Accounting Policies [Abstract] Accounting Policies [Abstract] Accounting Policy [Line Items] Accounting Policy [Line Items] Accounting Policy [Line Items] Accounting Policy [Table] Accounting Policy [Table] Accounting Policy [Table] Accounts Payable, Current Accounts payable Accounts Receivable, Net, Current Accounts receivable ($5,278 and $5,033 from a related party) Accounts Receivable, Related Parties, Current Accounts receivable from related party Accrued Liabilities, Current Accrued liabilities ($4,564 and $4,594 to related parties) Total accrued liabilities Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to pre-clinical and clinical trial activities, including those performed by third parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Accrued Preclinical And Clinical Trial Current Preclinical and clinical trial accruals Represents the long-term portion of the outstanding principal and accrued interest of advances in the form note agreements received by the entity to fund various product development efforts. Accrued Product Development Costs Product development obligations Accrued Professional Fees, Current Professional services Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive loss The amount of additional consideration based on net sales of product as defined under a collaboration agreement. Additional Consideration Based On Net Sales Additional consideration based on net sales description Additional Paid in Capital Additional paid-in capital Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net loss to net cash used in operating activities: Allocated Share-based Compensation Expense Total stock-based compensation expense Amendment Flag Amendment Flag Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Total anti-dilutive securities Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Arrangements and Non-arrangement Transactions [Domain] Arrangements and Non-arrangement Transactions [Domain] Assets Total assets Assets [Abstract] Assets Assets, Current Total current assets Assets, Current [Abstract] Current assets: Assets, Fair Value Disclosure Assets fair value disclosure Astellas Agreements [Member] Astellas Collaboration Agreement [Member] Astellas Agreement [Member] Astra Zeneca Agreements [Member] Astra Zeneca Agreements [Member] AstraZeneca Agreements [Member] Available-for-sale Securities Estimated Fair Value Investments Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax Gross Unrealized Holding Gains Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax Gross Unrealized Holding Losses Available-for-sale Securities, Amortized Cost Basis Amortized Cost Represents the maximum contractual maturity period for available-for-sale securities. Available For Sale Securities Contractual Maturity Period Contractual maturities of available-for-sale investments Available-for-sale Securities, Debt Securities, Current Short-term investments Available-for-sale Securities, Noncurrent Long-term investments Award Type [Axis] Award Type [Axis] Basis of Accounting, Policy [Policy Text Block] Basis of Presentation Business Description and Accounting Policies [Text Block] Description of Operations and Summary of Significant Accounting Policies Cash Cash Cash and Cash Equivalents [Abstract] Cash and Cash Equivalents [Abstract] Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents at end of period Cash and cash equivalents at beginning of period Assets fair value disclosure Total cash and cash equivalents Cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Net decrease in cash and cash equivalents The total cash consideration received under a collaboration agreement that has been allocated to the different significant units of accounting and includes the portion that has been deferred for revenue recognition. Cash Consideration Received Under Collaboration Agreement Total Consideration Cease Use Liability [Member] Cease Use Liability [Member] Cease-use liability [Member] China Single Unit Of Accounting [Member] China Single Unit Of Accounting [Member] China-single unit of accounting [Member] Represents the amount of milestone payments related to clinical development under the collaborative agreement. Clinical Development Milestone Clinical development milestones Clinical Development Milestone [Member] Clinical Development Milestones [Member] Clinical and Development Milestone [Member] CHINA China [Member] Co Development Information Sharing And Committee Services [Member] Co Development Information Sharing And Committee Services [Member] Co-development, information sharing & committee services [Member] Represents the amount of fixed and determinable co-development payments included under the collaborative agreement as arrangement consideration. Co Development Payments Development costs Revenue recognized from co-development services, manufacturing of clinical supplies, committee services and information services and other revenue. Collaboration Services And Other Revenue Collaboration services revenue Collaboration services and other revenue (includes $634 and $750 from a related party) Collaboration services and other revenue from a related party Collaborative Arrangement, Accounting Policy [Policy Text Block] Collaboration Agreements Collaborative Arrangement Disclosure [Text Block] Collaboration Agreements Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] Represents the amount of milestone payments related to commercial sales under the collaborative agreement. Commercial