| Organization and Summary of Significant Accounting Policies | Organization and Summary of Significant Accounting Policies Organization Arista Networks, Inc. (together with our subsidiaries, “we,” “our,” "Arista," "Company" or “us”) is a supplier of cloud networking solutions that use software innovations to address the needs of large-scale internet companies, cloud service providers and next-generation enterprise. Our cloud networking solutions consist of our EOS, a set of network applications and our 1/2.5/5/10/25/40/50/100/400 Gigabit Ethernet switching and routing platforms. We are incorporated in the state of Delaware. Our corporate headquarters are located in Santa Clara, California, and we have wholly-owned subsidiaries throughout the world, including North America, Europe, Asia and Australia. Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements include the accounts of Arista Networks, Inc. and its wholly owned subsidiaries and are prepared in accordance with GAAP. All significant intercompany accounts and transactions have been eliminated. Certain reclassifications of prior period amounts were made in the current year to conform to the current period presentation. Use of Estimates The preparation of the accompanying consolidated financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the amounts reported and disclosed in the consolidated financial statements and accompanying notes. Those estimates and assumptions include, but are not limited to, revenue recognition and deferred revenue; allowance for doubtful accounts, sales rebates and return reserves; valuation of goodwill and acquisition-related intangible assets, accounting for income taxes, including the recognition of deferred tax assets and liabilities related to an intra-entity transaction to sell our non-Americas economic and beneficial intellectual property, valuation allowance on deferred tax assets and reserves for uncertain tax positions; estimate of useful lives of long-lived assets including intangible assets; valuation of inventory and contract manufacturer/supplier liabilities; and the recognition and measurement of contingent liabilities. We evaluate our estimates and assumptions based on historical experience and other factors and adjust those estimates and assumptions when facts and circumstances dictate. Actual results could differ materially from those estimates. Concentrations of Business and Credit Risk We work closely with third-party contract manufacturers to manufacture our products. As of December 31, 2019 , we had two contract manufacturing partners, who provided substantially all of our electronic manufacturing services. Our contract manufacturing partners deliver our products to our third party direct fulfillment facilities. We and our fulfillment partners then perform labeling, final configuration, quality assurance testing and shipment to our customers. Our products rely on key components, including certain integrated circuit components and power supplies, some of which our contract manufacturing partners purchase on our behalf from a limited number of suppliers, including certain sole source providers. We generally do not have guaranteed supply contracts with our component suppliers, and our manufacturing partners could delay shipments or cease manufacturing such products or selling them to us at any time. If we are unable to obtain a sufficient quantity of these components on commercially reasonable terms or in a timely manner, or if we are unable to obtain alternative sources for these components, sales of our products could be delayed or halted entirely, or we may be required to redesign our products. Quality or performance failures of our products or changes in our contractors’ or vendors’ financial or business condition could disrupt our ability to supply quality products to our customers. Any of these events could result in lost sales and damage to our end-customer relationships, which would adversely impact our business, financial condition and results of operations. Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash, cash equivalents, marketable securities, restricted cash, and accounts receivable. Our cash equivalents, restricted cash and marketable securities are invested in high quality financial instruments with banks and financial institutions. Such deposits may be in excess of insured limits provided on such deposits. Our accounts receivable are unsecured and represent amounts due to us based on contractual obligations of our customers. We mitigate credit risk with respect to accounts receivable by performing ongoing credit evaluations of our customers to assess the probability of collection based on a number of factors, including past transaction experience with the customer, evaluation of their credit history, the credit limits extended, and review of the invoicing terms of the arrangement. In situations where a customer may be thinly capitalized and we have limited payment history with it, we will either establish a small credit limit or require it to prepay its purchases. We generally do not require our customers to provide collateral to support accounts receivable. We have recorded an allowance for doubtful accounts for those receivables that we have determined not to be collectible. We mitigate credit risk in respect to the notes receivable by performing ongoing credit evaluations of the borrower to assess the probability of collecting all amounts due to us under the existing contractual terms. We market and sell our products through both our direct sales force and our channel partners, including distributors, value-added resellers, system integrators and original equipment manufacturer (“OEM”) partners, and in conjunction with various technology partners. Significant customers are those which represent more than 10% of our total net revenue during the period or net accounts receivable balance at each respective balance sheet date. As of December 31, 2019 , we had one customer who represented 39% of total accounts receivable. As of December 31, 2018 , we had two customers who represented 35% and 10% of total accounts receivable, respectively. For the year ended December 31, 2019 , there were two customers who represented 23% and 17% of our total revenue, respectively. For the years ended December 