Pacific Biosciences of California (PACB) 10-K 26 Feb 21 2020 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Jan. 31, 2021	Jun. 30, 2020
Document And Entity Information [Abstract]
Document Type	10-K
Document Annual Report	true
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Transition Report	false
Entity File Number	001-34899
Entity Registrant Name	Pacific Biosciences of California, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	16-1590339
Entity Address, Address Line One	1305 O’Brien Drive
Entity Address, City or Town	Menlo Park
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94025
City Area Code	650
Local Phone Number	521-8000
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	PACB
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 498,891,052
Entity Common Stock Shares Outstanding		193,102,689
Amendment Flag	false
Entity Central Index Key	0001299130
Document Fiscal Period Focus	FY
Documents Incorporated by Reference	Portions of the registrant’s definitive Proxy Statement relating to its 2021 Annual Meeting of Stockholders to be held on June 16, 2021 are incorporated by reference into Part III of this Annual Report on Form 10-K where indicated. Such Proxy Statement will be filed with the U.S. Securities and Exchange Commission within 120 days after the end of the fiscal year to which this report relates.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 81,611	$ 29,627
Investments	237,203	19,472
Accounts receivable	16,837	15,266
Inventory	14,230	13,312
Prepaid expenses and other current assets	4,870	3,069
Short-term restricted cash	836	300
Total current assets	355,587	81,046
Property and equipment, net	24,899	30,070
Operating lease right-of-use assets, net	29,951	32,827
Long-term restricted cash	3,500	4,000
Other long-term assets	43	42
Total assets	413,980	147,985
Current liabilities
Accounts payable	3,579	8,368
Accrued expenses	17,350	13,242
Deferred revenue, current	8,722	7,610
Operating lease liabilities, current	4,332	3,837
Notes payable, current		15,871
Other liabilities, current	4,519	225
Total current liabilities	38,502	49,153
Deferred revenue, non-current	1,568	1,951
Operating lease liabilities, non-current	37,667	41,964
Other liabilities, non-current	752
Total liabilities	78,489	93,068
Commitments and contingencies
Stockholders' equity
Preferred stock, $0.001 par value: Authorized 50,000 shares; No shares issued or outstanding
Common stock, $0.001 par value: Authorized 1,000,000 shares; issued and outstanding 192,294 and 153,119 shares at December 31, 2020 and December 31, 2019, respectively	192	153
Additional paid-in capital	1,372,083	1,120,999
Accumulated other comprehensive income	85	5
Accumulated deficit	(1,036,869)	(1,066,240)
Total stockholders' equity	335,491	54,917
Total liabilities and stockholders' equity	$ 413,980	$ 147,985

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Consolidated Balance Sheets [Abstract]
Preferred Stock, par value	$ 0.001	$ 0.001
Preferred Stock, shares authorized	50,000,000	50,000,000
Preferred Stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0
Common Stock, par value	$ 0.001	$ 0.001
Common Stock, shares authorized	1,000,000,000	1,000,000,000
Common Stock, shares issued	192,294,000	153,119,000
Common Stock, shares outstanding	192,294,000	153,119,000

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue:
Total revenue	$ 78,893	$ 90,891	$ 78,626
Cost of Revenue:
Total cost of revenue	46,327	56,315	53,530
Gross profit	32,566	34,576	25,096
Operating Expense:
Research and development	64,152	59,630	62,594
Sales, general and administrative	72,799	75,491	63,489
Total operating expense	136,951	135,121	126,083
Operating loss	(104,385)	(100,545)	(100,987)
Gain from Reverse Termination Fee from Illumina	98,000
Gain from Continuation Advances from Illumina	34,000	18,000
Interest expense	(267)	(2,611)	(2,423)
Other income, net	2,055	1,022	848
Net income (loss)	29,403	(84,134)	(102,562)
Other comprehensive income (loss):
Unrealized gain (loss) on investments	80	41	(4)
Comprehensive income (loss)	$ 29,483	$ (84,093)	$ (102,566)
Net income (loss) per share:
Basic	$ 0.18	$ (0.55)	$ (0.76)
Diluted	$ 0.17	$ (0.55)	$ (0.76)
Weighted average shares outstanding used in calculating net income (loss) per share
Basic	165,187	152,527	135,094
Diluted	174,970	152,527	135,094
Product [Member]
Revenue:
Total revenue	$ 65,424	$ 77,742	$ 66,355
Cost of Revenue:
Total cost of revenue	35,424	44,771	42,053
Service and Other [Member]
Revenue:
Total revenue	13,469	13,149	12,271
Cost of Revenue:
Total cost of revenue	$ 10,903	$ 11,544	$ 11,477

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]Revision of Prior Period, Accounting Standards Update, Adjustment [Member]	Accumulated Deficit [Member]	Revision of Prior Period, Accounting Standards Update, Adjustment [Member]	Total
Balance (Accounting Standards Update 2014-09 [Member]) at Dec. 31, 2017				$ 189		$ 189
Balance at Dec. 31, 2017	$ 116	$ 965,752	$ (32)		$ (879,733)		$ 86,103
Balance, shares at Dec. 31, 2017	116,277
Net income (loss)					(102,562)		(102,562)
Other comprehensive income (loss)			(4)				(4)
Issuance of common stock in conjunction with equity plans	$ 4	9,648					9,652
Issuance of common stock in conjunction with equity plans, shares	3,357
Issuance of common stock from Underwritten Public Equity Offerings, net of issuance costs	$ 30	97,500					97,530
Issuance of common stock from Underwritten Public Equity Offerings, net of issuance costs, shares	30,610
Stock-based compensation expense		23,153					23,153
Balance at Dec. 31, 2018	$ 150	1,096,053	(36)		(982,106)		114,061
Balance, shares at Dec. 31, 2018	150,244
Net income (loss)					(84,134)		(84,134)
Other comprehensive income (loss)			41				41
Issuance of common stock in conjunction with equity plans	$ 3	8,545					8,548
Issuance of common stock in conjunction with equity plans, shares	2,875
Stock-based compensation expense		16,401					16,401
Balance (Accounting Standards Update 2019-04 [Member]) at Dec. 31, 2019				$ (32)		$ (32)
Balance at Dec. 31, 2019	$ 153	1,120,999	5		(1,066,240)		$ 54,917
Balance, shares at Dec. 31, 2019	153,119						153,119
Net income (loss)					29,403		$ 29,403
Other comprehensive income (loss)			80				80
Issuance of common stock in conjunction with equity plans	$ 10	46,350					46,360
Issuance of common stock in conjunction with equity plans, shares	9,819
Issuance of common stock from Underwritten Public Equity Offerings, net of issuance costs	$ 29	187,201					187,230
Issuance of common stock from Underwritten Public Equity Offerings, net of issuance costs, shares	29,356
Stock-based compensation expense		17,533					17,533
Balance at Dec. 31, 2020	$ 192	$ 1,372,083	$ 85		$ (1,036,869)		$ 335,491
Balance, shares at Dec. 31, 2020	192,294						192,294

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities
Net income (loss)	$ 29,403	$ (84,134)	$ (102,562)
Adjustments to reconcile net loss to net cash used in operating activities
Gain from Continuation Advances from Illumina	(34,000)	(18,000)
Depreciation	6,428	7,265	7,215
Amortization of right-of-use assets	2,876	2,683
Amortization of debt discount and financing costs	129	1,212	1,024
Stock-based compensation	17,533	16,401	23,153
Gain (loss) from derivative		(16)	(167)
Amortization and accretion for investment premium (discount)	(107)	(913)	(758)
Loss on disposition of equipment		194
Changes in assets and liabilities
Accounts receivable	(1,603)	(6,671)	4,838
Inventory	(1,096)	3,915	3,623
Prepaid expenses and other assets	(1,063)	(523)	(290)
Accounts payable	(5,072)	1,713	(2,239)
Accrued expenses	4,102	2,333	183
Deferred revenue	729	2,134	33
Operating lease liabilities	(3,802)	(3,428)
Other liabilities	5,046	(2,477)	(483)
Net cash provided by (used in) operating activities	19,503	(78,312)	(66,430)
Cash flows from investing activities
Purchase of property and equipment	(1,039)	(2,836)	(1,854)
Purchase of investments	(373,283)	(57,727)	(122,183)
Sales of investments	1,400	1,500	2,442
Maturities of investments	153,600	121,110	83,180
Net cash provided by (used in) investing activities	(219,322)	62,047	(38,415)
Cash flows from financing activities
Continuation Advances from Illumina	34,000	18,000
Proceeds from issuance of common stock from equity plans	46,360	8,548	9,652
Notes payable principal payoff	(16,000)
Proceeds from issuance of common stock from underwritten public equity offerings, net of issuance costs	187,479		97,530
Net cash provided by (used in) in investing activities	251,839	26,548	107,182
Net increase in cash and cash equivalents and restricted cash	52,020	10,283	2,337
Cash and cash equivalents and restricted cash at beginning of period	33,927	23,644	21,307
Cash and cash equivalents and restricted cash at end of period	85,947	33,927	23,644
Cash and cash equivalents at end of period	81,611	29,627	18,844
Restricted cash at end of period	4,336	4,300	4,800
Supplemental disclosure of cash flow information
Interest paid	491	1,400	1,400
Supplemental disclosure of non-cash investing and financing activities
Inventory transferred to property and equipment	1,097	2,062	1,871
Property and equipment transferred to inventory	$ (919)	$ (1,536)	$ (343)

Overview

Overview	12 Months Ended
	Dec. 31, 2020
Overview [Abstract]
Overview	NOTE 1. OVERVIEW We design, develop and manufacture sequencing systems to help scientists resolve genetically complex problems. Based on our novel Single Molecule, Real-Time (SMRT®) sequencing technology, our products enable: de novo genome assembly to finish genomes in order to more fully identify, annotate and decipher genomic structures; full-length transcript analysis to improve annotations in reference genomes, characterize alternatively spliced isoforms in important gene families, and find novel genes; targeted sequencing to more comprehensively characterize genetic variations; and real-time kinetic information for epigenome characterization. Our technology provides high accuracy, ultra-long reads, uniform coverage and the ability to simultaneously detect epigenetic changes. PacBio® sequencing systems, including associated consumables and software, provide a simple and fast end-to-end workflow for SMRT sequencing. Our current products include the Sequel II and Sequel IIe instruments and SMRT Cell 8M, which when used together are capable of sequencing up to approximately eight million DNA molecules simultaneously, and the previous generation Sequel instrument and Sequel SMRT Cell 1M, which when used together are capable of sequencing up to approximately one million DNA molecules simultaneously. In October 2020, we launched the Sequel IIe System, which has increased computational capacity, and is designed to enable customers to generate PacBio HiFi reads more efficiently. Our research and development efforts are focused on developing new products and further improving our existing products including continuing chemistry and sample preparation improvements to increase throughput and expand our supported applications. By providing access to genetic information that was previously inaccessible, we enable scientists to confidently increase their understanding of biological systems. The names “Pacific Biosciences,” “PacBio,” “SMRT,” “SMRTbell,” “Sequel” and our logo are our trademarks.