Sales Milestone Commercial sales milestone Commitments and Contingencies Commitments and Contingencies Committee Services [Member] Committee Services [Member] Committee services [Member] Common Stock [Member] Common stock [Member] Common Stock, Par or Stated Value Per Share Common stock, par value Common Stock, Shares Authorized Common stock, shares authorized Common Stock, Shares, Issued Common stock, shares issued Common Stock, Shares, Outstanding Common stock, shares outstanding Common Stock, Value, Issued Common stock, $0.01 par value; 225,000 shares authorized at March 31, 2015 and December 31, 2014; 59,268 and 59,046 shares issued and outstanding at March 31, 2015 and December 31, 2014 Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive loss Represents the amount of contingent payments provided for under the collaboration agreement. Contingent Payments Contingent payment Convertible Preferred Stock, Shares Issued upon Conversion Convertible preferred stock converted into shares of common stock Corporate Debt Securities [Member] Corporate bonds [Member] Total amount of revenue recognized for license and collaboration services under the collaboration agreement as of a given date. Cumulative Revenue License And Collaboration Services Revenue Recognized Cumulative Revenue Current Fiscal Year End Date Current Fiscal Year End Date Deferred Rent Credit, Noncurrent Deferred rent Deferred Revenue Deferred Revenue Deferred Revenue, Current Deferred revenue Deferred Revenue, Noncurrent Deferred revenue, net of current Depreciation Depreciation Represents the potential amount of milestone payments related to development and regulatory approval under the collaborative agreement. Development And Regulatory Approval Milestones Development and regulatory approval milestones Development Milestone Payment Received Development Milestone Payment Received Receipt of development milestone payment Development Milestones [Member] Development Milestones [Member] Development Milestone [Member] Development Services In Progress [Member] Development Services In Progress[Member] Development services-in progress [Member] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Stock-Based Compensation Document And Entity Information [Abstract] Document And Entity Information [Abstract] Document And Entity Information [Abstract] Document Fiscal Period Focus Document Fiscal Period Focus Document Fiscal Year Focus Document Fiscal Year Focus Document Period End Date Document Period End Date Document Type Document Type Due to Related Parties, Current Accrued liabilities to related parties Earnings Per Share [Abstract] Earnings Per Share [Abstract] Earnings Per Share, Basic and Diluted Net loss per basic and diluted share Earnings Per Share, Policy [Policy Text Block] Net Loss per Share Effect of Exchange Rate on Cash and Cash Equivalents Effect of exchange rate change on cash and cash equivalents Employee-related Liabilities, Current Payroll and related accruals Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] Employee Stock Option [Member] Employee stock options [Member] Entity Central Index Key Entity Central Index Key Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity [Domain] Entity [Domain] Entity Filer Category Entity Filer Category Entity Registrant Name Entity Registrant Name Equity Component [Domain] Equity Component [Domain] Equity Securities [Member] Equity investments [Member] Europe [Member] Europe [Member] Europe Preferred Stock [Member] Europe Preferred Stock [Member] FibroGen Europe preferred stock [Member] Represents the total amount of expected non-contingent upfront payments included under the collaborative agreement as arrangement consideration. Expected Proceeds From Upfront Non Contingent And Time Based Payments Expected upfront, non-contingent and time-based payments 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] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, Assets, Level 1 to Level 2 Transfers, Amount Transfers of assets from level 1 to 2 Fair Value, Assets, Level 2 to Level 1 Transfers, Amount Transfers of assets from level 2 to 1 Fair Value, Assets Measured on Recurring Basis [Table Text Block] Fair Values of Financial Assets Measured on Recurring Basis Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Liability Class [Axis] Liability Class [Axis] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Fair Value Disclosures [Text Block] Fair Value Measurements Fair Value Inputs, Discount Rate Discount rate applied Fair Value, Inputs, Level 1 [Member] Level 1 [Member] Fair Value, Inputs, Level 2 [Member] Level 2 [Member] Fair Value, Inputs, Level 3 [Member] Level 3 [Member] Fair Value, Liabilities, Level 1 to Level 2 Transfers, Amount Transfers of liabilities from level 1 to 2 Fair Value, Liabilities, Level 2 to Level 1 Transfers, Amount Transfers of liabilities from level 2 to 1 Fair Value, Liabilities Measured on Recurring and Nonrecurring Basis [Table Text Block] Fair Values of Financial Liabilities Carried at Historical Cost Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers Into Level 3 Transfers of liabilities into level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers out of Level 3 Transfers of liabilities out of level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 Transfers of assets into level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3 Transfers of assets out of level 3 Fair Value of Financial Instruments, Policy [Policy Text Block] Fair