Summary of Significant Accounting Policies	12 Months Ended
Dec. 31, 2021
Summary of Significant Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 1. ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIESBusiness OverviewWe are a premier life science technology company that is designing, developing and manufacturing advanced sequencing solutions to help scientists and clinical researchers resolve genetically complex problems. Our products and technology under development stem from two highly differentiated core technologies focused on accuracy, quality and completeness which include our existing HiFi long read sequencing technology and our emerging short read Sequencing by Binding (SBB®) technology. Our products address solutions across a broad set of applications including human germline sequencing, plant and animal sciences, infectious disease and microbiology, oncology, and other emerging applications. Our focus is on providing our customers with advanced sequencing technologies with higher throughput and improved workflows that we believe will enable dramatic advancements in routine healthcare. Our customers include academic and governmental research institutions, commercial testing and service laboratories, genome centers, public health labs, hospitals and clinical research institutes, contract research organizations (CROs), pharmaceutical companies and agricultural companies.References in this report to “PacBio,” “we,” “us,” the “Company,” and “our” refer to Pacific Biosciences of California, Inc. and its consolidated subsidiaries.Basis of Presentation Our consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States, or U.S. GAAP, as set forth in the Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC. The consolidated financial statements include the accounts of Pacific Biosciences and our wholly owned subsidiaries. All intercompany transactions and balances have been eliminated. Use of Estimates The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes to the financial statements. On an ongoing basis, we evaluate our significant estimates including, but not limited to, the valuation of inventory, the determination of stand-alone selling prices for revenue recognition, the fair value of contingent consideration, the valuation of acquired intangible assets, the fair value of certain equity awards, the useful lives assigned to long-lived assets, the computation of provisions for income taxes, the borrowing rate used in calculating the operating lease right-of-use assets and operating lease liabilities, the probability associated with variable payments under partnership development agreements, and the valuations related to our convertible senior notes. While the extent of the impact of the COVID-19 pandemic on our business is highly uncertain, we considered the impact on our assumptions and estimates used to determine the results reported and asset valuations as of December 31, 2021. Actual results could differ materially from these estimates. Functional CurrencyThe U.S. dollar is the functional currency of our international operations. We remeasure foreign subsidiaries monetary assets and liabilities to the U.S. dollar and record net gains or losses from remeasurement in other income, net, in the consolidated statement of operations and comprehensive (loss) income.Cash, Cash Equivalents, and Investments We consider all highly liquid investments purchased with an original maturity of 90 days or less to be cash equivalents. We classify our investments in debt securities as available-for sale and report the investments at fair value in current assets. We evaluate our available-for-sale investments in unrealized loss positions and assess whether the unrealized loss is credit-related. Unrealized gains and losses that are not credit-related are recognized in accumulated other comprehensive (loss) income in stockholders’ equity. Realized gains and losses, expected credit losses, as well as interest income, on available-for-sale securities are also reported in other income, net. The cost used in the determination of gains and losses of securities sold is based on the specific identification method. The cost of marketable securities is adjusted for the amortization of premiums and discounts to expected maturity. Premium and discount amortization is recorded in other income, net. Our investment portfolio at any point in time contains investments in cash deposits, money market funds, commercial paper, corporate debt securities and US government and agency securities with high credit ratings. We have established guidelines regarding diversification and maturities of investments with the objectives of maintaining safety and liquidity, while maximizing yield.Concentration and Credit Risks Financial instruments that potentially subject us to credit risk consist principally of interest-bearing investments and trade receivables. We maintain cash, cash equivalents and investments with various major financial institutions. The counterparties to the agreements relating to our investment securities consist of various major corporations, financial institutions, municipalities and government agencies of high credit standing. At December 31, 2021, most of our cash was deposited with U.S. financial institutions. Our investment policy generally restricts the amount of credit exposure to any one issuer. There is no limit to the percentage of the portfolio that may be maintained in securities issued by the U.S. Treasury and U.S. Government Agencies, or other securities fully backed by US Treasury or Government agencies. We have not experienced significant credit losses from financial institutions.Our trade receivables are derived from net revenue to customers and distributors located in the United States and other countries. We perform credit evaluations of our customers’ financial condition and, generally, require no collateral from our customers. The allowance for doubtful accounts is based on our assessment of the collectability of customer accounts. We regularly review