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 Entity Current Reporting Status Entity Current Reporting Status Entity Interactive Data Current Entity Interactive Data Current Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock Shares Outstanding Entity Shell Company Entity Shell Company Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Ex Transition Period Entity Ex Transition Period Title of 12(b) Security Security12b Title Trading Symbol Trading Symbol Security Exchange Name Security Exchange Name Entity File Number Entity File Number Entity Incorporation, State or Country Code Entity Incorporation State Country Code 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 Document Quarterly Report Document Quarterly Report Document Transition Report Document Transition Report Convertible preferred stock liability. Ordinary shares. Statement Of Financial Position [Abstract] Statement [Table] Statement [Table] Class of Stock Statement Class Of Stock [Axis] Class of Stock Class Of Stock [Domain] Convertible Preferred Stock Convertible Preferred Stock [Member] Convertible preferred shares. Convertible Preferred Shares Convertible Preferred Shares [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 Restricted cash Restricted Cash Current Prepaid and other current assets Prepaid Expense And Other Assets Current Total current assets Assets Current Property and equipment, net Property Plant And Equipment Net Deferred offering costs Deferred Costs Deferred tax assets Deferred Tax Assets Net Noncurrent Total assets Assets Liabilities, convertible preferred stock, convertible preferred shares and stockholders’ deficit Liabilities And Stockholders Equity [Abstract] Current liabilities: Liabilities Current [Abstract] Accounts payable Accounts Payable Current Accrued expenses Accrued Liabilities Current Convertible preferred stock liability Convertible Preferred Stock Liability Total current liabilities Liabilities Current Commitments and contingencies (Note 5) Commitments And Contingencies Convertible preferred stock and convertible preferred shares Temporary Equity Carrying Amount Attributable To Parent Stockholders’ deficit: Stockholders Equity [Abstract] Common stock Common Stock Value Ordinary shares Ordinary Shares Additional paid-in capital Additional Paid In Capital Common Stock Accumulated deficit Retained Earnings Accumulated Deficit Total stockholders’ deficit Stockholders Equity Total liabilities, convertible preferred stock, convertible preferred shares and stockholders’ deficit Liabilities And Stockholders Equity Income Statement [Abstract] Operating expenses: Operating Expenses [Abstract] Research and development Research And Development Expense General and administrative General And Administrative Expense Total operating expenses Operating Expenses Loss from operations Operating Income Loss Other (income) expenses, net Other Nonoperating Income Expense Net loss before tax Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest Income tax expense Income Tax Expense Benefit Net loss and comprehensive loss Net Income Loss Net loss per share, basic and diluted Earnings Per Share Basic And Diluted Weighted-average shares used to compute net loss per share, basic and diluted Weighted Average Number Of Share Outstanding Basic And Diluted Temporary equity, stock issued during period, shares, new issues. Temporary equity effects of reorganization adjustments shares. Temporary equity effects of reorganization adjustments value. Effects of reorganization adjustments value. Temporary equity, conversion of convertible note in to preferred shares, value. Statement Of Stockholders Equity [Abstract] Equity Components Statement Equity Components [Axis] Equity Component Equity Component [Domain] Ordinary shares. Ordinary Shares Ordinary Shares [Member] Common Stock Common Stock [Member] Additional Paid-in Capital Additional Paid In Capital [Member] Accumulated Deficit Retained Earnings [Member] Beginning balance Beginning balance, shares Temporary Equity Shares Outstanding Beginning balance Beginning balance, shares Shares Outstanding Issuance of ordinary shares Stock Issued During Period Value New Issues Issuance of ordinary shares, shares Stock Issued During Period Shares New Issues Issuance of convertible preferred shares, net of issuance costs Temporary Equity Stock Issued During Period Value New Issues Issuance of convertible preferred shares, net of issuance costs, shares Temporary Equity Stock Issued During Period Shares New Issues Temporary Equity, Effects of the Reorganization Temporary Equity Effects Of Reorganization Adjustments Value Temporary Equity, Effects of the Reorganization, shares Temporary Equity Effects Of Reorganization Adjustments Shares Effects of the Reorganization Effects Of Reorganization Adjustments Value Effects of reorganization adjustments shares. Effects of the Reorganization, shares Effects Of Reorganization Adjustments Shares Conversion of convertible note into preferred shares Temporary Equity Conversion Of Convertible Note In To Preferred Shares Value Temporary equity, conversion of convertible note in to preferred shares. Conversion of convertible note into preferred shares, shares Temporary Equity Conversion Of Convertible Note In To Preferred Shares Share-based compensation Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value Net loss and comprehensive loss Ending balance Ending