31, 2018 and 2017 , there was one customer who represented 27% and 16% of our total revenue, respectively. Cash and Cash Equivalents We consider all highly liquid investments with maturities of three months or less at the time of purchase to be cash equivalents. Cash and cash equivalents consist of cash on deposit with various financial institutions and highly liquid investments in money market funds. Interest is accrued as earned. As of December 31, 2019 and 2018 , we had restricted cash of $4.2 million for each year and that primarily included $4.0 million pledged as collateral representing a security deposit required for a facility lease. Our restricted cash is classified as other assets in our consolidated balance sheets. Marketable Securities We classify all highly liquid investments in debt and equity securities with maturities of greater than three months at the date of purchase as marketable securities. We have classified and accounted for our marketable securities as available-for-sale. We determine the appropriate classification of these investments at the time of purchase and reevaluate such designation at each balance sheet date. We may or may not hold securities with stated maturities greater than 12 months until maturity. After consideration of our risk versus reward objectives, as well as our liquidity requirements, we may sell these securities prior to their stated maturities. As we view these securities as available to support current operations, we classify securities with maturities beyond 12 months as current assets under the caption marketable securities in the accompanying consolidated balance sheets. We carry these securities at fair value, and report the unrealized gains and losses, net of taxes, as a component of stockholders’ equity, except for unrealized losses determined to be other-than-temporary, which we record as other income (expense), net. We determine any realized gains or losses on the sale of marketable securities on a specific identification method, and we record such gains and losses as a component of interest and other income, net. Accounts Receivable Accounts receivable are recorded at the invoiced amount, net of allowances for doubtful accounts, and sales rebates and returns reserves. We estimate our allowance for doubtful accounts based upon the collectability of the receivables in light of historical trends, adverse situations that may affect our customers’ ability to pay and prevailing economic conditions. This evaluation is done in order to identify issues which may impact the collectability of receivables and related estimated required allowance. Revisions to the allowance are recorded as an adjustment to bad debt expense. After appropriate collection efforts are exhausted, specific accounts receivable deemed to be uncollectible are charged against the allowance in the period they are deemed uncollectible. Recoveries of accounts receivable previously written-off are recorded as credits to bad debt expense. We primarily estimate our sales rebates and returns reserves based on historical rates applied against current period billings. Specific customer returns, rebates and allowances are considered when determining our estimates. Revisions to the reserves are recorded as adjustments to revenue. Fair Value Measurements Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. We apply fair value accounting for all financial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis. These assets and liabilities include cash and cash equivalents, marketable securities, accounts receivable, accounts payable, and accrued liabilities. Cash equivalents, accounts receivable, accounts payable and accrued liabilities are stated at carrying amounts as reported in the consolidated financial statements, which approximate fair value due to their short-term nature. Assets and liabilities recorded at fair value on a recurring basis in the accompanying consolidated balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair value. We use a fair value hierarchy to measure fair value, maximizing the use of observable inputs and minimizing the use of unobservable inputs. The three-tiers of the fair value hierarchy are as follows: Level I —Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level II —Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and Level III —Unobservable inputs that are supported by little or no market data for the related assets or liabilities and typically reflect management’s estimate of assumptions that market participants would use in pricing the asset or liability. Foreign Currency The functional currency of our foreign subsidiaries is either the U.S. dollar or their local currency . Transaction re-measurement - Assets and liabilities denominated in a currency other than a subsidiary’s functional currency are re-measured into the subsidiary's functional currency using exchange rates in effect at the end of the reporting period, with gains and losses recorded in other income (expense), net in the consolidated statements of operations. To date, foreign currency transaction gains and losses and exchange rate fluctuations have not been material to our financial statements. Translation - Assets and liabilities of subsidiaries denominated in foreign functional currencies are translated into U.S. dollars at the closing exchange rate on the balance sheet date and equity related balances are translated at historical exchange rates. Revenues, costs and expenses in foreign functional currencies are translated using average exchange rates that approximate those in effect during the period. Translation adjustments are accumulated as a separate component of accumulated other comprehensive income within stockholders’ equity. Inventory Valuation and Contract Manufacturer/Supplier Liabilities Inventories primarily consist of finished goods and strategic components, primarily integrated circuits. Inventories are stated at the lower of cost (computed using the first-in, first-out method) and net realizable value. Manufacturing overhead costs and inbound shipping costs are included in the cost of inventory. We record a provision when inventory is determined to be in excess of anticipated demand, or obsolete, to adjust inventory to its estimated realizable value. For the years ended December 