Summary of Significant Accounting Policies	12 Months Ended
Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation The accompanying consolidated financial statements of Harmonic include the accounts of the Company and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The Company’s fiscal quarters are based on 13-week periods, except for the fourth quarter which ends on December 31. Use of Estimates The preparation of consolidated financial statements in conformity with generally accepted accounting principles in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. The Company’s reported financial positions or results of operations may be materially different under changed conditions or when using different estimates and assumptions, particularly with respect to significant accounting policies. If estimates or assumptions differ from actual results, subsequent periods are adjusted to reflect more current information. Reclassifications Certain prior period balances have been reclassified to conform to the current year presentation. These reclassifications did not have a material impact on previously reported financial statements. Beginning in fiscal 2019, the Company changed the classification of total revenue and cost of revenue in the Consolidated Statements of Operations from the two previous categories, “Product” and “Service,” to two new categories, “Appliance and integration” and “SaaS and service.” The Company has also adjusted revenue and cost of revenue retrospectively into the two new categories for all prior periods to conform to the current period’s presentation. This reclassification within revenue and cost of revenue did not have an impact on total revenue, cost of revenue or segment revenue for any periods presented. Cash and Cash Equivalents Cash and cash equivalents include all cash and highly liquid investments with maturities of three months or less at the date of purchase. The carrying amount of cash and cash equivalents approximates fair value because of the short maturity of those instruments. Investments in Equity Securities From time to time, the Company may acquire certain equity investments for the promotion of business and strategic objectives and these investments may be in marketable equity securities or non-marketable equity securities. The Company accounts for its equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income. For equity investments that do not have readily determinable fair values, the Company measures these investments at cost minus impairment, if any. The Company’s total investments in equity securities of privately held companies were $3.6 million as of December 31, 2020 and 2019, respectively. The Company’s equity investments are classified as long-term investments and reported as a component of “Other non-current assets” on the Company’s Consolidated Balance Sheets. Credit Risk and Major Customers/Supplier Concentration Financial instruments which subject the Company to concentrations of credit risk consist primarily of cash, cash equivalents, and accounts receivable. Cash and cash equivalents are invested in short-term, highly liquid, investment-grade obligations of commercial or governmental issuers, in accordance with the Company’s investment policy. The investment policy limits the amount of credit exposure to any one financial institution, commercial or governmental issuer. The Company’s accounts receivable are derived from sales to worldwide cable, satellite, telco, and broadcast and media companies. The Company generally does not require collateral from its customers, and performs ongoing credit evaluations of its customers and provides for expected losses. The Company maintains an allowance for doubtful accounts based upon the expected collectability of its accounts receivable. One customer had a balance greater than 10% of the Company’s net accounts receivable balance as of December 31, 2020 and 2019. During the year ended December 31, 2020, 2019 and 2018, Comcast is the only customer accounted for more than 10% of the Company’s revenue. Certain of the components and subassemblies included in the Company’s products are obtained from a single source or a limited group of suppliers. Although the Company seeks to reduce dependence on those sole source and limited source suppliers, the partial or complete loss of certain of these sources could have at least a temporary adverse effect on the Company’s results of operations and damage customer relationships. Revenue Recognition The Company’s principal sources of revenue are from the sale of hardware, software, hardware and software maintenance contracts, and end-to-end solutions, encompassing design, manufacture, test, integration and installation of products. The Company also derives recurring revenue from subscriptions, which are comprised of subscription fees from customers utilizing the Company’s cloud-based video processing solutions. Revenue from contracts with customers is recognized using the following five steps: a) Identify the contract(s) with a customer; b) Identify the performance obligations in the contract; c) Determine the transaction price; d) Allocate the transaction price to the performance obligations in the contract; and e) Recognize revenue when (or as) the Company satisfies a performance obligation. A contract contains a promise (or promises) to transfer goods or services to a customer. A performance obligation is a promise (or a group of promises) that is distinct. The transaction price is the amount of consideration a Company expects to be entitled to from a customer in exchange for providing the goods or services. The unit of account for revenue recognition is a performance obligation. A contract may contain one or more performance obligations, including hardware, software, professional services and support and maintenance. Performance obligations are accounted for separately if they are distinct. A good or service is distinct if the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer, and the good or service is distinct in the context of the contract. Otherwise performance obligations will be combined with other promised goods or services until the Company identifies a bundle of goods or services that is distinct. The transaction price is allocated to all the separate performance obligations in an arrangement. It reflects the amount of consideration to which the Company expects to be entitled to in exchange for transferring goods or services, which may include an estimate of variable consideration to the extent that it is probable of not being subject to significant reversals in the future based on the Company’s experience with similar arrangements. The transaction price also reflects the impact of the time value of money if there is a significant financing component present in an arrangement. The transaction price excludes amounts collected on behalf of third parties, such as sales taxes. Revenue is recognized when the Company satisfies each performance obligation by transferring control of the promised goods or services to the customer. Goods or services can transfer at a point in time or over time depending on the nature of the arrangement. Refer to Note 3, “Revenue,” for additional information. Inventories Inventories are stated at the lower of cost (determined on first-in, first-out basis) or net realizable value. The cost of inventories is comprised of material and manufacturing labor and overheads. The Company establishes provisions for excess and obsolete inventories to reduce such inventories to their estimated net realizable value after evaluation of historical sales, future demand and market conditions, expected product life cycles and current inventory levels. Such provisions are charged to cost of revenue in the Company’s