Pacific Biosciences of California (PACB) 10-K 26 Feb 19 2018 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Feb. 22, 2019	Jun. 30, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Trading Symbol	PACB
Entity Registrant Name	PACIFIC BIOSCIENCES OF CALIFORNIA, INC.
Entity Central Index Key	1,299,130
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Public Float			$ 428,497
Entity Common Stock, Shares Outstanding		150,959,952

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 18,844	$ 16,507
Investments	83,510	46,365
Accounts receivable	8,595	13,433
Inventory	17,878	23,065
Prepaid expenses and other current assets	2,832	2,249
Total current assets	131,659	101,619
Property and equipment, net	34,073	37,920
Long-term restricted cash	4,500	4,500
Other long-term assets	43	45
Total assets	170,275	144,084
Current liabilities
Accounts payable	6,736	9,093
Accrued expenses	12,823	12,618
Deferred service revenue, current	6,537	6,319
Other liabilities, current	788	605
Total current liabilities	26,884	28,635
Deferred service revenue, non-current	890	1,075
Deferred rent, non-current	13,765	14,453
Notes payable	14,659	13,635
Financing derivative	16	183
Total liabilities	56,214	57,981
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 150,244 and 116,277 shares at December 31, 2018 and 2017, respectively	150	116
Additional paid-in-capital	1,096,053	965,752
Accumulated other comprehensive loss	(36)	(32)
Accumulated deficit	(982,106)	(879,733)
Total stockholders' equity	114,061	86,103
Total liabilities and stockholders' equity	$ 170,275	$ 144,084

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
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	150,244,000	116,277,000
Common Stock, shares outstanding	150,244,000	116,277,000

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue:
Revenue	$ 78,626	$ 93,468	$ 90,714
Cost of Revenue:
Cost of revenue	53,530	58,809	46,554
Gross profit	25,096	34,659	44,160
Operating Expense:
Research and development	62,594	65,324	67,617
Sales, general and administrative	63,489	59,119	47,787
Total operating expense	126,083	124,443	115,404
Operating loss	(100,987)	(89,784)	(71,244)
Interest expense	(2,423)	(2,921)	(3,234)
Other income, net	848	516	103
Net loss	(102,562)	(92,189)	(74,375)
Other comprehensive loss:
Unrealized gain (loss) on investments	(4)	(37)	12
Comprehensive loss	$ (102,566)	$ (92,226)	$ (74,363)
Net loss per share:
Basic and diluted net loss per share	$ (0.76)	$ (0.87)	$ (0.83)
Shares used in computing basic and diluted net loss per share	135,094	105,682	89,148
Product [Member]
Revenue:
Revenue	$ 66,355	$ 80,030	$ 64,609
Cost of Revenue:
Cost of revenue	42,053	42,900	34,512
Service and Other [Member]
Revenue:
Revenue	12,271	13,438	13,971
Cost of Revenue:
Cost of revenue	$ 11,477	$ 15,909	12,042
Contractual [Member]
Revenue:
Revenue			$ 12,134

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	At the Market Offering [Member]Common Stock [Member]	At the Market Offering [Member]Additional Paid-in Capital [Member]	At the Market Offering [Member]	Underwritten Public Equity Offering [Member]Common Stock [Member]	Underwritten Public Equity Offering [Member]Additional Paid-in Capital [Member]	Underwritten Public Equity Offering [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]	Total
Balance at Dec. 31, 2015							$ 80	$ 786,636	$ (7)	$ (713,169)	$ 73,540
Balance, shares at Dec. 31, 2015							79,983
Net loss										(74,375)	(74,375)
Other comprehensive loss									12		12
Issuance of common stock in conjunction with equity plans							$ 2	7,727			7,729
Issuance of common stock in conjunction with equity plans, shares							2,004
Issuance of common stock in conjunction with offering, net of issuance costs	$ 7	$ 58,193	$ 58,200
Issuance of common stock in conjunction with offering, net of issuance costs, shares	6,526
Issuance of common stock from exercise of warrant							$ 4	(4)
Issuance of common stock from exercise of warrant, shares							4,164
Stock-based compensation expense								19,562			19,562
Balance at Dec. 31, 2016							$ 93	872,114	5	(787,544)	84,668
Balance, shares at Dec. 31, 2016							92,677
Net loss										(92,189)	(92,189)
Other comprehensive loss									(37)		(37)
Issuance of common stock in conjunction with equity plans							$ 2	8,912			8,914
Issuance of common stock in conjunction with equity plans, shares							2,697
Issuance of common stock in conjunction with offering, net of issuance costs	$ 3	$ 11,862	$ 11,865	$ 18	$ 52,512	$ 52,530
Issuance of common stock in conjunction with offering, net of issuance costs, shares	3,171		3,200	17,732
Stock-based compensation expense								20,352			20,352
Balance at Dec. 31, 2017							$ 116	965,752	(32)	(879,733)	$ 86,103
Balance, shares at Dec. 31, 2017							116,277				116,277
Net loss										(102,562)	$ (102,562)
Other comprehensive loss									(4)		(4)
ASC606 adoption effect										189	189
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 in conjunction with offering, net of issuance costs				$ 30	$ 97,500	$ 97,530
Issuance of common stock in conjunction with offering, net of issuance costs, shares				30,610		30,600
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				150,244

Consolidated Statements of Cash

Consolidated Statements of Cash Flows $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Cash flows from operating activities
Net loss	$ (102,562)	$ (92,189)	$ (74,375)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and amortization	7,215	8,442	3,875
Amortization of debt discount and financing costs	1,024	1,203	1,158
Stock-based compensation	23,153	20,352	19,562
Non-cash portion of gain on lease amendments
(Gain) loss from derivative	(167)	653	(244)
Amortization and accretion for investment premium (discount)	(758)	47	97
Changes in assets and liabilities
Accounts receivable	4,838	(2,012)	(6,176)
Inventory	3,623	(8,442)	(6,151)
Prepaid expenses and other assets	(290)	7,803	(202)
Accounts payable	(2,239)	764	3,402
Accrued expenses	205	(3,986)	1,053
Deferred service revenue	33	(1,033)	469
Deferred contractual revenue			(12,134)
Other liabilities	(505)	880	1,737
Net cash used in operating activities	(66,430)	(67,518)	(67,929)
Cash flows from investing activities
Purchase of property and equipment	(1,854)	(10,433)	(8,207)
Proceeds from disposal of property and equipment		41	10
Purchase of investments	(122,183)	(86,339)	(95,848)
Sales of investments	2,442	7,111	23,285
Maturities of investments	83,180	88,071	65,896
Net cash used in investing activities	(38,415)	(1,549)	(14,864)
Cash flows from financing activities
Proceeds from issuance of common stock from equity plans	9,652	8,914	7,729
Notes payable principal payoff		(4,500)
Net cash provided by financing activities	107,182	68,809	65,929
Net decrease in cash and cash equivalents and restricted cash	2,337	(258)	(16,864)
Cash and cash equivalents and restricted cash at beginning of period	21,007	21,265	38,129
Cash and cash equivalents and restricted cash at end of period	23,344	21,007	21,265
Cash and cash equivalents at end of period	18,844	16,507	16,765
Restricted cash at end of period	4,500	4,500	4,500
Supplemental disclosure of cash flow information
Interest paid	1,400	1,687	1,799
Supplemental disclosure of non-cash investing and financing activities
Inventory transferred to property and equipment	1,871	1,267	1,282
Property and equipment paid by landlord		12,600
Changes in deposits for property and equipment paid in prior period		9,694
Property and equipment returned to landlord		1,854
At the Market Offering [Member]
Cash flows from financing activities
Proceeds from issuance of common stock from equity offerings, net of issuance costs		11,865	$ 58,200
Underwritten Public Equity Offering [Member]
Cash flows from financing activities
Proceeds from issuance of common stock from equity offerings, net of issuance costs	$ 97,530	$ 52,530

Overview

Overview	12 Months Ended
	Dec. 31, 2018
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 consumables and software, provide a simple and fast end-to-end workflow for SMRT sequencing. Our current products include the Sequel instrument and the Sequel SMRT Cell 1M, which together are capable of sequencing up to approximately one million DNA molecules simultaneously. We are continuously developing new products including the SMRT Cell 8M, which is designed to have up to eight times as much throughput capability as the current Sequel SMRT Cell 1M. We commenced our Early Access Program for the SMRT ® Cell 8M chip and platform, the Sequel ® II System, in January 2019 and the five Early Access sites selected have installed and operated their Sequel II Systems. Based on the early performance of the Sequel II Systems at these sites, we expect to begin commercial shipments of Sequel II Systems and SMRT Cell 8M products in the early part of the second quarter of 2019. On November 1, 2018, we entered into an Agreement and Plan of Merger with Illumina, Inc. (“Illumina”) and FC Ops Corp., a wholly-owned subsidiary of Illumina (the “Merger Agreement”) pursuant to which Illumina will acquire us for $8.00 per share of our common stock in an all-cash transaction and FC Ops Corp. will be merged with and into us (the “Merger”), with us surviving the Merger and becoming a wholly-owned subsidiary of Illumina. Completion of the transaction is subject to terms and conditions set forth in the Merger Agreement, including expiration or termination of any waiting periods applicable to the consummation of the Merger under the United States Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, and clearance under the antitrust laws of certain non-United States jurisdictions. At a Special Meeting of Stockholders held on January 24, 2019, our stockholders, among other things, approved the adoption of the Merger Agreement. We and Illumina have each received a request for additional information and documentary material, commonly referred to as a “second request,” from the United States Federal Trade Commission (the “FTC”) in connection with the Merger. The FTC’s “second request” has the effect of extending the waiting period applicable to the consummation of the Merger until the 30th day after substantial compliance by us and Illumina with the “second request,” unless the waiting period is extended voluntarily by the parties or terminated sooner by the FTC. The parties have entered into a timing agreement with the FTC that extends the waiting period of the “second request” to mid-2019. We and Illumina continue to expect the Merger to be completed in mid-2019, at which time we will become a wholly-owned subsidiary of Illumina and will cease to be a publicly-traded company. No assurance can be given that the required regulatory approvals will be obtained or that the required conditions to closing will be satisfied, and, even if all such approvals are obtained and the conditions are satisfied, no assurance can be given as to the terms, conditions and timing of the approvals. For more information about the effects of our agreement to be acquired by Illumina please see Item 1A Risk Factors under the section “Risks Related to Our Business”. The names “Pacific Biosciences,” “PacBio,” “SMRT,” “SMRTbell,” “Sequel” and our logo are our trademarks. 