our trade receivable including consideration of factors such as historical experience, the age of the accounts receivable balances, customer creditworthiness, customer industry, and current and forecasted economic conditions that may affect a customer’s ability to pay. We have not experienced any significant credit losses to date. Although we have historically not experienced significant credit losses, our exposure to credit losses may increase if our customers are adversely affected by changes in economic pressures or uncertainty associated with local or global economic recessions, disruption associated with the current COVID-19 pandemic, or other customer-specific factors. For the years ended December 31, 2021, 2020 and 2019, one customer, Gene Company Limited, accounted for approximately 13%, 14% and 17% our total revenue, respectively. As of December 31, 2021 and 2020, 53% and 43% of our accounts receivable were from domestic customers, respectively. As of December 31, 2021, no customer represented 10% of greater of our net accounts receivable. As of December 31, 2020, two customers, Berry Genomics Co., Ltd and Gene Company Limited, represented approximately 15% and 12% of our net accounts receivable, respectively. We currently purchase several key parts and components used in the manufacture of our products from a limited number of suppliers. Generally, we have been able to obtain an adequate supply of such parts and components but in certain instances have incurred additional costs to secure supply constrained materials. An extended interruption in the supply of parts and components currently obtained from our suppliers could adversely affect our business and consolidated financial statements. Inventory Inventories are stated at the lower of average cost or net realizable value. Cost is determined using the first-in, first-out (“FIFO”) method. Adjustments to reduce the cost of inventory to its net realizable value, if required, are made for estimated excess or obsolete balances. Cost includes depreciation, labor, material, and overhead costs, including product and process technology costs while determining net realizable value of inventories involves numerous judgements, including projecting future average selling prices, sales volumes, and costs to complete products in work in process inventories. We make inventory purchases and commitments to meet future shipment schedules based on forecasted demand for our products. The business environment in which we operate is subject to rapid changes in technology and customer demand. We perform a detailed assessment of inventory each period, which includes a review of, among other factors, demand requirements, product life cycle and development plans, component cost trends, product pricing, product expiration, and quality issues. Based on our analysis, we record adjustments to inventory for potentially excess, obsolete, or impaired goods, when appropriate, to report inventory at net realizable value. Inventory adjustments may be required if actual demand, component costs, supplier arrangements, or product life cycles differ from our estimates. Any such adjustments would result in a charge to our results of operations.Property and Equipment, Net Property and equipment are stated at cost, reviewed regularly for impairment charges, and depreciated over the estimated useful lives of the assets, using the straight-line method. Leasehold improvements are depreciated over the shorter of the lease term or the estimated useful life of the related asset. Major improvements are capitalized, while maintenance and repairs are expensed as incurred. Estimated useful lives of the major classes of property and equipment are as follows: Estimated Useful LivesLeasehold improvements 3 to 10 yearsLab equipment 3 to 5 yearsComputer equipment 3 to 5 yearsComputer software 3 yearsFurniture and fixtures 3 to 5 yearsImpairment of Tangible Long-Lived Assets We periodically review property and equipment for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset is impaired or the estimated useful lives are no longer appropriate. Fair value is estimated based on discounted future cash flows. If indicators of impairment exist and the undiscounted projected cash flows associated with such assets are less than the carrying amount of the asset, an impairment loss is recorded to write the asset down to its estimated fair value. To date, we have not recorded any impairment charges.Operating Leases We record operating lease right-of-use assets and liabilities on our Consolidated Balance Sheets for all leases with a term of more than 12 months. The operating lease right-of-use assets and liabilities are calculated as the present value of remaining minimum lease payments over the remaining lease term using our estimated secured incremental borrowing rates at the commencement date. Lease payments included in the measurement of the lease liability comprise the fixed rent per the term of the Lease. Operating lease expense is recognized on a straight-line basis over the lease term, with variable lease payments, such as common area maintenance fees, recognized in the period incurred. Goodwill and Intangible AssetsWe perform annual impairment testing of goodwill and in-process research and development project (“IPR&D”) in the second quarter of each year, or more frequently if indicators of potential impairment exist.We capitalize IPR&D assets and will begin to amortize the asset over the life of the product upon commercialization or record an impairment charge if the project is abandoned. We also capitalize finite-lived intangibles assets and amortize them on a straight-line basis over the estimated useful lives.Finite-lived intangibles assets include our acquired developed technology and customer relationships. We regularly review the carrying amount and useful lives of our finite-lived assets to determine whether indicators of impairment may exist which warrant adjustments to carrying values or estimated useful lives. Short-term Restricted Cash At December 