Fortress Biotech, Inc. Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity (Capital Raises) (Narrative) (Details)

Stockholders' Equity (Capital Raises) (Narrative) (Details) - USD ($)						1 Months Ended		3 Months Ended
	May 07, 2024	Jan. 05, 2024	May 05, 2023	Dec. 30, 2022	Apr. 23, 2021	Jan. 31, 2024	Jul. 31, 2018	Mar. 31, 2024	Mar. 31, 2023	Feb. 28, 2023	Jan. 09, 2024	Dec. 31, 2023	Oct. 11, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued				4,900,000
Common Stock, par value				$ 0.0001				$ 0.001				$ 0.001
Sale of stock, net proceeds				$ 150,000,000.0
Proceeds from Issuance of Common Stock								$ 894,000	$ 447,000
Gain (loss) on common stock warrant liabilities								667,000	(6,678,000)
Aggregate purchase price								10,119,000	13,194,000
Exercise of warrants for cash								$ 30,000	$ 0
Avenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of warrants													$ 116.25
Gain (loss) on common stock warrant liabilities		$ 300,000
Avenue \| Series A Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, price per share											$ 22.545
Avenue \| Series B Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, price per share											$ 22.545
Urica \| Convertible Class B Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued										135,494
Stock offering, price per share										$ 25.00
Stock offering, gross proceeds										$ 3,400,000
Stock offering, aggregate fees paid										$ 500,000
Preferred Stock, dividend rate percentage										8.00%
At the Market Offering [Member] \| MLV & Co. and FBR Capital Markets & Co [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued								500,000	40,000
At the Market Offering [Member] \| Common Stock [Member] \| Cantor Fitzgerald & Co., Oppenheimer & Co., Inc., H.C. Wainwright & Co. Inc., Jones Trading Institutional Services LLC. B. Riley and Dawson James Securities, Inc [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, price per share								$ 1.99	$ 11.43
Stock offering, gross proceeds								$ 900,000	$ 500,000
At the Market Offering [Member] \| Journey \| Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued								300,000
Stock offering, price per share								$ 5.28
Number of Shares issuable for At-the-Market offering								3,861,553
Stock offering, gross proceeds								$ 1,500,000
At the Market Offering [Member] \| Checkpoint \| Common Stock [Member] \| Founders Agreement [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued								193,905
Share Price								$ 2.04
Shares issued (in percent)								2.50%
At the Market Offering [Member] \| Mustang \| Common Stock [Member] \| Founders Agreement [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued								0	0
At the Market Offering [Member] \| Avenue \| Common Stock [Member] \| Founders Agreement [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued								5,513
Share Price								$ 14.25
Shelf Registration Statement [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount available for future stock offerings								$ 88,200,000
Shelf Registration Statement [Member] \| Mustang
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, commission rate							3.00%
Amount available for future stock offerings								195,600,000
Shelf Registration Statement [Member] \| Maximum \| Mustang
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, aggregate offering permitted by the agreement					$ 200,000,000
Shelf Registration 2023 Statement [Member] \| Checkpoint
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount available for future stock offerings								77,700,000
Shelf Registration 2023 Statement [Member] \| Maximum \| Checkpoint
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, aggregate offering permitted by the agreement			$ 150,000,000
Shelf Registration 2021 Statement [Member] \| Avenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount available for future stock offerings								24,900,000
IPO [Member] \| Checkpoint \| Pre-Funded Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants exercised, Number of shares	(3,825,233)
Direct Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of warrants						$ 3.21
Warrant expiration term						5 years
Sale of stock, net proceeds						$ 10,200,000
Direct Offering [Member] \| Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued						3,303,305
Unit Price Per Share						$ 3.33
Direct Offering [Member] \| Checkpoint
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Sale of stock, net proceeds						$ 12,800,000
Direct Offering [Member] \| Checkpoint \| Common Stock Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of warrants						$ 1.68
Warrant expiration term						5 years
Direct Offering [Member] \| Checkpoint \| Pre-Funded Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants issued						6,481,233
Number of shares called by warrants						1
Stock offering, price per share						$ 1.8049
Exercise price of warrants						0.0001
Direct Offering [Member] \| Checkpoint \| Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, price per share						$ 1.805
Sale of stock, net proceeds						$ 1,275,000
Direct Offering [Member] \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of warrants to purchase shares						3,303,305
Direct Offering [Member] \| Maximum \| Checkpoint \| Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of warrants to purchase shares						7,756,233
Private Placement \| Avenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise of warrants for cash		$ 4,500,000
Private Placement \| Avenue \| Series A Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of warrants to purchase shares		220,538
Private Placement \| Avenue \| Series B Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of warrants to purchase shares		220,538
Private Placement \| Avenue \| January 2023 Warrants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of warrants to purchase shares		25,871
Exercise price of warrants		$ 116.25
Exercise price of warrants agreed by investor		$ 22.545
Fair value of warrants								600,000
Private Placement \| Avenue \| November 2023 Warrants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of warrants to purchase shares		194,667
Exercise price of warrants		$ 22.545
Exercise price of warrants agreed by investor		$ 22.545
Fair value of warrants								$ 4,300,000