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Summary of Significant Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 2. 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. 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, revenue recognition, the valuation of a financing derivative and long-term notes, the valuation and recognition of share-based compensation, the useful lives assigned to long-lived assets, and the computation provisions for income taxes. Actual results could differ materially from these estimates. During 2017, we recorded a charge to cost of service and other revenue of $1.6 million relating to leased RS II instruments primarily due to a change in the estimated useful life of these instruments. The charge of $1.6 million increased loss per share by $0.01 for the year ended December 31, 2017. Fair Value of Financial Instruments 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. The carrying value of our other liabilities, non-current, approximates fair value due to the time to maturity and prevailing market rates. 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. A financial instrument’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. 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. 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, 2018 and December 31, 2017 respectively (in thousands):      December 31, 2018 December 31, 2017  (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 $ 18,844 $ — $ — $ 18,844 $ 14,858 $ — $ — $ 14,858  Commercial paper — — — — — 1,649 — 1,649  Total cash and cash equivalents 18,844 — — 18,844 14,858 1,649 — 16,507  Investments:  Commercial paper — 53,469 — 53,469 — 20,394 — 20,394  Corporate debt securities — 10,214 — 10,214 — 9,034 — 9,034  US government & agency securities — 19,827 — 19,827 — 16,937 — 16,937  Total investments — 83,510 — 83,510 — 46,365 — 46,365  Long-term restricted cash:  Cash 4,500 — — 4,500 4,500 — — 4,500  Total assets measured at fair value $ 23,344 $ 83,510 $ — $ 106,854 $ 19,358 $ 48,014 $ — $ 67,372   Liabilities  Financing derivative $ — $ — $ 16 $ 16 $ — $ — $ 183 $ 183  Total liabilities measured at fair value $ — $ — $ 16 $ 16 $ — $ — $ 183 $ 183   The estimated fair value of the Financing Derivative liability (as defined in “Note 6. Notes Payable’) was determined using Level 3 inputs, or significant unobservable inputs. Refer to “Note 6. Notes Payable” for a detailed description and valuation approach. Changes to the estimated fair value of the Financing Derivative are recorded in “Other income (expense), net” in the consolidated statements of operations and comprehensive loss. The following table provides the changes in the fair value of the Financing Derivative for the years ended December 31, 2018 and 2017 (in thousands), respectively:     Financing Derivative Amount  Balance as of December 31, 2016 $ 356  Loss on change in fair value of Financing Derivative 653  Change in fair value due to partial exercise of derivative associated with $4.5 million principal payoff (826)  Balance as of December 31, 2017 183  Gain on change in fair value of Financing Derivative (167)  Balance as of December 31, 2018 $ 16  For the year ended December 31, 2018, 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. Financial Assets and Liabilities Not Measured at Fair Value on a Recurring Basis We determined the fair value of the Notes (as defined in “Note 6. Notes Payable”) from the debt facility we entered into during the first quarter of 2013 using Level 3 inputs, or significant unobservable inputs. The value of the Notes was determined by comparing the difference between the fair value of the Notes with and without the Financing Derivative by calculating the respective present values from future cash flows using a 9.6% and 10.3% weighted average market yield at December 31, 2018 and December 31, 2017, respectively. Refer to “Note 6. Notes Payable” for additional details regarding the Notes. The estimated fair value and carrying value of the Notes are as follows (in thousands):      December 31, 2018 December 31, 2017  Fair Value Carrying Value Fair Value Carrying Value  Long-term notes payable $ 15,915 $ 14,659 $ 15,664 $ 13,635  Cash and Cash Equivalents We consider all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. Investments 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. 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 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, 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. During the years ended December 31, 2018, 2017 and 2016, we did not recognize 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. Concentration and Other Risks 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. Our accounts receivable 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. We regularly review our accounts receivable including consideration of factors such as historical experience, credit quality, the age of the accounts receivable balances and current economic conditions that may affect a customer’s ability to pay. We have not experienced any significant credit losses to date. Excluding contractual revenue from the Roche agreement, which has now been terminated, for the year ended December 31, 2018 and 2017, one customer , Gene Company Limited, accounted for approximately 26% and 31% of our total revenue, respectively. For the years ended December 31, 2016, no customer accounted for more than 10% of our total revenue. As of December 31, 2018 and 2017, 50% and 84% of our accounts receivable were from domestic customers, respectively. As of December 31, 2018 and 2017, one customer, Gene Company Limited, represented approximately 14% and 20% of our net accounts receivable , respectively. We currently purchase several key parts and components used in the manufacture of our products from a limited number of suppliers. Generally we have been able to obtain an adequate supply of such parts and components. 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. 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 to three years for computer equipment, three to five years for software, three to seven years for furniture and fixtures and three 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. Long-term Restricted Cash As required under the lease agreement for our corporate offices (the “O’Brien lease”), 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; and, as such, $4.5 million was recorded in “Long-term restricted cash” in the consolidated balance sheet as of such year and continued to be so recorded as of both December 31, 2018 and December 31, 2017. 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 not recorded any impairment charges. Going concern We may raise additional capital in the future. To the extent we raise additional funds through the sale of equity or convertible debt, the issuance of such securities will result in dilution to our stockholders. There can be no assurance that such funds will be available on favorable terms, or at all, particularly in light of restrictions under our debt agreement and the Merger Agreement . If adequate funds are not available, we may be required to obtain funds by entering into collaboration, licensing or debt agreements on unfavorable terms. If we are unable to raise funds on favorable terms, or at all, we may have to reduce our cash burn rate and may not be able to support our commercialization efforts, or to increase or maintain the level of our research and development activities. If we are unable to generate sufficient cash flows or to raise adequate funds to finance our forecasted expenditures, we may have to make significant changes to our operations, including delaying or reducing the scope of or eliminating some or all of our development programs. We also may have to reduce sales, marketing, engineering, customer support or other resources devoted to our existing or new products or cease operations. If our cash, cash equivalents and investments are insufficient to fund our projected operating requirements, and we are unable to raise capital, it would have a material adverse effect on our business, financial condition and results of operations. 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 consist primarily of revenue earned from product maintenance agreements with some additional revenue from instrument lease agreements and grant revenue. 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 an 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 primarily consist of deferred revenue. We record deferred service revenues when cash payments are received or due in advance of our performance for product maintenance agreements. Deferred service revenue is recognized over the related performance period, generally one 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. As of December 31, 2018, we had a total of $7.4 million of deferred service revenue from our service contracts, $6.5 million of which was recorded as “deferred service revenue, current” to be recognized over the next year and the remaining $0.9 million was recorded as “deferred service revenue, non-current” to be recognized in the next 2 to 5 years. Revenue recognized during the year ended December 31, 2018 includes $6.3 million of previously deferred revenue that was included in “deferred service revenue, current” as of December 31, 2017. Contract assets as of December 31, 2017 and December 31, 2018 were not material. Instrument lease agreements - Instrument leases are generally classified as operating-type leases and revenue from these leases is recognized on a straight-line basis over the respective lease term, once the lessee takes (or has the right to take) control/possession of the property under the lease. Effectively, this occurs once the installation is complete and control of the instrument is transferred to our customers. 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. 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. We record tenant improvement allowances as deferred rent liabilities and amortize the deferred rent over the term of the lease to rent expense on the statements of operations and comprehensive loss. 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 expense for all stock-based compensation awards , including stock options and also including shares issued under 2010 Employee Stock Purchase Plan (“ESPP”), is based on the grant date fair value estimated using the Black-Scholes option pricing model. Expected Term . Starting January 1, 2018, we determined the expected term using historical option experience . We determined expected term based on historical exercise patterns and an expectation of the time it will take for employees to exercise options still outstanding. Prior to 2018, we did not believe that we were able to rely on our historical employee exercise behavior to provide accurate data for estimating our expected term for use in determining the fair value of these options due to limited trading history. Therefore, for the period prior to 2018, the period the expected term of options is estimated based on the simplified method. Expected Volatility . Starting January 1, 2018, we estimate the volatility of our common stock at the date of grant based on the historical volatility of our common stock. Prior to 2018, we did not have sufficient trading history to solely rely on the volatility of our own common stock for establishing expected volatility. Therefore, we based our expected volatility on the historical stock volatilities of our common stock as well as several comparable publicly listed companies over a period equal to the expected term of the options. Risk-Free Rate. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for the expected term of the stock option. Dividends. We have never paid any cash dividends on our common stock and we do not anticipate paying any cash dividends in the foreseeable future. Consequently, we use an expected dividend yield of zero in the Black-Scholes option valuation model. Expected Forfeiture Rate. We estimate our forfeiture rate based on an analysis of our actual forfeitures and will continue to evaluate the adequacy of the forfeiture rate based on actual forfeiture experience, analysis of employee turnover behavior and other factors. The impact from a forfeiture rate adjustment will be recognized in full in the period of adjustment, and if the actual number of future forfeitures differs from that which was estimated, we may be required to record adjustments to stock-based compensation expense in future periods. We recognize compensation expense on a straight-line basis over the requisite service period. We elected to use the simplified method to calculate the beginning pool of excess tax benefits. Other Comprehensive Income (loss) Other comprehensive income (loss) is comprised of unrealized gains (losses) on our investment securities. Recent Accounting Pronouncements Recently Issued Accounting Standards In June 2018, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2018-07, Improvements to Nonemployee Share-Based Payment Accounting , to simplify the accounting for nonemployee share-based payment transactions by expanding the scope of Accounting Standards Codification, or ASC, Topic 718, Compensation - Stock Compensation, to include share-based payment transactions for acquiring goods and services from nonemployees. Under the new standard, most of the guidance on stock compensation payments to nonemployees would be aligned with the requirements for share-based payments granted to employees. This standard is effective for annual reporting periods beginning after December 15, 2018, including interim reporting periods within those annual reporting periods, with early adoption permitted. We expect to adopt this standard beginning in 2019. While we continue to assess the potential impact of this standard, we do not expect the adoption of this standard to have a material impact on our consolidated financial statements. In February 2018, the FASB issued ASU 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income , that allows for an entity to elect to reclassify the income tax effects on items within accumulated other comprehensive income resulting from U.S. tax reform to retained earnings. The guidance is effective for fiscal years beginning after December 15, 2018 with early adoption permitted, including interim periods within those years. We expect to adopt this standard beginning in 2019. While we continue to assess the potential impact of this standard, we do not expect the adoption of this standard to have a material impact on our consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases. The guidance in ASU 2016-02 supersedes the lease recognition requirements in ASC Topic 840, Leases. ASU 2016-02 requires an entity to recognize assets and liabilities arising from a lease for both financing and operating leases, along with additional qualitative and quantitative disclosures. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, with early adoption permitted. In July 2018, the FASB issued ASU No. 2018-11, “ Targeted Improvements - Leases (Topic 842)”. This update provides an optional transition method that allows entities to elect to apply the standard prospectively at its effective date, versus recasting the prior periods presented. If elected, an entity would recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. We intend to adopt the optional transition method and we expect to adopt this standard beginning in 2019. We have performed a preliminary assessment of the impact of the adoption of the amendments in these updates on our consolidated financial position and results of operations for our leases, which primarily consist of our O’Brien lease. Based on that assessment, we have estimated that the adoption of Topic 842 will result in the significant recognition of right-of-use assets and lease liabilities as of January 1, 2019 . Also, the impact from the adoption of Topic 842 to our accumulated deficit as of January 1, 2019 and to our consolidated results of operations for the year ending December 31, 2019 are not expected to be material. Recently Adopted Accounting Standards In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash , which requires restricted cash to be presented with cash and cash equivalents on the statement of cash flows and disclosure of how the statement of cash flows reconciles to the balance sheet if restricted cash is shown separately from cash and cash equivalents on the balance sheet. ASU 2016-18 is effective for interim and annual periods beginning after December 15, 2017, with early adoption permitted. We adopted this standard effective January 1, 2018 using the retrospective transition method by restating our consolidated statements of cash flows to include restricted cash of $4.5 million in the beginning and ending cash, cash equivalents, and restricted cash balances for all periods presented. As a result of adoption, n et cash flows for the year ended December 31, 2018 did not change as a result of including restricted cash with cash and cash equivalents when reconciling the beginning-of-period and end-of-period amounts presented on the statements of cash flows. In May 2014, the FASB issued ASU No. 2014-09, “ Revenue from Contracts with Customers (Topic 606)” as modified by subsequently issued ASUs 2015-14, 2016-08, 2016-10, 2016-12 and 2016-20 (collectively ASC 606). ASC 606 superseded existing revenue recognition standards with a single model unless those contracts are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. The revenue recognition principle in ASC 606 is that an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of Topic 606, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. On January 1, 2018, we adopted ASC 606 using the modified retrospective method with the cumulative effect of adoption recognized as an adjustment to our accumulated deficit on January 1, 2018. Prior period financial statements and disclosures have not been restated and continue to be reported under the accounting standards in effect for those periods. The adoption of ASC 606 did not have a material impact on our consolidated financial position, results of operations, equity or cash flows as of the adoption date or for the year ended December 31, 2018. In addition, the standard requires disclosure of the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. Upon adopting ASC 606, the incremental direct costs of obtaining a contract are now deferred and amortized over the period of contract performance or a longer period if renewals are expected and the renewal commission is not commensurate with the initial commission. We classify deferred commissions as “Prepaid ex

Contractual Revenue

Contractual Revenue	12 Months Ended
	Dec. 31, 2018
Contractual Revenue [Abstract]
Contractual Revenue	NOTE 3. CONTRACTUAL REVENUE In September 2013, we entered into a development, commercialization and license agreement with F. Hoffman-La Roche Ltd. (“Roche Agreement”), pursuant to which we accounted for, and recognized as revenue, the up-front payment received thereunder using the proportional performance method over the periods in which the delivery of elements pursuant to the Roche Agreement occurs. We recognized revenue under the Roche Agreement using a straight-line convention over the service periods of the deliverables as this method approximated our performance of services pursuant to the Roche Agreement, of which $12.1 million was recognized in 2016. Roche terminated this agreement in December 2016 and no further payments are expected to be received and no additional revenue was recognized. 

Cash and Cash Equivalents and I

Cash and Cash Equivalents and Investments	12 Months Ended
	Dec. 31, 2018
Cash and Cash Equivalents and Investments [Abstract]
Cash and Cash Equivalents and Investments	NOTE 4. CASH AND CASH EQUIVALENTS AND INVESTMENTS The following table summarizes our cash, cash equivalents and investments as of December 31, 2018 and December 31, 2017 (in thousands):     As of December 31, 2018  Gross Gross  Amortized unrealized unrealized Fair  Cost gains losses Value  Cash and cash equivalents:  Cash and money market funds $ 18,844 $ — $ — $ 18,844  Total cash and cash equivalents 18,844 — — 18,844  Investments:  Commercial paper 53,493 — (24) 53,469  Corporate debt securities 10,223 3 (12) 10,214  Asset backed securities — — — —  US government & agency securities 19,830 — (3) 19,827  Total investments 83,546 3 (39) 83,510  Total cash, cash equivalents and investments $ 102,390 $ 3 $ (39) $ 102,354   Long-term restricted cash:  Cash $ 4,500 $ — $ — $ 4,500   As of December 31, 2017  Gross Gross  Amortized unrealized unrealized Fair  Cost gains losses Value  Cash and cash equivalents:  Cash and money market funds $ 14,858 $ — $ — $ 14,858  Commercial paper 1,649 — — 1,649  Total cash and cash equivalents 16,507 — — 16,507  Investments:  Commercial paper 20,408 — (14) 20,394  Corporate debt securities 9,043 — (9) 9,034  US government & agency securities 16,946 — (9) 16,937  Total investments 46,397 — (32) 46,365  Total cash, cash equivalents and investments $ 62,904 $ — $ (32) $ 62,872   Long-term restricted cash:  Cash $ 4,500 $ — $ — $ 4,500    The following table summarizes the contractual maturities of our cash equivalents and available-for-sale investments, excluding money market funds, as of December 31, 2018:     (in thousands) Fair Value  Due in one year or less $ 82,023  Due after one year through five years 1,487  Total $ 83,510   Substantially all of 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, 2018
Balance Sheet Components [Abstract]
Balance Sheet Components	NOTE 5. BALANCE SHEET COMPONENTS Inventory As of December 31, 2018 and 2017, our inventory consisted of the following components:     December 31,  (in thousands) 2018 2017  Purchased materials $ 6,222 $ 8,884  Work in process 7,341 9,994  Finished goods 4,315 4,187  Inventory $ 17,878 $ 23,065  Property and Equipment, Net As of December 31, 2018 and 2017, our property and equipment, net, consisted of the following components:     December 31,  (in thousands) 2018 2017  Laboratory equipment and machinery $ 24,111 $ 24,703  Leasehold improvements 29,821 29,728  Computer equipment 9,484 8,301  Software 4,734 4,615  Furniture and fixtures 2,422 2,382  Construction in progress 608 385  71,180 70,114  Less: Accumulated depreciation (37,107) (32,194)  Property and equipment, net $ 34,073 $ 37,920  Depreciation expense during the years ended December 31, 2018, 2017 and 2016 was $7.2 million , $8.4 million and $3.9 million , respectively. Accrued Expenses As of December 31, 201 8 and 2017, our accrued expenses consisted of the following components:     December 31,  (in thousands) 2018 2017  Salaries and benefits $ 8,523 $ 7,570  Accrued product development costs 561 2,034  Accrued Tenant Improvements for Menlo Park building 694 —  Inventory accrual 499 626  Accrued professional services and legal fees 1,588 1,368  Other 958 1,020  Accrued expenses $ 12,823 $ 12,618  

Notes Payable

Notes Payable	12 Months Ended
	Dec. 31, 2018
Notes Payable [Abstract]
Notes Payable	 NOTE 6. NOTES PAYABLE Facility Agreement Under the terms of our February 2013 debt agreement with Deerfield (the “Facility Agreement”), we received $20.5 million and issued promissory notes in the aggregate principal amount of $20.5 million (the “Notes”). The Notes bear simple interest at a rate of 8.75% per annum, payable quarterly in arrears commencing on April 1, 2013 and on the first business day of each January, April, July and October thereafter. The Facility Agreement has a maximum term of seven years. We received net proceeds of $20.0 million, representing $20.5 million of gross proceeds, less a $500,000 facility fee, before deducting other expenses of the transaction. On June 23, 2017, pursuant to a partial exercise by the Notes holders of their right to elect to receive up to 25% of the net proceeds from any financing that includes an equity component, we paid $4.5 million of outstanding principal, together with accrued and unpaid interest, to one of the Note holders with proceeds from our underwritten public equity offering. As of December 31, 2018, we had an outstanding principal amount of $16.0 million remaining on the Notes. The principal is due to be repaid in February 2020. The Facility Agreement also contains various representations and warranties, and affirmative and negative covenants, customary for financings of this type, including restrictions on our ability to incur additional indebtedness or liens on our assets, except as permitted under the Facility Agreement. In addition, the Facility Agreement requires us to maintain consolidated cash and cash equivalents on the last day of each calendar quarter of not less than $2.0 million. As security for our repayment of our obligations under the Facility Agreement, we granted the lenders a security interest in substantially all of our property and interests in property. Subject to certain exceptions set forth in the Facility Agreement , holders representing a majority of the aggregate principal amount of the outstanding Notes issued pursuant to the Facility Agreement may elect to receive up to 25% of the net proceeds from any financing that includes an equity component. To the extent we raise additional capital in the future through the sale of common stock, including without limitation, sales of common stock pursuant to an “at-the-market” offering program, we may be obligated, at the election of the holders of the Notes, to pay 25% of the net proceeds from any such financing activities as partial payment of the Notes. Financing Derivative A number of features embedded in the Notes required accounting for 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, and (iv) the exercise of the warrant via offset to 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 Notes with and without the Financing Derivative by calculating the respective present values from future cash flows using a 9.6% and 10.3% weighted average market yield at December 31, 2018 and 2017, respectively. The estimated fair value of the Financing Derivative as of December 31, 2018 and 2017 was $0 and $0. 2 million, respectively. Notes We initially recorded the Notes and Warrants at $14.1 million and $6.4 million, respectively, based upon the relative fair value allocation of the $20.5 million of proceeds. The carrying value of the Notes at the inception of the debt was $12.8 million, resulting in an original issue discount of $7.7 million. As of both December 31, 201 8 and December 31, 201 7 , we had an outstanding principal amoun t of $16.0 million for the Notes, net of debt discount of $1.3 million and $2.4 million, respectively, resulting in a net $14.7 million and $13.6 million recorded as “Notes payable, non-current” on the consolidated balance sheets as of December 31, 201 8 and 201 7 , respectively, with repayment of all outstanding principal due in 2020 . As of December 31, 201 8 , payments due under the Facility Agreement, which include interest and principal, are as follows:    Amount  Years ending December 31, (in thousands)  2019 1,400  2020 16,491  Total remaining payments 17,891  Less: interest and discounts (3,232)  Notes payable $ 14,659  