31, 2021, the short-term restricted cash balance of $0.5 million consisted of security deposits for employee credit cards.Long-term Restricted Cash Under the lease agreement for our corporate offices, we were required to establish a letter of credit for the benefits of the landlord and to submit $4.5 million as a deposit for the letter of credit in October 2015. Subsequently pursuant to the terms of the O’Brien Lease, beginning on May 1, 2019, the amount of the letter of credit was reduced by $0.5 million each year thereafter on May 1. As such, $3.0 million and $3.5 million was recorded in long-term restricted cash related to the O’Brien Lease in the Consolidated Balance Sheets as of December 31, 2021 and December 31, 2020, respectively.In connection with the acquisition of Omniome in September 2021, we acquired $1.6 million of long-term restricted cash related to a letter of credit established for a facility lease.Revenue Recognition Our revenue is generated primarily from the sale of products and services. Product revenue primarily consists of sales of our instruments and related consumables. Service and other revenue consists primarily of revenue earned from product maintenance agreements. We account for a contract with a customer when there is a legally enforceable contract between us and the customer, the rights of the parties are identified, the contract has commercial substance, and collectability of the contract consideration is probable. Revenues are recognized when control of the promised goods or services is transferred to our customers or services are performed, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. Our instrument sales are generally sold in a bundled arrangement and commonly include the instrument, instrument accessories, installation, training, and consumables. Additionally, our instrument sale arrangements generally include a one-year period of service. For such bundled arrangements, we account for individual products and services separately if they are distinct, that is, if a product or service is separately identifiable from other items in the bundled package and if a customer can benefit from it on its own or with other resources that are readily available to the customer. Our customers cannot benefit from our instrument systems without installation, and installation can only be performed by us or qualified distributors. As a result, the system and installation are considered to be a single performance obligation recognized after installation is completed except for sales to qualified distributors, in which case the system is distinct and recognized when control has transferred to the distributor which typically occurs upon shipment. The consideration for bundled arrangements is allocated between separate performance obligations based on their individual standalone selling price. We determine the best estimate of standalone selling price using average selling prices over a 12-month period combined with an assessment of current market conditions. If the standalone selling price is not directly observable, then we will estimate the SSP by considering multiple factors including, but not limited to, overall market conditions, including geographic or regional specific factors, internal costs, profit objectives, pricing practices and other observable inputs. We recognize revenues as performance obligations are satisfied by transferring control of the product or service to the customer or over the term of a product maintenance agreement with a customer. Our revenue arrangements generally do not provide a right of return. Revenue is recorded net of discounts, distributor commissions, and sales taxes collected on behalf of governmental authorities. We record deferred revenues when cash payments are received or due in advance of our performance. Deferred revenue for instrument service contracts is recognized over the related performance period, generally one year to five years, on a straight-line basis as we are standing ready to provide services and a time-based measure of progress best reflects the satisfaction of the performance obligation. Cost of RevenueCost of revenue reflects the direct cost of product components, third-party manufacturing services and our internal manufacturing overhead and customer service infrastructure costs incurred to produce, deliver, maintain and support our instruments, consumables, and services. There are no incremental costs associated with our contractual revenue; all product development costs are reflected in research and development expense.Manufacturing overhead is predominantly comprised of labor and facility costs. We determine and capitalize manufacturing overhead into inventory based on a standard cost model that approximates actual costs. Service costs include the direct costs of components used in support, repair and maintenance of customer instruments as well as the cost of personnel, materials, shipping and support infrastructure necessary to support our installed customer base. Research and Development Research and development expense consists primarily of expenses for personnel engaged in the development of our core technology, the design and development of our future products and current product enhancements. These expenses also include prototype-related expenditures, development equipment and supplies, partner development costs, facilities costs and other related overhead. We expense research and development costs during the period in which the costs are incurred. However, we defer and capitalize non-refundable advance payments made for research and development activities until the related goods are received or the related services are rendered. Credit LossesWe adopted Topic 326 on January 1, 2020. The adoption of Topic 326 did not have a material impact on our financial statements and our bad debt expense was immaterial as of the years ended December 31, 2020 and 2021. Trade accounts receivable - The allowance for doubtful accounts is based on our assessment of the collectability of