Consolidated Statements of Operations. Capitalized Software Development Costs Internal-use software. The Company capitalizes costs associated with internally developed and/or purchased software systems for internal use that have reached the application development stage. Capitalized costs include external direct costs of materials and services utilized in developing or obtaining internal-use software and payroll and payroll-related expenses for employees who are directly associated with and devote time to the internal-use software project. Capitalization of such costs begins when the preliminary project stage is complete and ceases no later than the point at which the project is substantially complete and ready for its intended purpose. These capitalized costs are amortized on a straight-line basis over the estimated useful life, generally three years. During the years ended December 31, 2020, 2019 and 2018, the Company capitalized $2.3 million, $1.1 million and $0.9 million, respectively, of its software development costs related to the development of its SaaS offerings. Capitalized Software Implementation Costs In a hosting arrangement that is a service contract, the Company capitalizes costs for implementation activities in the application development stage depending on the nature of the costs. The costs incurred during the preliminary project and post-implementation stages are expensed as the activities are performed. The costs capitalized are expensed over the term of the hosting arrangement, which is the fixed, non-cancelable term of the arrangement, plus any reasonably certain renewal periods. The capitalized implementation costs are included in “Other non-current assets” in the Consolidated Balance Sheets, and the amortization expense related to these costs are primarily included in “Selling, general and administrative” in the Consolidated Statements of Operations. The payments for capitalized implementation costs are included as operating activities in the Consolidated Statements of Cash Flows. During the year ended December 31, 2020 and 2018, the capitalized software implementation costs were immaterial. During the year ended December 31, 2019, the Company capitalized $3.6 million of its software implementation costs. Property and Equipment Property and equipment are recorded at cost. Depreciation is computed using the straight-line method over the estimated useful lives of the assets. Estimated useful lives are generally, five years for furniture and fixtures, three years for software and four years for machinery and equipment. Depreciation for leasehold improvements are computed using the shorter of the remaining useful lives of the assets or the lease term of the respective assets. Goodwill As of December 31, 2020, the Company had goodwill of $243.7 million which represents the difference between the purchase price and the estimated fair value of the identifiable assets acquired and liabilities assumed. The Company tests for goodwill impairment at the reporting unit level on an annual basis, or more frequently if events or changes in circumstances indicate that the asset is more likely than not impaired. The Company has two reporting units, which are the same as its operating segments. On January 1, 2020, the Company adopted Accounting Standard Update (“ASU”) No. 2017-04, Intangibles – Goodwill and Other (Topic 350) using the prospective approach. The ASU eliminates step two from the goodwill impairment test. Under ASU No. 2017-04, the Company will recognize an impairment charge for the amount by which the carrying amount of a reporting unit exceeds its fair value up to the amount of goodwill allocated to that reporting unit. There was no impairment of goodwill resulting from the Company’s fiscal 2020 annual impairment testing. Refer to Note 7, “Goodwill,” for additional information. Long-lived Assets Long-lived assets represent property and equipment and purchased intangible assets. Purchased intangible assets from business combinations and asset acquisitions include customer contracts, trademarks and trade names, and maintenance agreements and related relationships, the amortization of which is charged to general and administrative expenses, and core technology and developed technology, the amortization of which is charged to cost of revenue. The Company evaluates the recoverability of intangible assets and other long-lived assets when indicators of impairment are present. When impairment indicators are present, the Company evaluates the recoverability of intangible assets and other long-lived assets on the basis of undiscounted cash flows expected to result from the use of each asset group and its eventual disposition. If the undiscounted expected future cash flows are less than the carrying amount of the asset, an impairment loss is recognized in order to write down the carrying value of the asset to its estimated fair market value. There were no impairment charges for long-lived assets in the years ended December 31, 2020, 2019 and 2018. Leases On January 1, 2019, the Company adopted ASC 842, Leases (“Topic 842”), using the modified retrospective method, applying Topic 842 to all leases existing at the date of initial application. The Company elected to use the effective date as the date of initial application. Consequently, prior period balances and disclosures have not been restated. The Company elected certain practical expedients, which among other things, allowed the Company to carry forward prior conclusions about lease identification and classification. Under Topic 842, operating lease expense is generally recognized evenly over the term of the lease. The Company has operating leases primarily consisting of facilities with remaining lease terms of 1 year to 10 years. The lease term represents the non-cancelable period of the lease. For certain leases, the Company has an option to extend the lease term. These renewal options are not considered in the remaining lease term unless it is reasonably certain that the Company will exercise such options. Refer to Note 4, “Leases,” for additional information. Foreign Currency The functional currency of the Company’s Israeli and Swiss subsidiaries is the U.S. dollar. All other foreign subsidiaries use the respective local currency as the functional currency. When the local currency is the functional currency, gains and losses from translation of these foreign currency financial statements into U.S. dollars are recorded as a separate component of other comprehensive income (loss) in stockholders’ equity. The Company’s foreign currency exposure is also related to its net position of monetary assets and monetary liabilities held by its foreign subsidiaries in their nonfunctional currencies. These monetary assets and liabilities are being remeasured into the subsidiaries’ respective functional currencies using exchange rates as of the balance sheet date. Such remeasurement gains and losses are included in “Other expense, net” in the Company’s Consolidated Statements of Operations. During the years ended December 31, 2020, 2019 and 2018, the Company recorded remeasurement losses of approximately $1.0 million, $1.5 million and $0.6 million, respectively. Derivative Instruments The Company enters into derivative instruments, primarily foreign currency forward contracts, to minimize the short-term impact of foreign currency exchange rate fluctuations on certain foreign currency denominated assets and liabilities as well as certain foreign currencies denominated expenses. The Company does not enter into derivative instruments for trading purposes and these derivatives generally have maturities within three months. The derivative instruments are recorded at fair value in prepaid expenses and other current assets or