31, 2019 , 2018 and 2017 , we recorded charges of $41.2 million , $20.8 million and $28.1 million , respectively, within cost of product revenue for inventory write-downs. Our contract manufacturers procure components and assemble products on our behalf based on our forecasts. We record a liability and a corresponding charge for non-cancellable, non-returnable purchase commitments with our contract manufacturers or suppliers for quantities in excess of our demand forecasts or that are considered obsolete due to manufacturing and engineering change orders resulting from design changes. For the year ended December 31, 2019 and 2017 , we recorded a charge of $11.7 million and $21.2 million , respectively, within cost of product revenue for such liabilities with our contract manufacturers and suppliers. For the year ended December 31, 2018 , we did no t incur a net loss on such supplier liabilities. We use significant judgment in establishing our forecasts of future demand and obsolete material exposures. These estimates depend on our assessment of current and expected orders from our customers, product development plans and current sales levels. If actual market conditions are less favorable than those projected by management, which may be caused by factors within and outside of our control, we may be required to increase our inventory write-downs and liabilities to our contract manufacturers and suppliers, which could have an adverse impact on our gross margins and profitability. We regularly evaluate our exposure for inventory write-downs and adequacy of our contract manufacturer liabilities. Property and Equipment Property and equipment are stated at cost, less accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the related assets, generally three years . Our leasehold improvements are depreciated over the shorter of the estimated useful lives of the improvements or the remaining lease term. Investments in Privately-Held Companies Our equity investments in privately-held companies without readily determinable fair values are measured using the measurement alternative, defined by ASC 321- Investments-Equity Securities as cost, less impairments, and adjusted up or down based on observable price changes in orderly transactions for identical or similar investments of the same issuer. Any adjustments resulting from impairments and/or observable price changes are recorded as “Other income (expense), net” in our consolidated statements of operations. Impairment of Long-Lived Assets and Investments The carrying amounts of our long-lived assets, including property and equipment and investments in privately held companies, are periodically reviewed for impairment whenever events or changes in circumstances indicate that the carrying value of these assets may not be recoverable. Recoverability of these assets is measured by comparison of the carrying amount of each asset to the future undiscounted cash flows the asset is expected to generate over their remaining lives. If the asset is considered to be impaired, the amount of any impairment is measured as the difference between the carrying value and the fair value of the impaired asset. We recognized impairment losses on certain private company investments during 2018. Refer to Note 5 for further discussion. No impairment of any other long-lived assets was identified for any of the periods presented. Loss Contingencies In the ordinary course of business, we are a party to claims and legal proceedings including matters relating to commercial, employee relations, business practices and intellectual property. In assessing loss contingencies, we use significant judgment and assumptions to estimate the likelihood of loss, impairment of an asset or the incurrence of a liability, as well as our ability to reasonably estimate the amount of loss. We record a provision for contingent losses when it is both probable that an asset has been impaired or a liability has been incurred and the amount of the loss can be reasonably estimated. We will record a charge equal to the minimum estimated liability for litigation costs or a loss contingency only when both of the following conditions are met: (i) information available prior to issuance of our consolidated financial statements indicates that it is probable that a liability had been incurred at the date of the financial statements and (ii) the range of loss can be reasonably estimated. We regularly evaluate current information available to us to determine whether such accruals should be adjusted and whether new accruals are required. Revenue Recognition We generate revenue from sales of our products, which incorporate our EOS software and accessories such as cables and optics, to direct customers and channel partners together with post-contract customer support (“PCS”). We typically sell products and PCS in a single contract. We recognize revenue upon transfer of control of promised products or services to customers in an amount that reflects the consideration we expect to be entitled to receive in exchange for those products or services. We apply the following five-step revenue recognition model: • 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 • Recognition of revenue when (or as) we satisfy the performance obligation Post-Contract Customer Support Post-contract support, which includes technical support, hardware repair and replacement parts beyond standard warranty, bug fixes, patches and unspecified upgrades on a when-and-if-available basis, is offered under renewable, fee-based contracts. We initially defer PCS revenue and recognize it ratably over the life of the PCS contract as there is no discernable pattern of delivery related to these promises. We do not provide unspecified upgrades on a set schedule and addresses customer requests for technical support if and when they arise, with the related expenses recognized as incurred. PCS contracts generally have a term of one to three years . We include billed but unearned PCS revenue in deferred revenue. Contracts with Multiple Performance Obligations Most of our contracts with customers, other than renewals of PCS, contain multiple performance obligations with a combination of products and PCS. Products and PCS generally qualify as distinct performance obligations. Our hardware