Entity Central Index Key Cover [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Entity Registrant Name Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Common Stock, Shares Outstanding Entity Common Stock Shares Outstanding Entity File Number Entity File Number Entity Tax Identification Number Entity Tax Identification Number Entity Address, Address Line One Entity Address Address Line1 Entity Address, Address Line Two Entity Address Address Line2 Entity Address, City or Town Entity Address City Or Town Entity Address, State or Province Entity Address State Or Province Entity Address, Postal Zip Code Entity Address Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Entity Incorporation, State or Country Code Entity Incorporation State Country Code Document Quarterly Report Document Quarterly Report Document Transition Report Document Transition Report Entity Interactive Data Current Entity Interactive Data Current Entity Current Reporting Status Entity Current Reporting Status Entity Shell Company Entity Shell Company Title of 12(b) Security Security12b Title Trading Symbol Trading Symbol Security Exchange Name Security Exchange Name Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to clinical trial services received from vendors, such as accrued contract research organization costs, patient costs, clinical site costs and clinical product cost. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Statement Of Financial Position [Abstract] Statement [Table] Statement [Table] Class of Warrant or Right Class Of Warrant Or Right [Axis] Class of Warrant or Right Class Of Warrant Or Right [Domain] 2018 PIPE warrant liability. 2018 PIPE Warrant Liability [Member] Two Thousand Eighteen P I P E Warrant Liability [Member] Statement [Line Items] Statement [Line Items] Assets Assets [Abstract] Current assets Assets Current [Abstract] Cash and cash equivalents Cash And Cash Equivalents At Carrying Value Prepaid expenses and other current assets Prepaid Expense And Other Assets Current Total current assets Assets Current Long-term assets Assets Noncurrent [Abstract] Property and equipment, net Property Plant And Equipment Net Operating lease right-of-use assets Operating Lease Right Of Use Asset Other long-term assets Other Assets Noncurrent Intangible assets, net Intangible Assets Net Excluding Goodwill Total assets Assets Liabilities and stockholders’ equity Liabilities And Stockholders Equity [Abstract] Current liabilities Liabilities Current [Abstract] Accounts payable Accounts Payable Current Accrued compensation Employee Related Liabilities Current Accrued clinical trial site costs Accrued Clinical Trial Costs Current Operating lease liabilities Operating Lease Liability Current Other current liabilities Other Liabilities Current Total current liabilities Liabilities Current Long-term liabilities Liabilities Noncurrent [Abstract] Warrant liability Derivative Liabilities Noncurrent Contingent liability for Essentialis purchase price Asset Acquisition Contingent Consideration Liability Noncurrent Operating lease liabilities, net of current Operating Lease Liability Noncurrent Total liabilities Liabilities Commitments and contingencies (Note 6) Commitments And Contingencies Stockholders’ equity Stockholders Equity [Abstract] Common stock, $0.001 par value, 250,000,000 shares authorized, 79,806,487 and 79,615,692 shares issued and outstanding at September 30, 2021 and December 31, 2020, respectively. Common Stock Value Additional paid-in-capital Additional Paid In Capital Common Stock Accumulated deficit Retained Earnings Accumulated Deficit Total stockholders’ equity Stockholders Equity Total liabilities and stockholders’ equity Liabilities And Stockholders Equity Common stock, par value (in dollars per share) Common Stock Par Or Stated Value Per Share Common stock, shares authorized Common Stock Shares Authorized Common stock, shares issued Common Stock Shares Issued Common stock, shares outstanding Common Stock Shares Outstanding Asset acquisition contingent consideration change in fair value. Income Statement [Abstract] Operating expenses Operating Expenses [Abstract] Research and development Research And Development Expense General and administrative General And Administrative Expense Change in fair value of contingent consideration Asset Acquisition Contingent Consideration Change In Fair Value Total operating expenses Operating Expenses Operating loss Operating Income Loss Other income (expense) Nonoperating Income Expense [Abstract] Change in fair value of warrants liabilities Fair Value Adjustment Of Warrants Interest income Other Nonoperating Income Expense Total other income (expense) Nonoperating Income Expense Net loss Net Income Loss Net loss per common share, basic and diluted Earnings Per Share Basic And Diluted Weighted-average common shares outstanding used to calculate basic and diluted net loss per common share