accrued and other current liabilities in the Company’s Consolidated Balance Sheets. The Company enters into derivative instruments to hedge existing foreign currency denominated assets or liabilities, the gains or losses on these hedges are recorded immediately in earnings to offset the changes in the fair value of the assets or liabilities being hedged. Research and Development Research and development (“R&D”) costs are expensed as incurred and consists primarily of employee salaries and related expenses, contractors and outside consultants, supplies and materials, equipment depreciation and facilities costs, all associated with the design and development of new products and enhancements of existing products. The Company’s French subsidiary participates in the French Crédit d’Impôt Recherche (“CIR”) program which allows companies to monetize eligible research expenses. The R&D tax credits receivable from the French government for spending on innovative R&D under the CIR program is recorded as an offset to R&D expenses. In the years ended December 31, 2020, 2019 and 2018, the Company had R&D tax credits of $4.5 million, $4.7 million and $5.9 million, respectively. Restructuring and Related Charges The Company’s restructuring charges consist primarily of employee severance, one-time termination benefits related to the reduction of its workforce, and other costs. Liabilities for costs associated with a restructuring activity are recognized when the liability is incurred and are measured at fair value. One-time termination benefits are expensed at the date the entity notifies the employee, unless the employee must provide future service, in which case the benefits are expensed ratably over the future service period. Termination benefits are calculated based on regional benefit practices and local statutory requirements. Refer to Note 10, “Restructuring and Related Charges,” for additional information. Warranty The Company accrues for estimated warranty costs at the time of revenue recognition and records such accrued liabilities as part of cost of revenue. Management periodically reviews its warranty liability and adjusts the accrued liability based on the terms of warranties provided to customers, historical and anticipated warranty claims experience, and estimates of the timing and cost of warranty claims. Advertising Expenses All advertising costs are expensed as incurred and included in “Selling, general and administrative expenses” in the Company’s Consolidated Statements of Operations. Advertising expense was $1.1 million, $0.7 million and $1.0 million for the years ended December 31, 2020, 2019 and 2018, respectively. Stock-based Compensation The Company measures and recognizes compensation expense for all stock-based compensation awards made to employees, including stock options, restricted stock units (“RSUs”) and stock purchase rights under the Company’s Employee Stock Purchase Plan (“ESPP”), based upon the grant-date fair value of those awards. The Company recognizes the impact of forfeitures as they occur. The fair value of the Company’s stock options and stock purchase rights under ESPP is estimated at grant date using the Black-Scholes option pricing model. The fair value of the Company’s RSUs and performance-based RSUs (“PRSUs”) is calculated based on the market value of the Company’s stock at the grant date. The fair value of the Company’s market-based RSUs (“MRSUs”) is estimated using the Monte-Carlo valuation model with market vesting conditions. The Company recognizes the stock-based compensation for options, RSUs, MRSUs and stock purchase rights under ESPP on straight-line basis over the requisite service period, which is generally the vesting period. The Company recognizes the stock-based compensation for PRSUs based on the probability of achieving performance criteria defined in the PRSU agreements. The Company estimates the number of PRSUs ultimately expected to vest and recognizes expense using the graded vesting attribution method over the requisite service period. Changes in the estimates related to probability of achieving certain performance criteria and number of PRSUs expected to vest could significantly affect the related stock-based compensation expense from one period to the next. Pension Plan Under French law, the Company’s subsidiary in France is obligated to provide for a defined benefit plan to its employees upon their retirement from the Company. The Company’s defined benefit pension plan in France is unfunded. The Company records its obligations relating to the pension plans based on calculations which include various actuarial assumptions including employees’ age and period of service with the company; projected mortality rates, mobility rates and increases in salaries; and a discount rate. The Company reviews its actuarial assumptions on an annual basis as of December 31 (or more frequently if a significant event requiring remeasurement occurs) and modifies the assumptions based on current rates and trends when it is appropriate to do so. The Company believes that the assumptions utilized in recording its obligations under its pension plan are reasonable based on its experience, market conditions and input from its actuaries. The Company accounts for the actuarial gains (losses) in accordance with ASC 715, “Compensation - Retirement Benefits.” If the net accumulated gain or loss exceeds 10% of the projected plan benefit obligation, a portion of the net gain or loss is amortized and included in expense for the following year based upon the average remaining service period of active plan participants, unless the Company’s policy is to recognize all actuarial gains (losses) when they occur. The Company elected to defer actuarial gains (losses) in accumulated other comprehensive income (loss). As of December 31, 2020, the Company did not meet the 10% threshold, and therefore no amortization of 2020 actuarial gain would be recorded in 2021. Refer to Note 12, “Employee Benefit Plans and Stock-based Compensation-French Pension Plan,” for additional information. Income Taxes In preparing the Company’s consolidated financial statements, the Company estimates the income taxes for each of the jurisdictions in which the Company operates. This involves estimating the Company’s current tax expense and assessing temporary and permanent differences resulting from differing treatment of items, such as reserves and accruals, for tax and accounting purposes. These temporary differences result in deferred tax assets and liabilities, which are included within the Company’s Consolidated Balance Sheets. The Company’s income tax policy is to record the estimated future tax effects of temporary differences between the tax bases of assets and liabilities and amounts reported in the Company’s accompanying Consolidated Balance Sheets, as well as operating loss and tax credit carryforwards. The Company follows the guidelines set forth in the applicable accounting guidance regarding the recoverability of any tax assets recorded on the Consolidated Balance Sheets and provides any necessary allowances as required. Determining necessary allowances requires the Company to make assessments about the timing of future events, including the probability of expected future taxable income and available tax planning opportunities. A history of operating losses in recent years has led to uncertainty with respect to our ability to realize certain of our net deferred tax assets, and as a result we applied a full valuation allowance against our U.S. net deferred tax assets as of December 31, 2020. In the event that actual results differ from these estimates or the Company adjusts these estimates in future periods, the Company’s operating results, and financial position could be