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies [Abstract]
Commitments and Contingencies	NOTE 7. COMMITMENTS AND CONTINGENCIES Lease On July 22, 2015, we entered into a lease agreement (the “O’Brien Lease”) with respect to our facility located at 1305 O’Brien Drive, Menlo Park, California (the “O’Brien Premises”). 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; and, as such, $4.5 million was recorded at such time and continued to be recorded in “Long-term restricted cash” in the consolidated balance sheet as of both December 31, 2018 and December 31, 2017. The landlord was obligated to construct certain warm shell improvements at the landlord’s cost and expense and provide us with a tenant improvement allowance in the amount of $12.6 million. Construction was completed in phases and we began moving into the O’Brien Premises during January 2017. By the end of the first quarter of 2017, improvements associated with the entire O’Brien Premises were substantially completed. As a result, during the first quarter of 2017 we capitalized $28.8 million of tenant improvements, of which $12.6 million was paid by the landlord as a tenant improvement allowance. As the $12.6 million tenant improvement allowance is accounted for as a lease incentive, we recorded the $12.6 million to “Deferred rent, non-current”, which will be amortized over the lease term of approximately 11 years. In addition, as the premises were completed in phases in 2017, tenant improvements were placed into service in phases once construction was substantially complete and the related asset was ready for its intended use. As of December 31, 2018, the future annual minimum lease payments under all noncancelable operating leases with remaining terms in excess of one year are as follows:     Amount  Years ending December 31, (in thousands)  2019 $ 6,930  2020 7,056  2021 7,272  2022 7,488  2023 7,704  Thereafter 31,518  Total minimum lease payments $ 67,968   Rent expense for the years ended December 31, 2018, 2017 and 2016 was $6.2 million, $6.3 million and $0.2 million, respectively. We are also required to pay our share of operating expenses with respect to the facilities in which we operate. In addition, we had other purchase commitments of an estimated amount of approximately $13.1 million as of December 31, 2018, consisting of open purchase orders and contractual obligations in the ordinary course of business, including commitments with contract manufacturers and suppliers for which we have not received the goods or services, and acquisition and licensing of intellectual property. A majority of these purchase obligations are due within a year. Although open purchase orders are considered enforceable and legally binding, the terms generally allow us the option to cancel, reschedule and adjust our requirements based on our business needs prior to the delivery of goods or performance of services. Contingencies We become subject to 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 Proceedings Legal Proceedings Regarding the Merger In connection with the proposed acquisition of us by Illumina, five lawsuits were filed, with each lawsuit naming us and our directors as defendants. Three putative class action complaints, captioned Wang v. Pacific Biosciences of California, Inc., et al. , No. 3:18-cv-7450 (N.D. Cal.), Morrison v. Pacific Biosciences of California, Inc., et al. , No. 3:18-cv-7654 (N.D. Cal.), and Speiser v. Pacific Biosciences of California, Inc., et al. , No. 3:19-cv-0072 (N.D. Cal.), were filed in the United States District Court for the Northern District of California on December 11, 2018, December 20, 2018, and January 4, 2019, respectively. A fourth putative class action complaint, captioned Rosenblatt v. Pacific Biosciences of California, Inc., et al. , No. 1:18-cv-2005 (D. Del.), was filed in the United States District Court for the District of Delaware on December 18, 2018. An individual complaint, captioned Washington v. Pacific Biosciences of California, Inc., et al. , No. 5:18-cv-7614 (N.D. Cal.), was filed in the United States District Court for the Northern District of California on December 19, 2018. Each of the lawsuits asserted claims under Section 14(a) and Section 20(a) of the Securities Exchange Act of 1934 in connection with the disclosures contained in our preliminary proxy statement on Schedule 14A, filed with the Securities Exchange Commission (the “SEC”) on December 5, 2018, our definitive proxy statement on Schedule 14A, filed with the SEC on December 18, 2018, or both. The complaints sought a variety of equitable and injunctive relief including, among other things, enjoining the consummation of the acquisition and awarding the plaintiffs costs and attorneys’ fees. Although we believed that the claims were without merit, we agreed to make supplemental disclosures in exchange for plaintiffs’ agreement that the supplemental disclosures would moot their claims. We made these supplemental disclosures in a proxy statement amendment on Schedule 14A, filed with the SEC on January 18, 2019. On January 29, 2019, all parties to each of the lawsuits reached an agreement pursuant to which we would pay a total of $300,000 in attorneys’ fees to the plaintiffs. On January 29, 2019, each plaintiff filed a voluntary dismissal of his or her lawsuit. As of December 31, 2018, we accrued a total amount of $240,000 for the four lawsuits filed in 2018. USITC Proceedings On November 2, 2016, we filed a complaint against Oxford Nanopore Technologies Ltd. (“ONT Ltd.”), Oxford Nanopore Technologies, Inc. (“ONT Inc.”) and Metrichor, Ltd. (“Metrichor” and, together with ONT Ltd. and ONT Inc., “ONT”) with the U.S. International Trade Commission (“USITC”) for patent infringement. On December 5, 2016, the USITC provided notice that an investigation had been instituted based on the complaint. We sought exclusionary relief with respect to several ONT products, including ONT’s MinION and PromethION devices. The complaint was based on our U.S. Patent No. 9,404,146, entitled “Compositions and methods for nucleic acid sequencing” which covers novel methods for sequencing single nucleic acid molecules using linked double-stranded nucleic acid templates, providing improved sequencing accuracy. On March 1, 2017, we filed an amended complaint to add a second patent in the same patent family, U.S. Patent No. 9,542,527, which was granted on January 10, 2017, to the investigation. We sought, among other things, an exclusion order permanently barring entry of infringing ONT products into the United States, and a cease and desist order preventing ONT from advertising and selling infringing products in the United States. On May 23, 2017, the Administrative Law Judge (“ALJ”) assigned to the matter issued an order construing certain claim terms of the asserted patents. On June 8, 2017, ONT filed a summary determination motion to terminate the proceedings based on the ALJ’s claim construction decision, and we did not oppose the motion. The ALJ granted the motion on July 19, 2017, and, on July 31, 2017, we filed a petition to review with the USITC to correct what we believe was an incorrect construction of the claims. On September 5, 2017, the USITC issued a notice granting our petition to review the ALJ’s claim construction decision. On February 7, 2018, the USITC issued a notice indicating that it had determined to adopt the ALJ’s claim construction and terminating the investigation. On February 13, 2018, we filed a petition to appeal the USITC’s ruling to the U.S. Court of Appeals for the Federal Circuit . (“Federal Circuit”). An oral hearing for this appeal was held on February 8, 2019. On February 12, 2019, the Federal Circuit filed a judgement affirming the USITC claim construction under Federal Circuit Rule 36 without a written opinion. 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”), entitled “Nanopore sequencing using n-mers” which covers novel methods for nanopore sequencing of nucleic acid molecules using the signals from multiple monomeric units. This patent was granted on January 17, 2017. We are seeking remedies including injunctive relief, damages and costs. On May 8, 2017, the defendants filed a motion to dismiss the complaint, alleging that the asserted patent claims recite patent ineligible subject matter. On November 9, 2017, the judge denied ONT Inc.’s motion to dismiss. On June 1, 2018, we filed a motion for leave to amend the complaint to add ONT Ltd. as a defendant. On August 20, 2018, the judge granted our motion, and on August 23, 2018, we filed an amended complaint, adding ONT Ltd. as a defendant in the 275 Action. On September 24, 2018, ONT Ltd. filed a motion to dismiss the amended complaint, alleging failure to state a claim. On September 12, 2018, ONT Inc. filed its answer, defenses and counterclaims in the 275 Action, seeking declaratory judgements of non-infringement and invalidity of the ’400 Patent and unenforceability of the ’400 Patent based on alleged inequitable conduct before the U.S. Patent and Trademark Office (“USPTO”), as well as antitrust, false advertising, and unfair competition counterclaims. On September 25, 2018, it was stipulated that the motion to dismiss ONT Inc.’s counterclaims that we submitted in the 1353 Action would also serve as our motion to dismiss ONT Inc.’s counterclaims in the 275 Action. Related to the 275 Action, on March 15, 2018, ONT Inc. filed a petition to institute an inter partes review with the Patent Trial and Appeal Board (“PTAB”) of the USPTO, alleging invalidity of the ’400 Patent. On July 5, 2018, we filed a preliminary response outlining for the PTAB why the petition should be denied, and no review should be instituted. On September 25, 2018, the PTAB denied ONT Inc.’s petition for institution of the inter partes review for all claims of the ’400 Patent. 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”) entitled “Control of Enzyme Translation in Nanopore Sequencing”, granted June 13, 2017, and U.S. Patent No. 9,738,929 (the “’929 Patent”) entitled “Nucleic Acid Sequence Analysis”, granted August 22, 2017. We are seeking remedies including injunctive relief, damages and costs. On December 14, 2017, the defendants filed a motion to dismiss the complaint, alleging that the asserted patent claims in the ’929 Patent recite patent ineligible subject matter. On March 22, 2018, the judge denied ONT Inc.’s motion to dismiss. On March 28, 2018, we added a claim for infringement of our U.S. Patent No. 9,772,323 (the “’323 Patent”), entitled “Nanopore sequencing using n-mers.” On June 1, 2018, we filed a motion for leave to amend the complaint to add ONT Ltd. as a defendant. On August 20, 2018, the judge granted our motion, and on August 23, 2018 we filed an amended complaint, adding ONT Ltd. as a defendant in the 1353 Action. On September 24, 2018, ONT filed a motion to dismiss the amended complaint, alleging failure to state a claim. On April 25, 2018, ONT Inc. filed its answer, defenses and counterclaims in the 1353 Action, seeking declaratory judgements of non-infringement and invalidity of the ’056 and ’323 Patents and unenforceability of the ’056 and ’323 Patents based on alleged inequitable conduct before the USPTO, as well as antitrust, false advertising, and unfair competition counterclaims. On June 15, 2018, we filed a motion to dismiss ONT Inc.’s counterclaims in the 1353 Action and, on June 18, 2018, we filed a motion to bifurcate and stay discovery on ONT Inc.’s antitrust counterclaims in the 1353 Action. On February 19, 2019, the judge granted our motion to dismiss ONT’s antitrust, false advertising, and unfair competition counterclaims.  Related to the 1353 Action, on September 24, 2108, ONT Inc. filed a first petition to institute an inter partes review with the PTAB of the USPTO, alleging invalidity of the ’929 Patent. On September 25, 2018, ONT filed a second petition to institute an inter partes review of the ’929 Patent based on the same art and arguments as the first petition. ONT Inc. subsequently filed a motion to withdraw the first petition, which motion was granted. On January 11, 2019, we filed a preliminary response to the second petition outlining for the PTAB why the petition should be denied, and no review should be instituted. Also related to the 1353 Action, on September 25, 2018, ONT Inc. filed a petition to institute an inter partes review with the PTAB of the USPTO, alleging invalidity of the ’056 Patent. On February 13, 2019, we filed a preliminary response to the second petition outlining for the PTAB why the petition should be denied and no review should be instituted. A claim construction (or “ Markman ”) hearing for the U.S. District Court matters was held on December 17, 2018. A trial for the U.S. District Court matters is scheduled to occur in March 2020. UK and German Court Proceedings On February 2, 2017, we filed a claim in the High Court of England and Wales against ONT Ltd. and Metrichor for infringement of Patent EP(UK) 3 045 542 (the “’542 Patent”), which is in the same patent family as the patents asserted in the USITC action referred to above. We sought remedies including injunctive relief, damages, and costs. On March 27, 2017, the defendants in the case filed their defense and counterclaim, denying infringement and seeking a declaration that the asserted patent is invalid. We filed our reply and defense to counterclaim on April 12, 2017. A case management conference was held on June 13, 2017. On August 31, 2017 we added a claim for infringement of a newly granted divisional, EP(UK) 3 170 904 (the “’904 Patent”). On December 22, 2017, ONT Ltd. added to the action a request for declaration of non-infringement of its 1D2 product. On January 12, 2018 we served reply to ONT Ltd.’s request for a declaration of non-infringement, asserting infringement of both patents by ONT’s 1D2 product. A trial for these matters was scheduled to occur in May 2018. On April 21, 2017, ONT Ltd. and Harvard University filed a claim against us in the High Court of England and Wales for infringement of Patent EP(UK) 1 192 453 (the “’453 Patent”), a patent owned by Harvard University and entitled “Molecular and atomic scale evaluation of biopolymers,” and for which ONT Ltd. alleges it holds an exclusive license. ONT Ltd. and Harvard University sought remedies including injunctive relief, damages, and costs. On April 25, 2017, ONT Ltd. announced that it also had filed a claim against us in the District Court of Mannheim, Germany, for infringement of the German version of the patent. On November 2, 2017, we filed our statement of defense in the German infringement matter and we also filed a separate nullity action in Germany to establish that the ’453 Patent is invalid. On December 6, 2017, we filed a cross-complaint in the German infringement matter alleging ONT Ltd.’s infringement in Germany of our ’542 Patent. The trial date for the German infringement matter and cross-complaint was set for July 27, 2018. A trial for the UK matter was scheduled to occur in March 2019. On May 8, 2018, the parties entered a settlement of all UK and German court proceedings pending as of such date. Under the terms of the settlement, ONT agreed not to make, dispose of, use or import any “2D” nanopore sequencing products, or to induce or assist others to carry out a “2D” sequencing process, in the UK or Germany, through the end of 2023. During this time, we agreed not to assert the ’542 Patent and ’904 Patent against either ONT or its customers in the UK or Germany. Accordingly, the High Court of England and Wales entered an order staying our UK action against ONT through the end of 2023. As part of the settlement, ONT and Harvard University dismissed their UK and German actions under the ’453 Patent and agreed not to assert the ’453 Patent against us or our customers through the end of 2023. We correspondingly agreed to dismiss our separate German nullity action seeking to invalidate the ’453 Patent, which expires on June 22, 2020. Related to these proceedings, on August 15, 2017, ONT Ltd. filed a notice of opposition to our ’542 Patent with the European Patent Office, and on August 16, 2017, an anonymous party filed a second notice of opposition to the same patent, each alleging invalidity of the patent. On April 5, 2018, we filed our response to the combined opposition. On January 22, 2019, an oral hearing in the matter occurred and the European Patent Office rendered a decision in favor of the opponents. We believe the European Patent Office erred in its decision, which we intend to appeal. The ’542 Patent will remain in effect while the appeal is pending. Furthermore, our settlement agreement with ONT Ltd. and Harvard University remains in effect. Also related to these proceedings, on May 16, 2018, ONT Ltd. filed a notice of opposition to our ’904 Patent with the European Patent Office alleging invalidity of the ’904 Patent. On October 11, 2018, we filed our response to the opposition. An oral hearing in the matter is scheduled for July 16, 2019. Litigation is inherently unpredictable, and it is too early in the proceedings to predict the outcome of these lawsuits or any impact they may have on us. As such, the estimated financial effect associated with these complaints cannot be made as of the date of filing of this Annual Report on Form 10-K. Litigation is a significant ongoing expense with an uncertain outcome, and has been in the past and may in the future be a material expense for us. Management believes this investment is important to protect our intellectual property position, even recognizing the uncertainty of the outcome. 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 fund raising 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 fund raising 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 at December 31, 2018.  

