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Private Placement Private Placement [Member] 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 Equity Component [Domain] Equity Component [Domain] Maturities of marketable securities Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-sale Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Litigation stay period (in days) Litigation Stay Period Litigation Stay Period Common stock issued (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period Award Type [Domain] Award Type [Domain] Assets Assets [Abstract] Statement [Line Items] Statement [Line Items] 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 Awarded (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Preferred stock—$0.001 par value, 5,000,000 shares authorized, no shares issued or outstanding Preferred Stock, Value, Issued Property and Equipment Property, Plant and Equipment, Policy [Policy Text Block] University Of Massachusetts (UMass) University Of Massachusetts (UMass) [Member] University Of Massachusetts (UMass) [Member] Outstanding, beginning balance (in shares) Outstanding, ending balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Entity Address, City or Town Entity Address, City or Town Schedule of Allocation of Share-based Compensation Costs by Award Type Share-based Payment Arrangement, Cost by Plan [Table Text Block] Available for sale securities Fair Value Debt Securities, Available-for-sale Accumulated Deficit Retained Earnings [Member] Counterparty Name [Domain] Counterparty Name [Domain] Prepaid expense and other assets Increase (Decrease) in Prepaid Expense and Other Assets Fair Value Measurements Fair Value Measurement and Measurement Inputs, Recurring and Nonrecurring [Text Block] Entity Address, State or Province Entity Address, State or Province Purchase of marketable securities Payments to Acquire Marketable Securities Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Loss before income tax benefit Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Significant other observable inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Change in working capital Increase (Decrease) in Working Capital Increase (Decrease) in Working Capital Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Subsidiary, Sale of Stock [Line Items] Subsidiary, Sale of Stock [Line Items] Amortized Cost Debt Securities, Available-for-sale, Amortized Cost Sustained delivery applications Sustained Delivery Applications [Member] Sustained Delivery Applications [Member] Purchase period (in months) Share-Based Compensation Arrangement By Share-based Payment Award, Purchase Period Share-Based Compensation Arrangement By Share-based Payment Award, Purchase Period Use of Estimates Use of Estimates, Policy [Policy Text Block] Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Schedule of computation of basic and diluted net loss per common share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Entity Shell Company Entity Shell Company Local Phone Number Local Phone Number Total other comprehensive income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Property and equipment Property, Plant and Equipment [Line Items] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Entity Interactive Data Current Entity Interactive Data Current Proceeds from issuance of common stock Proceeds from Issuance of Common Stock Total assets Assets Tax Credit Carryforward [Table] Tax Credit Carryforward [Table] Plan Name [Domain] Plan Name [Domain] Common stock, shares authorized (in shares) Common Stock, Shares Authorized Number of operating segments Number of Operating Segments Share-Based Compensation Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Basic (in dollars per share) Net loss per share of common stock - basic (in dollars per share) Earnings Per Share, Basic Available for Sale Securities Credit Loss, Financial Instrument [Policy Text Block] Summary of the Company's outstanding shares of RSU awards Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] Product and Service [Domain] Product and Service [Domain] Research and development Research and Development Expense 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 Document Type Document Type 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] Restricted Stock Units Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Entity Current Reporting Status Entity Current Reporting Status Payments for license fees Payments For License Fees Payments for License Fees Measurement Frequency [Axis] Measurement Frequency [Axis] Net cash used in operating activities Net Cash Provided by (Used in) Operating Activities C5 Licensed Product C5 Licensed Products [Member] Represents information pertaining to C5 Licensed products as defined by the agreement. Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] 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] Entity Tax Identification Number Entity Tax Identification Number 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 Subsequent Event [Line Items] Subsequent Event [Line Items] 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] Research and Development Research and Development Expense, Policy [Policy Text Block] Basic (in shares) Weighted average common shares outstanding - basic (in shares) Weighted Average Number of Shares Outstanding, Basic Diluted (in dollars per share) Net loss per share of common stock - diluted (in dollars per share) Earnings Per Share, Diluted Sale of stock price (in dollars per share) Sale of Stock, Price Per Share Subsequent Events Subsequent Events [Text Block] Plan Name [Axis] Plan Name [Axis] Comprehensive loss Comprehensive Income (Loss), Net of Tax, Attributable to Parent Quoted prices in active markets for identical assets (Level 1) Fair Value, Inputs, Level 1 [Member] Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Document Transition Report Document Transition Report Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Archemix Archemix Corp [Member] Represents information pertaining to Archemix Corp. Weighted average common shares outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] 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] Total liabilities and stockholders' equity Liabilities and Equity Corporate debt securities Corporate Debt Securities [Member] Clinical and marketing approval milestones Asset Acquisition, Clinical And Marketing Approval Milestones Asset Acquisition, Clinical And Marketing Approval Milestones First indication First Indication [Member] First Indication [Member] Exercised (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Additional paid-in capital Additional Paid in Capital Investments in