STOCKHOLDERS’ EQUITY (Details Narrative) - USD ($)					12 Months Ended
	May 25, 2022	Apr. 06, 2022	Jan. 10, 2022	Mar. 19, 2021	Dec. 31, 2023	Dec. 31, 2022	Mar. 03, 2022	Feb. 28, 2022	Jan. 13, 2022
Class of Stock [Line Items]
Stock issued during period, value, new issues					$ 2,781,438	$ 6,722,654
Reverse stock split, description					On February 28, 2022, the Company effected a 15-for-1 reverse stock split of its common stock which was made effective for trading purposes as of the commencement of trading on March 31, 2022. As of that date, each 15 shares of issued and outstanding common stock and equivalents was consolidated into one share of common stock. All shares have been restated to reflect the effects of the 15-for-1 reverse stock split. In addition, at the market open on March 1, 2022, the Company’s common stock started trading under a new CUSIP number 15117N602 although the Company’s ticker symbol, CLSN, remained unchanged.
Stockholders equity note changes in capital structure description					To continue listing on The NASDAQ Capital Market, which requires that the Company comply with the applicable listing requirements under NASDAQ Marketplace Rules, which requirements include, among others, a minimum bid price of at least $1.00 per share. On December 2, 2021, the Company received a letter from NASDAQ indicating that the closing bid price of the Company’s common stock fell below $1.00 per share for the previous 30 consecutive business days, and that the Company was therefore not in compliance with the minimum bid price requirement for continued inclusion on The NASDAQ Capital Market. The Company had 180 calendar days, until May 31, 2022, to regain compliance with this requirement, which occurs when the closing bid price of the Company’s common stock is at least $1.00 per share for a minimum of ten consecutive business days during the 180-day compliance period.
Common stock, shares outstanding					9,399,789	7,436,197		86,557,736
Reverse stock split					5,770,516
Preferred stock, shares issued					0	0
Preferred stock, stated value			$ 300		$ 0.01	$ 0.01	$ 300
Proceeds from issuance of preferred stock			$ 28,500,000
Preferred stock, shares outstanding					0	0
Proceeds from issuance under placement					$ 1,000,000
Proceeds from issuance of common stock					$ 2,781,438	$ 6,722,654
Series A Convertible Redeemable Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares issued			50,000
Preferred stock, stated value			$ 0.01
Share price			$ 300
Original issue discount rate			5.00%
Preferred stock, conversion price			$ 13.65
Conversion of stock, shares issued			1,098,901
Preferred stock, shares outstanding							50,000
Series B Convertible Redeemable Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares issued			50,000
Preferred stock, stated value			$ 0.01
Share price			$ 285						$ 300
Proceeds from issuance of preferred stock			$ 14,250,000
Preferred stock, conversion price									$ 15.00
Conversion of stock, shares issued									1,000,000
Preferred stock, shares outstanding							50,000
Market Offering Agreement [Member]
Class of Stock [Line Items]
Stock issued during period, value, new issues	$ 7,500,000
Number of shares sold					1,904,142	336,075
Proceeds from sale of stock					$ 2,781,438	$ 503,798
Securities Purchase Agreement [Member] | April 2022 Registered Direct Offering [Member]
Class of Stock [Line Items]
Share price		$ 5.27
Stock issued, shares		1,328,274
Proceeds from issuance of common stock		$ 7,000,000.0
Placement agent fee description		In connection with the April 2022 Offering, the Company entered into a placement agent agreement with A.G.P./Alliance Global Partners (the “April 2022 Placement Agent”) pursuant to which the Company agreed to pay the April 2022 Placement Agent a cash fee equal to 6.5% of the aggregate gross proceeds raised from the sale of the securities sold in the April 2022 Offering and reimburse the April 2022 Placement Agent for certain of their expenses in an amount not to exceed $50,000.
Maximum [Member]
Class of Stock [Line Items]
Common stock, shares outstanding					6,600,000
Warrants issued					2,500,000
Proceeds from issuance under placement					$ 110,000
Minimum [Member]
Class of Stock [Line Items]
Common stock, shares outstanding					400,000
Warrants issued					200,000
2021 Registration Statement [Member]
Class of Stock [Line Items]
Stock issued during period, value, new issues				$ 100,000,000
Public float				75,000,000
2021 Registration Statement [Member] | Baby Shelf Limitation [Member]
Class of Stock [Line Items]
Public float				$ 75,000,000