Financial Instrument [Axis]
Corporate Debt Securities [Member]
Measurement Frequency [Axis]
Fair Value, Measurements, Recurring [Member]
Fair Value Hierarchy and NAV [Axis]
Fair Value, Inputs, Level 1 [Member]
Fair Value, Inputs, Level 2 [Member]
Fair Value, Inputs, Level 3 [Member]
Business Acquisition [Axis]
EGEN Inc [Member]
Legal Entity [Axis]
IPR&D Drug Technology Platforms [Member]
Range [Axis]
Maximum [Member]
Contingent Consideration by Type [Axis]
Glioblastoma Multiforme Brain Cancer [Member]
Type of Arrangement and Non-arrangement Transactions [Axis]
Purchase Agreement [Member]
Finite-Lived Intangible Assets by Major Class [Axis]
Noncompete Agreements [Member]
Ovarian Cancer [Member]
Hercules Credit Agreement [Member]
Vesting [Axis]
Second Tranche [Member]
Debt Instrument [Axis]
Counterparty Name [Axis]
Hercules [Member]
Equity Components [Axis]
Warrant [Member]
Class of Warrant or Right [Axis]
Hercules Warrant [Member]
Loan Agreement [Member]
Hercules Technology Growth Capital, Inc. [Member]
Award Type [Axis]
Stock Options [Member]
Plan Name [Axis]
2007 Stock Incentive Plan [Member]
2018 Stock Incentive Plan [Member]
Minimum [Member]
Equity Stock Awards [Member]
First Tranche [Member]
Variable Rate [Axis]
Prime Rate [Member]
Restricted Stock Awards [Member]
Lease Arrangement, Type [Axis]
Lawrenceville New Jersey [Member]
Credit Facility [Axis]
Standby Letter of Credit [Member]
EGEN Asset Purchase Agreement [Member]
Huntsville Alabama [Member]
Legal Entity of Counterparty, Type [Axis]
Hisun [Member]
Underwriting Agreement [Member]
Oppenheimer & Co. Inc. [Member]
Investor Warrants [Member]
Sale of Stock [Axis]
October 2017 Underwritten Offering [Member]
July 2017 Direct Offering [Member]
Pre-Funded Series CCC Warrants [Member]
Series AAA Warrants [Member]
Series BBB Warrants [Member]
Series DDD Warrants [Member]
February 14, 2017 Public Offering [Member]
Series AA Warrant [Member]
Pre-Funded Series BB Warrant [Member]
2013 Warrants, 2014 Warrants, and June 2016 Warrants [Member]
2015 Warrants [Member]
May 2015 Common Stock Offering [Member]
June 2016 Warrants [Member]
Horizon Technology Finance Corporation [Member]
Horizon Credit Agreement [Member]
Horizon Warrants [Member]
LIBOR plus [Member]
Inducement Option Grants [Member]
Title of Individual [Axis]
Three New Employees [Member]
Restricted Stock Awards [Member]
Common Stock [Member]
Additional Paid in Capital [Member]
Treasury Stock [Member]
Accumulated Other Comprehensive Income [Member]
Accumulated Deficit [Member]
Hisun Agreement [Member]
Common Stock Sales Agreement [Member]
Related Party [Axis]
Aspire Capital Fund, LLC [Member]
Investment Type [Axis]
Short-term Investments [Member]
Fair Value, Measurements, Non-Recurring [Member]
In Process R&D [Member]
In Process R&D [Member]
Property, Plant and Equipment, Type [Axis]
Machinery and Equipment [Member]
Furniture and Fixtures [Member]
Leasehold Improvements [Member]
Income Tax Authority, Name [Axis]
Tax Reform Act [Member]
Income Tax Authority [Axis]
Federal Income Tax [Member]
Warrant Exchange Agreements [Member]
Investor [Member]
February 14, 2017 Public Offering [Member]
Exercise Agreements [Member]
Aspire Purchase Agreement [Member]
Capital on DemandTM Sales Agreement [Member]
ATM Agreement [Member]
Exercise Price Range [Axis]
Exercise Price One [Member]
Exercise Price Two [Member]
EGEN Inc [Member]
License Agreement [Member]
Duke University [Member]
U.S. Federal and State Tax [Member]
Geographical [Axis]
New Jersey [Member]
New Jersey [Member]
Asset Class [Axis]
Goodwill [Member]
IPR&D [Member]
Subsequent Event Type [Axis]
Subsequent Event [Member]
Asset Purchase Agreement [Member]
EGWU, Inc [Member]
Award Date [Axis]
March 28, 2019 [Member]
Capital on Demand Agreement [Member]
Document And Entity Information
Entity Registrant Name
Entity Central Index Key
Document Type
Document Period End Date
Amendment Flag
Current Fiscal Year End Date
Entity a Well-known Seasoned Issuer
Entity a Voluntary Filer
Entity's Reporting Status Current
Entity Filer Category
Entity Small Business Flag
Entity Emerging Growth Company
Entity Ex Transition Period
Entity Shell Company
Entity Public Float
Entity Common Stock, Shares Outstanding
Trading Symbol
Document Fiscal Period Focus
Document Fiscal Year Focus
Statement of Financial Position [Abstract]
ASSETS
Current assets:
Cash and cash equivalents
Investment securities - available for sale, at fair value
Accrued interest receivable on investment securities