materially affected. The Company is subject to examination of its income tax returns by various tax authorities on a periodic basis. The Company regularly assesses the likelihood of adverse outcomes resulting from such examinations to determine the adequacy of its provision for income taxes. The Company has applied the provisions of the applicable accounting guidance on accounting for uncertainty in income taxes, which requires application of a more-likely-than-not threshold to the recognition and de-recognition of uncertain tax positions. If the recognition threshold is met, the applicable accounting guidance permits the Company to recognize a tax benefit measured at the largest amount of tax benefit that, in the Company’s judgment, is more than 50% likely to be realized upon settlement. It further requires that a change in judgment related to the expected ultimate resolution of uncertain tax positions be recognized in earnings in the period of such change. The Company files annual income tax returns in multiple taxing jurisdictions around the world. A number of years may elapse before an uncertain tax position is audited and finally resolved. While it is often difficult to predict the final outcome or the timing of resolution of any particular uncertain tax position, the Company believes that its reserves for income taxes reflect the most likely outcome. The Company adjusts these reserves and penalties, as well as the related interest, in light of changing facts and circumstances. Changes in the Company’s assessment of its uncertain tax positions or settlement of any particular position could materially and adversely impact the Company’s income tax rate, operating results, financial position and cash flows. Segment Reporting Operating segments are defined as components of an enterprise that engage in business activities for which separate financial information is available and is evaluated by the Chief Operating Decision Maker (“CODM”), which for the Company is its Chief Executive Officer, in deciding how to allocate resources and assess performance. The Company has two operating segments: Video and Cable Access. Recently Adopted Accounting Pronouncements ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326) In June 2016, the Financial Accounting Standard Board (“FASB”) issued Accounting Standard Update (“ASU”) No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which changes the impairment model for most financial assets and certain other instruments. For trade receivables and other instruments, the Company is required to use a new forward-looking “expected loss” model. The Company adopted this new standard in the first quarter of fiscal 2020, and the adoption did not have a material impact on its consolidated financial statements. ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350) In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. The new ASU removes Step 2 of the goodwill impairment test and requires the assessment of fair value of individual assets and liabilities of a reporting unit to measure goodwill impairments. Goodwill impairment will then be the amount by which a reporting unit's carrying value exceeds its fair value. The Company adopted this new standard in the first quarter of fiscal 2020, and the adoption did not have an impact on its consolidated financial statements. ASU 2018-13, Fair Value Measurement (Topic 820) In August 2018, the FASB issued ASU No. 2018-13, which removes, modifies and adds to the disclosure requirements on fair value measurements in Topic 820. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. The Company adopted this new standard in the first quarter of fiscal 2020, and the adoption did not have a material impact on its consolidated financial statements. ASU 2019-08, Compensation—Stock Compensation (Topic 718) and Revenue from Contracts with Customers (Topic 606): Codification Improvements—Share-Based Consideration Payable to a Customer In November 2019, the FASB issued ASU No. 2019-08, Compensation - Stock Compensation (Topic 718) and Revenue from Contracts with Customers (Topic 606): Codification Improvements - Share-Based Consideration Payable to a Customer, which clarifies guidance on measurement and classification of share-based payments to customers. The Company adopted this new standard in the first quarter of fiscal 2020, and the adoption did not have a material impact on its consolidated financial statements. ASU 2018-14, Compensation – Retirement Benefits – Defined Benefits Plans- General (Subtopic 715-20) In August 2018, the FASB issued ASU No. 2018-14, Compensation - Retirement Benefits - Defined Benefit Plans - General Subtopic 715-20 - Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans. This new standard, which is designed to improve the effectiveness of disclosures by removing and adding disclosures related to defined benefit plans. The new ASU is effective for the Company for fiscal years ending after December 15, 2020, and early adoption is permitted. The Company adopted this new standard in the fourth quarter of fiscal 2020, and the adoption did not have a material impact on its consolidated financial statements and associated disclosures. Recently Issued Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Accounting for Convertible Instruments in an Entity’s Own Equity, which simplifies the accounting for convertible instruments and contracts on an entity’s own equity. Among other changes, ASU No. 2020-06 removes from U.S. GAAP the liability and equity separation model for convertible instruments with a cash conversion feature, and as a result, after adoption, entities will no longer separately present in equity an embedded conversion feature for such debt. Similarly, the embedded conversion feature will no longer be amortized into income as interest expense over the life of the instrument. Instead, entities will account for a convertible debt instrument wholly as debt unless (1) a convertible instrument contains features that require bifurcation as a derivative under ASC Topic 815, Derivatives and Hedging, or (2) a convertible debt instrument was issued at a substantial premium. Among other potential impacts, this change is expected to reduce reported interest expense, increase reported net income, and result in a reclassification of certain conversion feature balance sheet amounts from stockholders’ equity to liabilities as it relates to the Company’s convertible senior notes. Additionally, ASU No. 2020-06 requires the application of the if-converted method to calculate the impact of convertible instruments on diluted earnings per share (EPS), which would result in an increase in diluted shares for purposes of calculating diluted EPS for the Company. The new ASU is effective for interim and annual periods beginning after December 15, 2021, with early adoption permitted after December 15, 2020. Adoption of the new ASU can either be on a modified retrospective or full retrospective basis. The Company is currently evaluating the timing, method of adoption and overall impact of this standard on its consolidated financial statements. In January 2020, the FASB issued ASU No. 2020-01, to clarify certain interactions between the guidance to account for equity securities, the guidance to account for investments under the equity method of accounting, and the guidance to account for derivatives and hedging. The new ASU clarifies the application of measurement alternatives and the accounting for certain forward contracts and purchased options to acquire investments. The new ASU is effective for the Company for fiscal years ending after December 15, 2021, and early adoption is permitted. The Company is currently evaluating the impact of adopting the new ASU on its consolidated financial statements.