Termination of Merger with Illu

Termination of Merger with Illumina	12 Months Ended
	Dec. 31, 2020
Termination of Merger with Illumina [Abstract]
Termination of Merger with Illumina	NOTE 2. TERMINATION OF MERGER WITH ILLUMINA On November 1, 2018, we entered into an Agreement and Plan of Merger (as amended, the “Merger Agreement”) with Illumina, Inc. (“Illumina”) and FC Ops Corp., a wholly owned subsidiary of Illumina (“Merger Subsidiary”). On January 2, 2020, we, Illumina and Merger Subsidiary, entered into an agreement to terminate the Merger Agreement (the “Termination Agreement”). Continuation Advances from Illumina As part of the Termination Agreement, Illumina paid us cash payments (“Continuation Advances”), of $ 18.0 million during the fourth quarter of 2019 and $ 34.0 million during the first quarter of 2020. We recorded the $ 34.0 million and $ 18.0 million as a part of other income in the consolidated statements of operations and comprehensive income (loss) for the year ended December 31, 2020 and 2019, respectively. Please refer to “Note 4. Financial Instruments” for the accounting treatment of the Continuation Advances. Up to the full $ 52.0 million of Continuation Advances paid to us are repayable without interest to Illumina if, within two years of March 31, 2020, we enter into, or consummate a Change of Control Transaction or raise at least $ 100 million in a single equity or debt financing (that may have multiple closings), with the amount repayable dependent on the amount raised by us. Resulting from the issuance and sale of $ 900 million of 1.50 % Convertible Senior Notes due February 15, 2028 , $ 52.0 million of Continuation Advances were paid without interest to Illumina in February 2021. Please see “Note 11. Subsequent Events” for additional information. Reverse Termination Fee from Illumina As part of the Termination Agreement, Illumina paid us a $ 98.0 million termination fee (“Reverse Termination Fee”), from which we paid our financial advisor associated fees of $ 6.0 million in April 2020. We recorded the $ 6.0 million of associated fees we paid to our financial advisor in the “Sales, general and administrative” expense line in the consolidated statements of operations and comprehensive income (loss) for the year ended December 31, 2020. Pursuant to the Termination Agreement, in the event that, on or prior to September 30, 2020, we entered into a definitive agreement providing for, or consummated, a Change of Control Transaction, then we may have been required to repay the Reverse Termination Fee (without interest) to Illumina in connection with the consummation of such Change of Control Transaction. If such Change of Control Transaction was not consummated by the two year anniversary of the execution of the definitive agreement for such Change of Control Transaction, then we would not have been required to repay the Reverse Termination Fee. As indicated in ASC 450, Contingencies , a gain contingency usually is not recognized in the financial statements until the period in which all contingencies are resolved and the gain is realizable. As such, we deferred the gain from the Reverse Termination Fee from Illumina until the date when the associated contingency lapsed. On October 1, 2020, the contingency clauses lapsed and we recorded the $ 98.0 million as a part of other income in the consolidated statements of operations and comprehensive income (loss) for the year ended December 31, 2020.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Summary of Significant Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 3. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation and Consolidation 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. Translation adjustments resulting from translating foreign subsidiaries’ results of operations and assets and liabilities into U.S. dollars are immaterial for all periods presented. COVID-19 We are subject to risks and uncertainties as a result of the novel coronavirus pandemic (COVID-19). The extent of the impact of the COVID-19 pandemic on our business is highly uncertain as responses to the pandemic can change quickly and information is rapidly evolving. We considered the impact of COVID-19 on the assumptions and estimates used to determine the results reported and asset valuations as of December 31, 2020. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires us to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes to the financial statements. Our estimates include, but are not limited to, the valuation of inventory, the determination of stand-alone selling prices for revenue recognition, the valuation of a financing derivative and long-term notes, the probability of repaying the Continuation Advances and Reverse Termination Fee to Illumina, the valuation and recognition of share-based compensation, the expected renewal period for service contracts to derive the amortization period for capitalized commissions, the useful lives assigned to long-lived assets, the recognition and measurement of current and deferred income tax assets, along with the assessment of recoverability and the determination of the internal borrowing rate used in calculating the operating lease right-of-use assets and operating lease liabilities. Actual results could differ materially from these estimates. Reclassifications Certain prior year amounts in the consolidated financial statements have been reclassified to conform to the current year presentation with no effect on previously reported net loss, comprehensive loss, cash flows or stockholders’ equity. Accounting Changes In June 2016, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2016-13 Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“Topic 326”), which replaces existing incurred loss impairment guidance and establishes a single allowance framework for financial assets carried at amortized cost. We adopted Topic 326 on January 1, 2020, using a modified retrospective transition method, which requires a cumulative-effect adjustment to the opening balance of retained earnings/accumulated deficit to be recognized on the date of adoption with prior periods not restated. The adoption of Topic 326 did not have a material impact on our financial statements and our bad debt expense was immaterial as of December 31, 2020. Cash, Cash Equivalents and Investments We consider all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. We have designated all investments as available-for-sale and therefore, such investments are reported at fair value, with unrealized gains and losses recognized in accumulated other comprehensive income (loss) (“OCI”) in stockholders’ equity. The cost of marketable securities is adjusted for the amortization of premiums and discounts to expected maturity. Premium and discount amortization is included in other income, net. Realized gains and losses, as well as interest income, on available-for-sale securities are also included in other income, net. The cost of securities sold is based on the specific identification method. We include all of our available-for-sale securities in current assets. 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 of its investments and their maturities 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. We perform periodic evaluations of the relative credit standing of these financial institutions. In addition, we perform periodic evaluations of the relative credit quality of its investments. All of our investments are subject to a periodic impairment review. We recognize an impairment charge when a decline in the fair value of our investments below the cost basis is judged to be other-than-temporary. Factors considered in determining whether a loss is temporary include the length of time and the extent to which an investment’s fair value has been less than its cost basis, the financial condition and near-term prospects of the investee, the extent of the loss related to credit of the issuer, the expected cash flows from the security, our intent to sell the security and whether or not we will be required to sell the security before the recovery of its amortized cost. For the years ended December 31, 2020, 2019 and 2018, we did no t have any impairment charges on our investments as it is more likely than not that we will recover their amortized cost basis upon sale or maturity. 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, 2020, 2019 and 2018, one customer, Gene Company Limited, accounted for approximately 14 %, 17 % and 26 % our total revenue, respectively. As of December 31, 2020 and 2019, 43 % and 55 % of our accounts receivable were from domestic customers, respectively. 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. As of December 31, 2019, customer, Gene Company Limited, represented approximately 11 % of our net accounts receivable. 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. However, 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 enter into inventory purchases and commitments so that we can 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, in order 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, net of accumulated depreciation and any impairment charges. Depreciation is computed using the straight-line method over the estimated useful life of the asset, generally two years to three years for computer equipment, three years to five years for software, three years to seven years for furniture and fixtures and three years to five years for lab equipment. 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. Impairment of 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 no t recorded any impairment charges. Operating Leases We lease administrative, manufacturing and laboratory facilities under operating leases. Lease agreements may include rent holidays, rent escalation clauses and tenant improvement allowances. We recognize scheduled rent increases on a straight-line basis over the lease term beginning with the date we take possession of the leased space. Leasehold improvements are capitalized at cost and depreciated over the shorter of their expected useful life or the life of the lease. On January 1, 2019, we adopted ASC 842, which requires the recognition of the right-of-use assets and related operating and finance lease liabilities on the consolidated balance sheet. Operating lease assets and liabilities are reflected within “Operating lease right-of-use assets, net”, “Operating lease liabilities, current” and “Operating lease liabilities, non-current” on the consolidated balance sheets. These assets and liabilities are recognized at the commencement date based on the present value of remaining minimum lease payments over the lease term using our estimated secured incremental borrowing rates at the effective date of January 1, 2019. Leases with terms of 12 months or less are expensed on a straight-line basis over the term and are not recorded in the consolidated balance sheets. Short-term Restricted Cash At December 31, 2020 the short-term restricted cash balance of $ 0.8 million was comprised of $ 0.5 million of a customer deposit and $ 0.3 million of the security deposit for the credit cards for employees. 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, on May 1, 2019 the $ 4.5 million in restricted cash was reduced to $ 4.0 million and on May 1, 2020 the $ 4.0 million in restricted cash was reduced to $ 3.5 million. 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 primarily consists 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. Taxes we collect concurrent with revenue-producing activities are excluded from revenue. 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 (“SSP”). The SSP is determined based on observable prices at which we separately sell the products and services. If a SSP 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. Contract liabilities and contract assets - Contract liabilities consist of deferred revenue. We record deferred revenues when cash payments are received or due in advance of our performance for product maintenance agreements. Deferred revenue is recognized over the related performance period, generally one year to three 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. Other practical expedients and exemptions - Customers generally are invoiced upon acceptance of the system, which is also the start of the one year service period. As such, there is typically not more than a one year difference between the receipt of cash and the provision of services. Therefore, we apply the practical expedient and do not account for any potential significant financing benefit. However, it is noted that some customers will pre-order extended service periods at the time of the initial system sale. These customers may choose to make quarterly or annual payments or prepay multiple years of service upfront but there is no pricing difference between these different payment options. As such, no significant financing component is believed to exist with any of our existing arrangements. Cost of Revenue Cost 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 SMRT Sequencing technology, the design and development of our future products and current product enhancements. These expenses also include prototype-related expenditures, development equipment and supplies, 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 Losses We 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 December 31, 2020. 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 not required as of December 31, 2020. 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. 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. 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 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 would 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 on the date of grant using an option-pricing model. See Note 8 for further information regarding stock-based compensation. Other Comprehensive Income (loss) Other comprehensive income (loss) is comprised of unrealized gains (losses) on our investment securities. Shipping and Handling Costs related to shipping and handling are included in cost of revenues for all periods presented. Recent Accounting Pronouncements Recently Issued Accounting Standards In August 2020, the FASB issued 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 are currently evaluating the impact of the provisions of this guidance on our consolidated financial statements. 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 will be effective for our annual reporting periods beginning after December 15, 2020, including interim reporting periods within those fiscal years. We have evaluated the effect that this guidance will have on our Consolidated Financial Statements and determined it will not have a material impact. Recently Adopted Accounting Standards In June 2016, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2016-13 Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“Topic 326”), which replaces existing incurred loss impairment guidance and establishes a single allowance framework for financial assets carried at amortized cost. We adopted Topic 326 on January 1, 2020, using a modified retrospective transition method, which requires a cumulative-effect adjustment to the opening balance of retained earnings/accumulated deficit to be recognized on the date of adoption with prior periods not restated. The adoption of Topic 326 did not have a material impact on our financial statements and our bad debt expense was immaterial as of December 31, 2020.

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2020
Financial Instruments [Abstract]
Financial Instruments	NOTE 4. FINANCIAL INSTRUMENTS Fair Value of Financial Instruments The fair value hierarchy established under U.S. GAAP requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The three levels of inputs that may be used to measure fair value are as follows:  Level 1: quoted prices in active markets for identical assets or liabilities;  Level 2: inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices in active markets for similar assets or liabilities, quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and  Level 3: unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. We consider an active market as one in which transactions for the asset or liability occurs with sufficient frequency and volume to provide pricing information on an ongoing basis. Conversely, we view an inactive market as one in which there are few transactions for the asset or liability, the prices are not current, or price quotations vary substantially either over time or among market makers. Where appropriate, our non-performance risk, or that of our counterparty, is considered in determining the fair values of liabilities and assets, respectively. We classify our cash deposits and money market funds within Level 1 of the fair value hierarchy because they are valued using bank balances or quoted market prices. We classify our investments as Level 2 instruments based on market pricing and other observable inputs. We did not classify any of our investments within Level 3 of the fair value hierarchy. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the entire fair value measurement requires management to make judgments and consider factors specific to the asset or liability. The carrying amount of our accounts receivable, prepaid expenses, other current assets, accounts payable, accrued expenses and other liabilities, current, approximate fair value due to their short maturities. Assets and Liabilities Measured at Fair Value on a Recurring Basis The following table sets forth the fair value of our financial assets and liabilities that were measured on a recurring basis as of December 31, 2020 and 2019, respectively (in thousands): December 31, 2020 December 31, 2019 (in thousands) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash and cash equivalents: Cash and money market funds $ 43,040 $ — $ — $ 43,040 $ 18,644 $ — $ — $ 18,644 Commercial paper — 32,537 — 32,537 — 10,983 — 10,983 U.S. government & agency securities — 170 — 170 — — — — U.S. Treasury security — 5,864 — 5,864 — — — — Total cash and cash equivalents 43,040 38,571 — 81,611 18,644 10,983 — 29,627 Investments: Commercial paper — 112,644 — 112,644 — 16,971 — 16,971 Corporate debt securities — 17,456 — 17,456 — 2,501 — 2,501 U.S. government & agency securities — 107,103 — 107,103 — — — — Total investments — 237,203 — 237,203 — 19,472 — 19,472 Short-term restricted cash: Cash 836 — — 836 300 — — 300 Long-term restricted cash: Cash 3,500 — — 3,500 4,000 — — 4,000 Total assets measured at fair value $ 47,376 $ 275,774 $ — $ 323,150 $ 22,944 $ 30,455 $ — $ 53,399 Liabilities Financing Derivative $ — $ — $ — $ — $ — $ — $ — $ — Continuation Advances — — — — — — — — Total liabilities measured at fair value $ — $ — $ — $ — $ — $ — $ — $ — Estimated fair value of the Financing Derivative liability The estimated fair value of the Financing Derivative liability (as defined in the “Notes payable, current” section in “Note 5. Balance Sheet Components”) was determined using Level 3 inputs, or significant unobservable inputs. Changes to the estimated fair value of the Financing Derivative are recorded in “Other income, net” in the consolidated statements of operations and comprehensive loss. The estimated fair value of the Financing Derivative was determined by comparing the difference between the fair value of the promissory notes from the debt facility that we entered into during the first quarter of 2013 with and without the Financing Derivative by calculating the respective present values from future cash flows using a 6.5 % discount rate at December 31, 2019. The estimated fair value of the Financing Derivative as of December 31, 2019 was $ 0 . In February 2020, upon maturity of the promissory notes , the Financing Derivative was extinguished. Refer to the “Notes payable, current” section in “Note 5. Balance Sheet Components” for a detailed description and valuation approach. Estimated fair value of the Continuation Advances liability In accordance with the terms of the Merger Agreement, we received Continuation Advances of $ 34.0 million and $ 18.0 million from Illumina during the year ended December 31, 2020 and 2019, respectively. We determined that the Continuation Advances, which are subject to repayment under certain circumstances as discussed below, constitute a financial liability. The fair value option was elected for the financial liability because management believes that among all measurement methods allowed by Accounting Standards Codification, or ASC, 825, Financial Instruments , the fair value option would most fairly represent the value of such a financial liability. Management applied the income approach to estimate the fair value of this financial liability. The estimated fair value of the liability related to the Continuation Advances was determined using Level 3 inputs, or significant unobservable inputs. Management estimated that there would be no future cash outflows associated with this financial instrument because the probabilities of either of the following events occurring and requiring repayment to Illumina were evaluated as being remote as of December 31, 2020 and December 31, 2019:  we enter into a Change of Control Transaction within two years following March 31, 2020; or  we raise $ 100 million or more in a single equity or debt financing (that may have multiple closings) within two years following March 31, 2020. As a result, the estimated fair value of the liability associated with the contingent repayment of the Continuation Advances received was assessed to be zero as of December 31, 2020 and 2019, respectively, with a resulting non-operating gain of $ 34.0 million and $ 18.0 million recorded as “Gain from Continuation Advances from Illumina” for the year ended December 31, 2020 and 2019, respectively. For the year ended December 31, 2020, there were no transfers between Level 1, Level 2, or Level 3 assets or liabilities reported at fair value on a recurring basis and our valuation techniques did not change compared to the prior year. Cash, Cash Equivalents and Investments The following table summarizes our cash, cash equivalents and investments as of December 31, 2020 and 2019 (in thousands): As of December 31, 2020 Gross Gross Amortized unrealized unrealized Fair Cost gains losses Value Cash and cash equivalents: Cash and money market funds $ 43,040 $ — $ — $ 43,040 Commercial paper 32,538 — ( 1 ) 32,537 U.S. government & agency securities 170 — — 170 U.S. Treasury security 5,864 — — 5,864 Total cash and cash equivalents 81,612 — ( 1 ) 81,611 Investments: Commercial paper 112,648 4 ( 8 ) 112,644 Corporate debt securities 17,360 96 — 17,456 U.S. government & agency securities 107,109 6 ( 12 ) 107,103 Total investments 237,117 106 ( 20 ) 237,203 Total cash, cash equivalents and investments $ 318,729 $ 106 $ ( 21 ) $ 318,814 Short-term restricted cash: Cash $ 836 $ — $ — $ 836 Long-term restricted cash: Cash $ 3,500 $ — $ — $ 3,500 As of December 31, 2019 Gross Gross Amortized unrealized unrealized Fair Cost gains losses Value Cash and cash equivalents: Cash and money market funds $ 18,644 $ — $ — $ 18,644 Commercial paper 10,983 — — 10,983 Total cash and cash equivalents 29,627 — — 29,627 Investments: Commercial paper 16,971 1 ( 1 ) 16,971 Corporate debt securities 2,496 5 — 2,501 Total investments 19,467 6 ( 1 ) 19,472 Total cash, cash equivalents and investments $ 49,094 $ 6 $ ( 1 ) $ 49,099 Short-term restricted cash: Cash $ 300 $ — $ — $ 300 Long-term restricted cash: Cash $ 4,000 $ — $ — $ 4,000 The following table summarizes the contractual maturities of our cash equivalents and available-for-sale investments, excluding money market funds, as of December 31, 2020: Fair Value Due in one year or less $ 255,207 Due after one year through 5 years 20,567 Total investments $ 275,774 Our marketable debt investments are classified as current based on the nature of the investments and their availability for use in current operations. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations without call or prepayment penalties.