money market funds Cash Equivalents, at Carrying Value 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] Milestone Events [Axis] Milestone Events [Axis] Information pertaining to milestone events. Liabilities and Stockholders' Equity Liabilities and Equity [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 Accounts payable and accrued expenses Accounts Payable and Accrued Liabilities, Current Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Operating Activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Financial Instruments [Domain] Financial Instruments [Domain] Net Loss Per Common Share Earnings Per Share [Text Block] Operating expenses: Operating Expenses [Abstract] Minimum Minimum [Member] Unusual or Infrequent Item, or Both [Domain] Unusual or Infrequent Item, or Both [Domain] Income tax receivable Income tax receivable Income Taxes Receivable, Current Anti-dilutive securities Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Unrealized loss on available for sale securities, net of tax OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax Number of Shares Underlying Options Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Investing Activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Income Statement Location [Domain] Income Statement Location [Domain] Accumulated Other Comprehensive Income (Loss) Comprehensive Income [Member] Gross Unrealized Gains Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-sale [Table] Underwritten Offering Underwritten Offering [Member] Underwritten Offering 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 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] CARES Act CARES Act [Member] CARES Act [Member] Trading Symbol Trading Symbol Property and equipment, net Property, Plant and Equipment, Net Total operating expenses Operating Expenses Amounts reclassified from accumulated other comprehensive income, net of tax Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Adeno-Associated Virus Mediated Gene Therapy Program Adeno-Associated Virus Mediated Gene Therapy Program [Member] Adeno-Associated Virus Mediated Gene Therapy Program Current liabilities Liabilities, Current [Abstract] Issuance of common stock, net of issuance costs Stock Issued During Period, Value, New Issues General and administrative General and Administrative Expense Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Earnings Per Share [Abstract] Earnings Per Share [Abstract] Income tax refunds received Proceeds from Income Tax Refunds Share-Based Compensation Share-based Payment Arrangement [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. Significant unobservable inputs (Level 3) Fair Value, Inputs, Level 3 [Member] 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 Leases Lessee, Leases [Policy Text Block] Accounting Policies [Abstract] Accounting Policies [Abstract] Document Quarterly Report Document Quarterly Report Payments of stock issuance costs Payments of Stock Issuance Costs Exercise price of pre-funded warrants (in dollars per share) Class of Warrant or Right, Exercise Price of Warrants or Rights Issuance of common stock, net of issuance costs (in shares) Stock Issued During Period, Shares, New Issues Number of reporting segments Number of Reportable Segments 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 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 Common stock—$0.001 par value, 200,000,000 shares authorized, 90,386,770 and 90,120,797 shares issued and outstanding at June 30, 2021 and December 31, 2020, respectively Common Stock, Value, Issued Entity Common Stock, Shares Outstanding (in shares) Entity Common Stock, Shares Outstanding 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 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 Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Asset Acquisition [Domain] Asset Acquisition [Domain] 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. Subsequent Event [Table] Subsequent Event [Table] Stock-based compensation expense Share-based Payment Arrangement, Expense Unusual or Infrequent Item, or Both [Axis] Unusual or Infrequent Item, or Both [Axis] Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Underwritten Offering, Underwriters Underwritten Offering, Underwriters [Member] Underwritten Offering, Underwriters Net loss per common share: Basic and diluted net loss per common share calculation: Earnings Per Share, Basic and Diluted [Abstract] 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] Document Fiscal Period Focus Document Fiscal Period Focus Restricted stock units Restricted Stock [Member] Milestone Events [Domain] Milestone Events [Domain] Represents the types of milestone events. GA Product GA Product [Member] GA Product [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] 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. Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value [Abstract] Amortization of premium and discounts on investment securities Accretion (Amortization) of Discounts and Premiums, Investments 2019 Inducement Plan Two Thousand Nineteen Inducement Plan [Member] Two Thousand Nineteen Inducement Plan [Member] Achievement of specified commercial milestones Achievement Of Specified Commercial Milestones [Member] Represents information pertaining to the achievement of specified commercial milestones. Counterparty Name [Axis] Counterparty Name [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Document Period End Date Document Period End Date Shares issued for license fees (in shares) Shares Issued For License Fees Shares Issued For License Fees Beginning of period End of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Balance at beginning of period (in shares) Balance at end of period (in shares) Shares, Issued Number of shares issued in transaction (in shares) Sale of Stock, Number of Shares Issued in Transaction Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Entity Registrant Name Entity Registrant Name Number of licensed products Number Of Licensed Products Number of Licensed Products Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] 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 Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Risk-free interest rate, maximum Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum Current assets Assets, Current [Abstract] Pre-funded warrants outstanding (in shares) Class of Warrant or Right, Outstanding Cash, Cash Equivalents, and Short-term Investments [Abstract] Cash, Cash Equivalents, and Short-term Investments [Abstract] Interest income Interest Income (Expense), Nonoperating, Net 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] Private