The preparation of consolidated financial statements in conformity with generally accepted accounting principles in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. The Company’s reported financial positions or results of operations may be materially different under changed conditions or when using different estimates and assumptions, particularly with respect to significant accounting policies. If estimates or assumptions differ from actual results, subsequent periods are adjusted to reflect more current information.

Beginning in fiscal 2019, the Company changed the classification of total revenue and cost of revenue in the Consolidated Statements of Operations from the two previous categories, “Product” and “Service,” to two new categories, “Appliance and integration” and “SaaS and service.” The Company has also adjusted revenue and cost of revenue retrospectively into the two new categories for all prior periods to conform to the current period’s presentation. This reclassification within revenue and cost of revenue did not have an impact on total revenue, cost of revenue or segment revenue for any periods presented.

From time to time, the Company may acquire certain equity investments for the promotion of business and strategic objectives and these investments may be in marketable equity securities or non-marketable equity securities. The Company accounts for its equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income. For equity investments that do not have readily determinable fair values, the Company measures these investments at cost minus impairment, if any.

Financial instruments which subject the Company to concentrations of credit risk consist primarily of cash, cash equivalents, and accounts receivable. Cash and cash equivalents are invested in short-term, highly liquid, investment-grade obligations of commercial or governmental issuers, in accordance with the Company’s investment policy. The investment policy limits the amount of credit exposure to any one financial institution, commercial or governmental issuer.

The Company’s accounts receivable are derived from sales to worldwide cable, satellite, telco, and broadcast and media companies. The Company generally does not require collateral from its customers, and performs ongoing credit evaluations of its customers and provides for expected losses. The Company maintains an allowance for doubtful accounts based upon the expected collectability of its accounts receivable. One customer had a balance greater than 10% of the Company’s net accounts receivable balance as of December 31, 2020 and 2019. During the year ended December 31, 2020, 2019 and 2018, Comcast is the only customer accounted for more than 10% of the Company’s revenue.

Certain of the components and subassemblies included in the Company’s products are obtained from a single source or a limited group of suppliers. Although the Company seeks to reduce dependence on those sole source and limited source suppliers, the partial or complete loss of certain of these sources could have at least a temporary adverse effect on the Company’s results of operations and damage customer relationships.

The Company’s principal sources of revenue are from the sale of hardware, software, hardware and software maintenance contracts, and end-to-end solutions, encompassing design, manufacture, test, integration and installation of products. The Company also derives recurring revenue from subscriptions, which are comprised of subscription fees from customers utilizing the Company’s cloud-based video processing solutions.

The unit of account for revenue recognition is a performance obligation. A contract may contain one or more performance obligations, including hardware, software, professional services and support and maintenance. Performance obligations are accounted for separately if they are distinct. A good or service is distinct if the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer, and the good or service is distinct in the context of the contract. Otherwise performance obligations will be combined with other promised goods or services until the Company identifies a bundle of goods or services that is distinct.