customer accounts. We regularly review the allowance by considering factors such as the age of the accounts receivable balances, customer creditworthiness, customer industry, and current and forecasted economic conditions that may affect a customer’s ability to pay. Available-for-sale debt securities - Our investment portfolio at any point in time contains investments in cash deposits, money market funds, commercial paper, corporate debt securities and US government and agency securities. We regularly review the securities in an unrealized loss position and evaluate the current expected credit loss by considering factors such as significance of loss, historical experience, market data, issuer-specific factors, and current economic conditions and concluded that an allowance for credit losses was immaterial as of December 31, 2021. The unrealized losses on our investments are mainly attributable to government securities, including U.S. government and U.S. agency bond securities, impacted by movements in market rates and not due to issuer credit ratings. We have the ability to hold and do not intend to sell the investments in unrealized loss positions before the recovery of their amortized cost bases.Although we have historically not experienced significant credit losses, our exposure to credit losses may increase if our customers are adversely affected by changes in economic pressures or uncertainty associated with local or global economic recessions, disruptions associated with the evolution of the COVID-19 pandemic, or other customer-specific factors. Income Taxes We account for income taxes under the asset and liability method, which requires, among other things, that deferred income taxes be provided for temporary differences between the tax bases of our assets and liabilities and the amounts reported in the financial statements. In addition, deferred tax assets are recorded for the future benefit of utilizing net operating losses and research and development credit carryforwards. The effect of a change in tax rates on the deferred tax assets and liabilities is recognized in the provision for income taxes in the period that includes the enactment date. A full valuation allowance is provided against our net deferred tax assets as it is more likely than not that the deferred tax assets will not be fully realized. We regularly review our positions taken relative to income taxes. To the extent our tax positions are more likely than not going to result in additional taxes, we accrue the estimated amount of tax related to such uncertain positions. Stock-based Compensation We account for share-based payments using a fair-value based method for costs related to all share-based payments, including stock options, restricted stock units, and stock issued under our employee stock purchase plan (“ESPP”). We estimate the fair value of share-based payment awards that are stock options and issued under our ESPP on the date of grant using an option-pricing model. See Note 10. Stockholders’ Equity for further information regarding stock-based compensation.Other Comprehensive (Loss) IncomeOther comprehensive (loss) income is comprised of unrealized gains (losses) on our investment securities. Shipping and HandlingCosts related to shipping and handling are included in cost of revenues for all periods presented.Recent Accounting Pronouncements Recently Adopted Accounting StandardsIn August 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity. This guidance simplifies the accounting for convertible instruments primarily by eliminating the existing cash conversion and beneficial conversion models within Subtopic 470-20, which will result in fewer embedded conversion options being accounted for separately from the debt host. The guidance also amends and simplifies the calculation of earnings per share relating to convertible instruments. This guidance is effective for annual periods beginning after December 15, 2021, including interim periods within that reporting period, excluding smaller reporting companies. Early adoption is permitted, but no earlier than fiscal years beginning after December 15, 2020, including interim periods within that reporting period, using either a full or modified retrospective approach. We adopted ASU 2020-06 on January 1, 2021. Because we had no convertible instruments within the scope of ASU 2020-06 at the time of adoption, there was no impact of adoption on our consolidated financial statements. In February 2021, we issued $900 million of 1.50% Convertible Senior Notes due February 15, 2028, as described in Note 7. Convertible Senior Notes, which are accounted for under ASU 2020-06.In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. This ASU simplifies the accounting for income taxes by clarifying and amending existing guidance related to the recognition of franchise tax, the evaluation of a step up in the tax basis of goodwill, and the effects of enacted changes in tax laws or rates in the effective tax rate computation, among other clarifications. The standard is effective for our annual reporting periods beginning after December 15, 2020, including interim reporting periods within those fiscal years. We adopted ASU 2019-12 on January 1, 2021, and the adoption did not have a material impact on our consolidated financial statements. Accounting Pronouncements Pending AdoptionIn October 2021, the FASB issued ASU No. 2021-08, Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers. This ASU provides specific guidance on how to recognize contract assets and contract liabilities related to revenue contracts with customers acquired in a business combination. This amendment improves comparability for both the recognition and measurement of acquired revenue contracts with customers at the date of and after a business combination. This authoritative guidance will be effective for us in the first quarter of 2023, with early adoption permitted. We are currently evaluating the effect of this new guidance on our consolidated financial statements.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2021

