Note 5 - Acquisition of EGEN, Inc. (Details) - Fair Value of Consideration (USD $)	0 Months Ended	1 Months Ended	12 Months Ended
	Dec. 31, 2014	Jun. 20, 2014	Dec. 31, 2014
Consideration Paid at Closing
Cash, net of cash acquired			$ 2,820,649
Celsion common stock (2,712,188 shares valued at $3.48 which was the last closing price of our common stock at the time of closing the transaction on June 20, 2014)			10,850,977
Future Consideration
Earn-Out Payments (at fair value*)			13,878,204
EGEN, Inc. [Member]
Consideration Paid at Closing
Cash, net of cash acquired			2,821,000
Celsion common stock (2,712,188 shares valued at $3.48 which was the last closing price of our common stock at the time of closing the transaction on June 20, 2014)			9,438,000
Future Consideration
Holdback Shares (670,070 shares of Celsion common stock which were discounted by 38% to reflect the cost of the restriction)			1,441,000
Earn-Out Payments (at fair value*)	13,700,000	13,900,000	13,878,000	[1]
Total fair value of consideration		$ 27,600,000	$ 27,578,000

[1] The total aggregate purchase price for the Egen Acquisition included potential future Earn-Out Payments contingent upon achievement of certain milestones. The difference between the aggregate $30.4 million in future Earn-Out Payments and the $13.9 million included in the fair value of the acquisition consideration at June 20, 2014 was based on the Company's risk-adjusted assessment of each milestone and utilizing a discount rate based on the estimated time to achieve the milestone. These milestone payments will be fair valued at the end of each quarter and any change in their value will be recognized in the financial statement. As of December 31, 2014, the Company fair valued these milestones at $13.7 million and recognized a gain of $231,949 as a result of the change in the fair value of these milestones from June 30, 2014.