Awarded (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Document Type Document Type Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Other income (expense) Other Nonoperating Income (Expense) Issuance of common stock under the exercise of pre-funded warrants (in shares) Stock Issued During Period, Shares, Conversion of Units Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Amortization of premium and discounts on investment securities Accretion (Amortization) of Discounts and Premiums, Investments Accounts payable and accrued expenses Increase (Decrease) in Accounts Payable and Accrued Liabilities Second and third indication Second and Third Indication [Member] Second and Third Indication [Member] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Available for sale securities Fair Value Debt Securities, Available-for-sale Equity Components [Axis] Equity Components [Axis] Outstanding, expected to vest (in shares) Share-Based Compensation Arrangement By Share-based Payment Award, Equity Instruments Other Than Options, Expected To Vest, Number Share-Based Compensation Arrangement By Share-based Payment Award, Equity Instruments Other Than Options, Expected To Vest, Number Cash, Cash Equivalents and Available for Sale Securities Investments in Debt and Equity Instruments, Cash and Cash Equivalents, Unrealized and Realized Gains (Losses) [Text Block] Supplemental disclosure of cash paid Income Taxes Paid, Net [Abstract] Restricted stock units Restricted Stock [Member] 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 Schedule of Accumulated Other Comprehensive Income Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Increase in number of shares available under the Plan (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Share-based Payment Arrangement [Abstract] Share-based Payment Arrangement [Abstract] Significant unobservable inputs (Level 3) Fair Value, Inputs, Level 3 [Member] Minimum Minimum [Member] Leases Lessee, Leases [Policy Text Block] Outstanding, expected to vest (in dollars per share) Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Expected To Vest Weighted Average Grant Date Fair Value Represents the weighted average fair value of equity awards, other than options, that are expected to vest as of the reporting date. Income tax receivable, non-current Income Taxes Receivable, Noncurrent Lease liability Operating Lease, Liability, Current Unrecognized compensation costs, net of estimated forfeitures Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount Statistical Measurement [Domain] Statistical Measurement [Domain] Liabilities and Stockholders' Equity Liabilities and Equity [Abstract] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Stock Option and Compensation Plans Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Forfeited (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Asset-backed securities Asset-backed Securities [Member] Schedule of weighted-average assumptions used to estimate grant date fair value of stock options Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Achievement of specified clinical and regulatory milestones Achievement Of Specified Clinical And Regulatory Milestones [Member] Represents information pertaining to the achievement of specified clinical and regulatory milestones. Entity Interactive Data Current Entity Interactive Data Current Preferred Stock Preferred Stock [Member] Exercised (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Security Exchange Name Security Exchange Name Common Stock Stockholders' Equity Note Disclosure [Text Block] Summary of the stock option activity including weighted average exercise prices, options outstanding and exercisable Share-based Payment Arrangement, Option, Activity [Table Text Block] Share-Based Compensation Share-based Payment Arrangement [Policy Text Block] Loss from operations Operating Income (Loss) Unusual or Infrequent Item, or Both [Axis] Unusual or Infrequent Item, or Both [Axis] Issuance of common stock under the exercise of pre-funded warrants Stock Issued During Period, Value, Conversion of Units Total current liabilities Liabilities, Current 2019 Inducement Plan Two Thousand Nineteen Inducement Plan [Member] Two Thousand Nineteen Inducement Plan [Member] Primary Licensed Product Primary Licensed Product [Member] Primary Licensed Product [Member] Entity Registrant Name Entity Registrant Name Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Outstanding, beginning balance (in dollars per share) Outstanding, ending 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 Vested and exercisable, end of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Number Assets Assets [Abstract] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Accounting Policies [Abstract] Accounting Policies [Abstract] First indication First Indication [Member] First Indication [Member] Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Number of reporting segments Number of Reportable Segments Entity Address, State or