balance, shares Ending balance Ending balance Temporary equity, issuance costs. Temporary equity, partial settlement of convertible preferred stock liability. Temporary equity, recognition of convertible preferred stock liability. Temporary equity, issuance costs Temporary Equity Issuance Costs Temporary equity, partial settlement of convertible preferred stock liability Temporary Equity Partial Settlement Of Convertible Preferred Stock Liability Temporary equity, recognition of convertible preferred stock liability Temporary Equity Recognition Of Convertible Preferred Stock Liability Deferred tax assets. Revaluation of convertible preferred stock liability. Payment of deferred offering costs. Conversion of convertible note into preferred stock. Deferred offering costs included in accounts payable and accrued expenses. 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 Depreciation Share-based compensation Share Based Compensation Deferred tax assets Deferred Tax Assets Revaluation of convertible preferred stock liability Revaluation Of Convertible Preferred Stock Liability Changes in operating assets and liabilities: Increase Decrease In Operating Capital [Abstract] Prepaids and other current assets Increase Decrease In Prepaid Deferred Expense And Other Assets Accounts payable Increase Decrease In Accounts Payable Accrued expenses Increase Decrease In Accrued 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 issuance of convertible preferred stock and convertible preferred stock liability, net of issuance costs Proceeds From Issuance Of Convertible Preferred Stock Proceeds from issuance of common stock Proceeds From Issuance Of Common Stock Proceeds from issuance of convertible note Proceeds From Convertible Debt Payment of deferred offering costs Payment Of Deferred Offering Costs Net cash provided by financing activities Net Cash Provided By Used In Financing Activities Net increase in cash and cash equivalents, and restricted cash Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect Cash and cash equivalents, and restricted cash at beginning of period Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Cash and cash equivalents, and restricted cash at end of period Components of cash and cash equivalents, and restricted cash: Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents [Abstract] Restricted cash Restricted Cash And Cash Equivalents Supplemental disclosures of noncash investing and financing information: Noncash Investing And Financing Items [Abstract] Conversion of convertible note into preferred stock Conversion Of Convertible Note Into Preferred Stock Deferred offering costs included in accounts payable and accrued expenses Deferred Offering Costs Included In Accounts Payable And Accrued Expenses Organization Consolidation And Presentation Of Financial Statements [Abstract] Organization and Basis of Presentation Organization Consolidation And Presentation Of Financial Statements Disclosure [Text Block] Accounting Policies [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Fair Value Disclosures [Abstract] Fair Value Measurements Fair Value Disclosures [Text Block] Balance Sheet Related Disclosures [Abstract] Consolidated Balance Sheet Components Supplemental Balance Sheet Disclosures [Text Block] Commitments And Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments And Contingencies Disclosure [Text Block] Debt Disclosure [Abstract] Convertible Note Debt Disclosure [Text Block] Convertible preferred stock. Temporary Equity Disclosure [Abstract] Convertible Preferred Stock Convertible Preferred Stock Disclosure [Text Block] Common stock. Equity [Abstract] Common Stock Common Stock [Text Block] Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] Share-Based Compensation Disclosure Of Compensation Related Costs Share Based Payments [Text Block] Earnings Per Share [Abstract] Net Loss Per Share Earnings Per Share [Text Block] Related Party Transactions [Abstract] Related Party Transactions Related Party Transactions Disclosure [Text Block] Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Unaudited Condensed Consolidated Financial Statements Basis Of Accounting Policy Policy [Text Block] Use of Estimates Use Of Estimates Fair Value Measurements Fair Value Measurement Policy Policy [Text Block] Convertible preferred stock liability. Convertible Preferred Stock Liability Convertible Preferred Stock Liability Policy [Text Block] Deferred Offering Costs Deferred Charges Policy [Text Block] Recent Accounting Pronouncements New Accounting Pronouncements Policy Policy [Text Block] Summary of Liabilities Measured at Fair Value on Recurring Basis Schedule Of Fair Value Assets And Liabilities Measured On Recurring Basis Table [Text Block] Summary of Changes in Fair Value of Level 3 Liabilities Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Text Block] Schedule of Accrued Expenses Schedule Of Accrued Liabilities Table [Text Block] Schedule of Convertible Preferred Stock Temporary Equity Table [Text Block] Schedule of common stock reserved for issuance. Schedule of Common Stock Reserved for Issuance Schedule Of Common Stock Reserved For Issuance Table [Text Block] Summary of Share-Based Compensation Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Text Block] Summary of Estimated Fair Value of Option Awards Granted Using Black-Scholes Option-Pricing Model Schedule Of Share Based Payment Award Stock