Advances and deposits on clinical programs and other current assets
Total current assets
Property and equipment (at cost, less accumulated depreciation and amortization)
Other assets:
In-process research and development, net
Goodwill
Other intangible assets, net
Deposits and other assets
Total other assets
Total assets
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:
Accounts payable - trade
Other accrued liabilities
Deferred revenue - current portion
Total current liabilities
Earn-out milestone liability
Note Payable, net of deferred financing costs
Deferred revenue - non-current portion
Other liabilities - non-current
Total liabilities
Commitments
Stockholders' equity:
Preferred Stock - $0.01 par value (100,000 shares authorized, and no shares issued or outstanding at December 31, 2018 and 2017)
Common stock - $0.01 par value (112,500,000 shares authorized; 18,832,168 and 17,277,299 shares issued at December 31, 2018 and 2017, respectively, and 18,831,834 and 17,276,965 shares outstanding at December 31, 2018 and 2017, respectively)
Additional paid-in capital
Accumulated other comprehensive gain (loss)
Accumulated deficit
Total stockholders' equity before treasury stock
Treasury stock, at cost (334 shares at December 31, 2018 and 2017)
Total stockholders' equity
Total liabilities and stockholders' equity
Preferred stock, par value
Preferred stock, shares authorized
Preferred stock, shares issued
Preferred stock, shares outstanding
Common stock, par value
Common stock, shares authorized
Common stock, shares issued
Common stock, shares outstanding
Treasury stock, shares
Income Statement [Abstract]
Technology development and licensing revenue
Operating expenses:
Research and development
General and administrative
Total operating expenses
Loss from operations
Other income (expense):
Gain from change in earn-out milestone liability
Impairment of in-process research and development
Investment income, net
Interest expense
Other income
Total other expense
Net loss before income tax benefit
Income tax benefit
Net loss
Deemed dividend related to warrant modification
Net loss attributable to common shareholders
Net loss attributable to common shareholders per common share - basic and diluted
Weighted average common shares outstanding - basic and diluted
Statement of Comprehensive Income [Abstract]
Net loss
Changes in:
Realized loss on investment securities recognized in investment income, net
Unrealized gain (loss) on investment securities
Other comprehensive income (loss)
Comprehensive loss
Statement of Cash Flows [Abstract]
Cash flows from operating activities:
Non-cash items included in net loss:
Depreciation and amortization
Change in fair value of earn-out milestone liability
Impairment of in-process research and development
Stock-based compensation
Shares issued in exchange for services
Shares issued to satisfy certain obligations
Amortization of deferred finance charges and debt discount associated with note payable
Change in deferred rent liability
Net changes in:
Interest receivable on investments
Advances and deposits on clinical programs and other current assets
Other assets
Accounts payable - trade
Deferred revenue
Other accrued liabilities
Net cash used in operating activities
Cash flows from investing activities:
Purchases of investment securities
Proceeds from sale and maturity of investment securities
Refund on security for letter of credit
Purchases of property and equipment
Net cash (used in) provided by investing activities
Cash flows from financing activities:
Proceeds from issuance of common stock equity, net of issuance costs
Proceeds from note payable, net of issuance costs
Proceeds from exercise of common stock warrants
Principal payments on note payable
Net cash provided by financing activities
Increase in cash and cash equivalents
Cash and cash equivalents at beginning of period
Cash and cash equivalents at end of period
Cash (paid for) received from:
Interest paid
Income tax benefit
Non-cash financing activities:
Fair value of common stock issued as equity issuance costs charged against paid in capital
Fair value of common stock and warrants issued in connection with notes payable
Fair value of stock issued in exchange for cancelation of warrants
Fair value of modification of warrant exercise prices included in paid in capital
Fair value of deemed dividend related to modification of warrant exercise prices charged against paid in capital
Statement [Table]
Statement [Line Items]