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Taxes [Abstract]
Income Taxes	NOTE 8. 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 G lobal Intangible Low-taxed Income as a period cost. During the years ended December 31, 2018, 2017, and 2016 income before taxes from U.S. operations were ( $103.1 ) million, ( $92.7 ) million and ( $74.0 ) million, respectively, and income before taxes from foreign operations was $0.8 million, $1.0 million and ( $0.3 ) 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 loss as follows (in thousands):     Years ended December 31,  2018 2017 2016  Statutory tax rate 21.0 % 35.0 % 35.0 %  State tax rate, net of federal benefit 3.5 8.6 5.4  Stock-based compensation (1.6) (1.9) (1.6)  Tax credits 2.0 3.6 5.0  Remeasurement of deferred taxes due to tax reform - (123.3) -  Other (0.1) 0.3 (0.9)  Change in valuation allowance (24.8) 77.7 (42.9)  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: 2018 2017  Net operating loss carryforwards $ 212,424 $ 194,440  Research and development credits 42,635 39,145  Accruals and reserves 19,356 14,480  Deferred rent 3,315 3,360  Total deferred tax assets 277,730 251,425  Less: Valuation allowance (275,540) (249,202)  Total deferred tax assets: 2,190 2,223  Fixed assets (2,190) (2,223)  Total deferred tax liabilities (2,190) (2,223)  Net deferred tax assets $ — $ —  At December 31, 2018, we maintained a full valuation allowance against all of our deferred tax assets which totaled $27 5.5 million, including net operating loss carryforwards and research and development credits of $212.4 million and $42.6 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, 2018 and 2017, respectively. For the year ended December 31, 2018, our valuation allowance increased to $275.5 million primarily because of an increase to our net operating losses, and credits and changes in book to tax timing differences. For the year ended December 31, 201 7 , our valuation allowance de creased to $2 49.2 million primarily due to the Tax Cuts and Job Act of 2017. As of December 31, 2018, we had a net operating loss carryforward for federal income tax purposes of approximately $832 million, portion of which will begin to expire in 2024 . We had a total state net operating loss carryforward of approximately $566.6 million, which have expiration dates of 2018 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 $33.7 million, which will begin to expire in 2024 if not utilized and state research credits of approximately $34.4 million which have no expiration date. These tax credits are subject to the same limitations discussed above. As of December 31, 2018, our total unrecognized tax benefit was $20.4 million. A reconciliation of the beginning and ending unrecognized tax benefit balance is as follows (in thousands):     Decrease in balance related to tax positions taken in prior year $ (44)  Increase in balance related to tax positions taken during current year 1,827  Balance as of December 31, 2015 18,735  Increase in balance related to tax positions taken in prior year 1,942  Decrease in balance related to tax positions taken in current year (3,892)  Balance as of December 31, 2016 16,785  Decrease in balance related to tax positions taken in prior year —  Increase in balance related to tax positions taken during current year 2,001  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  Our practice is to recognize interest and/or penalties related to income tax matters in income tax expense. As of December 31, 2018 and 2017, 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 ha ve 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, 2015 to present and December 31, 2014 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. On December 22, 2017, the 2017 Tax Cuts and Jobs Act (Tax Act) was enacted into law and the new legislation contains several key tax provisions that affected us, including a one-time mandatory transition tax on accumulated foreign earnings and a reduction of the corporate income tax rate to 21% effective January 1, 2018, among others. We are required to recognize the effect of the tax law changes in the period of enactment, such as determining the transition tax, remeasuring our U.S. deferred tax assets and liabilities as well as reassessing the net realizability of our deferred tax assets and liabilities. In December 2017, the SEC staff issued Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (SAB 118), which allowed us to record provisional amounts during a measurement period not to extend beyond one year of the enactment date. As a result, we previously provided a provisional estimate of the effect of the Tax Act in our financial statements. In the fourth quarter of 2018, we completed our analysis to determine the effect of the Tax Act and recorded immaterial adjustments as of December 31, 2018.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2018
Stockholders' Equity [Abstract]
Stockholders' Equity	NOTE 9. 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, 2018 and 2017, 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. “At-the-Market” Offering For the year ended December 31, 2017, we issued 3.2 million shares of our common stock at an average price of $3.86 per share through our “at-the-market” offering program, resulting in net proceeds of $11.9 million. We terminated our “at-the-market” offering program in June 2017. We paid a commission equal to 3% of the gross proceeds from the sale of shares of our common stock under the sales agreement. Underwritten Public Equity Offerings In August 2017, we filed a shelf registration statement on Form S-3 with the SEC pursuant to which we may, from time to time, sell up to an aggregate of $150.0 million of our common stock, preferred stock, depository shares, warrants, units or debt securities. On August 18, 2017, the registration statement was declared effective by the SEC, which allows us to access the capital markets for the three-year period following this effective date. In June 2017, we issued and sold a total of 17.7 million shares of our common stock at a price to the public of $3.10 per share in an underwritten public offering. We paid a commission equal to 4% of the gross proceeds from the sale of shares of our common stock under the underwriting agreement. The total proceeds to us from the offering, after deducting the underwriting commission and offering expenses, were approximately $52.5 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. Subject to certain exceptions set forth in our Facility Agreement, holders of our Notes may elect to receive up to 25% of the net proceeds from financing activities that include an equity component as prepayment of the Notes to be applied first, to accrued and unpaid interest and second, to principal. However, in both February 2018 and September 2018, holders representing a majority of the aggregate principal amount of the outstanding Notes waived such right in connection with the issuance and sale of shares of common stock in our public offering. In June 2017, pursuant to a partial exercise by the Notes holders of this right, we repaid $4.5 million of outstanding principal, together with accrued and unpaid interest, to one of the Notes holders with proceeds from our underwritten public equity offering. Warrants In connection with the execution of the Facility Agreement, we issued immediately exercisable warrants to purchase 5.5 million shares of common stock at an exercise price per share initially equal to $2.63 , all of which were net exercised during 2016 resulting in the issuance of approximately 4.2 million shares. The cashless net exercise of the warrants did not result in any additional funds being collected by us. As of December 31, 2018 and 2017, no warrants remained outstanding. Equity Plans As of December 31, 2018, we had three active equity plans: 1) the 2010 Equity Incentive Plan or “2010 Plan,” 2) the 2010 Outside Director Equity Incentive Plan or “2010 Director Plan,” and 3) the 2010 ESPP, all of which we adopted upon the effectiveness of our initial public offering in October 2010. Prior to the adoption of these plans, we granted options pursuant to the 2004 Equity Incentive Plan and 2005 Stock Plan. Upon termination of the predecessor plans, the shares available for grant at the time of termination and shares subsequently returned to the plans upon forfeiture or option termination, were transferred to the successor plan in effect at the time of share return. Under the 2010 Plan, with the approval of the Compensation Committee of the Board of Directors, we may grant restricted stock, Restricted Stock Units (“RSU”), stock appreciation rights and new shares of common stock upon exercise of stock options. 2010 Equity Incentive Plan and Outside Director Equity Incentive Plan Stock options granted under the 2010 Plan may be either Incentive Stock Option (“ I SO”) or Non-Qualified Stock Option (“NSO”). ISOs may be granted only to employees. NSOs may be granted to employees, consultants and directors. Stock options under the 2010 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 employees vest at a rate of 25% upon the first anniversary of the vesting commencement date and 1/48th per month thereafter. In January 2019, an additional 7.5 million shares were reserved under the 2010 Plan. Stock options granted under the 2010 Director Plan provide for the grant of NSOs. Stock options under the 2010 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 directors generally vest over one year on a monthly basis and stock options granted to new directors generally vest over three years at a rate of one -third upon the first anniversary of the vesting commencement date and 1/36th per month thereafter. As of December 31, 2018 we had an aggregate of 11.3 million shares of common stock reserved for future issuance under the 2010 Plan and 2010 Director Plan. Stock Options The following table summarizes stock option activity for all stock option plans for the year ended December 31, 2018 (in thousands, except per share amounts):     Stock Options Outstanding  Shares available Number Weighted average  for grant of shares Exercise price exercise price  Balances, December 31, 2017 6,795 25,404 $ 1.16 – 16.00 $ 6.10  Additional shares reserved 6,976  Options granted (4,204) 4,204 $ 2.47 – 4.28 $ 2.57  Options exercised — (1,720) $ 1.16 – 7.05 $ 3.73  Options canceled 2,712 (2,712) $ 1.16 – 16.00 $ 6.19  Balances, December 31, 2018 12,279 25,176 $ 1.16 – 16.00 $ 5.66  The expired options as of December 31, 2018 totaled 1.2 million with exercise price range from $1.16 to $16.00 and weighted average exercise price per share of $7.15 .  The following table summarizes information with respect to stock options outstanding and exercisable under the plans at December 31, 2018:     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 – 1.60 438,233 3.84 $ 1.18 438,233 $ 1.18  $ 1.60 – 3.20 6,141,372 7.30 $ 2.53 2,877,885 $ 2.47  $ 3.20 – 4.80 3,587,706 4.63 $ 4.07 3,064,649 $ 4.10  $ 4.80 – 6.40 6,390,401 6.98 $ 5.45 4,258,318 $ 5.53  $ 6.40 – 8.00 2,868,379 5.74 $ 7.19 2,604,086 $ 7.14  $ 8.00 – 9.60 3,560,966 5.24 $ 8.77 2,853,592 $ 8.76  $ 9.60 – 11.20 1,293,448 5.82 $ 10.20 1,035,715 $ 10.23  $ 11.20 – 12.80 449,502 2.00 $ 12.13 449,502 $ 12.13  $ 12.80 – 14.40 323,250 1.08 $ 13.94 3,227,035 $ 13.94  $ 14.40 – 16.00 122,750 1.49 $ 15.99 122,750 $ 15.99  25,176,007 6.03 $ 5.66 18,027,465 $ 6.09   The aggregate intrinsic value of the outstanding and exercisable options presented in the table above totaled $ 58.0 million and $35.9 million, respectively. The aggregate intrinsic value represents the total pretax intrinsic value (i.e., the difference between $7.40 , our closing stock price on the last trading day of our fourth quarter of 2018 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, 2018. 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 5.08 years. The vested and expected to vest options as of December 31, 2018 totaled 22,475,000, with aggregate intrinsic value of $50.2 million, weighted average exercise price per share of $5.75 and weighted average remaining contractual life of 5.75 years. The total intrinsic value of stock options exercised during the years ended December 31, 2018, 2017 and 2016 was $5.3 million, $1.7 million and $4.7 million, respectively. The total fair value of stock options vested during the years ended December 31, 2018, 2017 and 2016 was $3.9 million, $6.4 million and $20.7 million, respectively . Time-based RSUs Beginning in the first quarter of 2018, the Compensation Committee of the Board of Directors has approved awards of RSUs with time-based vesting from the 2010 Plan to certain employees. Each RSU represents one equivalent share of our common stock to be awarded after the vesting 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. The number of RSUs vested includes shares of common stock that we will withhold on behalf of employees to satisfy the minimum statutory tax withholding requirements. 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, 2018 (in thousands, except per share amounts):    Weighted average  Number grant date  of shares fair value  RSUs outstanding at December 31, 2017 — $ —  RSUs granted 413 3.14  RSUs released — —  RSUs forfeited (42) 2.54  Unvested RSUs outstanding at December 31, 2018 371 $ 3.20  For the years ended December 31, 2018, we recognized compensation expense of $193,000 related to time-based RSUs. Performance-based RSUs During the first quarter of 2018, the Compensation Committee of the Board of Directors approved awards of RSUs with performance-based vesting from 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. The number of RSUs vested includes shares of common stock that we will withhold on behalf of employees to satisfy the minimum statutory tax withholding requirements. 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, 2018 (in thousands, except per share amounts):    Weighted average  Number grant date  of shares fair value  PSUs outstanding at December 31, 2017 — $ —  PSUs granted 657 2.58  PSUs released — —  PSUs forfeited (71) 2.54  Unvested PSUs outstanding at December 31, 2018 586 $ 2.58  For the year ended December 31, 2018, we recognized compensation expense of $614,000 related to performance-based RSUs. 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. For the years ended December 31, 2018, 2017 and 2016, 1,674,960 shares, 1,289,663 shares and 1,259,239 shares of common stock were purchased under the ESPP, respectively. As of December 31, 2018, 1,952,507 shares of our common stock remain available for issuance under our ESPP. 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. During January 2019, an additional 3.0 million shares were reserved under the ESPP. Per the terms of the Merger Agreement, the 2010 ESPP Plan will be terminated after the March 1, 2019 ESPP purchase. As a result, a pproximately $2.5 million of ES PP expense was accelerated and recognized in the fourth quarter of 2018.  Stock-based Compensation Total stock-based compensation expense consists of the following (in thousands):     Years Ended December 31,  2018 2017 2016  Cost of revenue $ 3,124 $ 2,311 $ 2,133  Research and development 10,076 8,506 8,257  Sales, general and administrative 9,953 9,535 9,172  Total stock-based compensation expense $ 23,153 $ 20,352 $ 19,562  As of December 31, 2018 and 2017, $0.7 million and $0.4 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, 2018, 2017 and 2016. Stock Options We estimated the fair value of employee stock option s 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 years ended December 31, 2018, 2017 and 2016, the weighted average fair value at grant date per stock option was $1.50 , $3.08 and $5.47 , respectively. We recorded stock-based compensation expense for stock options of $15.5 million, $17.2 million and $15.7 million for the years ended December 31, 2018, 2017 and 2016, respectively. For the years ended December 31, 2018, 2017 and 2016, the fair value of employee stock options was estimated using the following weighted average assumptions:     Years Ended December 31,  2018 2017 2016  Expected term (years) 5.2 years 6.1 years 6.1 years  Expected volatility 66.8% 70.0% 70.0%  Risk-free interest rate 2.6% 2.1% 1.5%  Dividend yield — — —   As of December 31, 2018, $ 14.3 million of total unrecognized compensation expense related to stock options was expected to be recognized over a weighted-average period of 2.0 years. Future option grants will increase the amount of compensation expense to be recorded in those future periods. Cash received from option exercises for the years ended December 31, 2018, 2017 and 2016 was $6.3 million, $3.6 million and $2.5 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, 2018, 2017 and 2016, weighted average fair value at grant date for shares to be issued under the ESPP was $1.47 , $2.28 and $4.21 , respectively. We recorded stock-based compensation expense for ESPP of $6.8 million, $3.1 million and $3.7 million for the years ended December 31, 2018, 2017 and 2016, respectively. Per the terms of the Merger Agreement, the ESPP will be terminated after the March 1, 2019 ESPP purchase. As a result, a pproximately $2.5 million of ES PP expense was accelerated and recognized in the fourth quarter of 2018.  For the years ended December 31, 2018, 2017 and 2016, the fair value of shares to be issued under the ESPP was estimated using the following assumptions:    Years Ended December 31,  2018 2017 2016  Expected term (years) 0.5 - 2.0 0.5 - 2.0 0.5 - 2.0  Expected volatility 65% - 67% 70.0% 70.0%  Risk-free interest rate 1.3%-2.7% 0.8%-1.4% 0.5%-0.9%  Dividend yield — — —  Cash received thro ugh the ESPP for the years ended December 31, 2018, 2017 and 2016 was $3.4 million, $5.3 million and $5.2 million, respectively .

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2018
Net Loss Per Share [Abstract]
Net Loss Per Share	NOTE 10. NET LOSS PER SHARE  The following options outstanding, time-based RSUs and performance-based RSUs 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) 2018 2017 2016  Options to purchase common stock 25,176 25,404 22,501  RSUs with time-based vesting 371 — —  RSUs with performance-based vesting 586 — —  

Segment And Geographic Informat

Segment And Geographic Information	12 Months Ended
	Dec. 31, 2018
Segment And Geographic Information [Abstract]
Segment And Geographic Information	NOTE 11. 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, 2018, 2017 and 2016 is as follows, with Roche related contractual revenue classified as revenue from the United States:     Years Ended December 31,  (in thousands) 2018 2017 2016  North America $ 35,598 $ 40,641 $ 50,871  Europe (including the Middle East and Africa) 13,958 14,026 21,132  Asia Pacific 29,070 38,801 18,711  Total $ 78,626 $ 93,468 $ 90,714 

Unaudited Selected Quarterly Fi

Unaudited Selected Quarterly Financial Data	12 Months Ended
	Dec. 31, 2018
Unaudited Selected Quarterly Financial Data [Abstract]
Unaudited Selected Quarterly Financial Data	NOTE 12. UNAUDITED SELECTED QUARTERLY FINANCIAL DATA The following tables summarize the unaudited quarterly financial data for the last two fiscal years:     Fiscal 2018 Quarter Ended  (in thousands, except per share data) March 31, June 30, September 30, December 31,  Total revenue $ 19,362 $ 21,578 $ 18,160 $ 19,526  Total gross profit 7,296 8,862 3,192 5,746  Total operating expenses 31,245 30,607 27,862 36,369  Loss from operations (23,949) (21,745) (24,670) (30,623)  Net loss (24,179) (22,540) (25,044) (30,799)  Basic and diluted net loss per share $ (0.20) $ (0.17) $ (0.19) $ (0.21)  Weighted average shares used in computing net loss per share 123,768 131,882 135,130 149,314   Fiscal 2017 Quarter Ended  (in thousands, except per share data) March 31, June 30, September 30, December 31,  Total revenue $ 24,915 $ 20,073 $ 23,545 $ 24,935  Total gross profit 8,937 8,001 8,227 9,494  Total operating expenses 32,236 32,388 29,796 30,023  Loss from operations (23,299) (24,387) (21,569) (20,529)  Net loss (23,867) (25,539) (22,021) (20,762)  Basic and diluted net loss per share $ (0.26) $ (0.26) $ (0.19) $ (0.18)  Weighted average shares used in computing net loss per share 92,970 97,360 115,771 116,259    

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2018
Subsequent Event [Abstract]
Subsequent Event	NOTE 13. SUBSEQUENT EVENT As disclosed in our Current Report on Form 8-K filed with the Securities and Exchange Commission on February 19, 2019, our board of directors (the “Board”) reinstated the base salaries and target bonus opportunities of Michael Hunkapiller, Ph.D., our Chief Executive Officer, and Susan K. Barnes, our Chief Financial Officer, as part of our annual executive compensation review process. Increases in Base Salaries: On February 15, 2019, the following annual base salary increases for Dr. Hunkapiller and Ms. Barnes were implemented, effective January 1, 2019:    Name 2018 Base Salary 2019 Base Salary  Michael Hunkapiller, Ph.D. $ 1.00 $ 582,900  Susan K. Barnes $ 1.00 $ 401,500   2019 Performance Bonuses: In connection with the annual base salary increases noted above, for our 2019 fiscal year, Dr. Hunkapiller’s annual target bonus opportunity was set at 100% of his base salary and Ms. Barnes’ annual target bonus opportunity was set at 65% of her base salary. Consistent with prior years, Dr. Hunkapiller and Ms. Barnes did not participate in our 2018 bonus plan. The 2019 bonuses for both Dr. Hunkapiller and Ms. Barnes will be based upon the achievement of performance objectives that consist of corporate operational, product performance and financial metrics, each with separate, varied weightings, and that are aggressive, but attainable, and align the compensation of Dr. Hunkapiller and Ms. Barnes with the priorities for our company .  2019 RSU Grant: In addition, on February 15, 2019, we granted a restricted stock unit award to each of Dr. Hunkapiller and Ms. Barnes covering 38,750 shares of our common stock and 21,250 shares of our common stock, respectively (the “ RSU Awards ”). The RSU Awards are scheduled to vest on the earlier of the (i) one -year anniversary of the date of grant of the RSU Awards and (ii) the completion of the Merger, subject to the recipient’s continued service with us through the vesting date. 