Options Valuation Assumptions Table [Text Block] Summary of Stock Option Activity Schedule Of Share Based Compensation Stock Options Activity Table [Text Block] Schedule of Outstanding Potentially Dilutive Securities Excluded From Calculation of Diluted Net Loss Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Text Block] Subsidiary Or Equity Method Investee Sale Of Stock By Subsidiary Or Equity Investee [Table] Subsidiary Or Equity Method Investee Sale Of Stock By Subsidiary Or Equity Investee [Table] Subsequent Event Type Subsequent Event Type [Axis] Subsequent Event Type Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Sale of Stock Subsidiary Sale Of Stock [Axis] Sale of Stock Sale Of Stock Name Of Transaction [Domain] IPO I P O [Member] Overallotment Option Over Allotment Option [Member] Subsidiary Sale Of Stock [Line Items] Subsidiary Sale Of Stock [Line Items] Date of incorporation Entity Incorporation Date Of Incorporation Reorganization exchange of equity percentage of common stock issued upon exchange. Reorganization exchange of equity percentage of ordinary shares exchanged. Reorganization exchange of equity percentage of ordinary shares exchanged Reorganization Exchange Of Equity Percentage Of Common Stock Issued Upon Exchange Reorganization exchange of equity percentage of common stock issued upon exchange Reorganization Exchange Of Equity Percentage Of Ordinary Shares Exchanged Reverse stock split conversion ratio Stockholders Equity Note Stock Split Conversion Ratio1 Reverse stock split, description Stockholders Equity Reverse Stock Split Payments of stock issuance costs, other. Shares issued and sold IPO price per share Shares Issued Price Per Share Payment of underwriting discounts, commissions Payments Of Stock Issuance Costs Other offering expenses Payments Of Stock Issuance Costs Other Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Measurement Frequency Fair Value By Measurement Frequency [Axis] Measurement Frequency Fair Value Measurement Frequency [Domain] Recurring Fair Value Measurements Recurring [Member] 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 Fair Value Inputs Level1 [Member] Level 2 Fair Value Inputs Level2 [Member] Level 3 Fair Value Inputs Level3 [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] Convertible preferred stock liability. Convertible Preferred Stock Liability Convertible Preferred Stock Liability [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] Total financial liabilities Financial Liabilities Fair Value Disclosure Fair value measurement with unobservable inputs reconciliation partial settlement of convertible preferred stock liability upon second closing. Fair value measurement with unobservable inputs reconciliation partial settlement of convertible preferred stock liability upon third closing. Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Table] Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Table] Fair Value Liabilities Measured on Recurring Basis Unobservable Input Reconciliation [Line Items] Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] Beginning balance Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value Recognition of convertible preferred stock liability upon issuance of convertible preferred stock Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Issues Revaluation of convertible preferred stock liability recorded in other (income) expense, net Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Earnings Partial settlement of convertible preferred stock liability upon second closing Fair Value Measurement With Unobservable Inputs Reconciliation Partial Settlement Of Convertible Preferred Stock Liability Upon Second Closing Partial settlement of convertible preferred stock liability upon third closing Fair Value Measurement With Unobservable Inputs Reconciliation Partial Settlement Of Convertible Preferred Stock Liability Upon Third Closing Ending balance Accrued research and development expense current. Payables And Accruals [Abstract] Accrued research and development expense Accrued Research And Development Expense Current Accrued employee and related expenses Employee Related Liabilities Current Total accrued expenses Asset transfer and license agreements initial nonrefundable upfront payment. Obligation to payment upon maximum achievement of certain clinical and commercial milestones. Loss Contingencies [Table] Loss Contingencies [Table] Collaborative Arrangement and Arrangement Other than Collaborative Type Of Arrangement [Axis] Collaborative Arrangement and Arrangement Other than Collaborative Arrangements And Nonarrangement Transactions [Member] Teva agreement. Teva Agreements Teva Agreement [Member] Research and Development Arrangement, Contract to Perform for Others, Type Research And Development Arrangement Contract To Perform For Others By Type [Axis] Research and Development Arrangement, Contract to Perform for Others, Type Research And Development Arrangement Contract To Perform For Others Type [Domain] Tevas glycoPEGylated FGF21 program. Teva’s GlycoPEGylated FGF21 Program Tevas Glyco P E Gylated F G F21 Program [Member] Tevas development program. Teva’s Development Program Tevas Development Program [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Nonrefundable upfront payment Asset Transfer And License Agreement Initial Nonrefundable Upfront Payment Payment upon achievement of certain clinical