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NOTES PAYABLE (Details Narrative) - USD ($) |  |  |  | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | ---
Jun. 18, 2021 | Aug. 28, 2020 | Jun. 27, 2018 | Dec. 31, 2021 | Dec. 31, 2020 | Sep. 30, 2021 | Feb. 28, 2020
Short-term Debt [Line Items] |  |  |  |  |  |  |
Financing fee |  |  |  |  |  | $ 145,539 |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights |  |  |  | 7,273 |  |  | 213,333
Class of Warrant or Right, Exercise Price of Warrants or Rights |  |  |  | $ 48.30 |  |  |
Horizon Credit Agreement Amendment [Member] |  |  |  |  |  |  |
Short-term Debt [Line Items] |  |  |  |  |  |  |
Amortization of Debt Issuance Costs |  |  |  | $ 139,428 | $ 483,439 |  |
Interest expense |  |  |  | $ 225,920 | $ 808,899 |  |
Horizon Technology Finance Corporation [Member] |  |  |  |  |  |  |
Short-term Debt [Line Items] |  |  |  |  |  |  |
Long-term Line of Credit | $ 5,425,000 |  |  |  |  |  |
SVB Loan Facility [Member] |  |  |  |  |  |  |
Short-term Debt [Line Items] |  |  |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity | 10,000,000 |  |  |  |  |  |
Proceeds from Lines of Credit | 6,000,000 |  |  |  |  |  |
Restricted Cash | 6,000,000.0 |  |  |  |  |  |
Line of Credit Facility, Remaining Borrowing Capacity | $ 4,000,000 |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage | 3.25% |  |  |  |  |  |
Final payment percentage | 3.00% |  |  |  |  |  |
Long-term Line of Credit | $ 10,000,000 |  |  |  |  |  |
Debt Instrument, Description | Payments under the loan agreement are interest only for the first 24 months after loan closing, followed by a 24-month amortization period of principal and interest through the scheduled maturity date. |  |  | Payments under the loan agreement are interest only (calculated based on one-month LIBOR plus 7.625%) for the first 24 months through July 2020, followed by a 21-month amortization period of principal and interest starting on August 1, 2020 and ending through the scheduled maturity date on April 1, 2023. |  |  |
Financing fees and expenses | $ 243,370 |  |  |  |  |  |
End of term charge percentage | 3.00% |  |  |  |  |  |
Amortization of Debt Issuance Costs | $ 300,000 |  |  |  |  |  |
Interest expense |  |  |  | $ 106,709 |  |  |
Amortization of Debt Issuance Costs and Discounts |  |  |  | 97,831 |  |  |
Horizon Credit Agreement [Member] |  |  |  |  |  |  |
Short-term Debt [Line Items] |  |  |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity |  |  | $ 10,000,000 |  |  |  |
Proceeds from Lines of Credit |  | $ 10,000,000 | 10,000,000 |  |  |  |
Line of Credit Facility, Remaining Borrowing Capacity |  | 5,000,000 |  |  |  |  |
Financing fees and expenses |  |  | $ 175,000 |  |  |  |
End of term charge percentage |  |  | 4.00% |  |  |  |
Debt Instrument, Fee Amount |  |  |  | 142,605 |  |  |
Loan Processing Fee |  |  | $ 100,000 |  |  |  |
Debt Instrument, Unamortized Discount |  |  | 782,116 |  |  |  |
Financing fee |  |  | 400,000 |  |  |  |
Fair Value Adjustment of Warrants |  |  | $ 507,116 |  |  |  |
End term fees |  |  |  | 275,000 |  |  |
Horizon Credit Agreement [Member] | Common Stock [Member] |  |  |  |  |  |  |
Short-term Debt [Line Items] |  |  |  |  |  |  |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights |  |  | 12,674 |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights |  |  | $ 39.45 |  |  |  |
Class of Warrant or Right, Outstanding |  |  | 6,337 |  |  |  |
Amendment to Horizon Credit Agreement [Member] | Horizon Technology Finance Corporation [Member] |  |  |  |  |  |  |
Short-term Debt [Line Items] |  |  |  |  |  |  |
Payment of debt end term charges |  | 200,000 |  |  |  |  |
Debt instrument face amount |  | $ 5,000,000 |  | 5,000,000 |  |  |
Debt Instrument, Interest Rate Terms |  | The obligations bore interest at a rate calculated based an amount by which the one-month LIBOR exceeds 2% plus 7.625%. In no event shall the interest rate be less than 9.625%. Payments pursuant to the Amendment were interest only for the first 12 months after August 1, 2020, followed by a 21-month amortization period of principal and interest through the scheduled maturity date on April 1, 2023. In addition, the remaining $5 million in obligations was subject to an end of term fee equal, in the aggregate, to $275,000, which amount was payable upon the maturity of the obligations or upon the date of final payment or default, as applicable. |  |  |  |  |
Payments of debt extinguishment costs |  | $ 5,000,000 |  | 5,000,000 |  |  |
Debt Instrument, Fee Amount |  | $ 275,000 |  |  |  |  |
Debt Instrument, Restrictive Covenants |  | In connection with the Amendment, Celsion agreed to a liquidity covenant which provided that, at all times, Celsion maintain unrestricted cash and/or cash equivalents on deposit in accounts over which the applicable lenders maintained an account control agreement in an amount not less than $2.5 million. In addition, pursuant to the Amendment, Celsion agreed to provide evidence to Horizon on or before March 31, 2021, that it received aggregate cash proceeds of not less than $5 million from the sale of equity, debt, its New Jersey NOLs, or a combination thereof, subsequent to the date of the Amendment. The Company met this requirement during the fourth quarter of 2020. |  |  |  |  |
Debt Instrument, Unamortized Discount |  |  |  | 109,706 |  |  |
Financing fee |  |  |  | 5,000 |  |  |
Warrants Not Settleable in Cash, Fair Value Disclosure |  |  |  | 247,548 |  |  |
Amendment to Horizon Credit Agreement [Member] | Horizon Technology Finance Corporation [Member] | Common Stock [Member] |  |  |  |  |  |  |
Short-term Debt [Line Items] |  |  |  |  |  |  |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights |  | 16,501 |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights |  | $ 15.15 |  |  |  |  |
Warrants cancelled |  | 6,337 |  |  |  |  |
Horizon Credit Agreement [Member] |  |  |  |  |  |  |
Short-term Debt [Line Items] |  |  |  |  |  |  |
Interest expense |  |  |  | 190,581 |  |  |
Gain (Loss) on Contract Termination |  |  |  | $ 234,419 |  |  |
Horizon Credit Agreement [Member] | Horizon Technology Finance Corporation [Member] |  |  |  |  |  |  |
Short-term Debt [Line Items] |  |  |  |  |  |  |
Debt instrument face amount |  | $ 10,000,000 |  |  |  |  |

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- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 + Details
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- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
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- Definition Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
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- Definition Amount of cash outflow for cost from early extinguishment and prepayment of debt. Includes, but is not limited to, third-party cost, premium paid, and other fee paid to lender directly for debt extinguishment or debt prepayment. Excludes accrued interest. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585 + Details
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- Definition Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(f)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 + Details
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- Definition Amount of cash restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=123431023&loc=SL98516268-108586 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(1)(a)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(2)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 + Details
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- Definition Fair value portion of warrants not settleable in cash classified as equity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258 + Details
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