includes EOS software, which together deliver the essential functionality of our products. For contracts which contain multiple performance obligations, we allocate revenue to each distinct performance obligation based on the standalone selling price (“SSP”). Judgment is required to determine the SSP for each distinct performance obligation. We use a range of amounts to estimate SSP for products and PCS sold together in a contract to determine whether there is a discount to be allocated based on the relative SSP of the various products and PCS. If we do not have an observable SSP, such as when we do not sell a product or service separately, then SSP is estimated using judgment and considering all reasonably available information such as market conditions and information about the size and/or purchase volume of the customer. We generally use a range of amounts to estimate SSP for individual products and services based on multiple factors including, but not limited to the sales channel (reseller, distributor or end customer), the geographies in which our products and services are sold, and the size of the end customer. We limit the amount of revenue recognition for contracts containing forms of variable consideration, such as future performance obligations, customer-specific returns, and acceptance or refund obligations. We include some or all of an estimate of the related at risk consideration in the transaction price only to the extent that it is probable that a significant reversal in the amount of cumulative revenue recorded under each contract will not occur when the uncertainties surrounding the variable consideration are resolved. Most of our contracts with customers have payment terms of 30 days with some large high volume customers having terms of up to 60 days . We have determined our contracts generally do not include a significant financing component because the Company and the customer have specific business reasons other than financing for entering into such contracts. Specifically, both we and our customers seek to ensure the customer has a simplified way of purchasing Arista products and services. We account for multiple contracts with a single partner as one arrangement if the contractual terms and/or substance of those agreements indicate that they may be so closely related that they are, in effect, parts of a single contract. We may occasionally accept returns to address customer satisfaction issues even though there is generally no contractual provision for such returns. We estimate returns for sales to customers based on historical returns rates applied against current-period shipments. Specific customer returns and allowances are considered when determining our sales return reserve estimate. Our policy applies to the accounting for individual contracts. However, we have elected a practical expedient to apply the guidance to a portfolio of contracts or performance obligations with similar characteristics so long as such application would not differ materially from applying the guidance to the individual contracts (or performance obligations) within that portfolio. Consequently, we have chosen to apply the portfolio approach when possible, which we do not believe will happen frequently. Additionally, we will evaluate a portfolio of data, when possible, in various situations, including accounting for commissions, rights of return and transactions with variable consideration. We report revenue net of sales taxes. We include shipping charges billed to customers in revenue and the related shipping costs are included in cost of product revenue. Contract Balances A contract asset is recognized when we have a contractual right to consideration for both completed and partially completed performance obligations that have not yet been invoiced. Contract assets are included in “Other current assets” on our consolidated balance sheets. A contract liability is recognized when we have received customer payments in advance of our satisfaction of a performance obligation under a contract that is cancellable. Contract liabilities are included in “Other current liabilities” and “Other long-term liabilities” on our consolidated balance sheets. Assets Recognized from Costs to Obtain a Contract with a Customer Effective January 1, 2018 in connection with the adoption of ASC 606, we recognize an asset for the incremental costs of obtaining a contract with a customer if we expect the benefit of those costs to be longer than one year. We have determined that certain sales commissions earned by our sales force meet the requirements for capitalization. These costs are deferred and then amortized over a period of benefit that we have determined to be five years . Total capitalized costs to obtain a contract are included in other current and long-term assets on our consolidated balance sheets. As of December 31, 2019 and 2018 , total capitalized costs to obtain contracts was $8.9 million and $6.4 million , respectively. Research and Development Expenses Costs related to the research, design and development of our products are charged to research and development expenses as incurred. Software development costs are capitalized beginning when a product’s technological feasibility has been established and ending when the product is available for general release to customers. Generally, our products are released soon after technological feasibility has been established. As a result, costs incurred subsequent to achieving technological feasibility have not been significant and accordingly, all software development costs have been expensed as incurred. Warranty We offer a one -year warranty on all of our hardware products and a 90 -day warranty against defects in the software embedded in the products. We use judgment and estimates when determining warranty costs based on historical costs to replace product returns within the warranty period at the time we recognize revenue. We accrue for potential warranty claims at the time of shipment as a component of cost of revenues based on historical experience and other relevant information. We reserve for specifically identified products if and when we determine we have a systemic product failure. Although we engage in extensive product quality programs, if actual product failure rates or use of