and commercial milestones Obligation To Payment Upon Maximum Achievement Of Certain Clinical And Commercial Milestones Asset transfer and license agreement termination period after written notice. Asset transfer and license agreement termination period notice of failure. Asset transfer and license agreement termination notice period if bankruptcy petition filed. Asset transfer and license agreement, termination period after written notice Asset Transfer And License Agreement Termination Period After Written Notice Asset transfer and license agreement, termination period notice of breach Asset Transfer And License Agreement Termination Period Notice Of Failure Asset transfer and license agreement termination notice period if bankruptcy petition filed Asset Transfer And License Agreement Termination Notice Period If Bankruptcy Petition Filed Debt Instrument [Table] Debt Instrument [Table] Series A convertible preferred stock. Series A Convertible Preferred Stock Series A Convertible Preferred Stock [Member] Long-term Debt, Type Longterm Debt Type [Axis] Long-term Debt, Type Longterm Debt Type [Domain] Convertible Note Convertible Debt [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Debt instrument, principal amount Debt Instrument Face Amount Fixed interest rate per annum Debt Instrument Interest Rate Stated Percentage Convertible note outstanding amount converted into shares Debt Conversion Converted Instrument Shares Issued1 Convertible note, conversion description Debt Conversion Converted Instrument Type Total amount of preferred shares issuable by the entity. Temporary Equity By Class Of Stock [Table] Temporary Equity By Class Of Stock [Table] Financial Instrument Financial Instrument [Axis] Financial Instruments Transfers And Servicing Of Financial Instruments Types Of Financial Instruments [Domain] Series A share purchase agreement. Series A Share Purchase Agreement Series A Share Purchase Agreement [Member] Statistical Measurement Range [Axis] Statistical Measurement Range [Member] Maximum Maximum [Member] Minimum [Member] Minimum [Member] Stock Conversion Description Conversion Of Stock By Unique Description [Axis] Conversion of Stock, Name Conversion Of Stock Name [Domain] Initial closing. Initial Closing Initial Closing [Member] Second closing. Second Closing Second Closing [Member] Third closing. Third Closing Third Closing [Member] Income Statement Location Income Statement Location [Axis] Income Statement Location Income Statement Location [Domain] Other (Income) Expense, Net Other Operating Income Expense [Member] Temporary Equity [Line Items] Temporary Equity [Line Items] Total amount of preferred shares issuable by the entity Amount Of Preferred Shares Issuable By Entity Per share price of issuance of shares Temporary Equity Par Or Stated Value Per Share Number of shares committed to purchase. Shares issued Temporary Equity Shares Issued Net cash proceeds Number of shares committed to purchase Number Of Shares Committed To Purchase Net value of commitment to purchase and sell shares. Expense recorded for revaluation of convertible preferred stock liability. Net value of commitment to purchase and sell shares Net Value Of Commitment To Purchase And Sell Shares Expense recorded for revaluation of convertible preferred stock liability Expense Recorded For Revaluation Of Convertible Preferred Stock Liability Temporary equity remaining shares issued. Remaining shares issued Temporary Equity Remaining Shares Issued Convertible preferred shares, outstanding Temporary equity shares issued and outstanding. Convertible preferred stock, shares authorized Temporary Equity Shares Authorized Convertible preferred stock, issued and outstanding Temporary Equity Shares Issued And Outstanding Convertible preferred stock, carrying value Convertible preferred stock, liquidation preference Temporary Equity Liquidation Preference Convertible preferred stock, liquidation preference per share Preferred Stock Liquidation Preference Convertible preferred stock automatically converted into common stock Convertible Preferred Stock Shares Issued Upon Conversion Schedule Of Stock By Class [Table] Schedule Of Stock By Class [Table] Consolidated Entities Consolidated Entities [Axis] Consolidated Entities Consolidated Entities [Domain] 89Bio Ltd. Subsidiaries [Member] Class Of Stock [Line Items] Class Of Stock [Line Items] Common stock, shares authorized Common Stock Shares Authorized Common stock, par value Common Stock Par Or Stated Value Per Share Common stock, shares issued Common Stock Shares Issued Common stock, shares outstanding Common Stock Shares Outstanding Award Type Award Type [Axis] Award Type Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain] Options issued and outstanding. Options Issued and Outstanding Reserved for Issuance Options Issued And Outstanding [Member] Shares available for future option grants. Shares Available for Future Option Grants Reserved for Issuance Shares Available For Future Option Grants [Member] Series A Convertible Preferred Stock Outstanding Reserved for Issuance Total common stock reserved for issuance Common Stock Capital Shares Reserved For Future Issuance Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Plan Name Plan Name [Axis] Plan Name Plan Name [Domain] 2019 equity incentive plan. 2019 Plan Two Thousand And Nineteen Equity Incentive Plan [Member] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Common