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2020
Balance Sheet Components [Abstract]
Balance Sheet Components	NOTE 5. BALANCE SHEET COMPONENTS Inventory As of December 31, 2020 and 2019, our inventory consisted of the following components: December 31, December 31, (in thousands) 2020 2019 Purchased materials $ 3,531 $ 3,966 Work in process 6,651 4,594 Finished goods 4,048 4,752 Inventory $ 14,230 $ 13,312 Property and Equipment, Net As of December 31, 2020 and 2019, our property and equipment, net, consisted of the following components: December 31, (in thousands) 2020 2019 Laboratory equipment and machinery $ 24,948 $ 25,173 Leasehold improvements 29,931 29,902 Computer equipment 12,400 11,851 Software 4,940 4,747 Furniture and fixtures 2,434 2,422 Construction in progress 137 193 74,790 74,288 Less: Accumulated depreciation ( 49,891 ) ( 44,218 ) Property and equipment, net $ 24,899 $ 30,070 Depreciation expense during the years ended December 31, 2020, 2019 and 2018 was $ 6.4 million, $ 7.3 million and $ 7.2 million, respectively. Accrued Expenses As of December 31, 2020 and 2019, our accrued expenses consisted of the following components: December 31, (in thousands) 2020 2019 Salaries and benefits $ 15,261 $ 9,748 Accrued product development costs 415 67 Accrued Tenant Improvements for Menlo Park building — 998 Inventory accrual 218 229 Accrued professional services and legal fees 726 943 Other 730 1,257 Accrued expenses $ 17,350 $ 13,242 Deferred Revenue As of December 31, 2020, we had a total of $ 10.3 million of deferred revenue from our service contracts, $ 8.7 million of which was recorded as “Deferred revenue, current” to be recognized over the next year and the remaining $ 1.6 million was recorded as “Deferred revenue, non-current” to be recognized in the next 3 years. Revenue recorded in the year ended December 31, 2020 includes $ 7.6 million, respectively, of previously deferred revenue that was included in “Deferred revenue, current” as of December 31, 2019. Contract assets as of December 31, 2020 and December 31, 2019 were not material. As of December 31, 2020, we had a total of $ 0.7 million of deferred commissions included in “Prepaid expenses and other current assets” which is recognized as the related revenue is recognized. Additionally, as a practical expedient, we expense costs to obtain a contract as incurred if the amortization period would have been a year or less. Notes payable, current As of December 31, 2019, a balance of $ 16.0 million aggregate principal amount of debt remained outstanding under the debt agreement with Deerfield entered into in February 2013 and was presented as “Notes payable, current” on the consolidated balance sheet as of December 31, 2019. In February 2020, upon the maturity of the debt agreement, we repaid the remaining outstanding principal of $ 16.0 million and interest. Financing Derivative A number of features embedded in the promissory notes required accounting for them as a derivative, including the indemnification of certain withholding taxes and the acceleration of debt upon (i) a qualified financing, (ii) an event of default, (iii) a Major Transaction (as such term is defined in the Facility Agreement), and (iv) the exercise of the warrant via offset to the debt principal. These features represent a single derivative (the “Financing Derivative”) that was bifurcated from the debt instrument and accounted for as a liability at fair value, with changes in fair value between reporting periods recorded in other income (expense), net. The estimated fair value of the Financing Derivative was determined by comparing the difference between the fair value of the promissory notes with and without the Financing Derivative by calculating the respective present values from future cash flows using a 6.5 % discount rate at December 31, 2019. The estimated fair value of the Financing Derivative as of December 31, 2019 was $ 0 . In February 2020, after we repaid the remaining outstanding principal of $ 16.0 million and interest to Deerfield, the related Financing Derivative expired. Other liabilities, current As of December 31, 2020 and 2019, our Other liabilities, current consisted of the following components: December 31, (in thousands) 2020 2019 Accrued ESPP $ 2,037 $ — Other 2,482 225 Other liabilities, current $ 4,519 $ 225 Pursuant to the terms of the then-in-process Merger Agreement with Illumina, offerings under our 2010 ESPP were suspended after the completion of the purchase period ended March 1, 2019, resulting in the balance for “Accrued ESPP” being $ 0 as of December 31, 2019. After the merger with Illumina was terminated in January 2020, we began offerings under the ESPP again starting with the offering period beginning March 1, 2020.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies [Abstract]
Commitments and Contingencies	NOTE 6. COMMITMENTS AND CONTINGENCIES Lease In July 2015 we entered into a lease agreement with respect to our facility located at 1305 O’Brien Drive, Menlo Park, California. The term of the O’Brien Lease is one hundred thirty-two ( 132 ) months. In December 2016, we entered into an amendment to the O’Brien Lease which defined the commencement date of the lease to be October 25, 2016, notwithstanding that such substantial completion did not occur until the first quarter of 2017. Base monthly rent was abated for the first six (6) months of the lease term and thereafter was $ 540,000 per month during the first year of the lease term, with specified annual increases thereafter until reaching $ 711,000 per month during the last twelve (12) months of the lease term. If the rent is not received within five days of the due date, there will be an additional sum equal to 5 % of the amount overdue as a late charge. Any amount not paid within 10 days after receipt of landlord’s written notice will bear interest from the date due until paid, at the lesser rate of (1) the prime rate of interest as published in the Wall Street Journal, plus 2 % or (2) the maximum rate allowed by law, in addition to the late payment charge. 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, on May 1, 2019 the $ 4.5 million in restricted cash was reduced to $ 4.0 million and on May 1, 2020 the $ 4.0 million in restricted cash was reduced to $ 3.5 million. All of our leases are operating leases. Lease payments comprise the base rent per the term of the Lease. Lease expense for these leases 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 those payments are incurred. We often have options to renew lease terms for buildings. For the O’Brien Lease, the renewal option is 5 years and the rent will be based on fair market value at the time of renewal and was not included in the lease term. In addition, certain lease arrangements may be terminated prior to their original expiration date at our discretion. We evaluate renewal and termination options at the lease commencement date to determine if we are reasonably certain to exercise the option on the basis of economic factors. The weighted average remaining lease term for our operating leases as of December 31, 2020 was 6.8 years. The discount rate implicit within our leases is generally not determinable and therefore we determine the discount rate based on our incremental borrowing rate. The incremental borrowing rate for our leases is determined based on lease term and currency in which lease payments are made, adjusted for impacts of collateral. The weighted average discount rate used to measure our operating lease liabilities as of December 31, 2020 was 7.9 %. The following table presents information as to the amount and timing of cash flows arising from our operating leases as of December 31, 2020: Maturity of Lease Liabilities Amount Years ending December 31, (in thousands) 2021 $ 7,330 2022 7,502 2023 7,704 2024 7,920 2025 8,136 Thereafter 15,462 Total undiscounted operating lease payments 54,054 Less: imputed interest ( 12,055 ) Present value of operating lease liabilities 41,999 Balance Sheet Classification Operating lease liabilities, current 4,332 Operating lease liabilities, non-current 37,667 Total operating lease liabilities 41,999 Cash Flows Cash paid for amounts included in the present value of operating lease liabilities was $ 7.2 million and $ 7.0 million for the year ended December 31, 2020 and 2019, respectively and were included in operating cash flow. Operating Lease Costs Operating lease costs were $ 6.2 million and $ 6.2 million for the year ended December 31, 2020 and 2019, respectively. For both 2020 and 2019 the operating lease costs primarily related to our operating leases, but also included immaterial amounts for variable leases. Contingencies We may become involved in legal proceedings, claims and assessments from time to time in the ordinary course of business. We accrue liabilities for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated. Legal U.S. District Court Proceedings On March 15, 2017, we filed a complaint in the U.S. District Court for the District of Delaware against ONT Inc. for patent infringement (C.A. No. 17-cv-275 (“275 Action”)). The complaint is based on our U.S. Patent No. 9,546,400 (the “’400 Patent”) which covers novel methods for nanopore sequencing of nucleic acid molecules using the signals from multiple monomeric units. We are seeking remedies including injunctive relief, damages and costs. On August 23, 2018, we filed an amended complaint, adding allegations of willful infringement and adding ONT Ltd. as a defendant in the 275 Action, which was granted on August 15, 2019. On September 25, 2017, we filed a second complaint in the U.S. District Court for the District of Delaware against ONT Inc. for patent infringement (C.A. No. 17-cv-1353 (“1353 Action”)). The complaint is based on our U.S. Patent No. 9,678,056 (the “’056 Patent”) and U.S. Patent No. 9,738,929. We are seeking remedies including injunctive relief, damages and costs. On March 28, 2018, we added a claim for infringement of our U.S. Patent No. 9,772,323 (the “’323 Patent”). On August 23, 2018 we filed an amended complaint, adding allegations of willful infringement and adding ONT Ltd. as a defendant in the 1353 Action, which was granted on August 15, 2019. A trial for the U.S. District Court matters was held from March 9 through March 18, 2020. The jury determined that ONT Inc. and ONT Ltd. infringed the ‘056 Patent, the ‘400 Patent, and the ‘323 Patent, but the jury declined to find these patents valid based on enablement and, in the case of claim one of the ’056 Patent, written description and indefiniteness. The jury declined to find valid or infringed U.S. Patent No. 9,738,929. We are pursuing an appeal of the decision at the U.S. Court of Appeals for the Federal Circuit. Unrelated to the preceding matters, on September 26, 2019, Personal Genomics of Taiwan, Inc. (“PGI”) filed a complaint in the U.S. District Court for the District of Delaware against us for patent infringement (C.A. No. 19-cv-1810). The matter from this complaint (the “PGI District Court matter”) is based on PGI’s U.S. Patent No. 7,767,441 (the “‘441 Patent”). We plan to vigorously defend in this matter. On November 20, 2019, we filed our answer to the complaint, denying infringement and seeking a declaratory judgement of invalidity of the ‘441 Patent. On June 22, 2020, we filed a petition requesting institution of an inter-partes review (IPR) to the Patent Trial and Appeals Board (the “Board”) at the United States Patent Office requesting the Board to find a set of claims in the ‘441 invalid. On June 27, 2020, we filed a second petition requesting institution of an IPR requesting the Board to find another set of claims in the ‘441 invalid. The two petitions (the “PacBio IPR Petitions”) requesting IPRs assert that all of the claims relevant to the PGI complaint are invalid. On January 19, 2021, the Board ordered that both PacBio IPR Petitions are instituted on all grounds presented. On August 19, 2020, the court ordered a stay of the PGI District Court matter based on a joint stipulation by the parties. With the institution of the PacBio IPR Petitions described above, pursuant to the joint stipulation, the matter is now stayed pending a final written decision on the IPRs. Proceedings in China On May 12, 2020, PGI filed a complaint in the Wuhan Intermediate People’s Court in China alleging infringement of one or more claims of China patent No. CN101743321B (the “CN321” Patent”), which is related to the ‘441 Patent. We were served on January 20, 2021 and plan to vigorously defend in this matter. On November 23, 2020 we filed an Invalidation Petition at the China National Intellectual Property Administration (CNIPA) demonstrating the invalidity of the claims in the CN321 Patent on grounds of insufficient disclosure, and the lack of support, essential technical features, clarity, novelty, and inventiveness. Other Proceedings From time to time, we may also be involved in a variety of other claims, lawsuits, investigations and proceedings relating to securities laws, product liability, patent infringement, contract disputes, employment and other matters that arise in the normal course of our business. In addition, third parties may, from time to time, assert claims against us in the form of letters and other communications. We record a provision for contingent losses when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. We currently do not believe that the ultimate outcome of any of the matters described above is probable or reasonably estimable, or that these matters will have a material adverse effect on our business; however, the results of litigation and claims are inherently unpredictable. Regardless of the outcome, litigation can have an adverse impact on us because of litigation and settlement costs, diversion of management resources and other factors. Indemnification Pursuant to Delaware law and agreements entered into with each of our directors and officers, we may have obligations, under certain circumstances, to hold harmless and indemnify each of our directors and officers against losses suffered or incurred by the indemnified party in connection with their service to us, and judgements, fines, settlements and expenses related to claims arising against such directors and officers to the fullest extent permitted under Delaware law, our bylaws and certificate of incorporation. We also enter and have entered into indemnification agreements with our directors and officers that may require us to indemnify them against liabilities that arise by reason of their status or service as directors or officers, except as prohibited by applicable law. In addition, we may have obligations to hold harmless and indemnify third parties involved with our fundraising efforts and their respective affiliates, directors, officers, employees, agents or other representatives against any and all losses, claims, damages and liabilities related to claims arising against such parties pursuant to the terms of agreements entered into between such third parties and us in connection with such fundraising efforts. To the extent that any such indemnification obligations apply to the lawsuits described above, any associated expenses incurred are included within the related accrued litigation expense amounts. No additional liability associated with such indemnification obligations has been recorded as of December 31, 2020.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Taxes [Abstract]
Income Taxes	NOTE 7. INCOME TAXES We are subject to income taxes in the United States and certain states in which we operate, and we use estimates in determining our provisions for income taxes. Significant management judgement is required in determining our provision for income taxes, deferred tax assets and liabilities and valuation allowances recorded against net deferred tax assets in accordance with U.S. GAAP. These estimates and judgements occur in the calculation of tax credits, benefits, and deductions, and in the calculation of certain tax assets and liabilities, which arise from differences in the timing of recognition of revenue and expense for tax and financial statement purposes, as well as the interest and penalties related to uncertain tax positions. Significant changes to these estimates may result in an increase or decrease to our tax provision in the current or subsequent period. We assess all material positions taken in any income tax return, including all significant uncertain positions, in all tax years that are still subject to assessment or challenge by relevant taxing authorities. Assessing an uncertain tax position begins with the initial determination of the position’s sustainability and is measured at the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement. As of each balance sheet date, unresolved uncertain tax positions must be reassessed, and we will determine whether the factors underlying the sustainability assertion have changed and the amount of the recognized tax benefit is still appropriate. We account for Global Intangible Low-taxed Income as a period cost. During the years ended December 31, 2020, 2019 and 2018 income (loss) before taxes from U.S. operations were $ 28.9 million, ($ 84.8 ) million and ($ 103.1 ) million, respectively, and income before taxes from foreign operations was $ 0.6 million, $ 0.9 million and $ 0.8 million, respectively. Income tax provision (benefit) related to continuing operations differ from the amounts computed by applying the statutory income tax rate of 21 % to pretax income or loss as follows: Years ended December 31, 2020 2019 2018 Statutory tax rate 21.0 % 21.0 % 21.0 % State tax rate, net of federal benefit ( 8.3 ) 4.9 3.5 Stock-based compensation ( 15.2 ) ( 0.8 ) ( 1.6 ) Tax credits ( 3.6 ) 2.2 2.0 Other ( 0.2 ) 0.2 ( 0.1 ) Change in valuation allowance 6.3 ( 27.5 ) ( 24.8 ) Total - % - % - % Deferred income taxes reflect the net tax effects of loss and credit carry forwards and temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of our deferred tax assets for federal and state income taxes are as follows (in thousands): December 31, Deferred tax assets: 2020 2019 Net operating loss carryforwards $ 233,225 $ 226,911 Research and development credits 49,179 45,853 Accruals and reserves 6,337 8,024 Stock-based compensation 9,717 16,219 ASC842 Operating lease liability 9,870 10,837 Total deferred tax assets 308,328 307,844 Less: Valuation allowance ( 300,505 ) ( 298,658 ) Total deferred tax assets: 7,823 9,186 Fixed assets ( 786 ) ( 1,425 ) ASC842 Operating lease right-of-use assets ( 7,037 ) ( 7,761 ) Total deferred tax liabilities ( 7,823 ) ( 9,186 ) Net deferred tax assets $ — $ — At December 31, 2020, we maintained a full valuation allowance against all of our deferred tax assets which totaled $ 300.5 million, including net operating loss carryforwards and research and development credits of $ 233.2 million and $ 49.2 million, respectively. Due to uncertainties surrounding the realization of deferred tax assets through future taxable income, we have provided a full valuation allowance and, therefore, have not recognized any benefits from net operating losses and other deferred tax assets. A valuation allowance is recorded when it is more likely than not that all or some portion of the deferred income tax assets will not be realized. We regularly assess the need for a valuation allowance against our deferred income tax assets by considering both positive and negative evidence related to whether it is more likely than not that our deferred income tax assets will be realized. In evaluating our ability to recover our deferred income tax assets within the jurisdiction from which they arise, we consider all available positive and negative evidence, including scheduled reversals of deferred income tax liabilities, projected future taxable income, tax-planning strategies, and results of recent operations. Accordingly, we have provided a full valuation allowance against our net deferred tax assets as of December 31, 2020 and 2019, respectively. For the year ended December 31, 2020, our valuation allowance increased to $ 300.5 million, primarily because of an increase in our net operating losses and tax credits offset by a decrease to our stock-based compensation deferred tax asset. For the year ended December 31, 2019, our valuation allowance increased to $ 298.7 million, primarily because of an increase to our net operating losses, tax credits and changes in book to tax timing differences. As of December 31, 2020, we had a net operating loss carryforward for federal income tax purposes of approximately $ 913.9 million, $ 755.9 million of which will begin to expire after 2024 and through 2037 , and $ 158.0 million of which do not expire. We had a total state net operating loss carryforward of approximately $ 634.3 million, which have expiration dates of 2025 and beyond. Utilization of some of the federal and state net operating loss and credit carryforwards are subject to annual limitations due to the “change of ownership” provisions of the Internal Revenue Code of 1986 and similar state provisions. The annual limitations may result in the expiration of net operating losses and credits before utilization. We have federal credits of approximately $ 30.7 million, which will begin to expire in 2024 if not utilized and state research credits of approximately $ 30.1 million which have no expiration date. These tax credits are subject to the same limitations discussed above. As of December 31, 2020, our total unrecognized tax benefit was $ 6.0 million. A reconciliation of the beginning and ending unrecognized tax benefit balance is as follows (in thousands): Balance as of December 31, 2017 $ 18,786 Decrease in balance related to tax positions taken in prior year — Increase in balance related to tax positions taken during current year 1,661 Balance as of December 31, 2018 $ 20,447 Decrease in balance related to tax positions taken in prior year — Increase in balance related to tax positions taken during current year 1,532 Balance as of December 31, 2019 $ 21,979 Decrease in balance related to tax positions taken in prior year ( 17,255 ) Increase in balance related to tax positions taken during current year 1,230 Balance as of December 31, 2020 $ 5,954 Decrease in balance related to tax positions taken in prior years of $ 17.3 million in 2020 relates to the fact that we completed a research and development credit study in 2020 and adjusted our associated uncertain tax position accordingly for the 2004-2019 tax years. Our practice is to recognize interest and/or penalties related to income tax matters in income tax expense. As of both December 31, 2020 and 2019, we had no accrued interest or penalties due to our net operating losses available to offset any tax adjustment. If total unrecognized tax benefits were realized in the future, it would not result in any tax benefit as we currently have a full valuation allowance. We file U.S. federal and various state income tax returns. For U.S. federal and state income tax purposes, the statute of limitations currently remains open for the years ending December 31, 2017 to present and December 31, 2016 to present, respectively. In addition, all of the net operating losses and research and development credit carryforwards that may be utilized in future years may be subject to examination. We are not currently under examination by income tax authorities in any jurisdiction. In response to the COVID-19 pandemic, the Coronavirus Aid, Relief and Economic Securities Act (CARES Act) was signed into law in the US in March 2020. The CARES Act adjusted a number of provisions in the tax code, including the calculation and eligibility of certain deductions and the treatment of net operating losses and tax credits. The enactment of the CARES Act did not result in any material adjustments to our income tax provision for the year ended December 31, 2020, or to our net deferred tax assets as of December 31, 2020. California Assembly Bill 85 (AB 85) was signed into law in June 2020. The legislation suspends the use of California Net Operating Loss deductions for 2020, 2021, and 2022 for certain taxpayers and imposes a limitation on the use of certain California Tax Credits for 2020, 2021, and 2022. The carryover periods for Net Operating Loss deductions disallowed by this provision will be extended. Given the Company’s net operating loss position in the current year, the new legislation will not impact the current year provision. The Company will continue to monitor possible California net operating loss and credit limitations in future periods.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity [Abstract]