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2018
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.
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, revenue recognition, the valuation of a financing derivative and long-term notes, the valuation and recognition of share-based compensation, the useful lives assigned to long-lived assets, and the computation provisions for income taxes. Actual results could differ materially from these estimates. During 2017, we recorded a charge to cost of service and other revenue of $1.6 million relating to leased RS II instruments primarily due to a change in the estimated useful life of these instruments. The charge of $1.6 million increased loss per share by $0.01 for the year ended December 31, 2017.
Fair Value of Financial Instruments	Fair Value of Financial Instruments 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. The carrying value of our other liabilities, non-current, approximates fair value due to the time to maturity and prevailing market rates. 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. A financial instrument’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. 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. 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, 2018 and December 31, 2017 respectively (in thousands):      December 31, 2018 December 31, 2017  (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 $ 18,844 $ — $ — $ 18,844 $ 14,858 $ — $ — $ 14,858  Commercial paper — — — — — 1,649 — 1,649  Total cash and cash equivalents 18,844 — — 18,844 14,858 1,649 — 16,507  Investments:  Commercial paper — 53,469 — 53,469 — 20,394 — 20,394  Corporate debt securities — 10,214 — 10,214 — 9,034 — 9,034  US government & agency securities — 19,827 — 19,827 — 16,937 — 16,937  Total investments — 83,510 — 83,510 — 46,365 — 46,365  Long-term restricted cash:  Cash 4,500 — — 4,500 4,500 — — 4,500  Total assets measured at fair value $ 23,344 $ 83,510 $ — $ 106,854 $ 19,358 $ 48,014 $ — $ 67,372   Liabilities  Financing derivative $ — $ — $ 16 $ 16 $ — $ — $ 183 $ 183  Total liabilities measured at fair value $ — $ — $ 16 $ 16 $ — $ — $ 183 $ 183   The estimated fair value of the Financing Derivative liability (as defined in “Note 6. Notes Payable’) was determined using Level 3 inputs, or significant unobservable inputs. Refer to “Note 6. Notes Payable” for a detailed description and valuation approach. Changes to the estimated fair value of the Financing Derivative are recorded in “Other income (expense), net” in the consolidated statements of operations and comprehensive loss. The following table provides the changes in the fair value of the Financing Derivative for the years ended December 31, 2018 and 2017 (in thousands), respectively:     Financing Derivative Amount  Balance as of December 31, 2016 $ 356  Loss on change in fair value of Financing Derivative 653  Change in fair value due to partial exercise of derivative associated with $4.5 million principal payoff (826)  Balance as of December 31, 2017 183  Gain on change in fair value of Financing Derivative (167)  Balance as of December 31, 2018 $ 16  For the year ended December 31, 2018, 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. Financial Assets and Liabilities Not Measured at Fair Value on a Recurring Basis We determined the fair value of the Notes (as defined in “Note 6. Notes Payable”) from the debt facility we entered into during the first quarter of 2013 using Level 3 inputs, or significant unobservable inputs. The value of the Notes was determined by comparing the difference between the fair value of the Notes with and without the Financing Derivative by calculating the respective present values from future cash flows using a 9.6% and 10.3% weighted average market yield at December 31, 2018 and December 31, 2017, respectively. Refer to “Note 6. Notes Payable” for additional details regarding the Notes. The estimated fair value and carrying value of the Notes are as follows (in thousands):      December 31, 2018 December 31, 2017  Fair Value Carrying Value Fair Value Carrying Value  Long-term notes payable $ 15,915 $ 14,659 $ 15,664 $ 13,635 
Cash And Cash Equivalents	Cash and Cash Equivalents We consider all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents.
Investments	Investments 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. 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 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, 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. During the years ended December 31, 2018, 2017 and 2016, we did not recognize 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.
Concentration and Other Risks	Concentration and Other Risks 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. Our accounts receivable 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. We regularly review our accounts receivable including consideration of factors such as historical experience, credit quality, the age of the accounts receivable balances and current economic conditions that may affect a customer’s ability to pay. We have not experienced any significant credit losses to date. Excluding contractual revenue from the Roche agreement, which has now been terminated, for the year ended December 31, 2018 and 2017, one customer , Gene Company Limited, accounted for approximately 26% and 31% of our total revenue, respectively. For the years ended December 31, 2016, no customer accounted for more than 10% of our total revenue. As of December 31, 2018 and 2017, 50% and 84% of our accounts receivable were from domestic customers, respectively. As of December 31, 2018 and 2017, one customer, Gene Company Limited, represented approximately 14% and 20% of our net accounts receivable , respectively. We currently purchase several key parts and components used in the manufacture of our products from a limited number of suppliers. Generally we have been able to obtain an adequate supply of such parts and components. 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.
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 to three years for computer equipment, three to five years for software, three to seven years for furniture and fixtures and three 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.
Long-Term Restricted Cash	Long-term Restricted Cash As required under the lease agreement for our corporate offices (the “O’Brien lease”), 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; and, as such, $4.5 million was recorded in “Long-term restricted cash” in the consolidated balance sheet as of such year and continued to be so recorded as of both December 31, 2018 and December 31, 2017.
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 not recorded any impairment charges.
Going Concern	Going concern We may raise additional capital in the future. To the extent we raise additional funds through the sale of equity or convertible debt, the issuance of such securities will result in dilution to our stockholders. There can be no assurance that such funds will be available on favorable terms, or at all, particularly in light of restrictions under our debt agreement and the Merger Agreement . If adequate funds are not available, we may be required to obtain funds by entering into collaboration, licensing or debt agreements on unfavorable terms. If we are unable to raise funds on favorable terms, or at all, we may have to reduce our cash burn rate and may not be able to support our commercialization efforts, or to increase or maintain the level of our research and development activities. If we are unable to generate sufficient cash flows or to raise adequate funds to finance our forecasted expenditures, we may have to make significant changes to our operations, including delaying or reducing the scope of or eliminating some or all of our development programs. We also may have to reduce sales, marketing, engineering, customer support or other resources devoted to our existing or new products or cease operations. If our cash, cash equivalents and investments are insufficient to fund our projected operating requirements, and we are unable to raise capital, it would have a material adverse effect on our business, financial condition and results of operations.
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 consist primarily of revenue earned from product maintenance agreements with some additional revenue from instrument lease agreements and grant revenue. 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 an 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 primarily consist of deferred revenue. We record deferred service revenues when cash payments are received or due in advance of our performance for product maintenance agreements. Deferred service revenue is recognized over the related performance period, generally one 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. As of December 31, 2018, we had a total of $7.4 million of deferred service revenue from our service contracts, $6.5 million of which was recorded as “deferred service revenue, current” to be recognized over the next year and the remaining $0.9 million was recorded as “deferred service revenue, non-current” to be recognized in the next 2 to 5 years. Revenue recognized during the year ended December 31, 2018 includes $6.3 million of previously deferred revenue that was included in “deferred service revenue, current” as of December 31, 2017. Contract assets as of December 31, 2017 and December 31, 2018 were not material. Instrument lease agreements - Instrument leases are generally classified as operating-type leases and revenue from these leases is recognized on a straight-line basis over the respective lease term, once the lessee takes (or has the right to take) control/possession of the property under the lease. Effectively, this occurs once the installation is complete and control of the instrument is transferred to our customers. 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.
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. We record tenant improvement allowances as deferred rent liabilities and amortize the deferred rent over the term of the lease to rent expense on the statements of operations and comprehensive loss.
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 Stock-based compensation expense for all stock-based compensation awards , including stock options and also including shares issued under 2010 Employee Stock Purchase Plan (“ESPP”), is based on the grant date fair value estimated using the Black-Scholes option pricing model. Expected Term . Starting January 1, 2018, we determined the expected term using historical option experience . We determined expected term based on historical exercise patterns and an expectation of the time it will take for employees to exercise options still outstanding. Prior to 2018, we did not believe that we were able to rely on our historical employee exercise behavior to provide accurate data for estimating our expected term for use in determining the fair value of these options due to limited trading history. Therefore, for the period prior to 2018, the period the expected term of options is estimated based on the simplified method. Expected Volatility . Starting January 1, 2018, we estimate the volatility of our common stock at the date of grant based on the historical volatility of our common stock. Prior to 2018, we did not have sufficient trading history to solely rely on the volatility of our own common stock for establishing expected volatility. Therefore, we based our expected volatility on the historical stock volatilities of our common stock as well as several comparable publicly listed companies over a period equal to the expected term of the options. Risk-Free Rate. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for the expected term of the stock option. Dividends. We have never paid any cash dividends on our common stock and we do not anticipate paying any cash dividends in the foreseeable future. Consequently, we use an expected dividend yield of zero in the Black-Scholes option valuation model. Expected Forfeiture Rate. We estimate our forfeiture rate based on an analysis of our actual forfeitures and will continue to evaluate the adequacy of the forfeiture rate based on actual forfeiture experience, analysis of employee turnover behavior and other factors. The impact from a forfeiture rate adjustment will be recognized in full in the period of adjustment, and if the actual number of future forfeitures differs from that which was estimated, we may be required to record adjustments to stock-based compensation expense in future periods. We recognize compensation expense on a straight-line basis over the requisite service period. We elected to use the simplified method to calculate the beginning pool of excess tax benefits.
Other Comprehensive Income (Loss)	Other Comprehensive Income (loss) Other comprehensive income (loss) is comprised of unrealized gains (losses) on our investment securities.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Recently Issued Accounting Standards In June 2018, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2018-07, Improvements to Nonemployee Share-Based Payment Accounting , to simplify the accounting for nonemployee share-based payment transactions by expanding the scope of Accounting Standards Codification, or ASC, Topic 718, Compensation - Stock Compensation, to include share-based payment transactions for acquiring goods and services from nonemployees. Under the new standard, most of the guidance on stock compensation payments to nonemployees would be aligned with the requirements for share-based payments granted to employees. This standard is effective for annual reporting periods beginning after December 15, 2018, including interim reporting periods within those annual reporting periods, with early adoption permitted. We expect to adopt this standard beginning in 2019. While we continue to assess the potential impact of this standard, we do not expect the adoption of this standard to have a material impact on our consolidated financial statements. In February 2018, the FASB issued ASU 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income , that allows for an entity to elect to reclassify the income tax effects on items within accumulated other comprehensive income resulting from U.S. tax reform to retained earnings. The guidance is effective for fiscal years beginning after December 15, 2018 with early adoption permitted, including interim periods within those years. We expect to adopt this standard beginning in 2019. While we continue to assess the potential impact of this standard, we do not expect the adoption of this standard to have a material impact on our consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases. The guidance in ASU 2016-02 supersedes the lease recognition requirements in ASC Topic 840, Leases. ASU 2016-02 requires an entity to recognize assets and liabilities arising from a lease for both financing and operating leases, along with additional qualitative and quantitative disclosures. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, with early adoption permitted. In July 2018, the FASB issued ASU No. 2018-11, “ Targeted Improvements - Leases (Topic 842)”. This update provides an optional transition method that allows entities to elect to apply the standard prospectively at its effective date, versus recasting the prior periods presented. If elected, an entity would recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. We intend to adopt the optional transition method and we expect to adopt this standard beginning in 2019. We have performed a preliminary assessment of the impact of the adoption of the amendments in these updates on our consolidated financial position and results of operations for our leases, which primarily consist of our O’Brien lease. Based on that assessment, we have estimated that the adoption of Topic 842 will result in the significant recognition of right-of-use assets and lease liabilities as of January 1, 2019 . Also, the impact from the adoption of Topic 842 to our accumulated deficit as of January 1, 2019 and to our consolidated results of operations for the year ending December 31, 2019 are not expected to be material. Recently Adopted Accounting Standards In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash , which requires restricted cash to be presented with cash and cash equivalents on the statement of cash flows and disclosure of how the statement of cash flows reconciles to the balance sheet if restricted cash is shown separately from cash and cash equivalents on the balance sheet. ASU 2016-18 is effective for interim and annual periods beginning after December 15, 2017, with early adoption permitted. We adopted this standard effective January 1, 2018 using the retrospective transition method by restating our consolidated statements of cash flows to include restricted cash of $4.5 million in the beginning and ending cash, cash equivalents, and restricted cash balances for all periods presented. As a result of adoption, n et cash flows for the year ended December 31, 2018 did not change as a result of including restricted cash with cash and cash equivalents when reconciling the beginning-of-period and end-of-period amounts presented on the statements of cash flows. In May 2014, the FASB issued ASU No. 2014-09, “ Revenue from Contracts with Customers (Topic 606)” as modified by subsequently issued ASUs 2015-14, 2016-08, 2016-10, 2016-12 and 2016-20 (collectively ASC 606). ASC 606 superseded existing revenue recognition standards with a single model unless those contracts are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. The revenue recognition principle in ASC 606 is that an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of Topic 606, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. On January 1, 2018, we adopted ASC 606 using the modified retrospective method with the cumulative effect of adoption recognized as an adjustment to our accumulated deficit on January 1, 2018. Prior period financial statements and disclosures have not been restated and continue to be reported under the accounting standards in effect for those periods. The adoption of ASC 606 did not have a material impact on our consolidated financial position, results of operations, equity or cash flows as of the adoption date or for the year ended December 31, 2018. In addition, the standard requires disclosure of the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. Upon adopting ASC 606, the incremental direct costs of obtaining a contract are now deferred and amortized over the period of contract performance or a longer period if renewals are expected and the renewal commission is not commensurate with the initial commission. We classify deferred commissions as “Prepaid expenses and other current assets” in our consolidated balance sheets. The cumulative effect of the changes made to our consolidated January 1, 2018 balance sheet for the adoption of ASC 606 was as follows (in thousands):    Balance Sheet Balance at December 31, 2017 Adjustments Due to ASC606 Balance at January 1, 2018  Assets  Prepaid expenses and other current assets $ 2,249 $ 189 $ 2,438  Liabilities and Stockholders' Equity  Accumulated deficit (879,733) 189 (879,544)  In accordance with ASC 606, the disclosure of the impact of adoption on our consolidated statement of operations and comprehensive loss, consolidated balance sheets, and consolidated statements of cash flows is as follows (in thousands):     Year Ended December 31, 2018  Statement of Operations and Comprehensive Loss As Reported Balances Without Adoption of ASC606 Effect of Change Higher/(Lower)  Operating Expense:  Sales, general and administrative $ 63,489 $ 63,547 $ (58)      As of December 31, 2018  Balance Sheet As Reported Balances Without Adoption of ASC606 Effect of Change Higher/(Lower)  Assets  Prepaid expenses and other current assets $ 2,832 $ 2,585 $ 247  Liabilities and Stockholders' Equity  Accumulated deficit $ (982,106) $ (981,859) $ 247     Year Ended December 31, 2018  Statement of Cash Flows As Reported Balances Without Adoption of ASC606 Effect of Change Higher/(Lower)  Cash Flows from Operating Activities  Net loss $ (102,562) $ (102,620) $ 58  Adjustments to reconcile net loss to net cash used in operating activities  Prepaid expenses and other current assets $ (290) $ (348) $ 58   At December 31, 2018, we had $0.2 million of deferred commissions included in “Prepaid expenses and other current assets” which will be 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. A summary of our revenue by category for the year ended December 31, 2018, 2017 and 2016 is as follows (in thousands):     Year Ended December 31,  (in thousands) 2018 2017 (1) 2016 (1)  Instrument revenue $ 28,492 $ 38,626 $ 40,956  Consumable revenue 37,863 41,404 23,653  Product revenue 66,355 80,030 64,609  Service and other revenue 12,271 13,438 13,971  Collaboration revenue — — 12,134  Total revenue $ 78,626 $ 93,468 $ 90,714   (1) As noted above, prior period amounts have not been adjusted under the modified retrospective method of ASC 606 .