Summary of Significant Accounting Policies [Abstract]

Summary of Significant Accounting Policies

NOTE 1. ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIESBusiness OverviewWe are a premier life science technology company that is designing, developing and manufacturing advanced sequencing solutions to help scientists and clinical researchers resolve genetically complex problems. Our products and technology under development stem from two highly differentiated core technologies focused on accuracy, quality and completeness which include our existing HiFi long read sequencing technology and our emerging short read Sequencing by Binding (SBB®) technology. Our products address solutions across a broad set of applications including human germline sequencing, plant and animal sciences, infectious disease and microbiology, oncology, and other emerging applications. Our focus is on providing our customers with advanced sequencing technologies with higher throughput and improved workflows that we believe will enable dramatic advancements in routine healthcare. Our customers include academic and governmental research institutions, commercial testing and service laboratories, genome centers, public health labs, hospitals and clinical research institutes, contract research organizations (CROs), pharmaceutical companies and agricultural companies.References in this report to “PacBio,” “we,” “us,” the “Company,” and “our” refer to Pacific Biosciences of California, Inc. and its consolidated subsidiaries.Basis of Presentation Our consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States, or U.S. GAAP, as set forth in the Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC. The consolidated financial statements include the accounts of Pacific Biosciences and our wholly owned subsidiaries. All intercompany transactions and balances have been eliminated. Use of Estimates The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes to the financial statements. On an ongoing basis, we evaluate our significant estimates including, but not limited to, the valuation of inventory, the determination of stand-alone selling prices for revenue recognition, the fair value of contingent consideration, the valuation of acquired intangible assets, the fair value of certain equity awards, the useful lives assigned to long-lived assets, the computation of provisions for income taxes, the borrowing rate used in calculating the operating lease right-of-use assets and operating lease liabilities, the probability associated with variable payments under partnership development agreements, and the valuations related to our convertible senior notes. While the extent of the impact of the COVID-19 pandemic on our business is highly uncertain, we considered the impact on our assumptions and estimates used to determine the results reported and asset valuations as of December 31, 2021. Actual results could differ materially from these estimates. Functional CurrencyThe U.S. dollar is the functional currency of our international operations. We remeasure foreign subsidiaries monetary assets and liabilities to the U.S. dollar and record net gains or losses from remeasurement in other income, net, in the consolidated statement of operations and comprehensive (loss) income.Cash, Cash Equivalents, and Investments We consider all highly liquid investments purchased with an original maturity of 90 days or less to be cash equivalents. We classify our investments in debt securities as available-for sale and report the investments at fair value in current assets. We evaluate our available-for-sale investments in unrealized loss positions and assess whether the unrealized loss is credit-related. Unrealized gains and losses that are not credit-related are recognized in accumulated other comprehensive (loss) income in stockholders’ equity. Realized gains and losses, expected credit losses, as well as interest income, on available-for-sale securities are also reported in other income, net. The cost used in the determination of gains and losses of securities sold is based on the specific identification method. The cost of marketable securities is adjusted for the amortization of premiums and discounts to expected maturity. Premium and discount amortization is recorded in other income, net. Our investment portfolio at any point in time contains investments in cash deposits, money market funds, commercial paper, corporate debt securities and US government and agency securities with high credit ratings. We have established guidelines regarding diversification and maturities of investments with the objectives of maintaining safety and liquidity, while maximizing yield.Concentration and Credit Risks Financial instruments that potentially subject us to credit risk consist principally of interest-bearing investments and trade receivables. We maintain cash, cash equivalents and investments with various major financial institutions. The counterparties to the agreements relating to our investment securities consist of various major corporations, financial institutions, municipalities and government agencies of high credit standing. At December 31, 2021, most of our cash was deposited with U.S. financial institutions. Our investment policy generally restricts the amount of credit exposure to any one issuer. There is no limit to the percentage of the portfolio that may be maintained in securities issued by the U.S. Treasury and U.S. Government Agencies, or other securities fully backed by US Treasury or Government agencies. We have not experienced significant credit losses from financial institutions.Our trade receivables are derived from net revenue to customers and distributors located in the United States and other countries. We perform credit evaluations of our customers’ financial condition and, generally, require no collateral from our customers. The allowance for doubtful accounts is based on our assessment of the collectability of customer accounts. We regularly