Province Entity Address, State or Province Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Proceeds from stock plans Proceeds from Stock Plans Clinical Milestone Clinical Milestone [Member] Clinical Milestone Schedule of Cash and Cash Equivalents [Table] Schedule of Cash and Cash Equivalents [Table] Research and development Research and Development Expense Research and Development Expense [Member] Amount to be paid on achievement of milestone Amount to be Paid On Achievement of Milestone Represents the amount to be paid by the entity on achievement of various milestones. Accumulated deficit Retained Earnings (Accumulated Deficit) Right-of-use asset, net Operating Lease, Right-of-Use Asset Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Risk-free interest rate, minimum Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum Outstanding, beginning balance (in shares) Outstanding, ending balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Schedule of assets and liabilities that are measured at fair value on a recurring basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Tax Credit Carryforward [Table] Tax Credit Carryforward [Table] Foreign Currency Translation Foreign Currency Transactions and Translations Policy [Policy Text Block] Sale of Stock [Axis] Sale of Stock [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Basic and diluted (in shares) Weighted average common shares outstanding - basic and dilutive (in shares) Weighted Average Number of Shares Outstanding, Basic and Diluted Preferred stock—$0.001 par value, 5,000,000 shares authorized, no shares issued or outstanding Preferred Stock, Value, Issued Cash Cash Gross Unrealized Losses Debt Securities, Available-for-sale, Unrealized Loss Income Taxes Income Tax, Policy [Policy Text Block] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-sale [Line Items] Total other comprehensive income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Total operating expenses Operating Expenses Document Transition Report Document Transition Report Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Pre-funded warrants outstanding (in shares) Class of Warrant or Right, Outstanding Share-Based Compensation Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Number of product candidates in preclinical development Number Of Product Candidates In Preclinical Development Number Of Product Candidates In Preclinical Development Share-based compensation APIC, Share-based Payment Arrangement, Increase for Cost Recognition Significant other observable inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Document Quarterly Report Document Quarterly Report Measurement Frequency [Domain] Measurement Frequency [Domain] Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period General and administrative General and Administrative Expense [Member] Equity [Abstract] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Unrealized gain on available for sale securities, net of tax Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent University Of Florida Research Foundation (UFRF) And University Of Pennsylvania (Penn) University Of Florida Research Foundation (UFRF) And University Of Pennsylvania (Penn) [Member] University Of Florida Research Foundation (UFRF) And University Of Pennsylvania (Penn) [Member] Stock options outstanding Employee And Nonemployee Stock Option [Member] An arrangement whereby an employee and non-employees are entitled to receive in the future, subject to vesting and other restrictions, a number of shares in the entity at a specified price, as defined in the agreement. Although there are variations, normally, after vesting, when an option is exercised, the holder pays the strike value in cash to the issuing employer-entity and receives equity shares. The equity shares can be sold into the market for cash at the current market price without restriction. Options may be used to attract, retain and incentivize employees, in addition to their regular salary and other benefits. Granted (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Milestone Events [Domain] Milestone Events [Domain] Represents the types of milestone events. Statement [Line Items] Statement [Line Items] Vested and expected to vest, end of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Schedule of potentially dilutive securities that have been excluded from the computations of diluted weighted average common shares outstanding Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Net loss per common share: Basic and diluted net loss per common share calculation: Earnings Per Share, Basic and Diluted [Abstract] Sustained delivery applications Sustained Delivery Applications [Member] Sustained Delivery Applications [Member] Accrued research and development expenses Increase (Decrease) In Accrued Research And Development Represents the increase (decrease) during the reporting period in the aggregate amount of research and development expenses incurred. Expected term of options (years) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Number of operating segments Number of Operating Segments Entity File Number Entity File Number Collaborative Arrangement and Arrangement Other than Collaborative [Table] Collaborative Arrangement and Arrangement Other than Collaborative [Table] Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Expired (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period Statement [Table] Statement [Table] Number of shares available for future purchase (in shares) Share-Based Compensation Arrangement By Share-based Payment Award, Number Of Shares Available For Future Purchase Share-Based Compensation Arrangement By Share-based Payment Award, Number Of Shares Available For Future Purchase Asset Acquisition [Domain] Asset Acquisition [Domain] [Domain] for Asset Acquisition [Axis] Commitments and contingencies Commitments and Contingencies [Line Items] Statistical Measurement [Axis] Statistical Measurement [Axis] Operating Activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Contingent consideration arrangements, contingently issuable shares as a percentage of shares outstanding Asset Acquisition, Contingent Consideration Arrangements, Contingently Issuable Shares As A Percentage Of Shares Outstanding Asset Acquisition, Contingent Consideration Arrangements, Contingently Issuable Shares As A Percentage Of Shares Outstanding Proceeds from employee stock plan purchases Proceeds From Stock Options And Warrants Exercised The cash inflow from associated with the amount received from holders exercising their stock options and warrants. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately. Deferred income taxes Deferred Income Taxes and Tax Credits Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Total Share-based Payment Arrangement, Expense Exercise price of pre-funded warrants (in dollars per share) Class of Warrant or Right, Exercise Price of Warrants or Rights AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member] Counterparty Name [Axis] Counterparty Name [Axis] Common stock—$0.001 par value, 200,000,000 shares authorized, 89,554,044 and 49,627,064 shares issued and outstanding at September 30, 2020 and December 31, 2019, respectively Common Stock, Value, Issued Basic and diluted (in dollars per share) Earnings Per Share, Basic and Diluted Document Fiscal Year Focus Document Fiscal Year Focus Smaller Reporting Company Entity Small Business Consolidation Consolidation, Policy [Policy Text Block] Increase (Decrease) in Stockholders' Equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Contingent consideration arrangements, maximum amount (in shares) Asset Acquisition, Contingent Consideration Arrangements, Range Of Outcomes, Shares Issuable, High Asset Acquisition, Contingent Consideration Arrangements, Range Of Outcomes, Shares Issuable, High Number of shares issued in transaction (in shares) Sale of Stock, Number of Shares Issued in Transaction Entity Current Reporting Status Entity Current Reporting Status Sale of stock price (in dollars per share) Sale of Stock, Price Per Share Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Proceeds from issuance of common stock Proceeds from Issuance of Common Stock Archemix Archemix Corp [Member] Represents information pertaining to Archemix Corp. Amendment Flag Amendment Flag GA Product GA Product [Member] GA Product [Member] Schedule of computation of basic and diluted net loss per common share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Weighted average common shares outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Awarded (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 Number of initial shares reserved for issuance under the Plan (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Research and Development Research and Development Expense, Policy [Policy Text Block] Common stock, shares issued (in shares) Common Stock, Shares, Issued Cash and cash equivalents Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Number of shares of common stock available for issuance under the Plan (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Inception 4 Inception 4 [Member] Inception 4 [Member] Schedule of Commitments and Contingencies [Table] Schedule of Commitments and Contingencies [Table] Schedule of information pertaining to commitments and contingencies. Annual increase in shares reserved for issuance under the Plan (as a percent) Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Annual Increase in Shares Reserved for Issuance Represents the percentage of annual increase in the shares reserved for issuance under the equity-based compensation plan. Amounts reclassified from accumulated other comprehensive income, net of tax Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Net cash used in operating activities Net Cash Provided by (Used in) Operating Activities 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] Issuance of common stock under employee stock compensation plans Stock Issued During Period, Value, Issued