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Summary of Significant Accounting Policies [Abstract]
Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis	   December 31, 2018 December 31, 2017  (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 $ 18,844 $ — $ — $ 18,844 $ 14,858 $ — $ — $ 14,858  Commercial paper — — — — — 1,649 — 1,649  Total cash and cash equivalents 18,844 — — 18,844 14,858 1,649 — 16,507  Investments:  Commercial paper — 53,469 — 53,469 — 20,394 — 20,394  Corporate debt securities — 10,214 — 10,214 — 9,034 — 9,034  US government & agency securities — 19,827 — 19,827 — 16,937 — 16,937  Total investments — 83,510 — 83,510 — 46,365 — 46,365  Long-term restricted cash:  Cash 4,500 — — 4,500 4,500 — — 4,500  Total assets measured at fair value $ 23,344 $ 83,510 $ — $ 106,854 $ 19,358 $ 48,014 $ — $ 67,372   Liabilities  Financing derivative $ — $ — $ 16 $ 16 $ — $ — $ 183 $ 183  Total liabilities measured at fair value $ — $ — $ 16 $ 16 $ — $ — $ 183 $ 183  
Changes in Fair Value of Financing Derivative	   Financing Derivative Amount  Balance as of December 31, 2016 $ 356  Loss on change in fair value of Financing Derivative 653  Change in fair value due to partial exercise of derivative associated with $4.5 million principal payoff (826)  Balance as of December 31, 2017 183  Gain on change in fair value of Financing Derivative (167)  Balance as of December 31, 2018 $ 16  
Estimated Fair Value and Carrying Value of Notes	   December 31, 2018 December 31, 2017  Fair Value Carrying Value Fair Value Carrying Value  Long-term notes payable $ 15,915 $ 14,659 $ 15,664 $ 13,635 
Anti-dilutive Shares Excluded from Computation of Diluted Net Loss per Share	   Years Ended December 31,  (in thousands) 2018 2017 2016  Options to purchase common stock 25,176 25,404 22,501  RSUs with time-based vesting 371 — —  RSUs with performance-based vesting 586 — — 
Schedule of Cumulative Effect on Consolidated Balance Sheet for Adoption of ASC 606	  Balance Sheet Balance at December 31, 2017 Adjustments Due to ASC606 Balance at January 1, 2018  Assets  Prepaid expenses and other current assets $ 2,249 $ 189 $ 2,438  Liabilities and Stockholders' Equity  Accumulated deficit (879,733) 189 (879,544) 
Schedule of Impact of Revenue Standards Adoption on Financial Statements	  Year Ended December 31, 2018  Statement of Operations and Comprehensive Loss As Reported Balances Without Adoption of ASC606 Effect of Change Higher/(Lower)  Operating Expense:  Sales, general and administrative $ 63,489 $ 63,547 $ (58)      As of December 31, 2018  Balance Sheet As Reported Balances Without Adoption of ASC606 Effect of Change Higher/(Lower)  Assets  Prepaid expenses and other current assets $ 2,832 $ 2,585 $ 247  Liabilities and Stockholders' Equity  Accumulated deficit $ (982,106) $ (981,859) $ 247     Year Ended December 31, 2018  Statement of Cash Flows As Reported Balances Without Adoption of ASC606 Effect of Change Higher/(Lower)  Cash Flows from Operating Activities  Net loss $ (102,562) $ (102,620) $ 58  Adjustments to reconcile net loss to net cash used in operating activities  Prepaid expenses and other current assets $ (290) $ (348) $ 58 
Summary of Revenue by Category	   Year Ended December 31,  (in thousands) 2018 2017 (1) 2016 (1)  Instrument revenue $ 28,492 $ 38,626 $ 40,956  Consumable revenue 37,863 41,404 23,653  Product revenue 66,355 80,030 64,609  Service and other revenue 12,271 13,438 13,971  Collaboration revenue — — 12,134  Total revenue $ 78,626 $ 93,468 $ 90,714   (1) As noted above, prior period amounts have not been adjusted under the modified retrospective method of ASC 606 .

Cash and Cash Equivalents and_2

Cash and Cash Equivalents and Investments (Tables)	12 Months Ended
	Dec. 31, 2018
Cash and Cash Equivalents and Investments [Abstract]
Summary of Cash, Cash Equivalents and Investments	   As of December 31, 2018  Gross Gross  Amortized unrealized unrealized Fair  Cost gains losses Value  Cash and cash equivalents:  Cash and money market funds $ 18,844 $ — $ — $ 18,844  Total cash and cash equivalents 18,844 — — 18,844  Investments:  Commercial paper 53,493 — (24) 53,469  Corporate debt securities 10,223 3 (12) 10,214  Asset backed securities — — — —  US government & agency securities 19,830 — (3) 19,827  Total investments 83,546 3 (39) 83,510  Total cash, cash equivalents and investments $ 102,390 $ 3 $ (39) $ 102,354   Long-term restricted cash:  Cash $ 4,500 $ — $ — $ 4,500   As of December 31, 2017  Gross Gross  Amortized unrealized unrealized Fair  Cost gains losses Value  Cash and cash equivalents:  Cash and money market funds $ 14,858 $ — $ — $ 14,858  Commercial paper 1,649 — — 1,649  Total cash and cash equivalents 16,507 — — 16,507  Investments:  Commercial paper 20,408 — (14) 20,394  Corporate debt securities 9,043 — (9) 9,034  US government & agency securities 16,946 — (9) 16,937  Total investments 46,397 — (32) 46,365  Total cash, cash equivalents and investments $ 62,904 $ — $ (32) $ 62,872   Long-term restricted cash:  Cash $ 4,500 $ — $ — $ 4,500   
Summary of Contractual Maturities of Cash Equivalents and Available-for-Sale Investments	   (in thousands) Fair Value  Due in one year or less $ 82,023  Due after one year through five years 1,487  Total $ 83,510  

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2018
Balance Sheet Components [Abstract]
Components of Inventory	   December 31,  (in thousands) 2018 2017  Purchased materials $ 6,222 $ 8,884  Work in process 7,341 9,994  Finished goods 4,315 4,187  Inventory $ 17,878 $ 23,065 
Components of Property and Equipment, Net	   December 31,  (in thousands) 2018 2017  Laboratory equipment and machinery $ 24,111 $ 24,703  Leasehold improvements 29,821 29,728  Computer equipment 9,484 8,301  Software 4,734 4,615  Furniture and fixtures 2,422 2,382  Construction in progress 608 385  71,180 70,114  Less: Accumulated depreciation (37,107) (32,194)  Property and equipment, net $ 34,073 $ 37,920 
Schedule of Accrued Expenses	   December 31,  (in thousands) 2018 2017  Salaries and benefits $ 8,523 $ 7,570  Accrued product development costs 561 2,034  Accrued Tenant Improvements for Menlo Park building 694 —  Inventory accrual 499 626  Accrued professional services and legal fees 1,588 1,368  Other 958 1,020  Accrued expenses $ 12,823 $ 12,618 

Notes Payable (Tables)

Notes Payable (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Payable [Abstract]
Schedule of Payments due under Notes Payabe	  Amount  Years ending December 31, (in thousands)  2019 1,400  2020 16,491  Total remaining payments 17,891  Less: interest and discounts (3,232)  Notes payable $ 14,659 

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies [Abstract]
Schedule of Future Annual Minimum Lease Payments	   Amount  Years ending December 31, (in thousands)  2019 $ 6,930  2020 7,056  2021 7,272  2022 7,488  2023 7,704  Thereafter 31,518  Total minimum lease payments $ 67,968 

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Taxes [Abstract]
Reconciliation of Federal Income Tax Rate	   Years ended December 31,  2018 2017 2016  Statutory tax rate 21.0 % 35.0 % 35.0 %  State tax rate, net of federal benefit 3.5 8.6 5.4  Stock-based compensation (1.6) (1.9) (1.6)  Tax credits 2.0 3.6 5.0  Remeasurement of deferred taxes due to tax reform - (123.3) -  Other (0.1) 0.3 (0.9)  Change in valuation allowance (24.8) 77.7 (42.9)  Total - % - % - % 
Reconciliation of Deferred Tax Assets and Liabilities	   December 31,  Deferred tax assets: 2018 2017  Net operating loss carryforwards $ 212,424 $ 194,440  Research and development credits 42,635 39,145  Accruals and reserves 19,356 14,480  Deferred rent 3,315 3,360  Total deferred tax assets 277,730 251,425  Less: Valuation allowance (275,540) (249,202)  Total deferred tax assets: 2,190 2,223  Fixed assets (2,190) (2,223)  Total deferred tax liabilities (2,190) (2,223)  Net deferred tax assets $ — $ — 
Reconciliation of Unrecognized Tax Benefit Accounts	   Decrease in balance related to tax positions taken in prior year $ (44)  Increase in balance related to tax positions taken during current year 1,827  Balance as of December 31, 2015 18,735  Increase in balance related to tax positions taken in prior year 1,942  Decrease in balance related to tax positions taken in current year (3,892)  Balance as of December 31, 2016 16,785  Decrease in balance related to tax positions taken in prior year —  Increase in balance related to tax positions taken during current year 2,001  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 

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2018
Stockholders' Equity [Abstract]
Summary of Stock Option Activity	   Stock Options Outstanding  Shares available Number Weighted average  for grant of shares Exercise price exercise price  Balances, December 31, 2017 6,795 25,404 $ 1.16 – 16.00 $ 6.10  Additional shares reserved 6,976  Options granted (4,204) 4,204 $ 2.47 – 4.28 $ 2.57  Options exercised — (1,720) $ 1.16 – 7.05 $ 3.73  Options canceled 2,712 (2,712) $ 1.16 – 16.00 $ 6.19  Balances, December 31, 2018 12,279 25,176 $ 1.16 – 16.00 $ 5.66 
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 – 1.60 438,233 3.84 $ 1.18 438,233 $ 1.18  $ 1.60 – 3.20 6,141,372 7.30 $ 2.53 2,877,885 $ 2.47  $ 3.20 – 4.80 3,587,706 4.63 $ 4.07 3,064,649 $ 4.10  $ 4.80 – 6.40 6,390,401 6.98 $ 5.45 4,258,318 $ 5.53  $ 6.40 – 8.00 2,868,379 5.74 $ 7.19 2,604,086 $ 7.14  $ 8.00 – 9.60 3,560,966 5.24 $ 8.77 2,853,592 $ 8.76  $ 9.60 – 11.20 1,293,448 5.82 $ 10.20 1,035,715 $ 10.23  $ 11.20 – 12.80 449,502 2.00 $ 12.13 449,502 $ 12.13  $ 12.80 – 14.40 323,250 1.08 $ 13.94 3,227,035 $ 13.94  $ 14.40 – 16.00 122,750 1.49 $ 15.99 122,750 $ 15.99  25,176,007 6.03 $ 5.66 18,027,465 $ 6.09  
Summary of Time-Based RSUs Activity	  Weighted average  Number grant date  of shares fair value  RSUs outstanding at December 31, 2017 — $ —  RSUs granted 413 3.14  RSUs released — —  RSUs forfeited (42) 2.54  Unvested RSUs outstanding at December 31, 2018 371 $ 3.20 
Summary of Performance-Based RSUs Activity	  Weighted average  Number grant date  of shares fair value  PSUs outstanding at December 31, 2017 — $ —  PSUs granted 657 2.58  PSUs released — —  PSUs forfeited (71) 2.54  Unvested PSUs outstanding at December 31, 2018 586 $ 2.58 
Schedule of Stock-Based Compensation Expense	   Years Ended December 31,  2018 2017 2016  Cost of revenue $ 3,124 $ 2,311 $ 2,133  Research and development 10,076 8,506 8,257  Sales, general and administrative 9,953 9,535 9,172  Total stock-based compensation expense $ 23,153 $ 20,352 $ 19,562 
Schedule of Fair Value of Employee Stock Options	   Years Ended December 31,  2018 2017 2016  Expected term (years) 5.2 years 6.1 years 6.1 years  Expected volatility 66.8% 70.0% 70.0%  Risk-free interest rate 2.6% 2.1% 1.5%  Dividend yield — — —  
Schedule of Fair Value of Employee Stock Purchase Plan	   Years Ended December 31,  2018 2017 2016  Expected term (years) 0.5 - 2.0 0.5 - 2.0 0.5 - 2.0  Expected volatility 65% - 67% 70.0% 70.0%  Risk-free interest rate 1.3%-2.7% 0.8%-1.4% 0.5%-0.9%  Dividend yield — — — 

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
Net Loss Per Share [Abstract]
Antidilutive Shares Excluded from Computation of Diluted Net Loss per Share	   Years Ended December 31,  (in thousands) 2018 2017 2016  Options to purchase common stock 25,176 25,404 22,501  RSUs with time-based vesting 371 — —  RSUs with performance-based vesting 586 — — 

Segment And Geographic Inform_2

Segment And Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2018
Segment And Geographic Information [Abstract]
Schedule of Revenue by Geographic Location	   Years Ended December 31,  (in thousands) 2018 2017 2016  North America $ 35,598 $ 40,641 $ 50,871  Europe (including the Middle East and Africa) 13,958 14,026 21,132  Asia Pacific 29,070 38,801 18,711  Total $ 78,626 $ 93,468 $ 90,714 

Unaudited Selected Quarterly _2

Unaudited Selected Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2018
Unaudited Selected Quarterly Financial Data [Abstract]
Schedule of Unaudited Quarterly Financial Data	   Fiscal 2018 Quarter Ended  (in thousands, except per share data) March 31, June 30, September 30, December 31,  Total revenue $ 19,362 $ 21,578 $ 18,160 $ 19,526  Total gross profit 7,296 8,862 3,192 5,746  Total operating expenses 31,245 30,607 27,862 36,369  Loss from operations (23,949) (21,745) (24,670) (30,623)  Net loss (24,179) (22,540) (25,044) (30,799)  Basic and diluted net loss per share $ (0.20) $ (0.17) $ (0.19) $ (0.21)  Weighted average shares used in computing net loss per share 123,768 131,882 135,130 149,314   Fiscal 2017 Quarter Ended  (in thousands, except per share data) March 31, June 30, September 30, December 31,  Total revenue $ 24,915 $ 20,073 $ 23,545 $ 24,935  Total gross profit 8,937 8,001 8,227 9,494  Total operating expenses 32,236 32,388 29,796 30,023  Loss from operations (23,299) (24,387) (21,569) (20,529)  Net loss (23,867) (25,539) (22,021) (20,762)  Basic and diluted net loss per share $ (0.26) $ (0.26) $ (0.19) $ (0.18)  Weighted average shares used in computing net loss per share 92,970 97,360 115,771 116,259   

Subsequent Event (Tables)

Subsequent Event (Tables)	12 Months Ended
	Dec. 31, 2018
Subsequent Event [Abstract]
Schedule of Increases in Base Salaries	  Name 2018 Base Salary 2019 Base Salary  Michael Hunkapiller, Ph.D. $ 1.00 $ 582,900  Susan K. Barnes $ 1.00 $ 401,500 

Overview (Narrative) (Details)

Overview (Narrative) (Details)	Dec. 31, 2018site	Nov. 01, 2018$ / shares
Early Access Program [Member]
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Number of sites | site	5
Illumina, FC Ops Corp [Member] | Pacific Biosciences of California, Inc. [Member]
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Purchase price, per share amount | $ / shares		$ 8

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2018USD ($)customer	Dec. 31, 2017USD ($)customer$ / shares	Dec. 31, 2016USD ($)	Jan. 01, 2018USD ($)	Oct. 31, 2015USD ($)
Summary Of Significant Accounting Policies [Line Items]
Charge to cost of service and other revenue related to change in estimated useful life of lease instruments		$ 1,600,000
Charge to cost of service and other revenue related to change in estimated useful life of lease instruments, impact on earnings per share | $ / shares		$ (0.01)
Fair value assets/liabilities transfer between levels	$ 0
Future cash flows weighted average market yield	9.60%	10.30%
Investments impariment charges	$ 0	$ 0	$ 0
Long-term restricted cash	4,500,000	4,500,000			$ 4,500,000
Long-lived assets impairment charges	0
Deferred service revenue	7,400,000
Deferred service revenue, current	6,537,000	6,319,000
Deferred service revenue, non-current	$ 890,000	1,075,000
Service period	1 year
Dividends paid	$ 0
Expected dividend payments	$ 0
Dividend yield	0.00%
Restricted cash	$ 4,500,000	4,500,000	$ 4,500,000
Prepaid expenses and other current assets	$ 2,832,000	$ 2,249,000		$ 2,438,000
Sales Revenue, Net [Member] | Gene Company Limited [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of individual customers | customer	1	1
Concentration risk, percentage	26.00%	31.00%
Accounts Receivable [Member] | Domestic Customers [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	50.00%	84.00%
Accounts Receivable [Member] | Gene Company Limited [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of individual customers | customer	1
Concentration risk, percentage	14.00%	20.00%
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred service revenue, performance period	1 year
Deferred service revenue, non-current, recognition period	2 years
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
Deferred service revenue, non-current, recognition period	5 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
Deferred Commission [Member]
Summary Of Significant Accounting Policies [Line Items]
Prepaid expenses and other current assets	$ 200,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies (Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets
Total cash and cash equivalents	$ 18,844	$ 16,507
Total investments	83,510	46,365
Long-term restricted cash	4,500	4,500
Total assets measured at fair value	106,854	67,372
Liabilities
Financing derivative	16	183
Total liabilities measured at fair value	16	183
Cash and money market funds [Member]
Assets
Total cash and cash equivalents	18,844	14,858
Commercial paper [Member]
Assets
Total cash and cash equivalents		1,649
Commercial paper, not included with cash and cash equivalents [Member]
Assets
Total investments	53,469	20,394
Corporate debt securities [Member]
Assets
Total investments	10,214	9,034
U.S. government and agency securities, not included with cash and cash equivalents [Member]
Assets
Total investments	19,827	16,937
Level 1 [Member]
Assets
Total cash and cash equivalents	18,844	14,858
Long-term restricted cash	4,500	4,500
Total assets measured at fair value	23,344	19,358
Level 1 [Member] | Cash and money market funds [Member]
Assets
Total cash and cash equivalents	18,844	14,858
Level 2 [Member]
Assets
Total cash and cash equivalents		1,649
Total investments	83,510	46,365
Total assets measured at fair value	83,510	48,014
Level 2 [Member] | Commercial paper [Member]
Assets
Total cash and cash equivalents		1,649
Level 2 [Member] | Commercial paper, not included with cash and cash equivalents [Member]
Assets
Total investments	53,469	20,394
Level 2 [Member] | Corporate debt securities [Member]
Assets
Total investments	10,214	9,034
Level 2 [Member] | U.S. government and agency securities, not included with cash and cash equivalents [Member]
Assets
Total investments	19,827	16,937
Level 3 [Member]
Liabilities
Financing derivative	16	183
Total liabilities measured at fair value	$ 16	$ 183