The transaction price is allocated to all the separate performance obligations in an arrangement. It reflects the amount of consideration to which the Company expects to be entitled to in exchange for transferring goods or services, which may include an estimate of variable consideration to the extent that it is probable of not being subject to significant reversals in the future based on the Company’s experience with similar arrangements. The transaction price also reflects the impact of the time value of money if there is a significant financing component present in an arrangement. The transaction price excludes amounts collected on behalf of third parties, such as sales taxes.

Inventories are stated at the lower of cost (determined on first-in, first-out basis) or net realizable value. The cost of inventories is comprised of material and manufacturing labor and overheads. The Company establishes provisions for excess and obsolete inventories to reduce such inventories to their estimated net realizable value after evaluation of historical sales, future demand and market conditions, expected product life cycles and current inventory levels. Such provisions are charged to cost of revenue in the Company’s Consolidated Statements of Operations.

Internal-use software. The Company capitalizes costs associated with internally developed and/or purchased software systems for internal use that have reached the application development stage. Capitalized costs include external direct costs of materials and services utilized in developing or obtaining internal-use software and payroll and payroll-related expenses for employees who are directly associated with and devote time to the internal-use software project. Capitalization of such costs begins when the preliminary project stage is complete and ceases no later than the point at which the project is substantially complete and ready for its intended purpose. These capitalized costs are amortized on a straight-line basis over the estimated useful life, generally three years.

In a hosting arrangement that is a service contract, the Company capitalizes costs for implementation activities in the application development stage depending on the nature of the costs. The costs incurred during the preliminary project and post-implementation stages are expensed as the activities are performed. The costs capitalized are expensed over the term of the hosting arrangement, which is the fixed, non-cancelable term of the arrangement, plus any reasonably certain renewal periods. The capitalized implementation costs are included in “Other non-current assets” in the Consolidated Balance Sheets, and the amortization expense related to these costs are primarily included in “Selling, general and administrative” in the Consolidated Statements of Operations. The payments for capitalized implementation costs are included as operating activities in the Consolidated Statements of Cash Flows.

Property and equipment are recorded at cost. Depreciation is computed using the straight-line method over the estimated useful lives of the assets. Estimated useful lives are generally, five years for furniture and fixtures, three years for software and four years for machinery and equipment. Depreciation for leasehold improvements are computed using the shorter of the remaining useful lives of the assets or the lease term of the respective assets.

As of December 31, 2020, the Company had goodwill of $243.7 million which represents the difference between the purchase price and the estimated fair value of the identifiable assets acquired and liabilities assumed. The Company tests for goodwill impairment at the reporting unit level on an annual basis, or more frequently if events or changes in circumstances indicate that the asset is more likely than not impaired. The Company has two reporting units, which are the same as its operating segments.

On January 1, 2020, the Company adopted Accounting Standard Update (“ASU”) No. 2017-04, Intangibles – Goodwill and Other (Topic 350) using the prospective approach. The ASU eliminates step two from the goodwill impairment test. Under ASU No. 2017-04, the Company will recognize an impairment charge for the amount by which the carrying amount of a reporting unit exceeds its fair value up to the amount of goodwill allocated to that reporting unit. There was no impairment of goodwill resulting from the Company’s fiscal 2020 annual impairment testing.

Long-lived assets represent property and equipment and purchased intangible assets. Purchased intangible assets from business combinations and asset acquisitions include customer contracts, trademarks and trade names, and maintenance agreements and related relationships, the amortization of which is charged to general and administrative expenses, and core technology and developed technology, the amortization of which is charged to cost of revenue. The Company evaluates the recoverability of intangible assets and other long-lived assets when indicators of impairment are present. When impairment indicators are present, the Company evaluates the recoverability of intangible assets and other long-lived assets on the basis of undiscounted cash flows expected to result from the use of each asset group and its eventual disposition. If the undiscounted expected future cash flows are less than the carrying amount of the asset, an impairment loss is recognized in order to write down the carrying value of the asset to its estimated fair market value. There were no impairment charges for long-lived assets in the years ended December 31, 2020, 2019 and 2018.

On January 1, 2019, the Company adopted ASC 842, Leases (“Topic 842”), using the modified retrospective method, applying Topic 842 to all leases existing at the date of initial application. The Company elected to use the effective date as the date of initial application. Consequently, prior period balances and disclosures have not been restated. The Company elected certain practical expedients, which among other things, allowed the Company to carry forward prior conclusions about lease identification and classification.

Under Topic 842, operating lease expense is generally recognized evenly over the term of the lease. The Company has operating leases primarily consisting of facilities with remaining lease terms of 1 year to 10 years. The lease term represents the non-cancelable period of the lease. For certain leases, the Company has an option to extend the lease term. These renewal options are not considered in the remaining lease term unless it is reasonably certain that the Company will exercise such options.

The functional currency of the Company’s Israeli and Swiss subsidiaries is the U.S. dollar. All other foreign subsidiaries use the respective local currency as the functional currency. When the local currency is the functional currency, gains and losses from translation of these foreign currency financial statements into U.S. dollars are recorded as a separate component of other comprehensive income (loss) in stockholders’ equity.