for Services Entity Central Index Key Entity Central Index Key Measurement Frequency [Axis] Measurement Frequency [Axis] Warrants issued in transaction (in shares) Warrants Or Rights Issued In Transaction Warrants Or Rights Issued In Transaction Summary of Significant Accounting Policies Basis of Presentation and Significant Accounting Policies [Text Block] Payments for license fees Payments For License Fees Payments for License Fees Financial Instruments [Domain] Financial Instruments [Domain] Available for Sale Securities Credit Loss, Financial Instrument [Policy Text Block] Total stockholders' equity Balance at beginning of period Balance at end of period Stockholders' Equity Attributable to Parent Payments of stock issuance costs Payments of Stock Issuance Costs Business Nature of Operations [Text Block] Investments in money market funds, U.S. Treasury securities and certain short-term investment-grade corporate debt securities with original maturities of 90 days or less Cash Equivalents, at Carrying Value Total liabilities and stockholders' equity Liabilities and Equity Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Income Taxes Income Tax Disclosure [Text Block] Income tax receivable Income tax receivable Income Taxes Receivable, Current Entity Address, City or Town Entity Address, City or Town Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Common stock issued (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period Clinical and marketing approval milestones Asset Acquisition, Clinical And Marketing Approval Milestones Asset Acquisition, Clinical And Marketing Approval Milestones Restricted stock units Restricted Stock Units (RSUs) [Member] Accounts payable and accrued expenses Accounts Payable and Accrued Liabilities, Current Specified clinical, marketing approval and reimbursement approval milestones with respect to a licensed product Specified Clinical, Marketing Approval and Reimbursement Approval Milestones Related to a Licensed Product [Member] Specified Clinical, Marketing Approval and Reimbursement Approval Milestones Related to a Licensed Product [Member] General and administrative General and Administrative Expense 2013 Plan Employee stock purchase plan Stock Incentive2013 Plan [Member] Represents information pertaining to the 2013 Stock Incentive Plan. Financial Instrument [Axis] Financial Instrument [Axis] Amortized Cost Debt Securities, Available-for-sale, Amortized Cost Unrecognized share-based compensation costs for option awards, net of estimated forfeitures Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount Total (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Underwritten Offering, Underwriters Underwritten Offering, Underwriters [Member] Underwritten Offering, Underwriters Gain on sale of property and equipment Gain (Loss) on Disposition of Property Plant Equipment Employee stock purchase plan Employee Stock [Member] Equity Component [Domain] Equity Component [Domain] Income Statement Location [Axis] Income Statement Location [Axis] Contingent consideration arrangements, maximum amount Asset Acquisition, Contingent Consideration Arrangements, Range Of Outcomes, Value, High Asset Acquisition, Contingent Consideration Arrangements, Range Of Outcomes, Value, High Entity Common Stock, Shares Outstanding (in shares) Entity Common Stock, Shares Outstanding Income Statement Location [Domain] Income Statement Location [Domain] Accumulated Other Comprehensive Income (Loss) Comprehensive Income [Member] Property and equipment, net Property, Plant and Equipment, Net Entity Tax Identification Number Entity Tax Identification Number GATHER2 Trial GATHER2 Trial [Member] GATHER2 Trial Interest income Interest Income (Expense), Nonoperating, Net Schedule of Allocation of Share-based Compensation Costs by Financial Statement Line Schedule Of Compensation Cost For Share-based Payment Arrangements, Allocation Of Share-based Compensation Costs By Financial Statement Line [Table Text Block] Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Financial Statement Line [Table Text Block] Share-Based Compensation Share-based Payment Arrangement [Text Block] Net loss Net loss Net loss Net Income (Loss) Attributable to Parent Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Issuance of common stock under employee stock compensation plan (in shares) Stock Issued During Period, Shares, Issued for Services Other assets Other Assets, Noncurrent Plan Name [Axis] Plan Name [Axis] Income tax refunds received Proceeds from Income Tax Refunds Issuance of common stock, net of issuance costs Stock Issued During Period, Value, New Issues Investments Cash and Cash Equivalents, Fair Value Disclosure RHO-adRP License Agreement RHO-adRP License Agreement [Member] RHO-adRP License Agreement [Member] Total assets Assets Total current assets Assets, Current Current Fiscal Year End Date Current Fiscal Year End Date Concentration of Suppliers Concentration of Suppliers Policy, [Policy Text Block] Disclosure of accounting