Stockholders' Equity	NOTE 8. STOCKHOLDERS’ EQUITY Preferred Stock Our Certificate of Incorporation, as amended and restated in October 2010 in connection with the closing of our initial public offering, authorizes us to issue 1,000,000,000 shares of $ 0.001 par value common stock and 50,000,000 shares of $ 0.001 par value preferred stock. As of December 31, 2020 and 2019, there were no shares of preferred stock issued or outstanding. Common Stock Common stockholders are entitled to dividends when and if declared by our board of directors. There have been no dividends declared to date. The holder of each share of common stock is entitled to one vote. Underwritten Public Equity Offerings In August 2020, we entered into an underwriting agreement, relating to the public offering of 19,430,000 shares of our common stock, $ 0.001 par value per share, at a price to the public of $ 4.47 per share. Under the terms of the underwriting agreement, we also granted the underwriters a 30 -day option to purchase up to an additional 2,914,500 shares of our common stock, which was subsequently exercised in full, and the offering including the sale of shares of common stock subject to the underwriters’ option, closed in August 2020. In total, we sold 22.3 million shares of our common stock. We paid a commission equal to 6 % of the gross proceeds from the sale of shares of our common stock. The total net proceeds to us from the offering after deducting the underwriting discount were approximately $ 93.9 million, excluding approximately $ 0.3 million of offering expenses. In November 2020, we entered into an underwriting agreement, relating to the public offering of 6,096,112 shares of our common stock, $ 0.001 par value per share, at a price to the public of $ 14.25 per share. Under the terms of the underwriting agreement, we also granted the underwriters a 30 -day option to purchase up to an additional 914,416 shares of our common stock, which was subsequently exercised in full, and the offering including the sale of shares of common stock subject to the underwriters’ option, closed in November 2020. In total, we sold 7.0 million shares of our common stock. We paid a commission equal to 6 % of the gross proceeds from the sale of shares of our common stock. The total net proceeds to us from the offering after deducting the underwriting discount were approximately $ 93.9 million, excluding approximately $ 0.3 million of offering expenses. In total, for the year ended December 31, 2020, we issued 29.4 million shares of our common stock through our two underwritten public offerings with an average offering price of $ 6.40 . The total net proceeds to us from the two offerings, after deducting the underwriting commission and offering expenses, were approximately $ 187.2 million. For the year ended December 31, 2018, we issued 30.6 million shares of our common stock through our two underwritten public offerings with an average offering price of $ 3.38 per share. The total net proceeds to us from the two offerings, after deducting the underwriting commissions and offering expenses, were approximately $ 97.5 million. Equity Plans As of December 31, 2019, we had two active equity plans: 1) the 2010 Equity Incentive Plan (the “2010 Plan”) and 2) the 2010 Outside Director Equity Incentive Plan (the “2010 Director Plan”), both of which we adopted upon the effectiveness of our initial public offering in October 2010. Pursuant to the terms of the then-in-process Merger Agreement with Illumina, offerings under our 2010 ESPP were suspended after the completion of the purchase period ended March 1, 2019. After the merger with Illumina was terminated in January 2020, we began offerings under the ESPP again starting with the offering period beginning March 1, 2020. As of June 30, 2020, in total, we had three active equity compensation plans: the 2010 Plan, the 2010 Director Plan and the 2010 ESPP. On July 29, 2020 our 2010 Plan and 2010 Director Plan expired. On August 4, 2020, stockholders approved our new 2020 Equity Incentive Plan (the “2020 plan”) and reserved 11,000,000 shares of the Company’s common stock for issuance pursuant to equity awards granted under the 2020 plan. On December 2, 2020, the Board of Directors (the “Board”) adopted the 2020 Inducement Equity Incentive Plan (the “Inducement Plan”) and reserved 2,500,000 shares of the Company’s common stock for issuance pursuant to equity awards granted under the Inducement Plan. 2020 Equity Incentive Plan Under the 2020 Plan, with the approval of the Compensation Committee of the Board of Directors, we may grant equity-based awards, including non-statutory stock options, restricted stock units (“RSUs”), restricted stock, stock appreciation rights, performance shares and performance units. Stock options granted under the 2020 Plan may be either incentive stock options (“ I SOs”) within the meaning of Internal Revenue code Section 422 or non-qualified stock options (“NSOs”). Stock options under the 2020 Plan may be granted with a term of up to ten years and at prices no less than the fair market value of our common stock on the date of grant. To date, stock options granted to existing employees generally vest over four years on a monthly basis and stock options granted to new employee vest at a rate of 25 % upon the first anniversary of the vesting commencement date and 1/48th per month thereafter, in each case, subject to continued service with us through the applicable vesting dates. Inducement Plan Under the Inducement Plan, with the approval of the Compensation Committee of the Board of Directors, we may grant equity-based awards, including non-statutory stock options, restricted stock units, restricted stock, stock appreciation rights, performance shares and performance units, and its terms are substantially similar to the 2020 Plan, including with respect to treatment of equity awards in the event of a “merger” or “change in control” as defined under the Inducement Plan, but with such other terms and conditions intended to comply with the NASDAQ Inducement Award exception. In accordance with Rule 5635(c)(4) of the NASDAQ Listing Rules, awards under the Inducement Plan may only be made to individuals not previously employees or non-employee directors of the Company (or following such individuals’ bona fide period of non-employment with the Company), as an inducement material to the individuals’ entry into employment with the Company or in connection with a merger or acquisition, to the extent permitted by Rule 5635(c)(3) of the NASDAQ Listing Rules. As of December 31, 2020, we had an aggregate of 10.3 million shares remained available for future issuance under the 2020 Plan and Inducement Plan. Stock Options The following table summarizes stock option activity for all of our stock option plans for the year ended December 31, 2020 (in thousands, except per share amounts): Stock Options Outstanding Weighted Number average of shares Exercise price exercise price Balances, December 31, 2019 22,697 $ 1.16 – 16.00 $ 5.57 Options granted 2,852 2.45 – 20.9 7.20 Options exercised ( 8,078 ) 1.16 – 15.98 5.44 Options canceled ( 2,833 ) 1.16 – 16 7.82 Balances, December 31, 2020 14,638 $ 1.16 – 20.90 $ 5.53 The expired options during the year ended December 31, 2020 totaled 2.4 million with exercise prices ranging from $ 1.16 to $ 16.00 and a weighted average exercise price per share of $ 8.49 . The following table summarizes information with respect to stock options outstanding and exercisable under the plans at December 31, 2020: Options Outstanding Options Exercisable Weighted average Number remaining contractual Weighted average Number Weighted average Exercise price outstanding life (Years) exercise price vested exercise price $ 0.00 – 3.67 4,254,183 5.45 $ 2.53 3,253,267 $ 2.51 $ 3.67 – 7.34 7,560,966 6.18 $ 5.68 5,396,883 $ 5.42 $ 7.34 – 11.01 2,591,433 5.78 $ 9.05 2,191,433 $ 8.95 $ 11.01 – 14.68 131,375 2.99 $ 12.49 96,375 $ 11.82 $ 14.68 – 18.35 500 0.13 $ 15.98 500 $ 15.98 $ 18.35 – 22.02 100,000 9.95 $ 20.90 — $ — $ 22.02 – 25.69 — — $ — — $ — $ 25.69 – 29.36 — — $ — — $ — $ 29.36 – 33.03 — — $ — — $ — $ 33.03 – 36.70 — — $ — — $ — 14,638,457 5.90 $ 5.53 10,938,458 $ 5.32 The aggregate intrinsic value of the outstanding and exercisable options presented in the table above totaled $ 298.8 million and $ 225.6 million, respectively. The aggregate intrinsic value represents the total pretax intrinsic value (i.e., the difference between $ 25.94 , our closing stock price on the last trading day of our fourth quarter of 2020 and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on December 31, 2020. The aggregate intrinsic value changes at each reporting date based on the fair market value of our common stock. The weighted average remaining contractual life for exercisable options is 4.89 years. The vested and expected to vest options as of December 31, 2020 totaled 13,677,000 , with aggregate intrinsic value of $ 279.0 million, weighted average exercise price per share of $ 5.54 and weighted average remaining contractual life of 5.73 years. The total intrinsic value of stock options exercised during the years ended December 31, 2020, 2019 and 2018 was $ 63.1 million, $ 2.6 million and $ 5.3 million, respectively. The weighted-average grant-date fair value of all options granted with exercise prices equal to fair market value was $ 4.14 in 2020, $ 0 in 2019, $ 1.50 in 2018 determined by the Black-Scholes option valuation method. There were no options granted with exercise prices lower than fair market value in 2020, 2019 and 2018. Time-based RSUs Each RSU represents one equivalent share of our common stock to be awarded after satisfying the applicable continued service-based vesting criteria over a specified period. These RSUs vest over four years at a rate of 25 % annually. The fair value for these RSUs is based on the closing price of our common stock on the date of grant. We measure compensation expense for these RSUs at fair value on the date of grant and recognize the expense over the expected vesting period on a straight-line basis. The RSUs do not entitle participants to the rights of holders of common stock, such as voting rights, until the shares are issued. RSUs that are expected to vest are net of estimated future forfeitures. The following table summarizes the time-based RSUs activity for the year ended December 31, 2020 (in thousands, except per share amounts): Weighted average Number grant date of shares fair value RSUs outstanding at December 31, 2019 1,086 $ 6.12 RSUs granted 6,556 5.18 RSUs released ( 1,000 ) 6.33 RSUs forfeited ( 723 ) 4.40 Unvested RSUs outstanding at December 31, 2020 5,919 $ 5.25 For the years ended December 31, 2020, 2019 and 2018, we recognized compensation expense of $ 7.7 million, $ 4.9 and $ 0.2 million, respectively, related to time-based RSUs. Performance-based RSUs Starting 2018 the Compensation Committee of the Board of Directors approved awards of RSUs with performance-based vesting under the 2010 Plan to certain employees. Each RSU represents one equivalent share of our common stock to be awarded upon vesting at the end of the performance periods, if specific performance goals set by the Compensation Committee of the Board of Directors are achieved. No RSUs with performance-based vesting will vest if the performance goals are not met. The fair value of these RSUs is based on the closing price of our common stock on the date of grant. We make a quarterly probability assessment as to whether the performance goals will be achieved. Changes in our assessment of the probability of vesting results in adjustments to stock-based compensation, which may include either a cumulative catch-up of expense or a reduction of expense depending on whether the likelihood of vesting has increased or decreased, that is recognized in the period such determination is made. The RSUs do not entitle participants to the rights of holders of common stock, such as voting rights, until the shares are issued. RSUs that are expected to vest are net of estimated future forfeitures. The following table summarizes the performance-based RSUs activity for the year ended December 31, 2020 (in thousands, except per share amounts): Weighted average Number grant date of shares fair value PSUs outstanding at December 31, 2019 138 $ 2.63 PSUs granted — — PSUs released — — PSUs forfeited ( 44 ) 2.63 Unvested PSUs outstanding at December 31, 2020 94 $ 2.63 2010 Employee Stock Purchase Plan We adopted the ESPP in October 2010. Our ESPP permits eligible employees to purchase common stock at a discount through payroll deductions during defined offering periods. Each offering period will generally consist of four purchase periods, each purchase period being approximately six months . The price at which the stock is purchased is equal to the lower of 85 % of the fair market value of the common stock at the beginning of an offering period or at the end of a purchase period. Each offering period will generally end and the shares will be purchased twice yearly on March 1 and September 1. If the stock price at the end of the purchase period is lower than the stock price at the beginning of the offering period, that offering period will then be terminated and new offering period comes to place. The ESPP provides for an annual increase to the shares available for issuance at the beginning of each calendar year equal to 2 % of the common shares then outstanding. Pursuant to the terms of the then-in-process Merger Agreement with Illumina, offerings under our 2010 ESPP were suspended after the completion of the purchase period ended March 1, 2019. After the merger with Illumina was terminated in January 2020, we began offerings under the ESPP again starting with the offering period beginning March 1, 2020. For the years ended December 31, 2020, 2019 and 2018, 834,677 shares, 1,306,329 shares and 1,674,960 shares of common stock were purchased under the ESPP, respectively. As of December 31, 2020, 5,878,770 shares of our common stock remain available for issuance under our ESPP. Stock-based Compensation Total stock-based compensation expense consists of the following (in thousands): Years Ended December 31, 2020 2019 2018 Cost of revenue $ 2,236 $ 1,857 $ 3,124 Research and development 7,061 7,699 10,076 Sales, general and administrative 8,236 6,845 9,953 Total stock-based compensation expense $ 17,533 $ 16,401 $ 23,153 As of both December 31, 2020 and 2019, $ 0.3 million of stock-based compensation cost was capitalized in inventory on our consolidated balance sheets, respectively. The tax benefit of stock-based compensation expense was immaterial for the years ended December 31, 2020, 2019 and 2018. Stock Options We estimated the fair value of employee stock options using the Black-Scholes option pricing model. The fair value of employee stock options is being amortized on a straight-line basis over the requisite service period of the awards. For the year ended December 31, 2019, we did no t grant any stock option. For the years ended December 31, 2020, 2019 and 2018, the fair value of employee stock options was estimated using the following weighted average assumptions: Years Ended December 31, 2020 2019 2018 Expected term (years) 5.0 years — 5.2 years Expected volatility 70.7 % — 66.8 % Risk-free interest rate 0.3 % — 2.6 % Dividend yield — — — We recorded stock-based compensation expense for stock options of $ 6.2 million, $ 11.0 million and $ 15.5 million for the years ended December 31, 2020, 2019 and 2018, respectively. As of December 31, 2020, $ 9.9 million of total unrecognized compensation expense related to stock options was expected to be recognized over a weighted-average period of 3 years. Cash received from option exercises for the years ended December 31, 2020, 2019 and 2018 was $ 43.9 million, $ 5.9 million and $ 6.3 million, respectively. ESPP We estimated the fair value of shares to be issued under the ESPP using the Black-Scholes option pricing model. For the years ended December 31, 2020, 2019 and 2018, weighted average fair value at grant date for shares to be issued under the ESPP was $ 1.68 , $ 0 and $ 1.47 , respectively. For the years ended December 31, 2020, 2019 and 2018, the fair value of shares to be issued under the ESPP was estimated using the following assumptions: Years Ended December 31, 2020 2019 2018 Expected term (years) 0.5 - 2.0 — 0.5 - 2.0 Expected volatility 57 % - 71 % — 65 % - 67 % Risk-free interest rate 0.1 %- 1.0 % — 1.3 %- 2.7 % Dividend yield — — — We recorded stock-based compensation expense for ESPP of $ 3.4 million, $ 0.5 million and $ 6.8 million for the years ended December 31, 2020, 2019 and 2018, respectively. Cash received through the ESPP for the years ended December 31, 2020, 2019 and 2018 was $ 2.4 million, $ 2.7 million and $ 3.4 million, respectively.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	12 Months Ended
	Dec. 31, 2020
Net Income (Loss) Per Share [Abstract]
Net Income (Loss) Per Share	NOTE 9. NET INCOME (LOSS) PER SHARE Basic net income (loss) per share and diluted net income (loss) per share are presented for the three years presented. Basic net income (loss) per share is computed by dividing net income (loss) by the weighted average number of shares of common stock outstanding during the period. Diluted net income (loss) per share is computed using the weighted average number of shares of common stock outstanding and potential shares assuming the dilutive effect of outstanding stock options, restricted stock units and common stock issuable pursuant to our ESPP, using the treasury stock method. The following table presents the calculation of weighted average shares of common stock used in the computations of basic and diluted net income (loss) per share amounts presented in the accompanying consolidated statements of operations and comprehensive income (loss) (in thousands, except per share amounts): Years Ended December 31, 2020 2019 2018 Numerator: Net income (Loss) $ 29,403 $ ( 84,134 ) $ ( 102,562 ) Denominator: Basic Weighted average shares used in computing basic net income (loss) per share 165,187 152,527 135,094 Basic net income (loss) per share $ 0.18 $ ( 0.55 ) $ ( 0.76 ) Diluted Weighted average shares used in computing basic net income (loss) per share 165,187 152,527 135,094 Add: weighted average stock options 6,092 — — Add: weighted average restricted stock units 2,324 — — Add: weighted average common stock issuable pursuant to our ESPP 1,367 — — Weighted average shares used in computing diluted net income (loss) per share 174,970 152,527 135,094 Diluted net income (loss) per share $ 0.17 $ ( 0.55 ) $ ( 0.76 ) The following options outstanding, time-based RSUs, performance-based RSUs and ESPP shares to purchase common stock were excluded from the computation of diluted net loss per share for the periods presented because the effect of including such shares would have been antidilutive: Years Ended December 31, (in thousands) 2020 2019 2018 Options to purchase common stock 4,908 22,697 25,176 RSUs with time-based vesting 100 1,086 371 RSUs with performance-based vesting 94 138 586 Common stock issuable pursuant to our ESPP 2,890 — —