Summary of Significant Accoun_6

Summary of Significant Accounting Policies (Changes in Fair Value of Financing Derivative) (Details) - USD ($) $ in Thousands	Jun. 23, 2017	Jun. 30, 2017	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, Beginning			$ 183	$ 356
(Gain) Loss on change in fair value of Financing Derivative			(167)	653
Change in fair value due to partial exercise of derivative associated with $4.5 million principal payoff				(826)
Balance, Ending			$ 16	183
Repayment of notes payable				4,500
Notes [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Repayment of notes payable	$ 4,500	$ 4,500		$ 4,500

Summary of Significant Accoun_7

Summary of Significant Accounting Policies (Estimated Fair Value and Carrying Value of Notes) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Estimated Fair Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term notes payable	$ 15,915	$ 15,664
Carrying Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term notes payable	$ 14,659	$ 13,635

Summary of Significant Accoun_8

Summary of Significant Accounting Policies (Schedule of Cumulative Effect on Consolidated Balance Sheet for Adoption of ASC 606) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Assets
Prepaid expenses and other current assets	$ 2,832	$ 2,438	$ 2,249
Liabilities and Stockholders’ Equity
Accumulated deficit	(982,106)	(879,544)	$ (879,733)
Accounting Standards Update 2014-09 [Member] | Effect of Change Higher/(Lower) [Member]
Assets
Prepaid expenses and other current assets	247	189
Liabilities and Stockholders’ Equity
Accumulated deficit	$ 247	$ 189

Summary of Significant Accoun_9

Summary of Significant Accounting Policies (Schedule of Impact of Revenue Standards Adoption on Financial Statements) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Operating Expense:
Sales, general and administrative									$ 63,489	$ 59,119	$ 47,787
Assets
Prepaid expenses and other current assets	$ 2,832				$ 2,249				2,832	2,249		$ 2,438
Liabilities and Stockholders’ Equity
Accumulated deficit	(982,106)				(879,733)				(982,106)	(879,733)		(879,544)
Cash flows from operating activities
Net loss	(30,799)	$ (25,044)	$ (22,540)	$ (24,179)	$ (20,762)	$ (22,021)	$ (25,539)	$ (23,867)	(102,562)	(92,189)	(74,375)
Adjustments to reconcile net loss to net cash used in operating activities
Prepaid expenses and other assets									(290)	$ 7,803	$ (202)
Balances Without Adoption of ASC 606 [Member]
Operating Expense:
Sales, general and administrative									63,547
Assets
Prepaid expenses and other current assets	2,585								2,585
Liabilities and Stockholders’ Equity
Accumulated deficit	(981,859)								(981,859)
Cash flows from operating activities
Net loss									(102,620)
Adjustments to reconcile net loss to net cash used in operating activities
Prepaid expenses and other assets									(348)
Accounting Standards Update 2014-09 [Member] | Effect of Change Higher/(Lower) [Member]
Operating Expense:
Sales, general and administrative									(58)
Assets
Prepaid expenses and other current assets	247								247			189
Liabilities and Stockholders’ Equity
Accumulated deficit	$ 247								247			$ 189
Cash flows from operating activities
Net loss									58
Adjustments to reconcile net loss to net cash used in operating activities
Prepaid expenses and other assets									$ 58

Summary of Significant Accou_10

Summary of Significant Accounting Policies (Summary of Revenue by Category) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Product Information [Line Items]
Total revenue	$ 78,626	$ 93,468	$ 90,714
Product [Member]
Product Information [Line Items]
Total revenue	66,355	80,030	64,609
Instrument [Member]
Product Information [Line Items]
Total revenue	28,492	38,626	40,956
Consumable [Member]
Product Information [Line Items]
Total revenue	37,863	41,404	23,653
Service and Other [Member]
Product Information [Line Items]
Total revenue	$ 12,271	$ 13,438	13,971
Collaboration [Member]
Product Information [Line Items]
Total revenue			$ 12,134

Contractual Revenue (Details)

Contractual Revenue (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue	$ 19,526,000	$ 18,160,000	$ 21,578,000	$ 19,362,000	$ 24,935,000	$ 23,545,000	$ 20,073,000	$ 24,915,000	$ 78,626,000	$ 93,468,000	$ 90,714,000
Contractual [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue											$ 12,134,000
Remaining potential for additional payments to be recognized upon the achievement of certain development milestones	$ 0								$ 0

Cash and Cash Equivalents and_3

Cash and Cash Equivalents and Investments (Summary of Cash, Cash Equivalents and Investments) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Cash, cash equivalents and investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 102,390	$ 62,904
Gross unrealized gains	3
Gross unrealized losses	(39)	(32)
Fair value	102,354	62,872
Cash and cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	18,844	16,507
Fair value	18,844	16,507
Cash and money market funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	18,844	14,858
Fair value	18,844	14,858
Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost		1,649
Fair value		1,649
Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	83,546	46,397
Gross unrealized gains	3
Gross unrealized losses	(39)	(32)
Fair value	83,510	46,365
Commercial paper, not included with cash and cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	53,493	20,408
Gross unrealized losses	(24)	(14)
Fair value	53,469	20,394
Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	10,223	9,043
Gross unrealized gains	3
Gross unrealized losses	(12)	(9)
Fair value	10,214	9,034
U.S. government and agency securities, not included with cash and cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	19,830	16,946
Gross unrealized losses	(3)	(9)
Fair value	19,827	16,937
Cash [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	4,500	4,500
Fair value	$ 4,500	$ 4,500

Cash and Cash Equivalents and_4

Cash and Cash Equivalents and Investments (Summary of Contractual Maturities of Cash Equivalents and Available-for-Sale Investments) (Details) $ in Thousands	Dec. 31, 2018USD ($)
Cash and Cash Equivalents and Investments [Abstract]
Due in one year or less	$ 82,023
Due after one year through five years	1,487
Total	$ 83,510

Balance Sheet Components (Narra

Balance Sheet Components (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Balance Sheet Components [Abstract]
Depreciation expense	$ 7,215	$ 8,442	$ 3,875

Balance Sheet Components (Compo

Balance Sheet Components (Components of Inventory) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Balance Sheet Components [Abstract]
Purchased materials	$ 6,222	$ 8,884
Work in process	7,341	9,994
Finished goods	4,315	4,187
Inventory	$ 17,878	$ 23,065

Balance Sheet Components (Com_2

Balance Sheet Components (Components of Property and Equipment, Net) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment	$ 71,180	$ 70,114
Less: Accumulated depreciation	(37,107)	(32,194)
Property and equipment, net	34,073	37,920
Laboratory Equipment And Machinery [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	24,111	24,703
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	29,821	29,728
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	9,484	8,301
Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	4,734	4,615
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	2,422	2,382
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 608	$ 385

Balance Sheet Components (Sched

Balance Sheet Components (Schedule of Accrued Expenses) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Balance Sheet Components [Abstract]
Salaries and benefits	$ 8,523	$ 7,570
Accrued product development costs	561	2,034
Accrued Tenant Improvements for Menlo Park building	694
Inventory accrual	499	626
Accrued professional services and legal fees	1,588	1,368
Accrued product development costs	958	1,020
Accrued Liabilities, Current, Total	$ 12,823	$ 12,618

Notes Payable (Narrative) (Deta

Notes Payable (Narrative) (Details)	Jun. 23, 2017USD ($)item	Jun. 30, 2017USD ($)item	Feb. 28, 2013USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Debt Instrument [Line Items]
Percentage of net proceeds from out side financing or equity component			25.00%
Repayment of notes payable					$ 4,500,000
Future cash flows weighted average market yield				9.60%	10.30%
Fair value of the financing derivative				$ 16,000	$ 183,000	$ 356,000
Notes payable				14,659,000	13,635,000
Facility Agreement [Member]
Debt Instrument [Line Items]
Proceeds from issuance of debt			$ 20,500,000
Facility agreement period			7 years
Proceeds from issuance of debt agreement, net of issuance costs			$ 20,000,000
Facility fee			500,000
Cash and cash equivalent minimum amount quarterly required			2,000,000
Notes [Member]
Debt Instrument [Line Items]
Proceeds from issuance of debt			20,500,000
Principal amount of notes			$ 20,500,000
Debt instrument, stated interest rate			8.75%
Percentage of net proceeds from out side financing or equity component	25.00%
Repayment of notes payable	$ 4,500,000	$ 4,500,000			4,500,000
Number of Notes holders paid | item	1	1
Aggregate principal amount				16,000,000	16,000,000
Fair value of the notes			$ 14,100,000
Fair value of the warrants			6,400,000
Carrying value of the notes			12,800,000
Original issue discount			$ 7,700,000
Debt discount that has yet to be amortized				1,300,000	2,400,000
Notes payable				$ 14,700,000	$ 13,600,000
Maturity date				Dec. 31, 2020

Notes Payable (Schedule of Paym

Notes Payable (Schedule of Payments due under Notes Payabe) (Details) $ in Thousands	Dec. 31, 2018USD ($)
Notes Payable [Abstract]
2,019	$ 1,400
2,020	16,491
Total remaining payments	17,891
Less: interest and discounts	(3,232)
Notes payable	$ 14,659

Commitments and Contingencies_2

Commitments and Contingencies (Narrative) (Details)	Jan. 19, 2019USD ($)	Dec. 18, 2018lawsuit	Jul. 22, 2015USD ($)	Jan. 04, 2019lawsuit	Jan. 04, 2019lawsuit	Mar. 31, 2017USD ($)	Dec. 31, 2018USD ($)lawsuit	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Oct. 31, 2015USD ($)
Operating Leased Assets [Line Items]
Long-term restricted cash							$ 4,500,000	$ 4,500,000		$ 4,500,000
Deferred rent, non-current							13,765,000	14,453,000
Other purchase commitments							$ 13,100,000
Number of lawsuits filed | lawsuit							4
Attorneys' fees	$ 300,000
Loss contingency, accrual							$ 240,000
Additional liability associated with indemnification obligations							0
Subsequent Event [Member]
Operating Leased Assets [Line Items]
Number of lawsuits filed | lawsuit				5
Punitive Class Action, United States District Court for the Northern District of California [Member] | Subsequent Event [Member]
Operating Leased Assets [Line Items]
Number of lawsuits filed | lawsuit					3
Punitive Class Action, United States District Court for the District of Delaware [Member]
Operating Leased Assets [Line Items]
Number of lawsuits filed | lawsuit		1
O’Brien Lease Agreement [Member]
Operating Leased Assets [Line Items]
Lease term			132 months			11 years
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
Long-term restricted cash										$ 4,500,000
Expected improvement allowance			$ 12,600,000
Tenant improvements						$ 28,800,000
Tenant allowance paid by landlord						12,600,000
Deferred rent, non-current						$ 12,600,000
Rent expense							$ 6,200,000	$ 6,300,000	$ 200,000
O’Brien Lease Agreement [Member] | Prime Rate [Member]
Operating Leased Assets [Line Items]
Basis spread on variable rate			2.00%

Commitments and Contingencies_3

Commitments and Contingencies (Schedule of Future Annual Minimum Lease Payments) (Details) $ in Thousands	Dec. 31, 2018USD ($)
Commitments and Contingencies [Abstract]
2,019	$ 6,930
2,020	7,056
2,021	7,272
2,022	7,488
2,023	7,704
Thereafter	31,518
Total minimum lease payments	$ 67,968

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Income before taxes from U.S. operations	$ (103,100)	$ (92,700)	$ (74,000)
Income before taxes from foreign operations	$ 800	$ 1,000	$ 300
Statutory tax rate	21.00%	35.00%	35.00%
Net operating loss carryforwards	$ 212,400
Research and development credit carryforward	42,600
Deferred tax assets	277,730	$ 251,425
Valuation allowance	275,540	249,202
Total unrecognized tax benefit	20,447	18,786	$ 16,785	$ 18,735
Accrued interest or penalties	0	$ 0
Federal [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 832,000
Net operating loss carryforward, expiration	2,024
Research and development credit carryforward	$ 33,700
Research and developmen tax credit carryforward, expiration	2,024
State [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 566,600
Net operating loss carryforward, expiration	2,018
Research and development credit carryforward	$ 34,400

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of Federal Income Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Abstract]
Statutory tax rate	21.00%	35.00%	35.00%
State tax rate, net of federal benefit	3.50%	8.60%	5.40%
Stock-based compensation	(1.60%)	(1.90%)	(1.60%)
Tax credits	2.00%	3.60%	5.00%
Remeasurement of deferred taxes due to tax reform		(123.30%)
Other	(0.10%)	0.30%	(0.90%)
Change in valuation allowance	(24.80%)	77.70%	(42.90%)
Total

Income Taxes (Reconciliation _2

Income Taxes (Reconciliation of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Net operating loss carryforwards	$ 212,424	$ 194,440
Research and development credits	42,635	39,145
Accruals and reserves	19,356	14,480
Deferred rent	3,315	3,360
Total deferred tax assets	277,730	251,425
Less: Valuation allowance	(275,540)	(249,202)
Total deferred tax assets:	2,190	2,223
Fixed assets	(2,190)	(2,223)
Total deferred tax liabilities	(2,190)	(2,223)
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, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Abstract]
Unrecognized tax benefit, Beginning balance	$ 18,786	$ 16,785	$ 18,735
Increase in balance related to tax positions taken in prior year			1,942
Decrease in balance related to tax positions taken in prior year				$ (44)
Increase in balance related to tax positions taken during current year	1,661	2,001		1,827
Decrease in balance related to tax positions taken in current year			(3,892)
Unrecognized tax benefit, Ending balance	$ 20,447	$ 18,786	$ 16,785	$ 18,735