Balance
Balance, shares
Registered direct and ATM common stock offerings
Registered direct and ATM common stock offerings, shares
Exercise of common stock warrants
Exercise of common stock warrants, shares
Shares issued to satisfy certain obligations
Shares issued to satisfy certain obligations, shares
Realized and unrealized gains and losses, net, on investments securities
Stock-based compensation expense
Issuance of restricted stock
Issuance of restricted stock, shares
Modification of warrant exercise prices
Deemed dividend related to warrant exercise price modifications
Effect of reverse stock split
Effect of reverse stock split, shares
Sale of equity through ATM and common stock purchase agreement
Sale of equity through ATM and common stock purchase agreement, shares
Common stock issuance in exchange for cancellation of common stock warrants
Common stock issuance in exchange for cancellation of common stock warrants, shares
Common stock and warrants to purchase common stock issued in connection with equity and debt facilities
Common stock and warrants to purchase common stock issued in connection with equity and debt facilities, shares
Balance
Balance, shares
Accounting Policies [Abstract]
Summary of Significant Accounting Policies
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Financial Condition
Investments, Debt and Equity Securities [Abstract]
Short Term Investments Available for Sale
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments
Business Combinations [Abstract]
Acquisition of EGEN, Inc.
Property, Plant and Equipment [Abstract]
Property and Equipment
Payables and Accruals [Abstract]
Other Accrued Liabilities
Debt Disclosure [Abstract]
Notes Payable
Income Tax Disclosure [Abstract]
Income Taxes
Equity [Abstract]
Stockholders' Equity
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation
Earn-out Milestone Liability
Earn-out Milestone Liability
Notes To Financial Statements [Abstract]
Warrants
Defined Benefit Plan [Abstract]
Celsion Employee Benefit Plans
Intangible Assets, Net (Including Goodwill) [Abstract]
Licenses of Intellectual Property and Patents
Technology Development And Licensing Agreements
Technology Development and Licensing Agreements
Commitments and Contingencies Disclosure [Abstract]
Commitments
Subsequent Events [Abstract]
Subsequent Events
Description of Business
Basis of Presentation
Use of Estimates
Revenue Recognition
Cash and Cash Equivalents
Fair Value of Investment Securities
Short Term Investments
Property and Equipment
Deposits
In-Process Research and Development, Other Intangible Assets and Goodwill
Impairment or Disposal of Long-Lived Assets
Comprehensive Income (Loss)
Research and Development
Net Loss Per Common Share
Income Taxes
Stock-Based Compensation
Recent Accounting Pronouncements
Short-term Investments [Abstract]
Schedule of Cost, Fair Value and Maturities of Short Term Investments
Summary of Investment Securities Gross Unrealized Gains (losses)
Summary of Net Realized Losses On Sales of Available for Sale Securities and Investment Income Interest and Dividends
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis
Schedule of Fair Value of Assets Acquired and Liabilities Assumed
Schedule of Future Amortization Amounts During the Remaining Life
Schedule of Fair Value of Assets Acquired
Summary of Property and Equipment
Schedule of Other Accrued Liabilities
Schedule of Future Principle Payments, Net of Unamortized Debt Discounts
Schedule of Income Tax Provision (Benefit)
Schedule of Effective Income Tax Rate Reconciliation
Schedule of Deferred Tax Assets and Liabilities
Summary of Stock Option Awards
Summary of Non-vested Restricted Stock Awards
Summary of Stock Options Outstanding
Schedule of Assumptions Used to Determine Fair Value of Options Granted
Schedule of Changes in Earn-out Milestone Liability
Summary of Warrant Activity
Schedule of Future Minimum Rental Payments for Operating Leases
Accounts receivable
Contract liabilities
Depreciation
Property, Plant and Equipment, Useful Life
Number of shares of common stock issuable upon exercise of warrants and equity awards
Tax benefits of EDA
Net proceeds from sale of net operating losses
Right-of-use assets
Related lease liabilities
Cumulated net losses
Cash, investment securities and interest receivable
Proceeds from available future sale of equity under common stock purchase agreement
Unrecognized tax benefits
Short-term investments - Fair Value
Short-term investments - Cost