The Company’s foreign currency exposure is also related to its net position of monetary assets and monetary liabilities held by its foreign subsidiaries in their nonfunctional currencies. These monetary assets and liabilities are being remeasured into the subsidiaries’ respective functional currencies using exchange rates as of the balance sheet date. Such remeasurement gains and losses are included in “Other expense, net” in the Company’s Consolidated Statements of Operations. During the years ended December 31, 2020, 2019 and 2018, the Company recorded remeasurement losses of approximately $1.0 million, $1.5 million and $0.6 million, respectively.

The Company enters into derivative instruments, primarily foreign currency forward contracts, to minimize the short-term impact of foreign currency exchange rate fluctuations on certain foreign currency denominated assets and liabilities as well as certain foreign currencies denominated expenses. The Company does not enter into derivative instruments for trading purposes and these derivatives generally have maturities within three months.

The derivative instruments are recorded at fair value in prepaid expenses and other current assets or accrued and other current liabilities in the Company’s Consolidated Balance Sheets. The Company enters into derivative instruments to hedge existing foreign currency denominated assets or liabilities, the gains or losses on these hedges are recorded immediately in earnings to offset the changes in the fair value of the assets or liabilities being hedged.

The Company’s French subsidiary participates in the French Crédit d’Impôt Recherche (“CIR”) program which allows companies to monetize eligible research expenses. The R&D tax credits receivable from the French government for spending on innovative R&D under the CIR program is recorded as an offset to R&D expenses. In the years ended December 31, 2020, 2019 and 2018, the Company had R&D tax credits of $4.5 million, $4.7 million and $5.9 million, respectively.

The Company’s restructuring charges consist primarily of employee severance, one-time termination benefits related to the reduction of its workforce, and other costs. Liabilities for costs associated with a restructuring activity are recognized when the liability is incurred and are measured at fair value. One-time termination benefits are expensed at the date the entity notifies the employee, unless the employee must provide future service, in which case the benefits are expensed ratably over the future service period. Termination benefits are calculated based on regional benefit practices and local statutory requirements.

The Company accrues for estimated warranty costs at the time of revenue recognition and records such accrued liabilities as part of cost of revenue. Management periodically reviews its warranty liability and adjusts the accrued liability based on the terms of warranties provided to customers, historical and anticipated warranty claims experience, and estimates of the timing and cost of warranty claims.

The Company measures and recognizes compensation expense for all stock-based compensation awards made to employees, including stock options, restricted stock units (“RSUs”) and stock purchase rights under the Company’s Employee Stock Purchase Plan (“ESPP”), based upon the grant-date fair value of those awards. The Company recognizes the impact of forfeitures as they occur.

The fair value of the Company’s stock options and stock purchase rights under ESPP is estimated at grant date using the Black-Scholes option pricing model. The fair value of the Company’s RSUs and performance-based RSUs (“PRSUs”) is calculated based on the market value of the Company’s stock at the grant date. The fair value of the Company’s market-based RSUs (“MRSUs”) is estimated using the Monte-Carlo valuation model with market vesting conditions.

The Company recognizes the stock-based compensation for options, RSUs, MRSUs and stock purchase rights under ESPP on straight-line basis over the requisite service period, which is generally the vesting period. The Company recognizes the stock-based compensation for PRSUs based on the probability of achieving performance criteria defined in the PRSU agreements. The Company estimates the number of PRSUs ultimately expected to vest and recognizes expense using the graded vesting attribution method over the requisite service period. Changes in the estimates related to probability of achieving certain performance criteria and number of PRSUs expected to vest could significantly affect the related stock-based compensation expense from one period to the next.

The Company records its obligations relating to the pension plans based on calculations which include various actuarial assumptions including employees’ age and period of service with the company; projected mortality rates, mobility rates and increases in salaries; and a discount rate. The Company reviews its actuarial assumptions on an annual basis as of December 31 (or more frequently if a significant event requiring remeasurement occurs) and modifies the assumptions based on current rates and trends when it is appropriate to do so. The Company believes that the assumptions utilized in recording its obligations under its pension plan are reasonable based on its experience, market conditions and input from its actuaries.

The Company accounts for the actuarial gains (losses) in accordance with ASC 715, “Compensation - Retirement Benefits.” If the net accumulated gain or loss exceeds 10% of the projected plan benefit obligation, a portion of the net gain or loss is amortized and included in expense for the following year based upon the average remaining service period of active plan participants, unless the Company’s policy is to recognize all actuarial gains (losses) when they occur. The Company elected to defer actuarial gains (losses) in accumulated other comprehensive income (loss). As of December 31, 2020, the Company did not meet the 10% threshold, and therefore no amortization of 2020 actuarial gain would be recorded in 2021.

In preparing the Company’s consolidated financial statements, the Company estimates the income taxes for each of the jurisdictions in which the Company operates. This involves estimating the Company’s current tax expense and assessing temporary and permanent differences resulting from differing treatment of items, such as reserves and accruals, for tax and accounting purposes. These temporary differences result in deferred tax assets and liabilities, which are included within the Company’s Consolidated Balance Sheets.