stock reserved and available for issuance as future option grants 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] Research and Development Research And Development Expense [Member] General and Administrative General And Administrative Expense [Member] Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] Share-based compensation Allocated Share Based Compensation Expense Expected term (years) Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 Expected volatility, minimum Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate Minimum Expected volatility, maximum Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate Maximum Risk-free interest rate, minimum Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate Minimum Risk-free interest rate, maximum Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate Maximum Expected dividend Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate 2018 equity incentive plan. 2018 Plan Two Thousand And Eighteen Equity Incentive Plan [Member] Number of Options Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Roll Forward Outstanding, Beginning Balance Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number Granted Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross Exercised Stock Issued During Period Shares Stock Options Exercised Cancelled Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period Outstanding, Ending Balance Exercisable as of September 30, 2019 Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number Weighted Average Exercise Price Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price Rollforward Weighted Average Exercise Price Outstanding, Beginning Balance Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price Weighted Average Exercise Price, Granted Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price Weighted Average Exercise Price, Exercised Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price Weighted Average Exercise Price, Cancelled Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price Weighted Average Exercise Price Outstanding, Ending Balance Weighted Average Exercise Price, Exercisable as of September 30, 2019 Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price Share based compensation arrangement by share based payment award options weighted average remaining contractual term. Weighted Average Remaining Contractual Term (In years) Share Based Compensation Arrangement By Share Based Payment Award Options Weighted Average Remaining Contractual Term [Abstract] Weighted Average Remaining Contractual Term (In years), Outstanding Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 Weighted Average Remaining Contractual Term (In years), Exercisable as of September 30, 2019 Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 Share based compensation arrangement by share based payment award options aggregate intrinsic value. Aggregate Intrinsic Value Share Based Compensation Arrangement By Share Based Payment Award Options Aggregate Intrinsic Value [Abstract] Aggregate Intrinsic Value Outstanding Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value Aggregate Intrinsic Value Outstanding Aggregate Intrinsic Value, Exercisable as of September 30, 2019 Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Antidilutive Securities Antidilutive Securities Excluded From Computation Of Earnings Per Share By Antidilutive Securities [Axis] Antidilutive Securities, Name Antidilutive Securities Name [Domain] Convertible preferred stock, as converted. Convertible Preferred Stock, as Converted Convertible Preferred Stock As Converted [Member] Stock Options to Purchase Ordinary Shares Employee Stock Option [Member] Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Antidilutive common stock equivalents excluded from calculation of diluted net loss per share Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount Schedule Of Related Party Transactions By Related Party [Table] Schedule Of Related Party Transactions By Related Party [Table] Title of Individual Title Of Individual [Axis] Title of Individual Title Of Individual With Relationship To Entity [Domain] Board of Directors Board Of Directors Chairman [Member] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Professional services expense Professional And Contract Services Expense Outstanding liability to related party Due To Related Parties Current And Noncurrent Number of shares issuable under share-based payment arrangement. Percentage of increase in number of shares of capital stock issued and outstanding. Subsequent Event [Table] Subsequent Event [Table] Subsequent Event [Line Items] Subsequent Event [Line Items] Number of common shares issuable under the plan (in shares) Number Of Shares Issuable Under Share Based Payment Arrangement Percentage of increase in number of shares of capital stock issued and outstanding Percentage Of Increase In Number Of Shares Of Capital Stock Issued And Outstanding Reverse stock split date. Reverse stock split date Reverse Stock Split Date Convertible preferred shares issuable Proceeds from issuance of common stock, net of underwriters discount and commissions Annual increase in lease payments. Rentable area Net Rentable Area Lease term Lessee Operating Lease Term Of Contract Initial rent Operating Leases Future Minimum Payments Due Current Annual increase lease payment Annual Increase In Lease Payments