review our trade receivable including consideration of factors such as historical experience, the age of the accounts receivable balances, customer creditworthiness, customer industry, and current and forecasted economic conditions that may affect a customer’s ability to pay. We have not experienced any significant credit losses to date. Although we have historically not experienced significant credit losses, our exposure to credit losses may increase if our customers are adversely affected by changes in economic pressures or uncertainty associated with local or global economic recessions, disruption associated with the current COVID-19 pandemic, or other customer-specific factors. For the years ended December 31, 2021, 2020 and 2019, one customer, Gene Company Limited, accounted for approximately 13%, 14% and 17% our total revenue, respectively. As of December 31, 2021 and 2020, 53% and 43% of our accounts receivable were from domestic customers, respectively. As of December 31, 2021, no customer represented 10% of greater of our net accounts receivable. As of December 31, 2020, two customers, Berry Genomics Co., Ltd and Gene Company Limited, represented approximately 15% and 12% of our net accounts receivable, respectively. We currently purchase several key parts and components used in the manufacture of our products from a limited number of suppliers. Generally, we have been able to obtain an adequate supply of such parts and components but in certain instances have incurred additional costs to secure supply constrained materials. An extended interruption in the supply of parts and components currently obtained from our suppliers could adversely affect our business and consolidated financial statements. Inventory Inventories are stated at the lower of average cost or net realizable value. Cost is determined using the first-in, first-out (“FIFO”) method. Adjustments to reduce the cost of inventory to its net realizable value, if required, are made for estimated excess or obsolete balances. Cost includes depreciation, labor, material, and overhead costs, including product and process technology costs while determining net realizable value of inventories involves numerous judgements, including projecting future average selling prices, sales volumes, and costs to complete products in work in process inventories. We make inventory purchases and commitments to meet future shipment schedules based on forecasted demand for our products. The business environment in which we operate is subject to rapid changes in technology and customer demand. We perform a detailed assessment of inventory each period, which includes a review of, among other factors, demand requirements, product life cycle and development plans, component cost trends, product pricing, product expiration, and quality issues. Based on our analysis, we record adjustments to inventory for potentially excess, obsolete, or impaired goods, when appropriate, to report inventory at net realizable value. Inventory adjustments may be required if actual demand, component costs, supplier arrangements, or product life cycles differ from our estimates. Any such adjustments would result in a charge to our results of operations.Property and Equipment, Net Property and equipment are stated at cost, reviewed regularly for impairment charges, and depreciated over the estimated useful lives of the assets, using the straight-line method. Leasehold improvements are depreciated over the shorter of the lease term or the estimated useful life of the related asset. Major improvements are capitalized, while maintenance and repairs are expensed as incurred. Estimated useful lives of the major classes of property and equipment are as follows: Estimated Useful LivesLeasehold improvements 3 to 10 yearsLab equipment 3 to 5 yearsComputer equipment 3 to 5 yearsComputer software 3 yearsFurniture and fixtures 3 to 5 yearsImpairment of Tangible Long-Lived Assets We periodically review property and equipment for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset is impaired or the estimated useful lives are no longer appropriate. Fair value is estimated based on discounted future cash flows. If indicators of impairment exist and the undiscounted projected cash flows associated with such assets are less than the carrying amount of the asset, an impairment loss is recorded to write the asset down to its estimated fair value. To date, we have not recorded any impairment charges.Operating Leases We record operating lease right-of-use assets and liabilities on our Consolidated Balance Sheets for all leases with a term of more than 12 months. The operating lease right-of-use assets and liabilities are calculated as the present value of remaining minimum lease payments over the remaining lease term using our estimated secured incremental borrowing rates at the commencement date. Lease payments included in the measurement of the lease liability comprise the fixed rent per the term of the Lease. Operating lease expense is recognized on a straight-line basis over the lease term, with variable lease payments, such as common area maintenance fees, recognized in the period incurred. Goodwill and Intangible AssetsWe perform annual impairment testing of goodwill and in-process research and development project (“IPR&D”) in the second quarter of each year, or more frequently if indicators of potential impairment exist.We capitalize IPR&D assets and will begin to amortize the asset over the life of the product upon commercialization or record an impairment charge if the project is abandoned. We also capitalize finite-lived intangibles assets and amortize them on a straight-line basis over the estimated useful lives.Finite-lived intangibles assets include our acquired developed technology and customer relationships. We regularly review the carrying amount and useful lives of our finite-lived assets to determine whether indicators of impairment may exist which warrant adjustments to carrying values or estimated useful lives. Short-term Restricted Cash