Value of Financial Instruments FibroGen Europe Oy [Member] FibroGen Europe Oy [Member] FibroGen Europe [Member] Foreign Subsidiaries [Member] Foreign Subsidiaries [Member] Foreign subsidiaries [Member] General and Administrative Expense General and administrative General and Administrative Expense [Member] General and administrative [Member] Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Loss before income taxes Income Statement [Abstract] Income Statement [Abstract] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Income Tax Disclosure [Text Block] Income Taxes Income Tax Expense (Benefit) Provision for income taxes Benefit from income taxes Income Tax Expense Benefit Unrealized Holding Gain Loss On Available For Sale Securities Income Tax Expense Benefit Unrealized Holding Gain Loss On Available For Sale Securities Tax benefit on unrealized gain on available-for-sale securities Increase (Decrease) in Accounts Payable Accounts payable Increase (Decrease) in Accounts Receivable Accounts receivable Increase (Decrease) in Accrued Liabilities Accrued liabilities Increase (Decrease) in Deferred Revenue Deferred revenue Increase (decrease) in the obligation recognized by the entity related to lease agreements for which the entity is determined to be the owner of the asset leased for accounting purposes and not legal purposes. Increase Decrease in Lease Financing Liability Lease financing liability Increase (Decrease) in Operating Capital [Abstract] Changes in operating assets and liabilities: Increase (Decrease) in Other Noncurrent Liabilities Other long-term liabilities Increase (Decrease) in Other Operating Assets Other assets Increase (Decrease) in Prepaid Expense and Other Assets Prepaid expenses and other current assets Interest Expense Interest expense Investment Income, Amortization of Premium Amortization of premium on investments Investments Schedule [Abstract] Investments Schedule [Abstract] Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [Domain] JAPAN Japan [Member] Junior Preferred Stock [Member] Junior Preferred Stock [Member] Junior Preferred Stock [Member] Non-current portion of the sum of the obligations recognized by the entity related to lease agreements for which the entity is determined to be the owner of the asset leased for accounting purposes and not legal purposes and the obligations related to not exercising the expansion option under lease agreements. Lease Financing Obligation Noncurrent Long-term portion of lease financing obligations Lease Financing Obligations [Member] Lease Financing Obligations [Member] Lease financing obligations [Member] Legal Entity [Axis] Legal Entity [Axis] Liabilities Total liabilities Liabilities and Equity Total liabilities and equity Liabilities and Equity [Abstract] Liabilities, stockholders' equity and non-controlling interests Liabilities, Current Total current liabilities Liabilities, Current [Abstract] Current liabilities: Financial and Nonfinancial Liabilities, Fair Value Disclosure Liabilities fair value disclosure License and Services Revenue License revenue Revenue from multiple-deliverable arrangements that include licensing fees and services revenue and the amount of consideration recognized during the period for milestones. Licensing revenue is consideration received from another party for the right to use, but not own, certain of the entity's intangible assets. Licensing arrangements include, but are not limited to, rights to use a patent, copyright, technology, manufacturing process, software or trademark. Licensing fees are generally, but not always, fixed as to amount and not dependent upon the revenue generated by the licensing party. An entity may receive licensing fees for licenses that also generate royalty payments to the entity. Services revenue may be derived by providing other, non-specified, services during the reporting period. License Fees And Milestones Revenue License and milestone revenue (includes $4,692 and $2,742 from a related party) Total license and milestone revenue License and milestone revenue from a related party License [Member] License [Member] License [Member] Manufacturing Clinical Supplies [Member] Manufacturing Clinical Supplies [Member] Manufacturing-clinical supplies [Member] Marketing Approval Milestone [Member] Marketing Approval Milestones [Member] Marketing approval milestone [Member] Maximum [Member] Maximum [Member] Minimum [Member] Minimum [Member] Stockholders' Equity Attributable to Noncontrolling Interest Non-controlling interests Money Market Funds, at Carrying Value Money market funds Money Market Funds [Member] Money market funds [Member] Net Cash Provided by (Used in) Financing Activities, Continuing Operations Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Financing activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations Net cash provided by investing activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Investing activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations Net cash used in operating activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Operating activities Net Income (Loss) Attributable to Parent Net loss Net loss New Accounting Pronouncements, Policy [Policy Text Block] Recent Accounting Pronouncements The non-contingent performance period related to a deliverable under a collaboration agreement. Non Contingent Performance Period Non-contingent performance period Represents the total amount of non-substantive milestones that