Weighted Average Number Of Share Outstanding Basic And Diluted Issuance of common stock shares under equity incentive plans. Issuance of common stock value under equity incentive plans. Statement Of Stockholders Equity [Abstract] Equity Components Statement Equity Components [Axis] Equity Component Equity Component [Domain] Common Stock [Member] Common Stock [Member] Additional Paid-In Capital [Member] Additional Paid In Capital [Member] Accumulated Deficit [Member] Retained Earnings [Member] Sale of Stock Subsidiary Sale Of Stock [Axis] Sale of Stock Sale Of Stock Name Of Transaction [Domain] IPO [Member] I P O [Member] Balances at beginning Balances at beginning (shares) Shares Outstanding Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase Decrease In Stockholders Equity Roll Forward Stock-based compensation Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value Issuance of common stock under equity incentive plan, net of tax withholdings Issuance Of Common Stock Value Under Equity Incentive Plans Issuance of common stock under equity incentive plan, net of tax withholdings (shares) Issuance Of Common Stock Shares Under Equity Incentive Plans Sale of common stock in public offering, net of costs of $3,778 Stock Issued During Period Value New Issues Sale of common stock in public offering, net of costs, (shares) Stock Issued During Period Shares New Issues Tax withholding payments for net share-settled equity awards Adjustments To Additional Paid In Capital Income Tax Deficiency From Share Based Compensation Tax withholding payments for net share-settled equity awards (shares) Shares Paid For Tax Withholding For Share Based Compensation Net loss Balances at ending Balances at end (shares) Payments of stock issuance costs Payments Of Stock Issuance Costs Noncash lease expense. Increase decrease in accrued clinical trial site costs. Increase decrease in operating lease liabilities. Deferred financing costs included in accounts payable. Statement Of Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided By Used In Operating Activities [Abstract] Net loss Profit Loss Adjustments to reconcile net loss to net cash used in operating activities: Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Depreciation and amortization Depreciation And Amortization Non-cash lease expense Noncash Lease Expense Stock-based compensation expense Share Based Compensation Change in fair value of stock warrants Change in operating assets and liabilities: Increase Decrease In Operating Capital [Abstract] Prepaid expenses and other current assets Increase Decrease In Prepaid Deferred Expense And Other Assets Other long-term assets Increase Decrease In Other Noncurrent Assets Accounts payable Increase Decrease In Accounts Payable Accrued compensation Increase Decrease In Employee Related Liabilities Accrued clinical trial site costs Increase Decrease In Accrued Clinical Trial Site Costs Operating lease liabilities Increase Decrease In Operating Lease Liabilities Other liabilities Increase Decrease In Other Operating Liabilities Net cash used in operating activities Net Cash Provided By Used In Operating Activities Cash flows from investing activities: Net Cash Provided By Used In Investing Activities [Abstract] Purchases of property and equipment Payments To Acquire Property Plant And Equipment Net cash used in investing activities Net Cash Provided By Used In Investing Activities Cash flows from financing activities: Net Cash Provided By Used In Financing Activities [Abstract] Proceeds from sale of common stock, net of costs Proceeds From Issuance Of Common Stock Tax withholding payments for net share-settled equity awards Payments Related To Tax Withholding For Share Based Compensation Proceeds from stock option exercises Proceeds From Stock Options Exercised Principal paid on finance lease liabilities Finance Lease Principal Payments Net cash provided by (used in) financing activities Net Cash Provided By Used In Financing Activities Net increase (decrease) in cash and cash equivalents Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect Cash and cash equivalents, beginning of period Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Cash and cash equivalents, end of period Supplemental disclosure of non-cash activities Cash Flow Noncash Investing And Financing Activities Disclosure [Abstract] Purchase of property and equipment in accounts payable Capital Expenditures Incurred But Not Yet Paid Right-of-use assets obtained in exchange for operating lease obligations Right Of Use Asset Obtained In Exchange For Operating Lease Liability Deferred financing costs included in accounts payable Deferred Financing Costs Included In Accounts Payable Accounting Policies [Abstract] Overview Business Description And Basis Of Presentation [Text Block] Going concern and management’s plans. Cash And Cash Equivalents [Abstract] Going Concern and Management's Plans