The Company’s income tax policy is to record the estimated future tax effects of temporary differences between the tax bases of assets and liabilities and amounts reported in the Company’s accompanying Consolidated Balance Sheets, as well as operating loss and tax credit carryforwards. The Company follows the guidelines set forth in the applicable accounting guidance regarding the recoverability of any tax assets recorded on the Consolidated Balance Sheets and provides any necessary allowances as required. Determining necessary allowances requires the Company to make assessments about the timing of future events, including the probability of expected future taxable income and available tax planning opportunities. A history of operating losses in recent years has led to uncertainty with respect to our ability to realize certain of our net deferred tax assets, and as a result we applied a full valuation allowance against our U.S. net deferred tax assets as of December 31, 2020. In the event that actual results differ from these estimates or the Company adjusts these estimates in future periods, the Company’s operating results, and financial position could be materially affected.

The Company is subject to examination of its income tax returns by various tax authorities on a periodic basis. The Company regularly assesses the likelihood of adverse outcomes resulting from such examinations to determine the adequacy of its provision for income taxes. The Company has applied the provisions of the applicable accounting guidance on accounting for uncertainty in income taxes, which requires application of a more-likely-than-not threshold to the recognition and de-recognition of uncertain tax positions. If the recognition threshold is met, the applicable accounting guidance permits the Company to recognize a tax benefit measured at the largest amount of tax benefit that, in the Company’s judgment, is more than 50% likely to be realized upon settlement. It further requires that a change in judgment related to the expected ultimate resolution of uncertain tax positions be recognized in earnings in the period of such change.

The Company files annual income tax returns in multiple taxing jurisdictions around the world. A number of years may elapse before an uncertain tax position is audited and finally resolved. While it is often difficult to predict the final outcome or the timing of resolution of any particular uncertain tax position, the Company believes that its reserves for income taxes reflect the most likely outcome. The Company adjusts these reserves and penalties, as well as the related interest, in light of changing facts and circumstances. Changes in the Company’s assessment of its uncertain tax positions or settlement of any particular position could materially and adversely impact the Company’s income tax rate, operating results, financial position and cash flows.

Operating segments are defined as components of an enterprise that engage in business activities for which separate financial information is available and is evaluated by the Chief Operating Decision Maker (“CODM”), which for the Company is its Chief Executive Officer, in deciding how to allocate resources and assess performance. The Company has two operating segments: Video and Cable Access.

In June 2016, the Financial Accounting Standard Board (“FASB”) issued Accounting Standard Update (“ASU”) No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which changes the impairment model for most financial assets and certain other instruments. For trade receivables and other instruments, the Company is required to use a new forward-looking “expected loss” model.

In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. The new ASU removes Step 2 of the goodwill impairment test and requires the assessment of fair value of individual assets and liabilities of a reporting unit to measure goodwill impairments. Goodwill impairment will then be the amount by which a reporting unit's carrying value exceeds its fair value.

In August 2018, the FASB issued ASU No. 2018-13, which removes, modifies and adds to the disclosure requirements on fair value measurements in Topic 820. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date.

In August 2018, the FASB issued ASU No. 2018-14, Compensation - Retirement Benefits - Defined Benefit Plans - General Subtopic 715-20 - Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans. This new standard, which is designed to improve the effectiveness of disclosures by removing and adding disclosures related to defined benefit plans. The new ASU is effective for the Company for fiscal years ending after December 15, 2020, and early adoption is permitted. The Company adopted this new standard in the fourth quarter of fiscal 2020, and the adoption did not have a material impact on its consolidated financial statements and associated disclosures.

In August 2020, the FASB issued ASU No. 2020-06, Accounting for Convertible Instruments in an Entity’s Own Equity, which simplifies the accounting for convertible instruments and contracts on an entity’s own equity. Among other changes, ASU No. 2020-06 removes from U.S. GAAP the liability and equity separation model for convertible instruments with a cash conversion feature, and as a result, after adoption, entities will no longer separately present in equity an embedded conversion feature for such debt. Similarly, the embedded conversion feature will no longer be amortized into income as interest expense over the life of the instrument. Instead, entities will account for a convertible debt instrument wholly as debt unless (1) a convertible instrument contains features that require bifurcation as a derivative under ASC Topic 815, Derivatives and Hedging, or (2) a convertible debt instrument was issued at a substantial premium. Among other potential impacts, this change is expected to reduce reported interest expense, increase reported net income, and result in a reclassification of certain conversion feature balance sheet amounts from stockholders’ equity to liabilities as it relates to the Company’s convertible senior notes. Additionally, ASU No. 2020-06 requires the application of the if-converted method to calculate the impact of convertible instruments on diluted earnings per share (EPS), which would result in an increase in diluted shares for purposes of calculating diluted EPS for the Company. The new ASU is effective for interim and annual periods beginning after December 15, 2021, with early adoption permitted after December 15, 2020. Adoption of the new ASU can either be on a modified retrospective or full retrospective basis. The Company is currently evaluating the timing, method of adoption and overall impact of this standard on its consolidated financial statements.

In January 2020, the FASB issued ASU No. 2020-01, to clarify certain interactions between the guidance to account for equity securities, the guidance to account for investments under the equity method of accounting, and the guidance to account for derivatives and hedging. The new ASU clarifies the application of measurement alternatives and the accounting for certain forward contracts and purchased options to acquire investments. The new ASU is effective for the Company for fiscal years ending after December 15, 2021, and early adoption is permitted. The Company is currently evaluating the impact of adopting the new ASU on its consolidated financial statements.