Segment And Geographic Informat

Segment And Geographic Information	12 Months Ended
	Dec. 31, 2020
Segment And Geographic Information [Abstract]
Segment And Geographic Information	NOTE 10. SEGMENT AND GEOGRAPHIC INFORMATION We are organized as, and operate in, one reportable segment: the development, manufacturing and marketing of an integrated platform for genetic analysis. Our chief operating decision-maker is our Chief Executive Officer. The Chief Executive Officer reviews financial information presented on a consolidated basis for purposes of evaluating financial performance and allocating resources, accompanied by information about revenue by geographic regions. Our assets are primarily located in the United States of America and not allocated to any specific region and we do not measure the performance of geographic regions based upon asset-based metrics. Therefore, geographic information is presented only for revenue. Revenue by geographic region is based on the ship to address on the customer order. A summary of our revenue by geographic location for the years ended December 31, 2020, 2019 and 2018 is as follows: Years Ended December 31, (in thousands) 2020 2019 2018 North America $ 37,277 $ 44,681 $ 35,598 Europe (including the Middle East and Africa) 19,065 19,600 13,958 Asia Pacific 22,551 26,610 29,070 Total $ 78,893 $ 90,891 $ 78,626 A summary of our revenue by category for the years ended December 31, 2020, 2019 and 2018 is as follows: Year Ended December 31, (in thousands) 2020 2019 2018 Instrument revenue $ 34,282 $ 45,126 $ 28,492 Consumable revenue 31,142 32,616 37,863 Product revenue 65,424 77,742 66,355 Service and other revenue 13,469 13,149 12,271 Total revenue $ 78,893 $ 90,891 $ 78,626

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	NOTE 11. SUBSEQUENT EVENTS Invitae Collaboration On January 12, 2021 we entered into a multi-year Development and Commercialization Agreement (the “Development Agreement”) with Invitae Corporation (“Invitae”), to begin development of a production-scale high-throughput sequencing platform, leveraging the power of PacBio’s highly accurate HiFi sequencing to expand Invitae’s whole genome testing capabilities. In connection with the development of the Program Products, Invitae will provide to the Company amounts equal to certain development costs incurred by the Company. Under the Development Agreement, we will be primarily responsible for conducting a development program to develop the Program Products pursuant to a schedule and budget. We will make decisions regarding the development program jointly with Invitae. The development program is expected to last approximately sixty months , but may be shorter or longer. The Program Products will be sold to Invitae as they are developed and we have the right to broadly commercialize Program Products with other customers. As a benefit of its contribution, Invitae will be entitled to preferred pricing on the Program Products if and when they are available for commercial sale. Each Program Product will have a preferential pricing period. During the initial period of preferred pricing for each Program Product, Invitae may purchase the Program Product at a substantially reduced margin until it has recouped a mutually agreed multiple of its contribution. Subsequently, for up to three years after the initial period of preferred pricing, Invitae has the right to purchase the Program Product at a higher price within a specified price range. We and Invitae may terminate the Development Agreement if the other party remains in material breach of the Development Agreement following a cure period to remedy the material breach. In addition, the Development Agreement includes certain other circumstances for termination by each party, including circumstances where Invitae may terminate for delays, IP concerns, change in control, or without cause. In certain termination circumstances, (i) we will be obligated to refund all or a portion of the development costs advanced by Invitae and/or (ii) we will owe Invitae a share of the revenue generated from the sale of the Program Products if and when they are commercialized until such time as Invitae has recouped the amounts reimbursed to us, and in certain circumstances, a mutually agreed return. We expect to incur significant development costs over the duration of the collaboration agreement in 2021. We are still evaluating the accounting impact of the agreement, including whether the funding received by the Company from Invitae represents discounts toward future supplies, funding of development efforts, or a combination of both. There can be no assurances that the development program will be successful or that the Program Platform will become ready for commercial sale. Issuance and Sale of 1.50% Convertible Senior Notes due February 15, 2028 On February 9, 2021, we entered into an investment agreement (the “Investment Agreement”) with SB Northstar LP (the “Purchaser”), a subsidiary of SoftBank Group Corp., relating to the issuance and sale to the Purchaser of $ 900 million in aggregate principal amount of the Company’s 1.50 % Convertible Senior Notes due February 15, 2028 (the “Notes”). The Notes were issued on February 16, 2021. Issuance of Convertible Notes The Notes are expected to be governed by an indenture (the “Indenture”) between the Company and U.S. Bank National Association, as trustee (the “Trustee”). The Notes will bear interest at a rate of 1.50 % per annum. Interest on the Notes is payable semi-annually in arrears on February 15 and August 15 commencing on August 15, 2021. The Notes will mature on February 15, 2028 , subject to earlier conversion, redemption or repurchase. The Notes are convertible at the option of the holder at any time until the second scheduled trading day prior to the maturity date, including in connection with a redemption by the Company. The Notes will be convertible into shares of the Company’s common stock based on an initial conversion rate of 22.9885 shares of common stock per $ 1,000 principal amount of the Notes (which is equal to an initial conversion price of $ 43.50 per share), in each case subject to customary anti-dilution and other adjustments as a result of certain extraordinary transactions. On or after February 20, 2026, the Notes will be redeemable by the Company in the event that the closing sale price of the Company’s common stock has been at least 150 % of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period (including the last trading day of such period) ending on, and including, the trading day immediately preceding the date on which the Company provides the redemption notice at a redemption price of 100 % of the principal amount of such Notes, plus accrued and unpaid interest to, but excluding, the redemption date. With certain exceptions, upon a change of control of the Company or the failure of the Company’s common stock to be listed on certain stock exchanges (a “Fundamental Change”), the holders of the Notes may require that the Company repurchase all or part of the principal amount of the Notes at a purchase price of par plus unpaid interest to, but excluding, the maturity date. The Indenture will include customary “events of default,” which may result in the acceleration of the maturity of the Notes under the Indenture. The Indenture will also include customary covenants for convertible notes of this type. Standstill Obligations Pursuant to the Investment Agreement, the Purchaser has agreed, subject to certain exceptions, that from the Closing and until the earliest of (i) the three year anniversary of the Closing, (ii) the effective date of a change of control of the Company and (iii) 90 days after the date on which none of the members of the Purchaser or its affiliates beneficially own any Notes or shares of the Company’s common stock received upon conversion of the Notes (the “Standstill Period”), the Purchaser will not, among other things: (i) make, or in any way participate in any “proxy contest” or other solicitation of proxies, (ii) form, join, influence or in any way participate in a voting trust or similar arrangement, (iii) acquire any securities of the Company if, immediately after such acquisition, the Purchaser or its affiliates would collectively own in the aggregate more than 19.99 % of the then outstanding voting securities of the Company, (iv) sell, transfer or otherwise dispose of any voting securities of the Company to any person who is (or will become upon consummation of such sale, transfer or other disposition) a beneficial owner of 10 % or more of the outstanding voting securities of the Company, (v) propose or seek to effect any tender or exchange offer, merger or other business combination involving the Company, or make any public statement with respect to such transaction, (vi) call or seek to call any meeting of stockholders or other referendum or consent solicitation, or (vii) take action to control or influence the Board of Directors or management of the Company. Transfer Restrictions; Registration Rights The Investment Agreement restricts the Purchaser’s ability to transfer the Notes and the Company’s common stock issuable or issued upon conversion of the Notes and enter into any hedging or other agreement that transfers the economic consequences of ownership of the Notes or the Company’s common stock issuable or issued upon conversion of the Notes, subject to certain exceptions specified in the Investment Agreement and summarized below. Except as described below, prior to the earlier of (i) the one year anniversary of the Closing or (ii) immediately prior to the consummation of a change of control of the Company, the Purchaser will be restricted from transferring or entering into any hedging or other agreement that transfers the economic consequences of ownership of the Notes or the Company’s common stock issuable or issued upon conversion of the Notes. Exceptions include: (A) transfers to affiliates, (B) transfers to the Company or any of its subsidiaries, (C) transfers to a third party where the net proceeds of such sale are solely used to satisfy a margin call or repay a permitted loan or (D) transfers in connection with certain merger and acquisition events. Subject to certain limitations, the Investment Agreement provides the Purchaser and any lender of a permitted loan to the Purchaser or its affiliates with certain registration rights for the shares of the Company’s common stock issuable or issued upon conversion of the Notes.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2020
Summary of Significant Accounting Policies [Abstract]
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation 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. Translation adjustments resulting from translating foreign subsidiaries’ results of operations and assets and liabilities into U.S. dollars are immaterial for all periods presented.
COVID-19	COVID-19 We are subject to risks and uncertainties as a result of the novel coronavirus pandemic (COVID-19). The extent of the impact of the COVID-19 pandemic on our business is highly uncertain as responses to the pandemic can change quickly and information is rapidly evolving. We considered the impact of COVID-19 on the assumptions and estimates used to determine the results reported and asset valuations as of December 31, 2020.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires us to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes to the financial statements. Our estimates include, but are not limited to, the valuation of inventory, the determination of stand-alone selling prices for revenue recognition, the valuation of a financing derivative and long-term notes, the probability of repaying the Continuation Advances and Reverse Termination Fee to Illumina, the valuation and recognition of share-based compensation, the expected renewal period for service contracts to derive the amortization period for capitalized commissions, the useful lives assigned to long-lived assets, the recognition and measurement of current and deferred income tax assets, along with the assessment of recoverability and the determination of the internal borrowing rate used in calculating the operating lease right-of-use assets and operating lease liabilities. Actual results could differ materially from these estimates.
Reclassifications	Reclassifications Certain prior year amounts in the consolidated financial statements have been reclassified to conform to the current year presentation with no effect on previously reported net loss, comprehensive loss, cash flows or stockholders’ equity.
Accounting Changes	Accounting Changes In June 2016, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2016-13 Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“Topic 326”), which replaces existing incurred loss impairment guidance and establishes a single allowance framework for financial assets carried at amortized cost. We adopted Topic 326 on January 1, 2020, using a modified retrospective transition method, which requires a cumulative-effect adjustment to the opening balance of retained earnings/accumulated deficit to be recognized on the date of adoption with prior periods not restated. The adoption of Topic 326 did not have a material impact on our financial statements and our bad debt expense was immaterial as of December 31, 2020.
Cash, Cash Equivalents and Investments	Cash, Cash Equivalents and Investments We consider all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. We have designated all investments as available-for-sale and therefore, such investments are reported at fair value, with unrealized gains and losses recognized in accumulated other comprehensive income (loss) (“OCI”) in stockholders’ equity. The cost of marketable securities is adjusted for the amortization of premiums and discounts to expected maturity. Premium and discount amortization is included in other income, net. Realized gains and losses, as well as interest income, on available-for-sale securities are also included in other income, net. The cost of securities sold is based on the specific identification method. We include all of our available-for-sale securities in current assets. 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 of its investments and their maturities with the objectives of maintaining safety and liquidity, while maximizing yield.
Concentration and Credit Risks	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. We perform periodic evaluations of the relative credit standing of these financial institutions. In addition, we perform periodic evaluations of the relative credit quality of its investments. All of our investments are subject to a periodic impairment review. We recognize an impairment charge when a decline in the fair value of our investments below the cost basis is judged to be other-than-temporary. Factors considered in determining whether a loss is temporary include the length of time and the extent to which an investment’s fair value has been less than its cost basis, the financial condition and near-term prospects of the investee, the extent of the loss related to credit of the issuer, the expected cash flows from the security, our intent to sell the security and whether or not we will be required to sell the security before the recovery of its amortized cost. For the years ended December 31, 2020, 2019 and 2018, we did no t have any impairment charges on our investments as it is more likely than not that we will recover their amortized cost basis upon sale or maturity. 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, 2020, 2019 and 2018, one customer, Gene Company Limited, accounted for approximately 14 %, 17 % and 26 % our total revenue, respectively. As of December 31, 2020 and 2019, 43 % and 55 % of our accounts receivable were from domestic customers, respectively. 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. As of December 31, 2019, customer, Gene Company Limited, represented approximately 11 % of our net accounts receivable. 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. However, 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	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 enter into inventory purchases and commitments so that we can 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, in order 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, Net Property and equipment are stated at cost, net of accumulated depreciation and any impairment charges. Depreciation is computed using the straight-line method over the estimated useful life of the asset, generally two years to three years for computer equipment, three years to five years for software, three years to seven years for furniture and fixtures and three years to five years for lab equipment. 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.
Impairment of Long-Lived Assets	Impairment of 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 no t recorded any impairment charges.
Operating Leases	Operating Leases We lease administrative, manufacturing and laboratory facilities under operating leases. Lease agreements may include rent holidays, rent escalation clauses and tenant improvement allowances. We recognize scheduled rent increases on a straight-line basis over the lease term beginning with the date we take possession of the leased space. Leasehold improvements are capitalized at cost and depreciated over the shorter of their expected useful life or the life of the lease. On January 1, 2019, we adopted ASC 842, which requires the recognition of the right-of-use assets and related operating and finance lease liabilities on the consolidated balance sheet. Operating lease assets and liabilities are reflected within “Operating lease right-of-use assets, net”, “Operating lease liabilities, current” and “Operating lease liabilities, non-current” on the consolidated balance sheets. These assets and liabilities are recognized at the commencement date based on the present value of remaining minimum lease payments over the lease term using our estimated secured incremental borrowing rates at the effective date of January 1, 2019. Leases with terms of 12 months or less are expensed on a straight-line basis over the term and are not recorded in the consolidated balance sheets.
Short-term Restriced Cash	Short-term Restricted Cash At December 31, 2020 the short-term restricted cash balance of $ 0.8 million was comprised of $ 0.5 million of a customer deposit and $ 0.3 million of the security deposit for the credit cards for employees.
Long-term Restricted Cash	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, on May 1, 2019 the $ 4.5 million in restricted cash was reduced to $ 4.0 million and on May 1, 2020 the $ 4.0 million in restricted cash was reduced to $ 3.5 million.
Revenue Recognition	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 primarily consists 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. Taxes we collect concurrent with revenue-producing activities are excluded from revenue. 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 (“SSP”). The SSP is determined based on observable prices at which we separately sell the products and services. If a SSP 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. Contract liabilities and contract assets - Contract liabilities consist of deferred revenue. We record deferred revenues when cash payments are received or due in advance of our performance for product maintenance agreements. Deferred revenue is recognized over the related performance period, generally one year to three 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. Other practical expedients and exemptions - Customers generally are invoiced upon acceptance of the system, which is also the start of the one year service period. As such, there is typically not more than a one year difference between the receipt of cash and the provision of services. Therefore, we apply the practical expedient and do not account for any potential significant financing benefit. However, it is noted that some customers will pre-order extended service periods at the time of the initial system sale. These customers may choose to make quarterly or annual payments or prepay multiple years of service upfront but there is no pricing difference between these different payment options. As such, no significant financing component is believed to exist with any of our existing arrangements.
Cost of Revenue	Cost of Revenue Cost 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 Research and development expense consists primarily of expenses for personnel engaged in the development of our SMRT Sequencing technology, the design and development of our future products and current product enhancements. These expenses also include prototype-related expenditures, development equipment and supplies, 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 Losses	Credit Losses We 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 December 31, 2020. 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 not required as of December 31, 2020. 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.
Income Taxes	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. 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 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 would accrue the estimated amount of tax related to such uncertain positions.
Stock-Based Compensation	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 on the date of grant using an option-pricing model. See Note 8 for further information regarding stock-based compensation.
Other Comprehensive Income (Loss)	Other Comprehensive Income (loss) Other comprehensive income (loss) is comprised of unrealized gains (losses) on our investment securities.
Shipping and Handling	Shipping and Handling Costs related to shipping and handling are included in cost of revenues for all periods presented.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Recently Issued Accounting Standards In August 2020, the FASB issued 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 are currently evaluating the impact of the provisions of this guidance on our consolidated financial statements. 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 will be effective for our annual reporting periods beginning after December 15, 2020, including interim reporting periods within those fiscal years. We have evaluated the effect that this guidance will have on our Consolidated Financial Statements and determined it will not have a material impact. Recently Adopted Accounting Standards In June 2016, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2016-13 Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“Topic 326”), which replaces existing incurred loss impairment guidance and establishes a single allowance framework for financial assets carried at amortized cost. We adopted Topic 326 on January 1, 2020, using a modified retrospective transition method, which requires a cumulative-effect adjustment to the opening balance of retained earnings/accumulated deficit to be recognized on the date of adoption with prior periods not restated. The adoption of Topic 326 did not have a material impact on our financial statements and our bad debt expense was immaterial as of December 31, 2020.