materials differ from estimates, additional warranty costs may be incurred, which could reduce our gross margin. The accrued warranty liability is recorded in accrued liabilities in the accompanying consolidated balance sheets. Segment Reporting We develop, market and sell cloud networking solutions, which consist of our Gigabit Ethernet switches and related software. We engage in one business activity and there are no segment managers who are held accountable for operations or operating results below the Company level. Our chief operating decision maker is our Chief Executive Officer, who reviews financial information presented on a consolidated basis for purposes of allocating resources and evaluating financial performance. Accordingly, we have determined that we operate as one reportable segment. Stock-Based Compensation Compensation expense related to stock-based transactions is measured and recognized in the financial statements based on the fair value of the equity granted on a straight-line basis over the requisite service periods of the awards, which typically ranges from two to five years. We account for forfeitures on all stock-based transactions as they occur. Income Taxes Income tax expense is an estimate of current income taxes payable in the current fiscal year based on reported income before income taxes. Deferred income taxes reflect the effect of temporary differences and carryforwards that we recognize for financial reporting and income tax purposes. We account for income taxes under the liability approach for deferred income taxes, which requires recognition of deferred income tax assets and liabilities for the expected future tax consequences of events that have been recognized in our consolidated financial statements, but have not been reflected in our taxable income. Estimates and judgments occur in the calculation of certain tax liabilities and in the determination of the recoverability of certain deferred income tax assets, which arise from temporary differences and carryforwards. Deferred income tax assets and liabilities are measured using the currently enacted tax rates that apply to taxable income in effect for the years in which those tax assets are expected to be realized or settled. We regularly assess the likelihood that our deferred income tax assets will be realized based on the positive and negative evidence available. We record a valuation allowance to reduce the deferred tax assets to the amount that we are more likely than not to realize. We believe that we have adequately reserved for our uncertain tax positions, although we can provide no assurance that the final tax outcome of these matters will not be materially different. To the extent that the final tax outcome of these matters is different than the amounts recorded, such differences will affect the provision for income taxes in the period in which such determination is made and could have a material impact on our financial condition and results of operations. The provision for income taxes includes the effects of any reserves that we believe are appropriate, as well as the related net interest and penalties. We regularly review our tax positions and benefits to be realized. We recognize tax liabilities based upon our estimate of whether, and to the extent to which, additional taxes will be due when such estimates are more likely than not to be sustained. An uncertain income tax position will not be recognized if it has less than a 50% likelihood of being sustained. We recognize interest and penalties related to income tax matters as income tax expense. Net Income per Share of Common Stock Basic and diluted net income per share attributable to common stockholders is calculated in conformity with the two-class method required for participating securities. Our shares of common stock subject to repurchase are considered participating securities. Under the two-class method, net income attributable to common stockholders is calculated as net income less earnings attributable to participating securities. In computing diluted net income attributable to common stockholders, undistributed earnings are re-allocated to reflect the potential impact of dilutive securities. Basic net income per common share is computed by dividing the net income attributable to common stockholders by the weighted-average number of common shares outstanding during the period. Diluted net income per share attributable to common stockholders is computed by dividing the net income attributable to common stockholders by the weighted-average number of common shares outstanding, including potential dilutive common shares assuming the dilutive effect of outstanding stock options, restricted stock units, and employee stock purchase plan using the treasury stock method. For purposes of this calculation, these amounts are excluded from the calculation of diluted net income per share of common stock if their effect is antidilutive. Business Combinations We use the acquisition method to account for our business combinations in accordance with ASC 805 - Business Combinations (“ASC 805”). We allocate the total fair value of purchase consideration to the tangible and intangible assets acquired and liabilities assumed based on their estimated fair values. The excess of the consideration transferred over the fair values of the assets acquired and liabilities assumed is recorded as goodwill. The results of operations of the acquired businesses are included in our consolidated financial statements from the date of acquisition. Acquisition-related costs and restructuring costs are expensed as incurred. During the measurement period, which is not to exceed one year from the acquisition date, we may record adjustments to the acquired assets and liabilities assumed, with a corresponding offset to goodwill or the preliminary purchase price, to reflect new information obtained about facts and circumstances that existed as of the acquisition date. Upon the conclusion of the measurement period, any subsequent adjustments are recorded to earnings. Goodwill and Intangible Assets We perform our annual goodwill impairment analysis in the fourth quarter of each year or more frequently if there are any events or circumstances that would indicate the carrying amount is not recoverable. We f |