Placement, Underwriters Private Placement, Underwriters [Member] Private Placement, Underwriters Entity Central Index Key Entity Central Index Key Income Taxes Income Tax, Policy [Policy Text Block] 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. Cash Cash Security Exchange Name Security Exchange Name Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Investments Cash and Cash Equivalents, Fair Value Disclosure Issuance of common stock under the exercise of pre-funded warrants Stock Issued During Period, Value, Conversion of Units Exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Diluted (in shares) Weighted average common shares outstanding - dilutive (in shares) Weighted Average Number of Shares Outstanding, Diluted Financial Instrument [Axis] Financial Instrument [Axis] Recurring basis Fair Value, Recurring [Member] Over-Allotment Option Over-Allotment Option [Member] Income Taxes Income Tax Disclosure [Text Block] Current Fiscal Year End Date Current Fiscal Year End Date Summary of the stock option activity including weighted average exercise prices, options outstanding and exercisable Share-based Payment Arrangement, Option, Activity [Table Text Block] License Agreements License Agreement Terms [Member] Common Stock Stockholders' Equity Note Disclosure [Text Block] Stock options Share-based Payment Arrangement, Option [Member] 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] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Equity [Abstract] Financial Instruments Fair Value of Financial Instruments, Policy [Policy Text Block] Issuance of common stock under employee stock compensation plans Stock Issued During Period, Value, Issued for Services Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] 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 Common Stock Common Stock [Member] Net cash provided by investing activities Net Cash Provided by (Used in) Investing Activities Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Second and third indication Second and Third Indication [Member] Second and Third Indication [Member] Schedule of Commitments and Contingencies [Table] Schedule of Commitments and Contingencies [Table] Schedule of information pertaining to commitments and contingencies. Current period changes in fair value before reclassifications, net of tax OCI, before Reclassifications, Net of Tax, Attributable to Parent Loss from operations Operating Income (Loss) 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 Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Other Licensed Product Other Licensed Product [Member] Other Licensed Product [Member] General and administrative General and Administrative Expense [Member] Consolidation Consolidation, Policy [Policy Text Block] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-sale [Line Items] Lease liability Operating Lease, Liability, Current Gross Unrealized Losses Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Expected term of options (years) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Income tax receivable Increase (Decrease) in Income Taxes Receivable Total current liabilities Liabilities, Current Employee stock purchase plan Employee Stock [Member] Increase (Decrease) in Stockholders' Equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Share-based compensation Share-based Payment Arrangement, Noncash Expense Additional paid-in capital Additional Paid-in Capital [Member] Cash and cash equivalents Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Depreciation and other expense Depreciation BEST1 License Agreement BEST1 License Agreement [Member] BEST1 License Agreement [Member] Money market funds Money Market Funds [Member] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Issuance of common stock under the exercise of pre-funded warrants (in shares) Stock Issued During Period, Shares, Conversion of Units Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Public Stock Offering Public Stock Offering [Member] Public Stock Offering Title of 12(b) Security Title of 12(b) Security Other expense, net Other Nonoperating Income (Expense) Proceeds from stock plans Proceeds from Stock Plans Statement [Table] Statement [Table] Collaborative Arrangement and Arrangement Other than Collaborative [Table] Collaborative Arrangement and Arrangement Other than Collaborative [Table] Asset-backed securities Asset-backed Securities [Member] Recently Adopted Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Share price calculation base, period (in days) Asset Acquisition, Milestone Payment Share Price Basis For Calculation, Trading Days Asset Acquisition, Milestone Payment Share Price Basis For Calculation, Trading Days Maximum Maximum [Member] Share-based Payment Arrangement [Abstract] Share-based Payment Arrangement [Abstract] Statistical Measurement [Axis] Statistical Measurement [Axis] Total liabilities Liabilities Subsequent Event Subsequent Event [Member] Cover [Abstract] Cover [Abstract] Award Type [Axis] Award Type [Axis] Preferred Stock Preferred Stock [Member] Granted (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price 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 Warrants issued in transaction (in shares) Warrants Or Rights Issued In Transaction Warrants Or Rights Issued In Transaction Total stockholders' equity Balance at beginning of period Balance at end of period Stockholders' Equity Attributable to Parent Issuance of common stock under employee stock compensation plan (in shares) Stock Issued During Period, Shares, Issued for Services 2013 Plan Employee stock purchase plan Stock Incentive2013 Plan [Member] Represents information pertaining to the 2013 Stock Incentive Plan. Common stock, shares issued (in shares) Common Stock, Shares, Issued 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 Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Accounts payable and accrued expenses Increase (Decrease) in Accounts Payable and Accrued Liabilities Business Nature of Operations [Text Block] 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] 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. Subsequent Event Type [Axis] Subsequent Event Type [Axis] Wet AMD Product Wet AMD Product [Member] Wet AMD Product [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. Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Estimated useful live (in years) Property, Plant and Equipment, Useful Life RHO-adRP License Agreement RHO-adRP License Agreement [Member] RHO-adRP License Agreement [Member] Stockholders' equity Stockholders' Equity Attributable to Parent [Abstract] Schedule of Accumulated Other Comprehensive Income Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]