Accounting Policies, by Policy (Policies)	9 Months Ended
Sep. 30, 2013
Accounting Policies [Abstract]
Business Description and Basis of Presentation [Text Block]	Celsion Corporation, referred to herein as “Celsion”, “We”, or “the Company,” a Delaware corporation based in Lawrenceville, New Jersey, is an oncology drug development company focused on improving treatment for those suffering with difficult-to-treat forms of cancer. We are working to develop and commercialize more efficient, effective, targeted chemotherapeutic oncology drugs based on our proprietary heat-activated liposomal technology. Our lead product ThermoDox®, is being tested in human clinical trials for the treatment of primary liver cancer, recurrent chest wall breast cancer and colorectal liver metastases.
Basis of Accounting, Policy [Policy Text Block]	The accompanying unaudited financial statements of Celsion have been prepared in accordance with generally accepted accounting principles (GAAP) in the United States for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. In the opinion of management, all adjustments, consisting only of normal recurring accruals considered necessary for a fair presentation, have been included in the accompanying unaudited financial statements. Operating results for the three and nine month periods ended September 30, 2013 are not necessarily indicative of the results that may be expected for any other interim period(s) or for any full year. For further information, refer to the financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2012 filed on March 18, 2013 and our Amendment No. 1 to the Annual Report on Form 10-K/A filed on April 30, 2013 with the Securities and Exchange Commission. The preparation of financial statements in conformity with GAAP requires management to make judgments, estimates, and assumptions that affect the amount reported in the Company’s financial statements and accompanying notes. Actual results could differ materially from those estimates. Events and conditions arising subsequent to the most recent balance sheet date have been evaluated for their possible impact on the financial statements and accompanying notes. On October 28, 2013, the Company effected a reverse stock split of the Company's common stock such that each 4.5 shares of issued common stock were reclassified into one share of common stock. All common stock share and per-share amounts for all periods presented in these financial statements have been adjusted to retroactively reflect the reverse stock split.
New Accounting Pronouncements, Policy [Policy Text Block]	From time to time, new accounting pronouncements are issued by Financial Accounting Standards Board (FASB) and are adopted by us as of the specified effective date. Unless otherwise discussed, we believe that the impact of recently issued accounting pronouncements will not have a material impact on the Company’s consolidated financial position, results of operations, and cash flows, or do not apply to our operations. In February 2013, the FASB issued Accounting Standards Update (ASU) No. 2013-02, Comprehensive Income (Topic 220): Reporting of Amounts Reclassified out of Accumulated Other Comprehensive Income , a new standard to improve the reporting of reclassifications out of accumulated other comprehensive income. The new standard requires the disclosure of significant amounts reclassified from each component of accumulated other comprehensive income and the income statement line items affected by the reclassification. The standard is effective prospectively for interim and annual periods beginning after December 15, 2012. The adoption of this guidance did not have a material effect on the financial statements on January 1, 2013, the date adopted.

Accounting Policies, by Policy (Policies)

9 Months Ended

Sep. 30, 2013

Business Description and Basis of Presentation [Text Block]

Celsion Corporation, referred to herein as “Celsion”, “We”, or “the Company,” a Delaware corporation based in Lawrenceville, New Jersey, is an oncology drug development company focused on improving treatment for those suffering with difficult-to-treat forms of cancer. We are working to develop and commercialize more efficient, effective, targeted chemotherapeutic oncology drugs based on our proprietary heat-activated liposomal technology. Our lead product ThermoDox®, is being tested in human clinical trials for the treatment of primary liver cancer, recurrent chest wall breast cancer and colorectal liver metastases.

Basis of Accounting, Policy [Policy Text Block]

The accompanying unaudited financial statements of Celsion have been prepared in accordance with generally accepted accounting principles (GAAP) in the United States for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations.

In the opinion of management, all adjustments, consisting only of normal recurring accruals considered necessary for a fair presentation, have been included in the accompanying unaudited financial statements. Operating results for the three and nine month periods ended September 30, 2013 are not necessarily indicative of the results that may be expected for any other interim period(s) or for any full year. For further information, refer to the financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2012 filed on March 18, 2013 and our Amendment No. 1 to the Annual Report on Form 10-K/A filed on April 30, 2013 with the Securities and Exchange Commission.

The preparation of financial statements in conformity with GAAP requires management to make judgments, estimates, and assumptions that affect the amount reported in the Company’s financial statements and accompanying notes. Actual results could differ materially from those estimates.

Events and conditions arising subsequent to the most recent balance sheet date have been evaluated for their possible impact on the financial statements and accompanying notes. On October 28, 2013, the Company effected a reverse stock split of the Company's common stock such that each 4.5 shares of issued common stock were reclassified into one share of common stock. All common stock share and per-share amounts for all periods presented in these financial statements have been adjusted to retroactively reflect the reverse stock split.

New Accounting Pronouncements, Policy [Policy Text Block]

From time to time, new accounting pronouncements are issued by Financial Accounting Standards Board (FASB) and are adopted by us as of the specified effective date. Unless otherwise discussed, we believe that the impact of recently issued accounting pronouncements will not have a material impact on the Company’s consolidated financial position, results of operations, and cash flows, or do not apply to our operations.

In February 2013, the FASB issued Accounting Standards Update (ASU) No. 2013-02, Comprehensive Income (Topic 220): Reporting of Amounts Reclassified out of Accumulated Other Comprehensive Income , a new standard to improve the reporting of reclassifications out of accumulated other comprehensive income. The new standard requires the disclosure of significant amounts reclassified from each component of accumulated other comprehensive income and the income statement line items affected by the reclassification. The standard is effective prospectively for interim and annual periods beginning after December 15, 2012. The adoption of this guidance did not have a material effect on the financial statements on January 1, 2013, the date adopted.