At December 31, 2021, the short-term restricted cash balance of $0.5 million consisted of security deposits for employee credit cards.Long-term Restricted Cash Under the lease agreement for our corporate offices, we were required to establish a letter of credit for the benefits of the landlord and to submit $4.5 million as a deposit for the letter of credit in October 2015. Subsequently pursuant to the terms of the O’Brien Lease, beginning on May 1, 2019, the amount of the letter of credit was reduced by $0.5 million each year thereafter on May 1. As such, $3.0 million and $3.5 million was recorded in long-term restricted cash related to the O’Brien Lease in the Consolidated Balance Sheets as of December 31, 2021 and December 31, 2020, respectively.In connection with the acquisition of Omniome in September 2021, we acquired $1.6 million of long-term restricted cash related to a letter of credit established for a facility lease.Revenue Recognition Our revenue is generated primarily from the sale of products and services. Product revenue primarily consists of sales of our instruments and related consumables. Service and other revenue consists primarily of revenue earned from product maintenance agreements. We account for a contract with a customer when there is a legally enforceable contract between us and the customer, the rights of the parties are identified, the contract has commercial substance, and collectability of the contract consideration is probable. Revenues are recognized when control of the promised goods or services is transferred to our customers or services are performed, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. Our instrument sales are generally sold in a bundled arrangement and commonly include the instrument, instrument accessories, installation, training, and consumables. Additionally, our instrument sale arrangements generally include a one-year period of service. For such bundled arrangements, we account for individual products and services separately if they are distinct, that is, if a product or service is separately identifiable from other items in the bundled package and if a customer can benefit from it on its own or with other resources that are readily available to the customer. Our customers cannot benefit from our instrument systems without installation, and installation can only be performed by us or qualified distributors. As a result, the system and installation are considered to be a single performance obligation recognized after installation is completed except for sales to qualified distributors, in which case the system is distinct and recognized when control has transferred to the distributor which typically occurs upon shipment. The consideration for bundled arrangements is allocated between separate performance obligations based on their individual standalone selling price. We determine the best estimate of standalone selling price using average selling prices over a 12-month period combined with an assessment of current market conditions. If the standalone selling price is not directly observable, then we will estimate the SSP by considering multiple factors including, but not limited to, overall market conditions, including geographic or regional specific factors, internal costs, profit objectives, pricing practices and other observable inputs. We recognize revenues as performance obligations are satisfied by transferring control of the product or service to the customer or over the term of a product maintenance agreement with a customer. Our revenue arrangements generally do not provide a right of return. Revenue is recorded net of discounts, distributor commissions, and sales taxes collected on behalf of governmental authorities. We record deferred revenues when cash payments are received or due in advance of our performance. Deferred revenue for instrument service contracts is recognized over the related performance period, generally one year to five years, on a straight-line basis as we are standing ready to provide services and a time-based measure of progress best reflects the satisfaction of the performance obligation. Cost of RevenueCost of revenue reflects the direct cost of product components, third-party manufacturing services and our internal manufacturing overhead and customer service infrastructure costs incurred to produce, deliver, maintain and support our instruments, consumables, and services. There are no incremental costs associated with our contractual revenue; all product development costs are reflected in research and development expense.Manufacturing overhead is predominantly comprised of labor and facility costs. We determine and capitalize manufacturing overhead into inventory based on a standard cost model that approximates actual costs. Service costs include the direct costs of components used in support, repair and maintenance of customer instruments as well as the cost of personnel, materials, shipping and support infrastructure necessary to support our installed customer base. Research and Development Research and development expense consists primarily of expenses for personnel engaged in the development of our core technology, the design and development of our future products and current product enhancements. These expenses also include prototype-related expenditures, development equipment and supplies, partner development costs, facilities costs and other related overhead. We expense research and development costs during the period in which the costs are incurred. However, we defer and capitalize non-refundable advance payments made for research and development activities until the related goods are received or the related services are rendered. Credit LossesWe adopted Topic 326 on January 1, 2020. The adoption of Topic 326 did not have a material impact on our financial statements and our bad debt expense was immaterial as of the years ended December 31, 2020 and 2021. Trade accounts receivable - The allowance for doubtful accounts is based on our assessment of the collectability