could be earned upon the achievement of certain pre-determined events from the total potential amount of milestone payments under the collaborative agreement. Non Substantive Milestones Non-substantive milestones Number of Operating Segments Number of operating segment Offering expenses related to the entity's first offering of stock to the public. Offering Expenses Offering expenses Operating Expenses Total operating expenses Operating Expenses [Abstract] Operating expenses: Operating Income (Loss) Loss from operations Option Indexed to Issuer's Equity, Type [Axis] Option Indexed to Issuer's Equity, Type [Axis] Option Indexed to Issuer's Equity, Type [Domain] Option Indexed to Issuer's Equity, Type [Domain] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Other Accrued Liabilities, Current Other Other Assets, Noncurrent Other assets Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax [Abstract] Available-for-sale investments: Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Net change in unrealized gain (loss) on available-for-sale investments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Foreign currency translation adjustments Other Comprehensive Income (Loss), Net of Tax Other comprehensive income (loss), net of taxes: Other Comprehensive Income (Loss), Net of Tax [Abstract] Other comprehensive income (loss): Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Reclassification from accumulated other comprehensive loss Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Unrealized gain (loss) on investments, net of tax effect Other Liabilities, Noncurrent Other long-term liabilities Other Nonoperating Income (Expense) Interest and other income, net Payables and Accruals [Abstract] Payables and Accruals [Abstract] Payments to Acquire Property, Plant, and Equipment Purchases of property and equipment Represents the percentage of costs that will be funded by the other party under a collaborative agreement for development costs. Percentage Of Funding For Costs Percentage of joint development costs committed to fund Represents the total potential amount of milestone payments related to development, regulatory approval and commercial sales under the collaborative agreement. Potential Milestones Total potential milestones Preferred Stock, Par or Stated Value Per Share Preferred stock, par value Preferred Stock, Shares Authorized Preferred stock, authorized shares Preferred stock, shares authorized Preferred Stock, Shares Issued Preferred stock, shares issued Preferred Stock, Shares Outstanding Convertible preferred stock outstanding Preferred stock, shares outstanding Preferred Stock, Value, Issued Preferred stock, $0.01 par value; 125,000 shares authorized at March 31, 2015 and December 31, 2014; no shares issued and outstanding at March 31, 2015 and December 31, 2014 Prepaid Expense and Other Assets, Current Prepaid expenses and other current assets The net cash inflow associated with the amount received from entity's first offering of stock to the public and concurrent private placement. Proceeds From Initial Public Offering And Concurrent Private Placement Net Net proceeds from initial public offering and concurrent private placement Proceeds from Issuance of Private Placement Common stock, aggregate purchase price Proceeds from Maturities, Prepayments and Calls of Available-for-sale Securities Proceeds from maturities of available-for-sale securities Proceeds from Stock Options Exercised Proceeds from issuance of common stock upon exercise of stock options Represents the amount of fixed and determinable non-contingent upfront payments included under the collaborative agreement as arrangement consideration. Proceeds From Upfront Non Contingent And Time Based Payments Upfront, non-contingent and time-based payments Represents the amount of upfront payments included under the collaborative agreement as arrangement consideration. Proceeds From Upfront Payments Proceeds from upfront payments Represents the amount of upfront payments included under the collaborative agreement as arrangement consideration with extended terms. Proceeds From Upfront Payments Extended Terms Upfront, non-contingent and time-based payments with extended payment terms Products and Services [Axis] Products and Services [Axis] Products and Services [Domain] Products and Services [Domain] Property, Plant and Equipment, Net Property and equipment, net Range [Axis] Range [Axis] Range [Domain] Range [Domain] Represents the amount of upfront payments received under the collaborative agreement as arrangement consideration. Receipt From Upfront Payments Payment received on execution of agreement Regulatory Milestone [Member] Regulatory Milestones [Member] Regulatory Milestone [Member] Related Party Transaction, Expenses from Transactions with Related Party Expense related to collaboration agreements Related Party Transaction [Line Items] Related Party Transaction [Line Items] Related Party Transactions [Abstract] Related Party Transactions [Abstract] Related Party Transactions Disclosure [Text Block] Related Party Transactions Represents the amount of remaining upfront and non-contingent and time based payments under the collaboration agreement. Remaining Upfront Non Contingent And Time Based Payments Remaining up-front, non-contingent and time-based payments Repayments of Other Long-term Debt Repayments of lease liability Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Research and Development Expense Research