policy for concentration of suppliers. Operating expenses: Operating Expenses [Abstract] Earnings Per Share [Abstract] Earnings Per Share [Abstract] Outstanding, beginning balance (in shares) Outstanding, ending balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Title of 12(b) Security Title of 12(b) Security Adeno-Associated Virus Mediated Gene Therapy Program Adeno-Associated Virus Mediated Gene Therapy Program [Member] Adeno-Associated Virus Mediated Gene Therapy Program Anti-dilutive securities Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Shares issued for license fees (in shares) Shares Issued For License Fees Shares Issued For License Fees Other Licensed Product Other Licensed Product [Member] Other Licensed Product [Member] Compensation Related Costs [Abstract] Compensation Related Costs [Abstract] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Achievement of specified commercial milestones Achievement Of Specified Commercial Milestones [Member] Represents information pertaining to the achievement of specified commercial milestones. Stockholders' equity Stockholders' Equity Attributable to Parent [Abstract] Transfer of assets from Level 1 to Level 2 of the fair value measurement hierarchy Fair Value, Assets, Level 1 to Level 2 Transfers, Amount Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Concentration of Credit Risk Concentration Risk, Credit Risk, Policy [Policy Text Block] Number of Shares Underlying Options Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Document Fiscal Period Focus Document Fiscal Period Focus Subsidiary, Sale of Stock [Line Items] Subsidiary, Sale of Stock [Line Items] Product and Service [Axis] Product and Service [Axis] Proceeds from sale of assets Proceeds from Sale of Productive Assets Milestone Events [Axis] Milestone Events [Axis] Information pertaining to milestone events. Total liabilities Liabilities Expected weighted average period to recognize share-based compensation costs (in years) Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Expected common stock price volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Entity Filer Category Entity Filer Category Common Stock Common Stock [Member] Property and equipment Property, Plant and Equipment [Line Items] Product and Service [Domain] Product and Service [Domain] Asset Acquisition [Axis] Asset Acquisition [Axis] Asset Acquisition [Axis] Risk-free interest rate, maximum Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Quoted prices in active markets for identical assets (Level 1) Fair Value, Inputs, Level 1 [Member] CARES Act CARES Act [Member] CARES Act [Member] Accrued interest receivable Increase (Decrease) in Accrued Interest Receivable, Net Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Restricted Stock Units Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] U.S. Treasury securities US Treasury Securities [Member] Underwritten Offering Underwritten Offering [Member] Underwritten Offering Issuance of common stock, net of issuance costs (in shares) Stock Issued During Period, Shares, New Issues University of Florida Research Foundation (UFRF) University of Florida Research Foundation (UFRF) [Member] University of Florida Research Foundation (UFRF) [Member] Additional paid-in capital Additional Paid-in Capital [Member] Unusual or Infrequent Item, or Both [Domain] Unusual or Infrequent Item, or Both [Domain] Money Market Funds Money Market Funds [Member] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Cash, Cash Equivalents, and Short-term Investments [Abstract] Cash, Cash Equivalents, and Short-term Investments [Abstract] Number of licensed products Number Of Licensed Products Number of Licensed Products Specified commercial sales milestones with respect to a licensed product Specified Commercial Sales Milestones Related to a Licensed Product [Member] Specified Commercial Sales Milestones Related to a Licensed Product [Member] 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] Balance at beginning of period (in shares) Balance at end of period (in shares) Shares, Issued Exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Net change 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 [Line Items] Cash and Cash Equivalents [Line Items] Financial Instruments Fair Value of Financial Instruments, Policy [Policy Text Block] Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] License Agreements License Agreement Terms [Member] Stock options Share-based Payment Arrangement, Option [Member] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] miniCEP290 miniCEP290 [Member] miniCEP290 [Member] Loss before income tax benefit Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Vested and exercisable, end of period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Exercise Price Research and development Research and Development Expense Forfeited (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Outstanding, beginning balance (in dollars per share) Outstanding, ending balance (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Sale of Stock [Domain] Sale of Stock [Domain] Accrued research and development expenses Accrued Research and Development Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer) for research and development related activities. Common stock, shares authorized (in shares) Common Stock, Shares Authorized Plan Name [Domain] Plan Name [Domain] Private Placement, Underwriters Private Placement, Underwriters [Member] Private Placement, Underwriters Additional paid-in capital Additional Paid in Capital Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] Income tax benefit Income tax benefit Income Tax Expense (Benefit) Summary of the Company's outstanding shares of RSU awards Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] Beginning of period End of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Property and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-sale [Table] Purchase of marketable securities Payments to Acquire Marketable Securities Lease liability, non-current Operating Lease, Liability, Noncurrent Prepaid expense and other assets Increase (Decrease) in Prepaid Expense and Other Assets Local Phone Number Local Phone Number Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Use of Estimates Use of Estimates, Policy [Policy Text Block] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value [Abstract] Tax Credit Carryforward [Line Items] Tax Credit Carryforward [Line Items] Current assets Assets, Current [Abstract] Gross Unrealized Gains Debt Securities, Available-for-sale, Unrealized Gain Investing Activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Depreciation and other expense Depreciation Entity Address, Address Line One Entity Address, Address Line One Entity Address, Address Line Two Entity Address, Address Line Two Emerging Growth Company Entity Emerging Growth Company Wet AMD Product Wet AMD Product [Member] Wet AMD Product [Member] Comprehensive loss Comprehensive Income (Loss), Net of Tax, Attributable to Parent Expected dividend yield Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share BEST1 License Agreement BEST1 License Agreement [Member] BEST1 License Agreement [Member] Income Statement and Statement of Comprehensive Income [Abstract] [Abstract] Income Statement and Statement of Comprehensive Income [Abstract] Income Statement and Statement of Comprehensive Income [Abstract] Award Type [Axis] Award Type [Axis] 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 [Abstract] Counterparty Name [Domain] Counterparty Name [Domain] Current period changes in fair value before reclassifications, net of tax OCI, before Reclassifications, Net of Tax, Attributable to Parent City Area Code City Area Code Maximum Maximum [Member] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Document Period End Date Document Period End Date Fair Value Measurements Fair Value Measurement and Measurement Inputs, Recurring and Nonrecurring [Text Block] Accumulated Deficit Retained Earnings [Member] Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Fair Value Measurements Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Net cash (used in) provided by investing activities Net Cash Provided by (Used in) Investing Activities Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Income tax receivable Increase (Decrease) in Income Taxes Receivable Award Type [Domain] Award Type [Domain] Number Of Patients Planned To Enroll In Trial Number Of Patients Planned To Enroll In Trial Number Of Patients Planned To Enroll In Trial Corporate debt securities Corporate Debt Securities [Member] Trading Symbol Trading Symbol Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] C5 Licensed Product C5 Licensed Products [Member] Represents information pertaining to C5 Licensed products as defined by the agreement. Schedule of Allocation of Share-based Compensation Costs by Award Type Share-based Payment Arrangement, Cost by Plan [Table Text Block] Share-based compensation Share-based Payment Arrangement, Noncash Expense Private Placement Private Placement [Member] Net Loss Per Common Share Earnings Per Share [Text Block] Cover [Abstract] Cover [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Schedule of Available for Sale Securities Debt Securities, Available-for-sale [Table Text Block] Current liabilities Liabilities, Current [Abstract] Financing Activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Entity Shell Company Entity Shell Company University Of Massachusetts (UMass) University Of Massachusetts (UMass) [Member] University Of Massachusetts (UMass) [Member] Recurring basis Fair Value, Recurring [Member] Vested and expected to vest, 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 Segment and geographic information Segment Reporting, Policy [Policy Text Block] Expired (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price Estimated useful lives Property, Plant and Equipment, Useful Life Recently Adopted and Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract]