deferred commissions	(2,482)	(2,142)
Total deferred tax liabilities	(22,553)	(20,735)
Net deferred tax assets	$ 15,811	$ 18,830

Note 12 - Income Taxes - Schedule of Unrecognized Tax Benefits Roll Forward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Unrecognized tax benefits beginning balance	$ 7,778	$ 6,406	$ 5,112
Gross increase for tax positions of prior years	4	0	279
Gross decrease for tax positions of prior years	0	(12)	(227)
Gross increase for tax positions of current year	1,258	1,384	1,399
Lapse of statute of limitations	(185)	0	(157)
Total unrecognized tax benefits	$ 8,855	$ 7,778	$ 6,406

Note 13 - Segment Information and Information about Geographic Area (Details Textual)	12 Months Ended
	Dec. 31, 2020
Number of Operating Segments	1
Number of Reportable Segments	1

Note 13 - Segment Information and Information about Geographic Area - Revenue and Property and Equipment, Net by Geographic Area (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues	$ 362,963	$ 321,607	$ 278,889
Property and equipment, net	64,850	60,579
UNITED STATES
Revenues	230,444	206,555	185,887
Property and equipment, net	43,791	46,100
Foreign [Member]
Revenues	132,519	115,052	$ 93,002
INDIA
Property and equipment, net	12,465	9,221
Other Geographic Areas [Member]
Property and equipment, net	$ 8,594	$ 5,258

Note 14 - Net Income Per Share - Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net income	$ 23,816	$ 22,743	$ 26,319	$ 18,694	$ 20,664	$ 19,174	$ 16,232	$ 13,266	$ 91,572	$ 69,336	$ 57,304
Weighted-average shares used in computing net income per share - basic (in shares)									39,167	39,075	38,876
Common stock options (in shares)									1,267	1,807	2,401
Restricted stock units (in shares)									389	463	620
Weighted-average shares used in computing net income per share - diluted (in shares)									40,823	41,345	41,897
Basic (in dollars per share)	$ 0.61	$ 0.58	$ 0.67	$ 0.48	$ 0.53	$ 0.49	$ 0.41	$ 0.34	$ 2.34	$ 1.77	$ 1.47
Diluted (in dollars per share)	$ 0.59	$ 0.56	$ 0.64	$ 0.46	$ 0.50	$ 0.47	$ 0.39	$ 0.32	$ 2.24	$ 1.68	$ 1.37

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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

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Note 14 - Net Income Per Share - Anti-dilutive Net Income Per Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Antidilutive securities (in shares)	700	487	199
Share-based Payment Arrangement, Option [Member]
Antidilutive securities (in shares)	620	461	177
Restricted Stock Units (RSUs) [Member]
Antidilutive securities (in shares)	80	26	22

Note 15 - Selected Quarterly Financial Information (Unaudited) - Schedule of Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues	$ 94,801	$ 93,069	$ 88,830	$ 86,263	$ 84,664	$ 82,671	$ 78,929	$ 75,343
Income from operations	24,412	26,303	25,508	20,431	19,545	22,549	16,108	14,051	$ 96,654	$ 72,253	$ 50,361
Other income (expense), net	680	1,331	1,586	1,786	1,757	1,786	2,401	1,786	5,383	7,730	5,107
Income before income taxes	25,092	27,634	27,094	22,217	21,302	24,335	18,509	15,837	102,037	79,983	55,468
Net income	$ 23,816	$ 22,743	$ 26,319	$ 18,694	$ 20,664	$ 19,174	$ 16,232	$ 13,266	$ 91,572	$ 69,336	$ 57,304
Basic (in dollars per share)	$ 0.61	$ 0.58	$ 0.67	$ 0.48	$ 0.53	$ 0.49	$ 0.41	$ 0.34	$ 2.34	$ 1.77	$ 1.47
Diluted (in dollars per share)	$ 0.59	$ 0.56	$ 0.64	$ 0.46	$ 0.50	$ 0.47	$ 0.39	$ 0.32	$ 2.24	$ 1.68	$ 1.37

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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