Short-term investment maturities - Within 3 months, cost
Short-term investment maturities - Between 3-12 months, cost
Total, cost
Short-term investment maturities - Within 3 months, fair value
Short-term investment maturities - Between 3-12 months, fair value
Total, fair value
Less than 12 months, unrealized gains, fair value
Less than 12 months, unrealized losses, fair value
Investment securities - available for sale, at fair value
Less than 12 months, unrealized holding gains
Less than 12 months, unrealized holding losses
Unrealized holding gains (losses)
Interest and dividends accrued and paid
Accretion of investment discounts and premiums, net
Losses investment maturity and sales, net
Investment income
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers into Level 3
Investment securities, available for sale
Liabilities, fair value
Total purchase price for the asset acquisition
Potential future earn-out payments
Payments to Acquire Businesses, Gross
Stock issued during period, shares, acquisitions
Number of common stock issued or issuable
Indefinite lived intangible assets
Asset impairment charges, total
Business Combination, Consideration Transferred, Liabilities Incurred
IPR&D costs
Finite-lived intangible assets, net, ending balance
Gain (Loss) from Change in Fair Value of Earn out Milestone Liability
Initial assets value
Assets
Finite-lived intangible assets acquired
Finite-lived intangible asset, useful life
Amortization expense
Finite-lived intangible assets, accumulated amortization
Goodwill, acquisition
Property and equipment, net
In-process research and development
Other Intangible assets (Covenant not to compete)
Total assets:
Accounts payable and accrued liabilities
Net assets acquired
2019
2020
2021
Total
Intangible assets, beginning balance
Amortization
Impairment charge
Intangible assets, ending balance
Estimated useful life
Property and equipment, gross
Less accumulated depreciation and amortization
Total
Amounts due to contract research organizations and other contractual agreements
Accrued payroll and related benefits
Accrued professional fees
Other
Total
Line of credit facility, maximum borrowing capacity
Proceeds from lines of credit, total
Line of credit, interest rate
Debt effective interest rate
Percentage of outstanding principle balance, description
Class of warrant or right, number of securities called by each warrant or right
Class of warrant or right, exercise price of warrants or rights
Debt instrument, unamortized discount, total
Financing fees and expenses
Loan origination fees
Debt issuance costs, net, total
Percentage for original debt, amount
Debt issuance costs, gross
Interest expense, debt, total
Amortization of debt issuance costs
Repayments of lines of credit
Payments to acquire businesses, gross
Debt instrument, basis spread on variable rate
Warrant date
Original debt, amount
2019
2020
2021
2022
2023 and thereafter
Subtotal of future principle payments
Net of unamortized debt issuance costs
Total
Income tax, description
Income tax, U.S. corporate income tax rate
Net operating losses
Net operating losses, unused
Net operating losses expiration, description
Net operating losses carryforward limits, description
Operating loss carry forwards, limitation on use
Operating loss carry forwards, limitation on use
Proceeds from sale of NOLs
Federal, Current
Federal, Deferred
State and Local, Current
State and Local, Deferred
Effective tax rate
Federal statutory rate
State taxes, net of federal tax benefit
Permanent differences
Other
Change in valuation allowance and deferred rate change, net
Effective tax rate
Net operating loss carryforwards
Other Deferred tax assets, net
Subtotal
Valuation allowance
Total deferred tax asset
Shelf registration statement amount
Aggregate of common and preferred stock, shares authorized
Reverse stock split
Stock issued during period split stock
Stock issued during period reverse stock split
Class of warrant or right, outstanding
Share-based compensation arrangement by share-based payment award, options, outstanding, number, ending balance
Stock issued during period, shares, new issues
Common stock, par or stated value per share
Class of warrant or right, number of securities called by warrants or rights
Warrant, description
Class of warrant or right, offered price of warrants or rights
Warrants issued, expiration period
Number of warrant to surrender
Number of exchange surrender received common stock
Broker and legal fees