of customer accounts. We regularly review the allowance by considering factors such as the age of the accounts receivable balances, customer creditworthiness, customer industry, and current and forecasted economic conditions that may affect a customer’s ability to pay. Available-for-sale debt securities - Our investment portfolio at any point in time contains investments in cash deposits, money market funds, commercial paper, corporate debt securities and US government and agency securities. We regularly review the securities in an unrealized loss position and evaluate the current expected credit loss by considering factors such as significance of loss, historical experience, market data, issuer-specific factors, and current economic conditions and concluded that an allowance for credit losses was immaterial as of December 31, 2021. The unrealized losses on our investments are mainly attributable to government securities, including U.S. government and U.S. agency bond securities, impacted by movements in market rates and not due to issuer credit ratings. We have the ability to hold and do not intend to sell the investments in unrealized loss positions before the recovery of their amortized cost bases.Although we have historically not experienced significant credit losses, our exposure to credit losses may increase if our customers are adversely affected by changes in economic pressures or uncertainty associated with local or global economic recessions, disruptions associated with the evolution of the COVID-19 pandemic, or other customer-specific factors. Income Taxes We account for income taxes under the asset and liability method, which requires, among other things, that deferred income taxes be provided for temporary differences between the tax bases of our assets and liabilities and the amounts reported in the financial statements. In addition, deferred tax assets are recorded for the future benefit of utilizing net operating losses and research and development credit carryforwards. The effect of a change in tax rates on the deferred tax assets and liabilities is recognized in the provision for income taxes in the period that includes the enactment date. A full valuation allowance is provided against our net deferred tax assets as it is more likely than not that the deferred tax assets will not be fully realized. We regularly review our positions taken relative to income taxes. To the extent our tax positions are more likely than not going to result in additional taxes, we accrue the estimated amount of tax related to such uncertain positions. Stock-based Compensation We account for share-based payments using a fair-value based method for costs related to all share-based payments, including stock options, restricted stock units, and stock issued under our employee stock purchase plan (“ESPP”). We estimate the fair value of share-based payment awards that are stock options and issued under our ESPP on the date of grant using an option-pricing model. See Note 10. Stockholders’ Equity for further information regarding stock-based compensation.Other Comprehensive (Loss) IncomeOther comprehensive (loss) income is comprised of unrealized gains (losses) on our investment securities. Shipping and HandlingCosts related to shipping and handling are included in cost of revenues for all periods presented.Recent Accounting Pronouncements Recently Adopted Accounting StandardsIn August 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity. This guidance simplifies the accounting for convertible instruments primarily by eliminating the existing cash conversion and beneficial conversion models within Subtopic 470-20, which will result in fewer embedded conversion options being accounted for separately from the debt host. The guidance also amends and simplifies the calculation of earnings per share relating to convertible instruments. This guidance is effective for annual periods beginning after December 15, 2021, including interim periods within that reporting period, excluding smaller reporting companies. Early adoption is permitted, but no earlier than fiscal years beginning after December 15, 2020, including interim periods within that reporting period, using either a full or modified retrospective approach. We adopted ASU 2020-06 on January 1, 2021. Because we had no convertible instruments within the scope of ASU 2020-06 at the time of adoption, there was no impact of adoption on our consolidated financial statements. In February 2021, we issued $900 million of 1.50% Convertible Senior Notes due February 15, 2028, as described in Note 7. Convertible Senior Notes, which are accounted for under ASU 2020-06.In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. This ASU simplifies the accounting for income taxes by clarifying and amending existing guidance related to the recognition of franchise tax, the evaluation of a step up in the tax basis of goodwill, and the effects of enacted changes in tax laws or rates in the effective tax rate computation, among other clarifications. The standard is effective for our annual reporting periods beginning after December 15, 2020, including interim reporting periods within those fiscal years. We adopted ASU 2019-12 on January 1, 2021, and the adoption did not have a material impact on our consolidated financial statements. Accounting Pronouncements Pending AdoptionIn October 2021, the FASB issued ASU No. 2021-08, Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers. This ASU provides specific guidance on how to recognize contract assets and contract liabilities related to revenue contracts with customers acquired in a business combination. This amendment improves comparability for both the recognition and measurement of acquired revenue contracts with customers at the date of and after a business combination. This authoritative guidance will be effective for us in the first quarter of 2023, with early adoption permitted. We are currently evaluating the effect of this new guidance on our consolidated financial statements.