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2020
Financial Instruments [Abstract]
Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis	December 31, 2020 December 31, 2019 (in thousands) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash and cash equivalents: Cash and money market funds $ 43,040 $ — $ — $ 43,040 $ 18,644 $ — $ — $ 18,644 Commercial paper — 32,537 — 32,537 — 10,983 — 10,983 U.S. government & agency securities — 170 — 170 — — — — U.S. Treasury security — 5,864 — 5,864 — — — — Total cash and cash equivalents 43,040 38,571 — 81,611 18,644 10,983 — 29,627 Investments: Commercial paper — 112,644 — 112,644 — 16,971 — 16,971 Corporate debt securities — 17,456 — 17,456 — 2,501 — 2,501 U.S. government & agency securities — 107,103 — 107,103 — — — — Total investments — 237,203 — 237,203 — 19,472 — 19,472 Short-term restricted cash: Cash 836 — — 836 300 — — 300 Long-term restricted cash: Cash 3,500 — — 3,500 4,000 — — 4,000 Total assets measured at fair value $ 47,376 $ 275,774 $ — $ 323,150 $ 22,944 $ 30,455 $ — $ 53,399 Liabilities Financing Derivative $ — $ — $ — $ — $ — $ — $ — $ — Continuation Advances — — — — — — — — Total liabilities measured at fair value $ — $ — $ — $ — $ — $ — $ — $ —
Summary of Cash, Cash Equivalents and Investments	As of December 31, 2020 Gross Gross Amortized unrealized unrealized Fair Cost gains losses Value Cash and cash equivalents: Cash and money market funds $ 43,040 $ — $ — $ 43,040 Commercial paper 32,538 — ( 1 ) 32,537 U.S. government & agency securities 170 — — 170 U.S. Treasury security 5,864 — — 5,864 Total cash and cash equivalents 81,612 — ( 1 ) 81,611 Investments: Commercial paper 112,648 4 ( 8 ) 112,644 Corporate debt securities 17,360 96 — 17,456 U.S. government & agency securities 107,109 6 ( 12 ) 107,103 Total investments 237,117 106 ( 20 ) 237,203 Total cash, cash equivalents and investments $ 318,729 $ 106 $ ( 21 ) $ 318,814 Short-term restricted cash: Cash $ 836 $ — $ — $ 836 Long-term restricted cash: Cash $ 3,500 $ — $ — $ 3,500 As of December 31, 2019 Gross Gross Amortized unrealized unrealized Fair Cost gains losses Value Cash and cash equivalents: Cash and money market funds $ 18,644 $ — $ — $ 18,644 Commercial paper 10,983 — — 10,983 Total cash and cash equivalents 29,627 — — 29,627 Investments: Commercial paper 16,971 1 ( 1 ) 16,971 Corporate debt securities 2,496 5 — 2,501 Total investments 19,467 6 ( 1 ) 19,472 Total cash, cash equivalents and investments $ 49,094 $ 6 $ ( 1 ) $ 49,099 Short-term restricted cash: Cash $ 300 $ — $ — $ 300 Long-term restricted cash: Cash $ 4,000 $ — $ — $ 4,000
Summary of Contractual Maturities of Cash Equivalents and Available-for-Sale Investments	Fair Value Due in one year or less $ 255,207 Due after one year through 5 years 20,567 Total investments $ 275,774

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2020
Balance Sheet Components [Abstract]
Components of Inventory	December 31, December 31, (in thousands) 2020 2019 Purchased materials $ 3,531 $ 3,966 Work in process 6,651 4,594 Finished goods 4,048 4,752 Inventory $ 14,230 $ 13,312
Components of Property and Equipment, Net	December 31, (in thousands) 2020 2019 Laboratory equipment and machinery $ 24,948 $ 25,173 Leasehold improvements 29,931 29,902 Computer equipment 12,400 11,851 Software 4,940 4,747 Furniture and fixtures 2,434 2,422 Construction in progress 137 193 74,790 74,288 Less: Accumulated depreciation ( 49,891 ) ( 44,218 ) Property and equipment, net $ 24,899 $ 30,070
Schedule of Accrued Expenses	December 31, (in thousands) 2020 2019 Salaries and benefits $ 15,261 $ 9,748 Accrued product development costs 415 67 Accrued Tenant Improvements for Menlo Park building — 998 Inventory accrual 218 229 Accrued professional services and legal fees 726 943 Other 730 1,257 Accrued expenses $ 17,350 $ 13,242
Schedule of Other Liabilities, Current	December 31, (in thousands) 2020 2019 Accrued ESPP $ 2,037 $ — Other 2,482 225 Other liabilities, current $ 4,519 $ 225

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies [Abstract]
Schedule of Amount, Timing and Uncertainty of Cash Flows from Operating Leases	Maturity of Lease Liabilities Amount Years ending December 31, (in thousands) 2021 $ 7,330 2022 7,502 2023 7,704 2024 7,920 2025 8,136 Thereafter 15,462 Total undiscounted operating lease payments 54,054 Less: imputed interest ( 12,055 ) Present value of operating lease liabilities 41,999 Balance Sheet Classification Operating lease liabilities, current 4,332 Operating lease liabilities, non-current 37,667 Total operating lease liabilities 41,999

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Taxes [Abstract]
Reconciliation of Federal Income Tax Rate	Years ended December 31, 2020 2019 2018 Statutory tax rate 21.0 % 21.0 % 21.0 % State tax rate, net of federal benefit ( 8.3 ) 4.9 3.5 Stock-based compensation ( 15.2 ) ( 0.8 ) ( 1.6 ) Tax credits ( 3.6 ) 2.2 2.0 Other ( 0.2 ) 0.2 ( 0.1 ) Change in valuation allowance 6.3 ( 27.5 ) ( 24.8 ) Total - % - % - %
Reconciliation of Deferred Tax Assets and Liabilities	December 31, Deferred tax assets: 2020 2019 Net operating loss carryforwards $ 233,225 $ 226,911 Research and development credits 49,179 45,853 Accruals and reserves 6,337 8,024 Stock-based compensation 9,717 16,219 ASC842 Operating lease liability 9,870 10,837 Total deferred tax assets 308,328 307,844 Less: Valuation allowance ( 300,505 ) ( 298,658 ) Total deferred tax assets: 7,823 9,186 Fixed assets ( 786 ) ( 1,425 ) ASC842 Operating lease right-of-use assets ( 7,037 ) ( 7,761 ) Total deferred tax liabilities ( 7,823 ) ( 9,186 ) Net deferred tax assets $ — $ —
Reconciliation of Unrecognized Tax Benefit Accounts	Balance as of December 31, 2017 $ 18,786 Decrease in balance related to tax positions taken in prior year — Increase in balance related to tax positions taken during current year 1,661 Balance as of December 31, 2018 $ 20,447 Decrease in balance related to tax positions taken in prior year — Increase in balance related to tax positions taken during current year 1,532 Balance as of December 31, 2019 $ 21,979 Decrease in balance related to tax positions taken in prior year ( 17,255 ) Increase in balance related to tax positions taken during current year 1,230 Balance as of December 31, 2020 $ 5,954

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity [Abstract]
Summary of Stock Option Activity	Stock Options Outstanding Weighted Number average of shares Exercise price exercise price Balances, December 31, 2019 22,697 $ 1.16 – 16.00 $ 5.57 Options granted 2,852 2.45 – 20.9 7.20 Options exercised ( 8,078 ) 1.16 – 15.98 5.44 Options canceled ( 2,833 ) 1.16 – 16 7.82 Balances, December 31, 2020 14,638 $ 1.16 – 20.90 $ 5.53
Reconciliation of Outstanding and Exercisable Stock Options	Options Outstanding Options Exercisable Weighted average Number remaining contractual Weighted average Number Weighted average Exercise price outstanding life (Years) exercise price vested exercise price $ 0.00 – 3.67 4,254,183 5.45 $ 2.53 3,253,267 $ 2.51 $ 3.67 – 7.34 7,560,966 6.18 $ 5.68 5,396,883 $ 5.42 $ 7.34 – 11.01 2,591,433 5.78 $ 9.05 2,191,433 $ 8.95 $ 11.01 – 14.68 131,375 2.99 $ 12.49 96,375 $ 11.82 $ 14.68 – 18.35 500 0.13 $ 15.98 500 $ 15.98 $ 18.35 – 22.02 100,000 9.95 $ 20.90 — $ — $ 22.02 – 25.69 — — $ — — $ — $ 25.69 – 29.36 — — $ — — $ — $ 29.36 – 33.03 — — $ — — $ — $ 33.03 – 36.70 — — $ — — $ — 14,638,457 5.90 $ 5.53 10,938,458 $ 5.32
Summary of Time-Based RSUs Activity	Weighted average Number grant date of shares fair value RSUs outstanding at December 31, 2019 1,086 $ 6.12 RSUs granted 6,556 5.18 RSUs released ( 1,000 ) 6.33 RSUs forfeited ( 723 ) 4.40 Unvested RSUs outstanding at December 31, 2020 5,919 $ 5.25
Summary of Performance-Based RSUs Activity	Weighted average Number grant date of shares fair value PSUs outstanding at December 31, 2019 138 $ 2.63 PSUs granted — — PSUs released — — PSUs forfeited ( 44 ) 2.63 Unvested PSUs outstanding at December 31, 2020 94 $ 2.63
Schedule of Stock-Based Compensation Expense	Years Ended December 31, 2020 2019 2018 Cost of revenue $ 2,236 $ 1,857 $ 3,124 Research and development 7,061 7,699 10,076 Sales, general and administrative 8,236 6,845 9,953 Total stock-based compensation expense $ 17,533 $ 16,401 $ 23,153
Schedule of Fair Value of Employee Stock Options	Years Ended December 31, 2020 2019 2018 Expected term (years) 5.0 years — 5.2 years Expected volatility 70.7 % — 66.8 % Risk-free interest rate 0.3 % — 2.6 % Dividend yield — — —
Schedule of Fair Value of Employee Stock Purchase Plan	Years Ended December 31, 2020 2019 2018 Expected term (years) 0.5 - 2.0 — 0.5 - 2.0 Expected volatility 57 % - 71 % — 65 % - 67 % Risk-free interest rate 0.1 %- 1.0 % — 1.3 %- 2.7 % Dividend yield — — —

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Net Income (Loss) Per Share [Abstract]
Computation of Basic and Diluted Net Income (Loss) per Share	Years Ended December 31, 2020 2019 2018 Numerator: Net income (Loss) $ 29,403 $ ( 84,134 ) $ ( 102,562 ) Denominator: Basic Weighted average shares used in computing basic net income (loss) per share 165,187 152,527 135,094 Basic net income (loss) per share $ 0.18 $ ( 0.55 ) $ ( 0.76 ) Diluted Weighted average shares used in computing basic net income (loss) per share 165,187 152,527 135,094 Add: weighted average stock options 6,092 — — Add: weighted average restricted stock units 2,324 — — Add: weighted average common stock issuable pursuant to our ESPP 1,367 — — Weighted average shares used in computing diluted net income (loss) per share 174,970 152,527 135,094 Diluted net income (loss) per share $ 0.17 $ ( 0.55 ) $ ( 0.76 )
Antidilutive Shares Excluded from Computation of Diluted Net Loss per Share	Years Ended December 31, (in thousands) 2020 2019 2018 Options to purchase common stock 4,908 22,697 25,176 RSUs with time-based vesting 100 1,086 371 RSUs with performance-based vesting 94 138 586 Common stock issuable pursuant to our ESPP 2,890 — —