Proceeds from issuance of common stock and warrants
Share price
Proceeds from issuance of common stock, gross
Beneficial ownership percentage threshold
Proceeds from issuance of warrants
Class of warrant or right, exercised during period
Shares issued, price per share
Class of warrant or right, term
Maximum beneficial ownership of the purchaser
Proceeds from issuance of common stock
Stock issued during period, shares, exercise of warrants
Proceeds from warrant exercises
Increase (decrease) in fair value of warrants
Aggregate offering price, additions
Aggregate offering price, term
Aggregate offering price
Maximum number of shares purchased per day
Aggregate offering price, description
Maximum number of shares purchased per day, additional
Aspire purchase agreement, terms
Fair value of common stock issued as equity issuance costs and charged against paid in capital
Commission percentage for gross proceeds from common stock
Proceeds from sale equity
Sale of common stock, shares
Equity awards, number of stock authorized
Percentage of fair market value of shares
Percentage of outstanding stock determining factor for incentive stock price
Shares issued
Inducement option grant, exercise price per share
Options expiration period
Number of shares reserved for future issuance
Number of equity awards granted
Number of equity awards available for future issuance
Compensation cost
Unrecognized compensation cost related to non-vested stock based compensation
Stock based compensation cost expected to be recognized, weighted average period
Weighted average grant date fair value of stock option awards granted
Number Outstanding, Outstanding, Beginning Balance
Number Outstanding, Granted
Number Outstanding, Cancelled or expired
Number Outstanding, Ending Balance
Number Outstanding, Exercisable
Weighted Average Exercise Price, Outstanding, Beginning Balance
Weighted Average Exercise Price, Granted
Weighted Average Exercise Price, Cancelled or expired
Weighted Average Exercise Price, Outstanding, Ending Balance
Weighted Average Exercise Price, Excercisable
Weighted Average Remaining Contractual Term (years), Outstanding, Ending Balance
Weighted Average Remaining Contractual Term (years), Exercisable
Aggregate Intrinsic Value, Outstanding, Ending Balance
Aggregate Intrinsic Value, Exercisable
Number Outstanding, Non-vested stock awards outstanding, Beginning Balance
Number Outstanding, Non-vested stock awards outstanding, Granted
Number Outstanding, Non-vested stock awards outstanding, Vested and issued
Number Outstanding, Non-vested stock awards outstanding, Forfeited
Number Outstanding, Non-vested stock awards outstanding, Ending Balance
Weighted Average Grant Date Fair Value, Beginning Balance
Weighted Average Grant Date Fair Value, Granted
Weighted Average Grant Date Fair Value, Vested and issued
Weighted Average Grant Date Fair Value, Forfeited
Weighted Average Grant Date Fair Value, Ending Balance
Range of Exercise Prices, Upper
Range of Exercise Prices, Lower
Options Outstanding, Number
Options Outstanding, Weighted Average Remaining Contractual Term (in years)
Options Outstanding, Weighted Average Exercise Price
Options Exercisable, Number
Options Exercisable, Weighted Average Remaining Contractual Term (in years)
Options Exercisable, Weighted Average Exercise Price
Risk-free interest rate
Expected volatility
Expected life (in years)
Expected dividend yield
Future earn-out payments
Fair value of Acquisition consideration
Risk adjusted assessment of each milestone
Estimated time to achieve the milestone
Gain (loss) from change in fair value of earn out milestone liability
Earn-out Milestone Liability - Schedule Of Changes In Earn-out Milestone Liability
Earn-out liabilities, beginning balance
Non-cash charge from the adjustment for the change in fair value included in net loss
Earn-out liabilities, ending balance
Number of shares, Warrant rights
Common stock shares issued
Warrants outstanding
Proceeds from warrant
Warrants, weighted average exercise price
Warrants expiring
Strike price per share
Warrant expiration date
Number of Warrants Issued, Warrants outstanding, Beginning Balance
Number of Warrants Issued, Warrants issued
Number of Warrants Issued, Warrants exercised
Number of Warrants Issued, Warrants cancelled in exchange for common stock
Number of Warrants Issued, Warrants expired
Number of Warrants Issued, Warrants outstanding and exercisable, Ending Balance
Weighted Average Exercise Price, Warrants outstanding, Beginning Balance