Stockholders' Equity (Narrative

Stockholders' Equity (Narrative) (Details) $ / shares in Units, $ in Thousands	Jun. 23, 2017USD ($)item	Jan. 31, 2019shares	Jun. 30, 2017USD ($)$ / sharesitemshares	Dec. 31, 2018USD ($)item$ / sharesshares	Dec. 31, 2018USD ($)item$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Aug. 31, 2017USD ($)	Feb. 28, 2013$ / sharesshares	Oct. 31, 2010$ / sharesshares
Stockholders' Equity [Line Items]
Common Stock, shares authorized | shares				1,000,000,000	1,000,000,000	1,000,000,000				1,000,000,000
Common Stock, par value | $ / shares				$ 0.001	$ 0.001	$ 0.001				$ 0.001
Preferred Stock, shares authorized | shares				50,000,000	50,000,000	50,000,000				50,000,000
Preferred Stock, par value | $ / shares				$ 0.001	$ 0.001	$ 0.001				$ 0.001
Preferred Stock, shares issued | shares				0	0	0
Preferred Stock, shares outstanding | shares				0	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
Amount of common stock, preferred stock, depositiry shares, warrants, units or debt securities available in future public offerings								$ 150,000
Repayment of notes payable						$ 4,500
Number of shares of common stock called by issuance of warrants | shares							4,200,000		5,500,000
Aggregate exercise price of common stock called by issuance of warrants | $ / shares									$ 2.63
Number of shares of common stock called by issuance of warrants, outstanding | shares				0	0	0
Number of equity compensation plans | item				3	3
Accelerated compensation				$ 2,500
Aggregate intrinsic value outstanding				58,000	$ 58,000
Aggregate intrinsic value exercisable options				$ 35,900	$ 35,900
Stock price | $ / shares				$ 7.40	$ 7.40
Weighted average remaining contractual life for exercisable					5 years 29 days
Vested and expected to vest, outstanding | shares				22,475,000	22,475,000
Vested and expected to vest, aggregate intrinsic value				$ 50,200	$ 50,200
Vested and expected to vest, weighted average exercise price | $ / shares				$ 5.75	$ 5.75
Vested and expected to vest, weighted average remaining contractual life					5 years 9 months
Total intrinsic value of options exercised					$ 5,300	$ 1,700	$ 4,700
Fair value of options vested					3,900	6,400	20,700
Stock-based compensation cost capitalized in inventory					700	400
Stock-based compensation					$ 23,153	$ 20,352	$ 19,562
2010 Plan [Member]
Stockholders' Equity [Line Items]
Stock option grant, term					10 years
Stock option grant, vest					4 years
Stock option grant, vest rate upon first anniversary				25.00%	25.00%
Stock option grant, vest rate per month thereafter				2.08%	2.08%
Vesting period					4 years
2010 Director Plan [Member]
Stockholders' Equity [Line Items]
Stock option grant, term					10 years
Stock option grant, vest rate upon first anniversary				33.00%	33.00%
Stock option grant, vest rate per month thereafter				2.78%	2.78%
2010 Director Plan [Member] | Minimum [Member]
Stockholders' Equity [Line Items]
Stock option grant, vest					1 year
Vesting period					1 year
2010 Director Plan [Member] | Maximum [Member]
Stockholders' Equity [Line Items]
Stock option grant, vest					3 years
Vesting period					3 years
2010 Plan and 2010 Director Plan [Member]
Stockholders' Equity [Line Items]
Common stock reserved for issuance | shares				11,300,000	11,300,000
ESPP [Member]
Stockholders' Equity [Line Items]
Common stock reserved for issuance | shares				1,952,507	1,952,507
Percentage of outstanding common stock used to determine annual plan increase					2.00%
Number of purchase periods | item				4	4
Purchase period of ESPP					6 months
Percentage of fair market value at which stock can be purchased					85.00%
Weighted average fair value at grant date | $ / shares					$ 1.47	$ 2.28	$ 4.21
Stock-based compensation					$ 6,800	$ 3,100	$ 3,700
Common stock purchased under plan | shares					1,674,960	1,289,663	1,259,239
Cash received from option exercises					$ 3,400	$ 5,300	$ 5,200
At the Market Offering [Member]
Stockholders' Equity [Line Items]
Aggregate offering price of shares sold						$ 11,865	58,200
Shares issued | shares						3,200,000
Average common stock price per share | $ / shares						$ 3.86
Proceeds from issuance of common stock from equity offerings, net of issuance costs						$ 11,865	58,200
Commissions, percentage of gross proceeds			3.00%
At the Market Offering [Member] | Common Stock [Member]
Stockholders' Equity [Line Items]
Aggregate offering price of shares sold						$ 3	$ 7
Shares issued | shares						3,171,000	6,526,000
Underwritten Public Equity Offering [Member]
Stockholders' Equity [Line Items]
Aggregate offering price of shares sold					$ 97,530	$ 52,530
Shares issued | shares			17,700,000		30,600,000
Proceeds from issuance of common stock from equity offerings, net of issuance costs					$ 97,530	52,530
Commissions, percentage of gross proceeds			4.00%
Holders may elect to receive net proceeds from financing activities, percentage					25.00%
Number of offerings | item					2
Price per share | $ / shares			$ 3.10	$ 3.38	$ 3.38
Underwritten Public Equity Offering [Member] | Common Stock [Member]
Stockholders' Equity [Line Items]
Aggregate offering price of shares sold					$ 30	$ 18
Shares issued | shares					30,610,000	17,732,000
Stock Options [Member]
Stockholders' Equity [Line Items]
Weighted average remaining contractual life					2 years
Weighted average fair value at grant date | $ / shares					$ 1.50	$ 3.08	$ 5.47
Stock-based compensation					$ 15,500	$ 17,200	$ 15,700
Unrecognized compensation costs				$ 14,300	14,300
Cash received from option exercises					$ 6,300	$ 3,600	$ 2,500
Stock Options [Member] | $1.16 – 16.00 [Member]
Stockholders' Equity [Line Items]
Common stock reserved for issuance | shares				12,279,000	12,279,000	6,795,000
Options expired | shares					1,200,000
Exercise price, lower range | $ / shares					$ 1.16	$ 1.16
Exercise price, upper range | $ / shares					16	$ 16
Options expired, weighted average exercise price | $ / shares					$ 7.15
Time-Based Restricted Stock Units (RSUs) [Member] | 2010 Plan [Member]
Stockholders' Equity [Line Items]
Stock option grant, vest					4 years
Vesting period					4 years
Stock-based compensation					$ 193
Performance-Based Restricted Stock Units (RSUs) [Member] | 2010 Plan [Member]
Stockholders' Equity [Line Items]
Stock-based compensation					$ 614
Subsequent Event [Member] | 2010 Plan [Member]
Stockholders' Equity [Line Items]
Additional common stock reserved for issuance | shares		7,500,000
Subsequent Event [Member] | ESPP [Member]
Stockholders' Equity [Line Items]
Additional common stock reserved for issuance | shares		3,000,000
Notes [Member]
Stockholders' Equity [Line Items]
Repayment of notes payable	$ 4,500		$ 4,500			$ 4,500
Number of Notes holders paid | item	1		1
Share-based Compensation Award, Tranche One, Two, Three and Four [Member] | Time-Based Restricted Stock Units (RSUs) [Member] | 2010 Plan [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 shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares available for grant, Additional shares reserved	6,976
$1.16 – 16.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares available for grant, Balances, December 31, 2017	6,795
Shares available for grant, Balances, December 31, 2018	12,279	6,795
Number of shares, Balances, December 31, 2017	25,404
Number of shares, Balances, December 31, 2018	25,176	25,404
Exercise price, lower range	$ 1.16	$ 1.16
Exercise price, upper range	16	16
Weighted average exercise price, Balances, December 31, 2017	6.10
Weighted average exercise price, Balances, December 31, 2018	$ 5.66	$ 6.10
$2.47 – 4.28 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares available for grant, Options granted	(4,204)
Number of shares, Options granted	4,204
Exercise price, lower range	$ 2.47
Exercise price, upper range	4.28
Weighted average exercise price, Options granted	$ 2.57
$1.16 – 7.05 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares, Options exercised	(1,720)
Exercise price, lower range	$ 1.16
Exercise price, upper range	7.05
Weighted average exercise price, Options exercised	$ 3.73
$1.16 - 16.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares available for grant, Options canceled	2,712
Number of shares, Options canceled	(2,712)
Exercise price, lower range	$ 1.16
Exercise price, upper range	16
Weighted average exercise price, Options canceled	$ 6.19

Stockholders' Equity (Reconcili

Stockholders' Equity (Reconciliation of Outstanding and Exercisable Stock Options) (Details) - Stock Options [Member]	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Number outstanding | shares	25,176,007
Weighted average remaining contractual life (Years)	6 years 11 days
Weighted average exercise price	$ 5.66
Number vested | shares	18,027,465
Weighted average exercise price	$ 6.09
$0.00 - 1.60 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	0
Exercise price, upper range	$ 1.60
Number outstanding | shares	438,233
Weighted average remaining contractual life (Years)	3 years 10 months 2 days
Weighted average exercise price	$ 1.18
Number vested | shares	438,233
Weighted average exercise price	$ 1.18
$1.60 - 3.20 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	1.60
Exercise price, upper range	$ 3.20
Number outstanding | shares	6,141,372
Weighted average remaining contractual life (Years)	7 years 3 months 18 days
Weighted average exercise price	$ 2.53
Number vested | shares	2,877,885
Weighted average exercise price	$ 2.47
$3.20 - 4.80 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	3.20
Exercise price, upper range	$ 4.80
Number outstanding | shares	3,587,706
Weighted average remaining contractual life (Years)	4 years 7 months 17 days
Weighted average exercise price	$ 4.07
Number vested | shares	3,064,649
Weighted average exercise price	$ 4.10
$4.80 - 6.40 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	4.80
Exercise price, upper range	$ 6.40
Number outstanding | shares	6,390,401
Weighted average remaining contractual life (Years)	6 years 11 months 23 days
Weighted average exercise price	$ 5.45
Number vested | shares	4,258,318
Weighted average exercise price	$ 5.53
$6.40 - 8.00 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	6.40
Exercise price, upper range	$ 8
Number outstanding | shares	2,868,379
Weighted average remaining contractual life (Years)	5 years 8 months 27 days
Weighted average exercise price	$ 7.19
Number vested | shares	2,604,086
Weighted average exercise price	$ 7.14
$8.00 - 9.60 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	8
Exercise price, upper range	$ 9.60
Number outstanding | shares	3,560,966
Weighted average remaining contractual life (Years)	5 years 2 months 27 days
Weighted average exercise price	$ 8.77
Number vested | shares	2,853,592
Weighted average exercise price	$ 8.76
$9.60 - 11.20 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	9.60
Exercise price, upper range	$ 11.20
Number outstanding | shares	1,293,448
Weighted average remaining contractual life (Years)	5 years 9 months 26 days
Weighted average exercise price	$ 10.20
Number vested | shares	1,035,715
Weighted average exercise price	$ 10.23
$11.20 - 12.80 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	11.20
Exercise price, upper range	$ 12.80
Number outstanding | shares	449,502
Weighted average remaining contractual life (Years)	2 years
Weighted average exercise price	$ 12.13
Number vested | shares	449,502
Weighted average exercise price	$ 12.13
$12.80 - 14.40 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	12.80
Exercise price, upper range	$ 14.40
Number outstanding | shares	323,250
Weighted average remaining contractual life (Years)	1 year 29 days
Weighted average exercise price	$ 13.94
Number vested | shares	3,227,035
Weighted average exercise price	$ 13.94
$14.40 - 16.00 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	14.40
Exercise price, upper range	$ 16
Number outstanding | shares	122,750
Weighted average remaining contractual life (Years)	1 year 5 months 27 days
Weighted average exercise price	$ 15.99
Number vested | shares	122,750
Weighted average exercise price	$ 15.99

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, 2018$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, outstanding at December 31, 2017 | shares
Number of shares, granted | shares	413
Number of shares, released | shares
Number of shares, forfeited | shares	(42)
Number of shares, Unvested outstanding at December 31, 2018 | shares	371
Weighted average grant date fair value, outstanding at December 31, 2017 | $ / shares
Weighted average grant date fair value, granted | $ / shares	3.14
Weighted average grant date fair value, released | $ / shares
Weighted average grant date fair value, forfeited | $ / shares	2.54
Weighted average grant date fair value, Unvested outstanding at December 31, 2018 | $ / shares	$ 3.20

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, 2018$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, outstanding at December 31, 2017 | shares
Number of shares, granted | shares	657
Number of shares, released | shares
Number of shares, forfeited | shares	(71)
Number of shares, Unvested outstanding at December 31, 2018 | shares	586
Weighted average grant date fair value, outstanding at December 31, 2017 | $ / shares
Weighted average grant date fair value, granted | $ / shares	2.58
Weighted average grant date fair value, released | $ / shares
Weighted average grant date fair value, forfeited | $ / shares	2.54
Weighted average grant date fair value, Unvested outstanding at December 31, 2018 | $ / shares	$ 2.58

Stockholders' Equity (Schedule

Stockholders' Equity (Schedule of Stock-Based Compensation Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 23,153	$ 20,352	$ 19,562
Cost of revenue [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	3,124	2,311	2,133
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	10,076	8,506	8,257
Sales, general and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 9,953	$ 9,535	$ 9,172

Stockholders' Equity (Schedul_2

Stockholders' Equity (Schedule of Fair Value of Employee Stock Options) (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividend yield	0.00%
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	5 years 2 months 12 days	6 years 1 month 6 days	6 years 1 month 6 days
Expected volatility	66.80%	70.00%	70.00%
Risk-free interest rate	2.60%	2.10%	1.50%
Dividend yield

Stockholders' Equity (Schedul_3

Stockholders' Equity (Schedule of Fair Value of Employee Stock Purchase Plan) (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividend yield	0.00%
ESPP [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility		70.00%	70.00%
Risk-free interest rate, minimum	1.30%	0.80%	0.50%
Risk-free interest rate, maximum	2.70%	1.40%	0.90%
Dividend yield
ESPP [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	6 months	6 months	6 months
Expected volatility	65.00%
ESPP [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	2 years	2 years	2 years
Expected volatility	67.00%

Net Loss Per Share (Antidilutiv

Net Loss Per Share (Antidilutive Shares Excluded From Computation Of Diluted Net Loss Per Share) (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stock Options [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share	25,176	25,404	22,501
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	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	586

Segment And Geographic Inform_3

Segment And Geographic Information (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2018USD ($)segment	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of reportable segments | segment									1
Total revenue	$ 19,526	$ 18,160	$ 21,578	$ 19,362	$ 24,935	$ 23,545	$ 20,073	$ 24,915	$ 78,626	$ 93,468	$ 90,714
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									35,598	40,641	50,871
Europe (including the Middle East and Africa) [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									13,958	14,026	21,132
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									$ 29,070	$ 38,801	$ 18,711

Unaudited Selected Quarterly _3

Unaudited Selected Quarterly Financial Data (Schedule Of Unaudited Quarterly Financial Data) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Unaudited Selected Quarterly Financial Data [Abstract]
Total revenue	$ 19,526	$ 18,160	$ 21,578	$ 19,362	$ 24,935	$ 23,545	$ 20,073	$ 24,915	$ 78,626	$ 93,468	$ 90,714
Total gross profit	5,746	3,192	8,862	7,296	9,494	8,227	8,001	8,937	25,096	34,659	44,160
Total operating expenses	36,369	27,862	30,607	31,245	30,023	29,796	32,388	32,236	126,083	124,443	115,404
Loss from operations	(30,623)	(24,670)	(21,745)	(23,949)	(20,529)	(21,569)	(24,387)	(23,299)	(100,987)	(89,784)	(71,244)
Net loss	$ (30,799)	$ (25,044)	$ (22,540)	$ (24,179)	$ (20,762)	$ (22,021)	$ (25,539)	$ (23,867)	$ (102,562)	$ (92,189)	$ (74,375)
Basic and diluted net loss per share	$ (0.21)	$ (0.19)	$ (0.17)	$ (0.20)	$ (0.18)	$ (0.19)	$ (0.26)	$ (0.26)
Weighted average shares used in computing net loss per share	149,314	135,130	131,882	123,768	116,259	115,771	97,360	92,970	135,094	105,682	89,148

Subsequent Event (Narrative) (D

Subsequent Event (Narrative) (Details) - shares	Feb. 15, 2019	Dec. 31, 2019
Restricted Stock Units (RSUs) [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Vesting period	1 year
Restricted Stock Units (RSUs) [Member] | Subsequent Event [Member] | Chief Executive Officer, Michael Hunkapiller, Ph.D. [Member]
Subsequent Event [Line Items]
Number of shares, granted	38,750
Restricted Stock Units (RSUs) [Member] | Subsequent Event [Member] | Chief Financial Officer, Susan K. Barnes [Member]
Subsequent Event [Line Items]
Number of shares, granted	21,250
Scenario, Forecast [Member] | Chief Executive Officer, Michael Hunkapiller, Ph.D. [Member]
Subsequent Event [Line Items]
Annual target bonus opportunity, percentage of base salary		100.00%
Scenario, Forecast [Member] | Chief Financial Officer, Susan K. Barnes [Member]
Subsequent Event [Line Items]
Annual target bonus opportunity, percentage of base salary		65.00%

Subsequent Event (Schedule of I

Subsequent Event (Schedule of Increases in Base Salaries) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Chief Financial Officer, Susan K. Barnes [Member]
Subsequent Event [Line Items]
Officers compensation		$ 1
Chief Financial Officer, Susan K. Barnes [Member] | Scenario, Forecast [Member]
Subsequent Event [Line Items]
Officers compensation	$ 401,500
Chief Executive Officer, Michael Hunkapiller, Ph.D. [Member]
Subsequent Event [Line Items]
Officers compensation		$ 1
Chief Executive Officer, Michael Hunkapiller, Ph.D. [Member] | Scenario, Forecast [Member]
Subsequent Event [Line Items]
Officers compensation	$ 582,900