and development Research and Development Expense [Member] Research and development [Member] Restricted Cash and Cash Equivalents, Noncurrent Restricted cash Restricted Stock Units (RSUs) [Member] RSUs granted [Member] Retained Earnings (Accumulated Deficit) Accumulated deficit Revenue from Related Parties Revenue related to collaboration agreements Tabular disclosure of the recognition of revenue by the different types of revenue under a collaboration agreement. Revenue Recognition By Type [Table Text Block] Summary of Revenue Recognized under Agreement Revenue Recognition, Deferred Revenue [Policy Text Block] Deferred Revenue Revenue Recognition, Milestone Method, Revenue Recognized Milestones revenue Revenue Recognition, Multiple-deliverable Arrangements [Line Items] Revenue Recognition, Multiple-deliverable Arrangements [Line Items] Revenue Recognition, Multiple-deliverable Arrangements [Table] Revenue Recognition, Multiple-deliverable Arrangements [Table] Revenue Recognition, Multiple-deliverable Arrangements [Table Text Block] Total Arrangement Consideration Allocated to Deliverables along with Associated Deferred Revenue Disclosure of accounting policy for revenue recognition for royalty fees, which is consideration or a share of the proceeds paid by another party to the owner of a right (that is, the entity) for its use and collagen feasibility sales. Revenue Recognition Other Policy [Text Block] Other Revenues Revenue Recognition, Policy [Policy Text Block] Revenue Recognition Revenues Revenue recognized Total revenue Revenues [Abstract] Revenue: Implied royalty rate used to find the net present value of future cash flows. Royalty Rate On Net Revenue Royalty rate against projected net revenues Schedule of Accrued Liabilities [Table Text Block] Schedule of Accrued Liabilities Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Schedule of Anti-dilutive Securities Excluded from Calculation of Diluted Net Loss per Share Schedule of Available-for-sale Securities [Line Items] Schedule of Available-for-sale Securities [Line Items] Schedule of Available-for-sale Securities Reconciliation [Table Text Block] Summary of Amortized Cost, Gross Unrealized Holding Gains or Losses, and Fair Value of Available-for-Sale Investments Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Schedule of Cash and Cash Equivalents [Table Text Block] Schedule of Cash and Cash Equivalents Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions [Table] Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions [Table] 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] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block] Schedule of Allocated Stock-Based Compensation Expense Related to Options Granted Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Schedule of Weighted-average Assumptions used to Estimate Fair Value of Stock Options and Stock Options Granted Geographical [Domain] Geographical [Domain] Senior Preferred Stock [Member] Senior Preferred Stock [Member] Senior Preferred Stock [Member] Share-based Compensation Stock-based compensation 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, Fair Value Assumptions, Expected Term Expected term (in years) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Expected volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Weighted average estimated fair value Equity Award [Domain] Equity Award [Domain] Represents the total amount of development costs that will be shared under collaborative agreement. Shared Development Costs Shared development costs Shares Issued, Price Per Share Public offering price Equity Components [Axis] Equity Components [Axis] Geographical [Axis] Geographical [Axis] Statement [Line Items] Statement [Line Items] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Statement [Table] Statement [Table] Stockholders' Equity Attributable to Parent Total stockholders' equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Stockholders' equity: Stockholders' Equity Note, Stock Split, Conversion Ratio Reverse stock split ratio Stockholders' Equity, Reverse Stock Split Description reverse stock split Stock Issued During Period, Shares, New Issues Common stock shares sold Subsequent Event [Member] Subsequent Event [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Represents the total amount of substantive milestones that could be earned upon the achievement of certain pre-determined events from the total potential amount of milestone payments under the collaborative agreement. Substantive Milestones Substantive milestones Supplemental Balance Sheet Disclosures [Text Block] Balance Sheet Components Trading Symbol Trading Symbol Type of Arrangement and Non-arrangement Transactions [Axis] Type of Arrangement and Non-arrangement Transactions [Axis] Underwriting discounts and commissions related to the entity's first offering of stock to the public. Underwriting Discounts And Commissions Underwriting discounts and commissions United States And Rest Of World [Member] United States And Rest Of World [Member] U.S./RoW [Member] U- S- Rest of World Agreement [Member] U- S- Rest of World Agreement [Member] U.S./Rest of World Agreement [Member] Warrant [Member] Warrants [Member] Weighted Average Number of Shares Outstanding, Basic and Diluted Weighted average number of common shares used in net loss per basic and diluted share When And If Available Compounds [Member] When And If Available Compounds [Member] When and if available compounds [Member]