Going Concern And Managements Plans [Text Block] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Fair Value Disclosures [Abstract] Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Warrant Liability Disclosure [Text Block] Text Block [Abstract] Warrant Liabilities Warrant Liability Disclosure [Text Block] Commitments And Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments And Contingencies Disclosure [Text Block] Equity [Abstract] Stockholders' Equity Shareholders Equity And Share Based Payments [Text Block] Earnings Per Share [Abstract] Net loss per share Earnings Per Share [Text Block] Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Basis of Presentation Basis Of Accounting Policy Policy [Text Block] Use of Estimates Use Of Estimates Recent Accounting Standards New Accounting Pronouncements Policy Policy [Text Block] Summary of Financial Instruments Measured at Fair Value on Recurring Basis Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Table [Text Block] Summary of Changes in Fair Value of Level 3 Financial Instruments Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Text Block] Fair Value of Convertible Preferred Stock Warrant Liability Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques Table [Text Block] Reconciliation of Undiscounted Future Minimum Lease Payments Remaining under Operating Lease Lessee Operating Lease Liability Maturity Table [Text Block] Schedule of Components of Lease Expense Lease Cost Table [Text Block] Summary of Stock Based Compensation Expense Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Text Block] Schedule of Fair Value of Award Granted Using Black-Scholes Option Pricing Model Schedule Of Share Based Payment Award Stock Options Valuation Assumptions Table [Text Block] Summary of Stock Option Transactions Schedule Of Share Based Compensation Stock Options Activity Table [Text Block] Summary of Restricted Stock Unit Transactions Schedule Of Share Based Compensation Restricted Stock Units Award Activity Table [Text Block] Schedule of Potentially Dilutive Securities Outstanding Excluded from Computations of Diluted Weighted-Average Shares Outstanding Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Text Block] Common stock, maximum aggregate value purchase price. Schedule Of Cash And Cash Equivalents [Table] Schedule Of Cash And Cash Equivalents [Table] Collaborative Arrangement and Arrangement Other than Collaborative Type Of Arrangement [Axis] Collaborative Arrangement and Arrangement Other than Collaborative Arrangements And Nonarrangement Transactions [Member] Controlled equity offering sales agreement. Controlled Equity Offering Sales Agreement [Member] Controlled Equity Offering Sales Agreement [Member] Counterparty Name Counterparty Name [Axis] Counterparty Name Repurchase Agreement Counterparty Name [Domain] Cantor Fitzgerald and Co. Cantor [Member] Cantor Fitzgerald And Co [Member] Cash And Cash Equivalents [Line Items] Cash And Cash Equivalents [Line Items] Net cash used in operating activities Common stock, maximum aggregate purchase price Common Stock Maximum Aggregate Purchase Price Asset acquisition contingent consideration arrangements. Schedule Of Significant Accounting Policies [Line Items] Schedule Of Significant Accounting Policies [Table] Schedule Of Significant Accounting Policies [Table] Schedule Of Significant Accounting Policies [Table] Asset purchase. Asset Purchase Asset Purchase [Axis] Asset purchase. Asset Purchase Asset Purchase [Domain] Essentialis, Inc. Essentialis, Inc. [Member] Essentialis Inc [Member] Contingent Consideration by Type Contingent Consideration By Type [Axis] Contingent Consideration Type Contingent Consideration Type [Domain] Earnout Payments [Member] Earnout Payments [Member] Earnout Payments [Member] Schedule Of Significant Accounting Policies [Line Items] Schedule Of Significant Accounting Policies [Line Items] Maximum potential cash earnout payments Asset Acquisition Contingent Consideration Arrangements Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Fair Value Hierarchy and NAV Fair Value By Fair Value Hierarchy Level [Axis] Fair Value Hierarchy and NAV Fair Value Measurements Fair Value Hierarchy [Domain] Level 1 [Member] Fair Value Inputs Level1 [Member] Level 2 [Member] Fair Value Inputs Level2 [Member] Level 3 [Member] Fair Value Inputs Level3 [Member] Measurement Frequency Fair Value By Measurement Frequency [Axis] Measurement Frequency Fair Value Measurement Frequency [Domain] Fair Value, Measurements, Recurring [Member] Fair Value Measurements Recurring [Member] Liability Class Fair Value By Liability Class [Axis] Fair Value by Liability Class Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation By Liability Class [Domain] Derivative Financial Instruments, Liabilities [Member] Derivative Financial Instruments Liabilities [Member] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] Liabilities Liabilities Fair Value Disclosure [Abstract] Total common stock warrant and contingent consideration liability Liabilities Fair Value Disclosure Fair value measurement with unobservable inputs reconciliation recurring basis liability expiration. Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Table] Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Table] Common Stock Warrant Liability [Member] Common stock warrant liability [Member] Common Stock Warrant Liability [Member] Purchase price contingent liability. Purchase price contingent liability [Member] Purchase Price Contingent Liability [Member] Series C Warrants [Member] Series C Warrant [Member] Series C Warrants [Member] 2017 PIPE warrant liability. 2017 PIPE Warrant Liability [Member] Two Thousand Seventeen P I P E Warrant Liability [Member] Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation Calculation Roll Forward Balance at the beginning of period Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value Balance at the beginning of period, in shares Class Of Warrant Or Right Outstanding Change in value of liabilities Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Earnings Balance at end of period Balance at the end of period, in shares Expiration of warrants Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Expiration Expiration of warrants. Expiration of warrants, in shares Expiration Of Warrants Class Of Warrant Or Right [Table] Class Of Warrant Or Right [Table] Two thousand eighteen PIPE warrant liability to purchase common stock. 2018 PIPE Warrant Liability [Member] Two Thousand Eighteen P I P E Warrant Liability To Purchase Common Stock [Member] Statistical Measurement Range [Axis] Statistical Measurement Range [Member] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Measurement Input Type Measurement Input Type [Axis] Measurement Input Type Measurement Input Type [Domain] Expected Dividend Yield [Member] Measurement Input Expected Dividend Rate [Member] Class Of Warrant Or Right [Line Items] Class Of Warrant Or Right [Line Items] Fair value of estimated warrants Warrants And Rights Outstanding Class of Warrant or Right, Exercise Price Description Number of common stock purchased upon issuance of warrants Class Of Warrant Or Right Number Of Securities Called By Warrants Or Rights Warrant to call common stock Class Of Warrant Or Right Number Of Securities Called By Each Warrant Or Right Exercise price of warrants exercised Class Of Warrant Or Right Exercise Price Of Warrants Or Rights1 Warrant issuance description Class Of Warrant Or Right Exercise Price Description Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Table] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Table] Volatility [Member] Measurement Input Price Volatility [Member] Contractual Term [Member] Measurement Input Expected Term [Member] Risk-free Rate [Member] Measurement Input Risk Free Interest Rate [Member] Fair Value Measurement Inputs and Valuation Techniques [Line Items] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] Measurement input Warrants And Rights Outstanding Measurement Input Measurement term Warrants And Rights Outstanding Term Lessee, operating lease commencement month and year. Lessee, operating lease month and year of expiration. Commitments and contingencies. Commitments and contingencies. Commitments And Contingencies [Table] Commitments And Contingencies [Table] Geographical Statement Geographical [Axis] Geographical Segment Geographical [Domain] Redwood City, California [Member] C A Long-Lived Tangible Asset Property Plant And Equipment By Type [Axis] Long-Lived Tangible Asset Property Plant And Equipment Type [Domain] Facility leases. Facility Leases [Member] Facility Leases [Member] Commitments And Contingencies [Line Items] Commitments And Contingencies [Line Items] Area of operating lease Area Of Real Estate Property Operating lease, description Lessee Operating Lease Description Operating lease beginning date Lessee Operating Lease Commencement Month And Year Operating lease, expiration Lessee Operating Lease Month And Year Of Expiration Right-of-use asset Right-of-use liability Operating Lease Liability Operating lease, short-term liability Operating lease, long-term liability Operating lease, weighted average discount rate Operating Lease Weighted Average Discount Rate Percent Operating lease remaining term Operating Lease Weighted Average Remaining Lease Term1 Undiscounted future minimum lease payments: Operating Lease Liabilities Payments Due [Abstract] 2021 (remainder of the year) Lessee Operating Lease Liability Payments Remainder Of Fiscal Year 2022 Lessee Operating Lease Liability Payments Due Next Twelve Months 2023 Lessee Operating Lease Liability Payments Due Year Two Total undiscounted future minimum lease payments Lessee Operating Lease Liability Payments Due Less: amount representing imputed interest Lessee Operating Lease