Segment And Geographic Inform_2

Segment And Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2020
Segment And Geographic Information [Abstract]
Schedule of Revenue by Geographic Location	Years Ended December 31, (in thousands) 2020 2019 2018 North America $ 37,277 $ 44,681 $ 35,598 Europe (including the Middle East and Africa) 19,065 19,600 13,958 Asia Pacific 22,551 26,610 29,070 Total $ 78,893 $ 90,891 $ 78,626
Summary of Revenue by Category	Year Ended December 31, (in thousands) 2020 2019 2018 Instrument revenue $ 34,282 $ 45,126 $ 28,492 Consumable revenue 31,142 32,616 37,863 Product revenue 65,424 77,742 66,355 Service and other revenue 13,469 13,149 12,271 Total revenue $ 78,893 $ 90,891 $ 78,626

Termination of Merger with Il_2

Termination of Merger with Illumina (Narrative) (Details) - USD ($)	Feb. 09, 2021	Feb. 26, 2021	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Merger Termination [Line Items]
Continuation Advances from Illumina			$ 34,000,000	$ 18,000,000	$ 34,000,000	$ 18,000,000
Gain from Continuation Advances from Illumina					34,000,000	$ 18,000,000
Possible Continuation Advances payable					$ 52,000,000
Period in which company must repay continuation advances if change-of-control transaction is entered into with third party					2 years
Equity or debt financing that must be raised in a single transaction					$ 100,000,000
Termination fee received					98,000,000
Advisor fees paid					$ 6,000,000
Subsequent Event [Member]
Merger Termination [Line Items]
Continuation Advances paid to Illumina		$ 52,000,000
Notes [Member] | Subsequent Event [Member]
Merger Termination [Line Items]
Principal amount of notes	$ 900,000,000
Debt instrument, stated interest rate	1.50%
Maturity date	Feb. 15, 2028

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2020USD ($)customer	Dec. 31, 2019USD ($)customer	Dec. 31, 2018USD ($)customer	May 01, 2020USD ($)	Apr. 30, 2020USD ($)	May 01, 2019USD ($)	Apr. 30, 2019USD ($)	Oct. 31, 2015USD ($)
Summary Of Significant Accounting Policies [Line Items]
Investments impariment charges	$ 0	$ 0	$ 0
Long-lived assets impairment charges	0
Short-term restriced cash	$ 800,000
Long-term restriced cash				$ 3,500,000	$ 4,000,000	$ 4,000,000	$ 4,500,000	$ 4,500,000
Service period	1 year
Sales Revenue, Net [Member] | Gene Company Limited [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of individual customers | customer	1	1	1
Concentration risk, percentage	14.00%	17.00%	26.00%
Accounts Receivable [Member] | Gene Company Limited [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	12.00%	11.00%
Accounts Receivable [Member] | Domestic Customers [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	43.00%	55.00%
Accounts Receivable [Member] | Berry Genomics Co., Ltd and Gene Company Limited [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of individual customers | customer	2
Accounts Receivable [Member] | Berry Genomics Co., Ltd [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	15.00%
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred service revenue, performance period	1 year
Minimum [Member] | Computer Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life	2 years
Minimum [Member] | Software [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life	3 years
Minimum [Member] | Furniture and Fixtures [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life	3 years
Minimum [Member] | Lab Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life	3 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred service revenue, performance period	3 years
Maximum [Member] | Computer Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life	3 years
Maximum [Member] | Software [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life	5 years
Maximum [Member] | Furniture and Fixtures [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life	7 years
Maximum [Member] | Lab Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life	5 years
Customer Deposit [Member]
Summary Of Significant Accounting Policies [Line Items]
Short-term restriced cash	$ 500,000
Security Deposit [Member]
Summary Of Significant Accounting Policies [Line Items]
Short-term restriced cash	$ 300,000

Financial Instruments (Narrativ

Financial Instruments (Narrative) (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)item	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)item
Financial Instruments [Line Items]
Fair value of the financing derivative		$ 0		$ 0
Continuation Advances from Illumina	$ 34,000,000	18,000,000	$ 34,000,000	18,000,000
Period in which company must repay continuation advances if change-of-control transaction is entered into with third party			2 years
Equity or debt financing that must be raised in a single transaction			$ 100,000,000
Period in which company must raise equity or debt financing in a single transaction			2 years
Estimated fair value of the liability		$ 0	$ 0	0
Gain from Continuation Advances from Illumina			34,000,000	$ 18,000,000
Fair value assets/liabilities transfer between levels			$ 0
Measurement Input, Discount Rate [Member]
Financial Instruments [Line Items]
Derivative liability, measurement input | item		0.065		0.065

Financial Instruments (Summary

Financial Instruments (Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets
Total cash and cash equivalents	$ 81,611	$ 29,627
Total investments	237,203	19,472
Short-term restricted cash: Cash	836	300
Long-term restricted cash: Cash	3,500	4,000
Total assets measured at fair value	323,150	53,399
Cash and money market funds [Member]
Assets
Total cash and cash equivalents	43,040	18,644
Commercial paper [Member]
Assets
Total cash and cash equivalents	32,537	10,983
U.S. government and agency securities [Member]
Assets
Total cash and cash equivalents	170
U.S. Treasury security [Member]
Assets
Total cash and cash equivalents	5,864
Commercial paper, not included with cash and cash equivalents [Member]
Assets
Total investments	112,644	16,971
Corporate debt securities [Member]
Assets
Total investments	17,456	2,501
U.S. government & agency securities, not included with cash and cash equivalents [Member]
Assets
Total investments	107,103
Level 1 [Member]
Assets
Total cash and cash equivalents	43,040	18,644
Short-term restricted cash: Cash	836	300
Long-term restricted cash: Cash	3,500	4,000
Total assets measured at fair value	47,376	22,944
Level 1 [Member] | Cash and money market funds [Member]
Assets
Total cash and cash equivalents	43,040	18,644
Level 2 [Member]
Assets
Total cash and cash equivalents	38,571	10,983
Total investments	237,203	19,472
Total assets measured at fair value	275,774	30,455
Level 2 [Member] | Commercial paper [Member]
Assets
Total cash and cash equivalents	32,537	10,983
Level 2 [Member] | U.S. government and agency securities [Member]
Assets
Total cash and cash equivalents	170
Level 2 [Member] | U.S. Treasury security [Member]
Assets
Total cash and cash equivalents	5,864
Level 2 [Member] | Commercial paper, not included with cash and cash equivalents [Member]
Assets
Total investments	112,644	16,971
Level 2 [Member] | Corporate debt securities [Member]
Assets
Total investments	17,456	$ 2,501
Level 2 [Member] | U.S. government & agency securities, not included with cash and cash equivalents [Member]
Assets
Total investments	$ 107,103

Financial Instruments (Summar_2

Financial Instruments (Summary of Cash, Cash Equivalents and Investments) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Cash, cash equivalents and investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 318,729	$ 49,094
Gross unrealized gains	106	6
Gross unrealized losses	(21)	(1)
Fair value	318,814	49,099
Cash and cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	81,612	29,627
Gross unrealized losses	(1)
Fair value	81,611	29,627
Cash and money market funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	43,040	18,644
Fair value	43,040	18,644
Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	32,538	10,983
Gross unrealized losses	(1)
Fair value	32,537	10,983
U.S. government and agency securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	170
Fair value	170
U.S. Treasury security [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	5,864
Fair value	5,864
Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	237,117	19,467
Gross unrealized gains	106	6
Gross unrealized losses	(20)	(1)
Fair value	237,203	19,472
Commercial paper, not included with cash and cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	112,648	16,971
Gross unrealized gains	4	1
Gross unrealized losses	(8)	(1)
Fair value	112,644	16,971
Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	17,360	2,496
Gross unrealized gains	96	5
Fair value	17,456	2,501
U.S. government & agency securities, not included with cash and cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	107,109
Gross unrealized gains	6
Gross unrealized losses	(12)
Fair value	107,103
Short-Term Restricted Cash [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	836	300
Fair value	836	300
Long-term restricted cash [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	3,500	4,000
Fair value	$ 3,500	$ 4,000

Financial Instruments (Summar_3

Financial Instruments (Summary of Contractual Maturities of Cash Equivalents and Available-for-Sale Investments) (Details) $ in Thousands	Dec. 31, 2020USD ($)
Financial Instruments [Abstract]
Due in one year or less	$ 255,207
Due after one year through 5 years	20,567
Total investments	$ 275,774

Balance Sheet Components (Narra

Balance Sheet Components (Narrative) (Details)	1 Months Ended	12 Months Ended
	Feb. 29, 2020USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)item	Dec. 31, 2018USD ($)
Balance Sheet Components [Line Items]
Depreciation		$ 6,428,000	$ 7,265,000	$ 7,215,000
Deferred revenue, current		8,722,000	7,610,000
Deferred revenue, non-current		1,568,000	1,951,000
Prepaid expenses and other current assets		4,870,000	3,069,000
Notes payable, current			16,000,000
Repayment of notes payable	$ 16,000,000	16,000,000
Fair value of the financing derivative			0
Estimated fair value of the liability		0	0
Accrued ESPP		2,037,000	$ 0
Service [Member]
Balance Sheet Components [Line Items]
Deferred revenue		10,300,000
Deferred revenue, current		8,700,000
Deferred revenue, non-current		1,600,000
Prepaid expenses and other current assets		$ 700,000
Service [Member] | Minimum [Member]
Balance Sheet Components [Line Items]
Deferred service revenue, noncurrent, recognition period		3 years
Measurement Input, Discount Rate [Member]
Balance Sheet Components [Line Items]
Derivative liability, measurement input | item			0.065

Balance Sheet Components (Compo

Balance Sheet Components (Components of Inventory) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Components [Abstract]
Purchased materials	$ 3,531	$ 3,966
Work in process	6,651	4,594
Finished goods	4,048	4,752
Inventory	$ 14,230	$ 13,312

Balance Sheet Components (Com_2

Balance Sheet Components (Components of Property and Equipment, Net) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment	$ 74,790	$ 74,288
Less: Accumulated depreciation	(49,891)	(44,218)
Property and equipment, net	24,899	30,070
Laboratory Equipment And Machinery [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	24,948	25,173
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	29,931	29,902
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	12,400	11,851
Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	4,940	4,747
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	2,434	2,422
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 137	$ 193

Balance Sheet Components (Sched

Balance Sheet Components (Schedule of Accrued Expenses) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Components [Abstract]
Salaries and benefits	$ 15,261	$ 9,748
Accrued product development costs	415	67
Accrued Tenant Improvements for Menlo Park building		998
Inventory accrual	218	229
Accrued professional services and legal fees	726	943
Other	730	1,257
Accrued expenses	$ 17,350	$ 13,242

Balance Sheet Components (Sch_2

Balance Sheet Components (Schedule of Other Liabilities, Current) (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Components [Abstract]
Accrued ESPP	$ 2,037,000	$ 0
Other	2,482,000	225,000
Other liabilities, current	$ 4,519,000	$ 225,000

Commitments and Contingencies_2

Commitments and Contingencies (Narrative) (Details)	Jun. 22, 2020item	Jul. 22, 2015USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	May 01, 2020USD ($)	May 01, 2019USD ($)	Oct. 31, 2015USD ($)	Jul. 31, 2015
Commitments and Contingencies [Line Items]
Long-term restricted cash			$ 3,500,000	$ 4,000,000	$ 3,500,000	$ 4,000,000	$ 4,500,000
Rent payments			7,200,000	7,000,000
Operating lease cost			6,200,000	$ 6,200,000
Additional liability associated with indemnification obligations			$ 0
1305 O’Brien Drive, Menlo Park, California [Member]
Commitments and Contingencies [Line Items]
Renewal term			5 years
Weighted average remaining lease term			6 years 9 months 18 days
Weighted average discount rate			7.90%
PacBio IPR Petitions [Member]
Commitments and Contingencies [Line Items]
Number of petitions | item	2
O’Brien Lease Agreement [Member]
Commitments and Contingencies [Line Items]
Lease term								132 months
Rent expense first twelve months		$ 540,000
Rent expense last twelve months		$ 711,000
Period in which payment must be received without incurring late charge		5 days
Late charge, percent		5.00%
Amount not paid after written notice, bear interest from date due until date paid, period		10 days
O’Brien Lease Agreement [Member] | Prime Rate [Member]
Commitments and Contingencies [Line Items]
Basis spread on variable rate		2.00%

Commitments and Contingencies_3

Commitments and Contingencies (Schedule of Amount, Timing and Uncertainty of Cash Flows from Operating Leases) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Maturity of Lease Liabilities
2021	$ 7,330
2022	7,502
2023	7,704
2024	7,920
2025	8,136
Thereafter	15,462
Total undiscounted operating lease payments	54,054
Less: imputed interest	(12,055)
Present value of operating lease liabilities	41,999
Balance Sheet Classification
Operating lease liabilities, current	4,332	$ 3,837
Operating lease liabilities, non-current	37,667	$ 41,964
Total operating lease liabilities	$ 41,999

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Line Items]
Income before taxes from U.S. operations	$ 28,900	$ (84,800)	$ (103,100)
Income before taxes from foreign operations	$ 600	$ 900	$ 800
Statutory tax rate	21.00%	21.00%	21.00%
Valuation allowance	$ 300,505	$ 298,658
Net operating loss carryforwards	233,200
Research and development credit carryforward	49,200
Total unrecognized tax benefit	5,954	21,979	$ 20,447	$ 18,786
Decrease in balance related to tax positions taken in prior year	17,255
Accrued interest or penalties	0	$ 0
Federal [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	913,900
Research and development credit carryforward	$ 30,700
Research and developmen tax credit carryforward, expiration	2024
Federal [Member] | With Expiration [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 755,900
Federal [Member] | No Expiration [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	158,000
State [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 634,300
Net operating loss carryforward, expiration	2025
Research and development credit carryforward	$ 30,100
Minimum [Member] | Federal [Member]
Income Taxes [Line Items]
Net operating loss carryforward, expiration	2024
Maximum [Member] | Federal [Member]
Income Taxes [Line Items]
Net operating loss carryforward, expiration	2037

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of Federal Income Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Abstract]
Statutory tax rate	21.00%	21.00%	21.00%
State tax rate, net of federal benefit	(8.30%)	4.90%	3.50%
Stock-based compensation	(15.20%)	(0.80%)	(1.60%)
Tax credits	(3.60%)	2.20%	2.00%
Other	(0.20%)	0.20%	(0.10%)
Change in valuation allowance	6.30%	(27.50%)	(24.80%)
Total

Income Taxes (Reconciliation _2

Income Taxes (Reconciliation of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 233,225	$ 226,911
Research and development credits	49,179	45,853
Accruals and reserves	6,337	8,024
Stock-based compensation	9,717	16,219
ASC842 Operating lease liability	9,870	10,837
Total deferred tax assets	308,328	307,844
Less: Valuation allowance	(300,505)	(298,658)
Total deferred tax assets:	7,823	9,186
Fixed assets	(786)	(1,425)
ASC842 Operating Lease right-of-use assets	(7,037)	(7,761)
Total deferred tax liabilities	(7,823)	(9,186)
Net deferred tax assets

Income Taxes (Reconciliation _3

Income Taxes (Reconciliation of Unrecognized Tax Benefit Accounts) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Abstract]
Unrecognized tax benefit, Beginning balance	$ 21,979	$ 20,447	$ 18,786
Decrease in balance related to tax positions taken in prior year	(17,255)
Increase in balance related to tax positions taken during current year	1,230	1,532	1,661
Unrecognized tax benefit, Ending balance	$ 5,954	$ 21,979	$ 20,447