Weighted Average Exercise Price, Warrants issued
Weighted Average Exercise Price, Warrants exercised
Weighted Average Exercise Price, Warrants cancelled in exchange for common stock
Weighted Average Exercise Price, Warrants expired
Weighted Average Exercise Price, Warrants outstanding and exercisable, Ending Balance
Aggregate intrinsic value of outstanding warrants
Weighted average remaining contractual terms (years)
Number of days before issuance factoring into average closing price
Amount of time after effective date of license agreement for registration rights to take place
Common stock, shares, issued
Common stock, value, issued
Number of trademark protection application pending for thermo dox
Non-refundable research and development fee
Deferred revenue
Deferred revenue amortization period
Area of premises
Lease term
The number of months in which free rent is provided
Payment for rent
Irrevocable and unconditional standby letter of credit
Contractual obligation reduction nineteen months from initial term
Contractual obligation remaining
Operating lease, description
Operating leases, monthly rent payment in first year
Operating leases, monthly rent payment in final year
Operating leases, monthly rent payment
Payment of lease
2019
2020
2021
2022
2023
Total minimum lease payments
Cash consideration payable
Consideration payble by issuane of stock
Warrants to purchase common stock
Warrants strike price
Represents Controlled Equity Offering Sales Agreement (the “ATM Agreement”) with Cantor Fitzgerald & Co., as sales agent.
The aggregate maximum number of common shares and nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.
Represents the additional aggregate offering price for shares of common stock that the Company may offer and sell through a sales agent.
Aggregate offering price.
Aspire Purchase Agreement [Member]
The current amount of amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).
Amount of accumulated unrealized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position.
Beneficial ownership percentage threshold for purchase of shares of company's common stock.
The amount of cash, investment securities and interest receivable.
The number of warrants or rights exercised during period.
Offered price per share or per unit of warrants or rights.
Period of time the warrants or rights are issued, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
Represents the reduction of the contractual obligation that will occur nineteen months from initial term.
The remaining amount due under contractual obligations.
Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) unrealized gain less than 12 months.
Amount of accumulated unrealized gain on investment in debt security measured at fair value with change in other comprehensive income (available-for-sale), unrealized gain for less than 12 months.
Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next rolling three to twelve months.
Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next rolling three to twelve months.
Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) with single maturity date and allocated without single maturity date, maturing in next rolling three months.
Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next rolling three months.
Dividends deemed that are related to warrant modifications..
Deferred finance charges.
The amortization period for deferred revenue.
Disclosure of accounting policy for deposits.
Description of Business [Policy Text Block]
EGEN Asset Purchase Agreement [Member]
Information pertaining to the business acquisition of EGEN, Inc.
The amount of earn-out milestone liability as of the balance sheet.
Equity Stock Awards [Member]
The amount of estimated time to achieve the milestone.
Fair value of common stock issued as equity issuance costs and charged against paid in capital.
Represents the public offering on February 14, 2017.
First Tranche [Member]
Gain from change in earn-out milestone liability.
The amount of gain (loss) from the change in the fair value of earn-out milestone liability.
The amount recognized in earnings related to the change in fair value during the period of milestone liability.
Glioblastoma Multiforme Brain Cancer [Member]
Represents a loan agreement with Hercules Technology Growth Capital, Inc. (“Hercules”).
Represents Hercules Technology Growth Capital, Inc..
Hercules Technology Growth Capital, Inc. [Member]
Represents Hercules Technology Growth Capital, Inc..