Liability Undiscounted Excess Amount Finance lease cost. Operating lease cost Operating Lease Cost Amortization of right-of-use assets Finance Lease Right Of Use Asset Amortization Interest on lease liabilities Finance Lease Interest Expense Total finance lease cost Finance Lease Cost Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Award Type Award Type [Axis] Award Type Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain] Stock Options [Member] Employee Stock Option [Member] Incentive Stock Options [Member] ISOs [Member] Incentive Stock Options [Member] Plan Name Plan Name [Axis] Plan Name Plan Name [Domain] 2014 equity incentive plan. 2014 Equity Incentive Plan [Member] Two Thousand And Fourteen Equity Incentive Plan [Member] Two thousand twenty inducement equity incentive plan. 2020 Inducement Equity Incentive Plan [Member] Two Thousand Twenty Inducement Equity Incentive Plan [Member] Performance-Based Options [Member] Performance Shares [Member] Restricted Stock Units [Member] Restricted Stock Units R S U [Member] Employee Stock Purchase Plan [Member] Employee Stock [Member] Warrants To Purchase Stock [Member] Warrants to Purchase Stock [Member] Warrants To Purchase Common Stock [Member] Underwriter [Member] Underwriter [Member] Underwriter [Member] Debt Instrument Debt Instrument [Axis] Debt Instrument, Name Debt Instrument Name [Domain] Two Thousand and Ten and Two Thousand and Twelve Convertible Promissory Notes [Member] 2010 and 2012 Convertible Promissory Notes [Member] Two Thousand And Ten And Two Thousand And Twelve Convertible Promissory Notes [Member] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Shares sold under at the market program Ownership interest, percentage of voting rights of stock. Ownership interest of voting rights of all classes of stock (percent) Ownership Interest Percentageof Voting Rightsof Stock Percentage of fair market value Sharebased Compensation Arrangement By Sharebased Payment Award Purchase Price Of Common Stock Percent Vesting period Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Period1 Contractual term of option Sharebased Compensation Arrangement By Sharebased Payment Award Expiration Period Number of shares available for grant Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant Number of shares reserved for issuance Common Stock Capital Shares Reserved For Future Issuance Stock units granted Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Income tax benefits recognized from stock-based compensation Employee Service Share Based Compensation Tax Benefit From Compensation Expense Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Table] Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Table] Income Statement Location Income Statement Location [Axis] Income Statement Location Income Statement Location [Domain] Research and Development [Member] Research And Development Expense [Member] General and Administrative [Member] General And Administrative Expense [Member] Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] Stock-based compensation expense Allocated Share Based Compensation Expense Number of options granted Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross Expected life (years) Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 Risk-free interest rate Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate Volatility Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate Dividend rate Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate Expected dividend yield Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Roll Forward Beginning balance Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number Options granted Options exercised Stock Issued During Period Shares Stock Options Exercised Options canceled/forfeited Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures And Expirations In Period Ending balance Options vested at end of period (shares) Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested Number Of Shares Options vested and expected to vest at end of period (shares) Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Number Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward] Weighted-Average Exercise Price per Share Sharebased Compensation Arrangementby Sharebased Payment Award Options Nonvested Weighted Average Grant Date Fair Value Roll Forward Beginning balance (in dollars per share) Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price Options granted (in dollars per share) Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price Options exercised (in dollars per share) Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price Options canceled/forfeited (in dollars per share) Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price Ending balance (in dollars per share) Options vested at end of period (in dollars per share) Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested Weighted Average Grant Date Fair Value Options vested and expected to vest at end of period (in dollars per share) Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Weighted Average Remaining Contractual Term Weighted Average Remaining Contractual Term Share Based Compensation Arrangement By Share Based Payment Award Options Additional Disclosures [Abstract] Options outstanding at end of period Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 Options vested at end of period Sharebased Compensation Arrangementby Sharebased Payment Award Options Vestedin Period Weighted Average Remaining Contractual Term Options vested and expected to vest at end of period Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested And Expected To Vest Outstanding Weighted Average Remaining Contractual Term1 Share based compensation arrangement by share based payment award options non vested aggregate intrinsic value. Share based compensation arrangement by share based payment award options vested aggregate intrinsic value. Aggregate Intrinsic Value Share Based Compensation Arrangement By Share Based Payment Award Options Non Vested Aggregate Intrinsic Value [Abstract] Options outstanding at end of period Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value Options vested at end of period Share Based Compensation Arrangement By Share Based Payment Award Options Vested Aggregate Intrinsic Value Options vested and expected to vest at end of period Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Aggregate Intrinsic Value Weighted average grant date fair value per option granted (in dollars per share) Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value Future stock-based compensation for unvested employee options granted and outstanding Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Stock Options Future stock-based compensation, requisite service period Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1 Vesting percentage Sharebased Compensation Arrangement By Sharebased Payment Award Award Vesting Rights Percentage Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Roll Forward Beginning balance Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number Restricted stock units granted Restricted stock units vested Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Ending balance Weighted-average grant date fair value Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value Roll Forward Beginning balance (in dollars per share) Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value Restricted stock units granted (in dollars per share) Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value Restricted stock units vested (in dollars per share) Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Weighted Average Grant Date Fair Value Ending balance (in dollars per share) Weighted average grant-date fair value of all restricted stock units granted Fair value of restricted stock units vested Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Total Fair Value Unrecognized stock based compensation expense Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Share Based Awards Other Than Options Weighted average remaining vesting period Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested And Expected To Vest Exercisable Weighted Average Remaining Contractual Term1 Percentage of outstanding stock maximum Share Based Compensation Arrangement By Share Based Payment Award Percentage Of Outstanding Stock Maximum Number of shares available for issuance under the plan on the first day of each year Number of shares purchases by employees Stock Issued During Period Shares Employee Stock Purchase Plans Class Of Warrant Or Right, Warrant Term Class of warrant or right warrants expiration month and year. Warrants outstanding (in shares) Exercise price of warrants (in dollars per share) Warrants term Class Of Warrant Or Right Warrant Term Warrants expiration period Class Of Warrant Or Right Warrants Expiration Month And Year Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Warrants Issued to Underwriter to Purchase Common Stock [Member] Series D Warrants To Purchase Common Stock [Member] Series D Warrants To Purchase Common Stock [Member] Series D Warrants To Purchase Common Stock [Member] 2017 PIPE Warrants [Member] 2018 PIPE Warrants [Member] Antidilutive Securities Antidilutive Securities Excluded From Computation Of Earnings Per Share By Antidilutive Securities [Axis] Antidilutive Securities, Name Antidilutive Securities Name [Domain] Warrants Issued to 2010/2012 Convertible Note Holders to Purchase Common Stock [Member] Convertible Debt Securities [Member] Options to Purchase Common Stock [Member] Stock Option [Member] Outstanding Restricted Stock Units [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Antidilutive securities excluded from computations of diluted weighted-average shares outstanding Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount