Organization and Basis of Presentation - Additional Information (Details)						1 Months Ended	3 Months Ended		6 Months Ended	9 Months Ended
	Aug. 14, 2025 USD ($)	Aug. 12, 2025 USD ($) shares	Jun. 25, 2025 USD ($) $ / shares shares	Dec. 16, 2024 $ / shares shares	Aug. 05, 2022 USD ($)	Nov. 05, 2025 shares	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($) shares	Jun. 30, 2025 USD ($)	Sep. 30, 2025 USD ($) Candidate shares	Sep. 30, 2024 USD ($) shares	Dec. 31, 2024 USD ($)
Organization And Basis Of Presentation [Line Items]
Number of product candidates \| Candidate										2
Net Income (Loss)							$ (11,269,000)	$ (10,646,000)		$ (8,686,000)	$ (41,104,000)
Accumulated deficit							$ (200,891,000)			(200,891,000)		$ (192,205,000)
Stock Issued During Period, Value, New Issues								4,074,000		5,038,000	7,715,000
Net proceeds										5,038,000	7,715,000
Common Stock
Organization And Basis Of Presentation [Line Items]
Stock Issued During Period, Value, New Issues								$ 7,000		$ 10,000	$ 13,000
Shares of common stock sold and issued \| shares								683,851		987,772	1,268,741
Underwriters' Overallotment Option \| Common Stock
Organization And Basis Of Presentation [Line Items]
Shares of common stock sold and issued \| shares				2,000,000
December 2024 Public Offering
Organization And Basis Of Presentation [Line Items]
Gross proceeds before deducting underwriting discounts and commissions, and offering expenses									$ 92,000,000
December 2024 Public Offering \| Common Stock
Organization And Basis Of Presentation [Line Items]
Shares of common stock sold and issued \| shares				12,000,001
Public offering price \| $ / shares				$ 6
Common stock, public offering price \| $ / shares				0.01
December 2024 Public Offering \| Pre-funded warrants
Organization And Basis Of Presentation [Line Items]
Class of warrants issued per share \| $ / shares				$ 5.99
Number of warrants outstanding \| shares				3,333,333
Combination of Common Stock, Preferred Stock, Debt Securities, Warrants and/or Units \| Maximum [Member]
Organization And Basis Of Presentation [Line Items]
Stock Issued During Period, Value, New Issues	$ 300,000,000				$ 200,000,000
ATM Program
Organization And Basis Of Presentation [Line Items]
Shares of common stock sold and issued \| shares		3,923,829
Net proceeds		$ 20,900,000
ATM Program \| Maximum [Member]
Organization And Basis Of Presentation [Line Items]
Stock Issued During Period, Value, New Issues	50,000,000				75,000,000
2022 ATM Program
Organization And Basis Of Presentation [Line Items]
Shares of common stock sold and issued \| shares		3,923,829
Net proceeds		$ 20,900,000
2022 ATM Program \| Maximum [Member]
Organization And Basis Of Presentation [Line Items]
Stock Issued During Period, Value, New Issues					$ 75,000,000
2025 ATM Program \| Common Stock \| Subsequent Event
Organization And Basis Of Presentation [Line Items]
Shares of common stock sold and issued \| shares						0
2025 ATM Program \| Maximum [Member]
Organization And Basis Of Presentation [Line Items]
Stock Issued During Period, Value, New Issues	$ 50,000,000
Registered Direct Offering \| Common Stock
Organization And Basis Of Presentation [Line Items]
Shares of common stock sold and issued \| shares			3,221,395
Public offering price \| $ / shares			$ 4.67
Gross proceeds before deducting underwriting discounts and commissions, and offering expenses			$ 15,000,000

Candel Therapeutics, Inc. 10-Q