Stockholders' Equity (Narrative

Stockholders' Equity (Narrative) (Details) $ / shares in Units, $ in Thousands	1 Months Ended		12 Months Ended
	Nov. 30, 2020USD ($)$ / sharesshares	Aug. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2020USD ($)item$ / sharesshares	Dec. 31, 2019USD ($)item$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesitemshares	Dec. 02, 2020shares	Aug. 04, 2020shares	Jun. 30, 2020item	Oct. 31, 2010$ / sharesshares
Stockholders' Equity [Line Items]
Common Stock, shares authorized			1,000,000,000	1,000,000,000					1,000,000,000
Common Stock, par value | $ / shares			$ 0.001	$ 0.001					$ 0.001
Preferred Stock, shares authorized			50,000,000	50,000,000					50,000,000
Preferred Stock, par value | $ / shares			$ 0.001	$ 0.001					$ 0.001
Preferred Stock, shares issued			0	0
Preferred Stock, shares outstanding			0	0
Common stock, dividends declared | $ / shares			$ 0
Voting right of common stock share holders			one
Voting right of common stock share holdes, number of votes | item			1
Proceeds from issuance of common stock from underwritten public equity offerings, net of issuance costs | $			$ 187,479		$ 97,530
Number of equity compensation plans | item				2				3
Stock-based compensation cost capitalized in inventory | $			300	$ 300
Stock-based compensation | $			$ 17,533	$ 16,401	$ 23,153
Common Stock [Member]
Stockholders' Equity [Line Items]
Shares issued			29,356,000		30,610,000
2010 Plan and 2010 Director Plan [Member]
Stockholders' Equity [Line Items]
Common stock remain available for issuance			10,300,000
ESPP [Member]
Stockholders' Equity [Line Items]
Common stock remain available for issuance			5,878,770
Percentage of outstanding common stock used to determine annual plan increase			2.00%
Number of purchase periods | item			4
Purchase period of ESPP			6 months
Percentage of fair market value at which stock can be purchased			85.00%
Weighted average fair value options vested at grant date | $ / shares			$ 1.68	$ 0	$ 1.47
Stock-based compensation | $			$ 3,400	$ 500	$ 6,800
Common stock purchased under plan			834,677	1,306,329	1,674,960
Cash received from option exercises | $			$ 2,400	$ 2,700	$ 3,400
2020 Equity Incentive Plan [Member]
Stockholders' Equity [Line Items]
Stock option grant, term			10 years
Stock option grant, vest rate upon first anniversary			25.00%
Stock option grant, vest rate per month thereafter			2.08%
Shares authorized							11,000,000
Vesting period			4 years
2020 Inducement Equity Incentive Plan [Member]
Stockholders' Equity [Line Items]
Shares authorized						2,500,000
Underwritten Public Equity Offering [Member]
Stockholders' Equity [Line Items]
Shares issued			29,400,000		30,600,000
Proceeds from issuance of common stock from underwritten public equity offerings, net of issuance costs | $			$ 187,200	97,500
Number of offerings | item			2		2
Price per share | $ / shares			$ 6.40		$ 3.38
Underwriting Agreement [Member]
Stockholders' Equity [Line Items]
Common Stock, par value | $ / shares	$ 0.001	$ 0.001
Public offering	6,096,112	19,430,000
Common stock offering price per share | $ / shares	$ 14.25	$ 4.47
Public offering, option to purchase additionl shares, period	30 days	30 days
Public offering, option to purchase additional shares, shares	914,416	2,914,500
Shares issued	7,000,000	22,300,000
Commissions, percentage of gross proceeds	6.00%	6.00%
Proceeds from issuance of common stock from underwritten public equity offerings, net of issuance costs | $	$ 93,900	$ 93,900
Offering costs | $	$ 300	$ 300
Stock Options [Member]
Stockholders' Equity [Line Items]
Aggregate intrinsic value outstanding | $			$ 298,800
Aggregate intrinsic value exercisable options | $			$ 225,600
Stock price | $ / shares			$ 25.94
Weighted average remaining contractual life			3 years
Weighted average remaining contractual life for exercisable			4 years 10 months 20 days
Vested and expected to vest, outstanding			13,677,000
Vested and expected to vest, aggregate intrinsic value | $			$ 279,000
Vested and expected to vest, weighted average exercise price | $ / shares			$ 5.54
Vested and expected to vest, weighted average remaining contractual life			5 years 8 months 23 days
Total intrinsic value of options exercised | $			$ 63,100	$ 2,600	$ 5,300
Weighted average fair value at grant date | $ / shares			$ 4.14	$ 0	$ 1.50
Stock-based compensation | $			$ 6,200	$ 11,000	$ 15,500
Options granted				0
Unrecognized compensation costs | $			9,900
Cash received from option exercises | $			$ 43,900	$ 5,900	6,300
Stock Options [Member] | $1.16 – 16.00 [Member]
Stockholders' Equity [Line Items]
Options expired			2,400,000
Exercise price, lower range | $ / shares			$ 1.16	$ 1.16
Exercise price, upper range | $ / shares			16	$ 16
Options expired, weighted average exercise price | $ / shares			8.49
Stock Options [Member] | $2.45 – 20.90 [Member]
Stockholders' Equity [Line Items]
Exercise price, lower range | $ / shares			2.45
Exercise price, upper range | $ / shares			$ 20.9
Options granted			2,852,000
Time-Based Restricted Stock Units (RSUs) [Member]
Stockholders' Equity [Line Items]
Ratio of number of shares into which the share instrument may be converted			1
Vesting period			4 years
Stock-based compensation | $			$ 7,700	$ 4,900	$ 200
Share-based Compensation Award, Tranche One, Two, Three and Four [Member] | Time-Based Restricted Stock Units (RSUs) [Member]
Stockholders' Equity [Line Items]
Vesting percentage			25.00%

Stockholders' Equity (Summary o

Stockholders' Equity (Summary of Stock Option Activity) (Details) - Stock Options [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares, Options granted		0
$1.16 – 16.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares, Balances, December 31, 2019	22,697,000
Number of shares, Balances, December 31, 2020		22,697,000
Exercise price, lower range	$ 1.16	$ 1.16
Exercise price, upper range	16	16
Weighted average exercise price, Balances, December 31, 2019	$ 5.57
Weighted average exercise price, Balances, December 31, 2020		$ 5.57
$2.45 – 20.90 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares, Options granted	2,852,000
Exercise price, lower range	$ 2.45
Exercise price, upper range	20.9
Weighted average exercise price, Options granted	$ 7.20
$1.16 – 15.98 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares, Options exercised	(8,078,000)
Exercise price, lower range	$ 1.16
Exercise price, upper range	15.98
Weighted average exercise price, Options exercised	$ 5.44
$1.16 – 16 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares, Options canceled	(2,833,000)
Exercise price, lower range	$ 1.16
Exercise price, upper range	16
Weighted average exercise price, Options canceled	$ 7.82
$1.16 – 20.90 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares, Balances, December 31, 2020	14,638,000
Exercise price, lower range	$ 1.16
Exercise price, upper range	20.90
Weighted average exercise price, Balances, December 31, 2020	$ 5.53

Stockholders' Equity (Reconcili

Stockholders' Equity (Reconciliation of Outstanding and Exercisable Stock Options) (Details) - Stock Options [Member]	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Number outstanding | shares	14,638,457
Weighted average remaining contractual life (Years)	5 years 10 months 24 days
Weighted average exercise price	$ 5.53
Number vested | shares	10,938,458
Weighted average exercise price	$ 5.32
$0.00 – 3.67 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	0
Exercise price, upper range	$ 3.67
Number outstanding | shares	4,254,183
Weighted average remaining contractual life (Years)	5 years 5 months 12 days
Weighted average exercise price	$ 2.53
Number vested | shares	3,253,267
Weighted average exercise price	$ 2.51
$3.67 – 7.34 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	3.67
Exercise price, upper range	$ 7.34
Number outstanding | shares	7,560,966
Weighted average remaining contractual life (Years)	6 years 2 months 4 days
Weighted average exercise price	$ 5.68
Number vested | shares	5,396,883
Weighted average exercise price	$ 5.42
$7.34 – 11.01 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	7.34
Exercise price, upper range	$ 11.01
Number outstanding | shares	2,591,433
Weighted average remaining contractual life (Years)	5 years 9 months 10 days
Weighted average exercise price	$ 9.05
Number vested | shares	2,191,433
Weighted average exercise price	$ 8.95
$11.01 – 14.68 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	11.01
Exercise price, upper range	$ 14.68
Number outstanding | shares	131,375
Weighted average remaining contractual life (Years)	2 years 11 months 26 days
Weighted average exercise price	$ 12.49
Number vested | shares	96,375
Weighted average exercise price	$ 11.82
$14.68 – 18.35 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	14.68
Exercise price, upper range	$ 18.35
Number outstanding | shares	500
Weighted average remaining contractual life (Years)	1 month 17 days
Weighted average exercise price	$ 15.98
Number vested | shares	500
Weighted average exercise price	$ 15.98
$18.35 – 22.02 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	18.35
Exercise price, upper range	$ 22.02
Number outstanding | shares	100,000
Weighted average remaining contractual life (Years)	9 years 11 months 12 days
Weighted average exercise price	$ 20.90
$22.02 – 25.69 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	22.02
Exercise price, upper range	25.69
$25.69 – 29.36 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	25.69
Exercise price, upper range	29.36
$29.36 – 33.03 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	29.36
Exercise price, upper range	33.03
$ 33.03 – 36.70 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	33.03
Exercise price, upper range	$ 36.70

Stockholders' Equity (Summary_2

Stockholders' Equity (Summary of Time-Based RSUs Activity) (Details) - Time-Based Restricted Stock Units (RSUs) [Member] shares in Thousands	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, outstanding at December 31, 2019 | shares	1,086
Number of shares, granted | shares	6,556
Number of shares, released | shares	(1,000)
Number of shares, forfeited | shares	(723)
Number of shares, Unvested outstanding at December 31, 2020 | shares	5,919
Weighted average grant date fair value, outstanding at December 31, 2019 | $ / shares	$ 6.12
Weighted average grant date fair value, granted | $ / shares	5.18
Weighted average grant date fair value, released | $ / shares	6.33
Weighted average grant date fair value, forfeited | $ / shares	4.40
Weighted average grant date fair value, Unvested outstanding at December 31, 2020 | $ / shares	$ 5.25

Stockholders' Equity (Summary_3

Stockholders' Equity (Summary of Performance-Based RSUs Activity) (Details) - Performance-Based Restricted Stock Units (RSUs) [Member] shares in Thousands	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, outstanding at December 31, 2019 | shares	138
Number of shares, granted | shares
Number of shares, released | shares
Number of shares, forfeited | shares	(44)
Number of shares, Unvested outstanding at December 31, 2020 | shares	94
Weighted average grant date fair value, outstanding at December 31, 2019 | $ / shares	$ 2.63
Weighted average grant date fair value, granted | $ / shares
Weighted average grant date fair value, released | $ / shares
Weighted average grant date fair value, forfeited | $ / shares	2.63
Weighted average grant date fair value, Unvested outstanding at December 31, 2020 | $ / shares	$ 2.63

Stockholders' Equity (Schedule

Stockholders' Equity (Schedule of Stock-Based Compensation Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 17,533	$ 16,401	$ 23,153
Cost of revenue [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	2,236	1,857	3,124
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	7,061	7,699	10,076
Sales, general and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 8,236	$ 6,845	$ 9,953

Stockholders' Equity (Schedul_2

Stockholders' Equity (Schedule of Fair Value of Employee Stock Options) (Details) - Stock Options [Member]	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	5 years		5 years 2 months 12 days
Expected volatility	70.70%		66.80%
Risk-free interest rate	0.30%		2.60%
Dividend yield

Stockholders' Equity (Schedul_3

Stockholders' Equity (Schedule of Fair Value of Employee Stock Purchase Plan) (Details) - ESPP [Member]	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility
Risk-free interest rate
Risk-free interest rate, minimum	0.10%		1.30%
Risk-free interest rate, maximum	1.00%		2.70%
Dividend yield
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	6 months		6 months
Expected volatility	57.00%		65.00%
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	2 years		2 years
Expected volatility	71.00%		67.00%

Net Income (Loss) Per Share (Co

Net Income (Loss) Per Share (Computation Of Basic And Diluted Net Loss Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator
Net income (loss)	$ 29,403	$ (84,134)	$ (102,562)
Basic
Weighted average shares used in computing basic net income (loss) per share	165,187	152,527	135,094
Basic net income (loss) per share	$ 0.18	$ (0.55)	$ (0.76)
Diluted
Weighted average shares used in computing basic net income (loss) per share	165,187	152,527	135,094
Weighted average shares used in computing diluted net income (loss) per share	174,970	152,527	135,094
Diluted net income (loss) per share	$ 0.17	$ (0.55)	$ (0.76)
Stock Options [Member]
Diluted
Add: weighted average	6,092
Restricted Stock Units (RSUs) [Member]
Diluted
Add: weighted average	2,324
ESPP [Member]
Diluted
Add: weighted average	1,367

Net Income (Loss) Per Share (An

Net Income (Loss) Per Share (Antidilutive Shares Excluded From Computation Of Diluted Net Loss Per Share) (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stock Options [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share	4,908	22,697	25,176
Time-Based Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share	100	1,086	371
Performance-Based Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share	94	138	586
ESPP [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share	2,890

Segment And Geographic Inform_3

Segment And Geographic Information (Narrative) (Details)	12 Months Ended
	Dec. 31, 2020segment
Segment And Geographic Information [Abstract]
Number of reportable segments	1

Segment And Geographic Inform_4

Segment And Geographic Information (Schedule of Revenue by Geographic Location) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 78,893	$ 90,891	$ 78,626
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	37,277	44,681	35,598
Europe (including the Middle East and Africa) [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	19,065	19,600	13,958
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 22,551	$ 26,610	$ 29,070

Segment And Geographic Inform_5

Segment And Geographic Information (Summary of Revenue by Category) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 78,893	$ 90,891	$ 78,626
Product [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	65,424	77,742	66,355
Instrument [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	34,282	45,126	28,492
Consumable [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	31,142	32,616	37,863
Service and Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 13,469	$ 13,149	$ 12,271

Subsequent Events (Narrative) (

Subsequent Events (Narrative) (Details) - Subsequent Event [Member]	Feb. 09, 2021USD ($)item$ / sharesshares	Jan. 12, 2021
Development program term		60 months
Notes [Member]
Principal amount of notes	$ 900,000,000
Debt instrument, stated interest rate	1.50%
Maturity date	Feb. 15, 2028
Shares issued conversion rate per $1,000 principal amount | shares	22.9885
Principal amount for conversion rate	$ 1,000
Conversion price per share | $ / shares	$ 43.50
Threshold number of trading days for conversion	20 days
Threshold number of consecutive trading days for conversion	30 days
Threshold percentage for conversion	150.00%
Redemption price, percentage	100.00%
Investment Agreement [Member] | Standstill Obligations [Member]
Covenant, anniversary period from closing date	3 years
Covenant, number of days no member of purchaser may beneficially own any Notes of the Company	90 days
Covenant, number of members of purchaser that may beneficially own any notes of the Company | item	0
Covenant, maximum collective ownership aggregate percentage permitted	19.99%
Covenant, maximum benefical ownership permitted	10.00%
Investment Agreement [Member] | Transfer Restrictions; Registration Rights [Member]
Covenant, anniversary period from closing date	1 year