Hisun Agreement [Member]
Hisun [Member]
Horizon Credit Agreement [Member]
Horizon Technology Finance Corporation [Member]
Horizon Warrants [Member]
Huntsville Alabama [Member]
IPR&D Drug Technology Platforms [Member]
Impairment of in-process research and development.
The amount of increase (decrease) in the fair value of warrants exercised.
Inducement Option Grants [Member]
Initial assets value.
Investor Warrants [Member]
Represents the information pertaining to the direct offering agreement on July 6, 2017.
June 2016 Warrants [Member]
Lawrenceville New Jersey [Member]
The entire disclosure for a contractual arrangement, in which the Company gave another party an exclusive license.
Loan Agreement [Member]
Represents the maximum beneficial ownership of the Purchaser.
Maximum number of shares purchased per day.
Maximum number of shares purchased per day, additional.
Represents a securities purchase agreement with certain investors into which the entity entered in May 2015.
Net proceeds from sale of net operating losses
Note to financial statement details textual.
The number of months in which free rent is provided.
Represents the total number of Shares of common stock issuable upon exercise of warrants and equity awards.
Number of warrants expiring in period.
Represents the October 2017 Underwritten Offering.
Represents the payment to be paid each month under an operating lease.
Represents the payment to be paid each month in the final year under an operating lease.
Represents the payment to be paid each month in the first year under an operating lease.
Oppenheimer & Co. Inc. [Member]
Ovarian Cancer [Member]
Percentage of fair market value of shares
Percentage of outstanding stock determining factor for incentive stock price.
Information relating to Pre-Funded Series BB Warrant.
Represents the information pertaining to the Pre-Funded Series CCC Warrants.
Precentage of outstanding principle balance, description.
The cash inflow from the additional capital contribution to the entity and from issuance of rights to purchase common shares at predetermined price (usually issued together with corporate debt).
The cash inflow from the additional capital contribution to the entity before the deduction of costs related to the issuance (for example, the placement agent fee and offering expenses).
Purchase Agreement [Member]
Aspire purchase agreement, terms.
The percentage of risk-adjusted assessment of each milestone.
The disclosure of transactions regarding the changes in earn-out liabilities during the period.
Tabular disclosure of warrant activity.
Second Tranche [Member]
Represents the information pertaining to the Series AAA Warrants.
Information relating to Series AA warrants.
Represents the information pertaining to the Series BBB Warrants.
Represents the information pertaining to Series DDD Warrants.
Shares issued in exchange for services.
Shelf Registration statement.
Exercise of common stock warrants, shares.
The number of new stock issued with the exercise of warrants during the period.
Common stock issuance in exchange for cancellation of common stock warrants, shares.
Common stock and warrants to purchase common stock issued in connection with equity and debt facilities, shares.
Sale of equity through ATM and common stock purchase agreement, shares.
Exercise of common stock warrants.
Common stock issuance in exchange for cancellation of common stock warrants.
Common stock and warrants to purchase common stock issued in connection with equity and debt facilities.
The monetary effect of the reduction in the number of shares during the period as a result of a reverse stock split.
Sale of equity through ATM and common stock purchase agreement.
Three New Employees [Member]
2018 Stock Incentive Plan [Member]
2007 Stock Incentive Plan [Member]
Represents the information pertaining to the 2015 Warrants.
Represents the information pertaining to the 2013 Warrants, 2014 Warrants, and June 2016 Warrants.
Underwriting Agreement [Member]
Warrant date.
The number of years after which warrants issued are set to expire.
Warrants [Text Block]
Tax benefits of EDA
Proceeds from available future sale of equity under common stock purchase agreement.
Common Stock Sales Agreement [Member]
Aspire Capital Fund, LLC [Member]
In Process R and D - GBM Two [Member]
Tax Reform Act [Member]
Net operating losses expiration, description.
Federal Income Tax [Member]
Net operating losses, unused.
Net operating losses carryforward limits, description.
Operating loss carry forwards, limitation on use
Numbe of warant to surrender.
Number of exchange surrender received common stock.
Warrant Exchange Agreements [Member]
February 14, 2017 Public Offering [Member]
Exercise Agreements [Member]
Aggregate offering price, term.
Aggregate offering price, description.
Capital on DemandTM Sales Agreement [Member]
Commission percentage for gross proceeds from common stock.
Exercise Price One [Member]
Exercise Price Two [Member]
EGEN Inc [Member]
Number of days before issuance factoring into average closing price.
Amount of time after effective date of license agreement for registration rights to take place.
Number of trademark protection application pending for thermo dox.
License Agreement [Member]
Duke University [Member]
Number of Warrants Issued, Warrants issued.
Weighted Average Exercise Price, Warrants issued
Number of Warrants Issued, Warrants exercised.
Number of Warrants Issued, Warrants expired.
Weighted Average Exercise Price, Warrants exercised.
Weighted Average Exercise Price, Warrants expired.
Strike price per share.
U.S. Federal and State Tax [Member]
New Jersey [Member]
The disclosure related to earn-out milestone liabilities.
Fair value of common stock and warrants issued in connection with notes payable.
Fair value of modification of warrant exercise prices included in paid in capital.
Fair value of deemed dividend related to modification of warrant exercise prices charged against paid in capital.
IPR&D [Member]
Asset Purchase Agreement [Member]
EGWU, Inc [Member]
Effective income tax rate reconciliation permanent differences.
Proceeds from sale of NOLs.
March 28, 2019 [Member]
Capital on Demand Agreement [Member]
InProcessResearchAndDevelopmentTwoMember
FebruaryFourteenTwoThousandAndSeventeenPublicOfferingMember
EGENMember
NEW JERSEY
Assets, Current
Assets, Noncurrent
Liabilities, Current
Liabilities
Stockholders' Equity before Treasury Stock
Treasury Stock, Value
Stockholders' Equity Attributable to Parent
Liabilities and Equity
Operating Expenses
Operating Income (Loss)
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)
Nonoperating Income (Expense)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax
Comprehensive Income (Loss), Net of Tax, Attributable to Parent
Loss from change in valuation of earn-out milestone liability
Increase (Decrease) in Deposit Assets
Increase (Decrease) in Prepaid Expense and Other Assets
Increase (Decrease) in Other Current Assets
Increase (Decrease) in Accounts Payable
Increase (Decrease) in Other Accrued Liabilities
Net Cash Provided by (Used in) Operating Activities
Payments to Acquire Available-for-sale Securities
Payments to Acquire Property, Plant, and Equipment
Net Cash Provided by (Used in) Investing Activities
Repayments of Notes Payable
Net Cash Provided by (Used in) Financing Activities
Cash and Cash Equivalents, Period Increase (Decrease)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations
Interest Paid, Excluding Capitalized Interest, Operating Activities
Shares, Outstanding
Stock Issued During Period, Value, Issued for Services
Dividends
EarnoutMilestoneLiabilityDisclosureTextBlock
Commitments Disclosure [Text Block]
Property, Plant and Equipment, Policy [Policy Text Block]
Income Tax, Policy [Policy Text Block]
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]
Cost
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value
Less than 12 months, unrealized gains, fair value
Less than 12 months, unrealized gains
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss
Unrealized gains (losses)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net
Amortization of Intangible Assets
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months
Long-term Debt, Maturities, Repayments of Principal in Year Two
Long-term Debt, Maturities, Repayments of Principal in Year Three
Long-term Debt, Gross
Debt Instrument, Unamortized Discount (Premium), Net
Long-term Debt
Operating Loss Carryforwards, Limitations on Use
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent
Effective Income Tax Rate Reconciliation, Percent
Deferred Tax Assets, Gross
Deferred Tax Assets, Valuation Allowance
Deferred Tax Assets, Net of Valuation Allowance
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Options Forfeited, Number of Shares
Share-based Compensation Arrangement by Share-based Payment Award, Option, Nonvested, Weighted Average Exercise Price
clsn_EarnoutMilestoneLiability
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding
Deferred Revenue
Operating Leases, Future Minimum Payments Due, Next Twelve Months
Operating Leases, Future Minimum Payments, Due in Two Years
Operating Leases, Future Minimum Payments, Due in Three Years
Operating Leases, Future Minimum Payments, Due in Four Years
Operating Leases, Future Minimum Payments Due