Fortress Biotech, Inc. Quarterly report [Sections 13 or 15(d)]

Quarterly report [Sections 13 or 15(d)]

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

Stockholders' Equity (Capital Raises) (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands				1 Months Ended							5 Months Ended	9 Months Ended
	Apr. 01, 2025	Jun. 12, 2024	Dec. 30, 2022	Aug. 31, 2025	Jul. 31, 2025	Apr. 30, 2025	Mar. 31, 2025	Feb. 28, 2025	Jan. 31, 2025	May 31, 2024	May 31, 2025	Sep. 30, 2025	Sep. 30, 2024	Mar. 09, 2025	Dec. 31, 2024
Share-based Compensation Arrangement by Share-based Payment Award
Stock offering, number of shares issued			4,900,000
Exercise of warrants for cash												$ 2,279	$ 30
Sale of stock, net proceeds			$ 150,000
Warrants exercised, Number of shares												1,355,582
Outstanding warrants												13,050,619			14,406,201
Common Stock, par value			$ 0.0001									$ 0.001			$ 0.001
Series C-2 warrants
Share-based Compensation Arrangement by Share-based Payment Award
Outstanding warrants												284,452
Checkpoint
Share-based Compensation Arrangement by Share-based Payment Award
Exercise price of warrants														$ 3.62
Number of warrants to purchase shares														5,853,659
Checkpoint \| Founder agreement with Mustang)
Share-based Compensation Arrangement by Share-based Payment Award
Stock offering, number of shares issued											18,500
Shares issued (in percent)									2.50%
Checkpoint \| 2025 Warrant
Share-based Compensation Arrangement by Share-based Payment Award
Exercise of warrants for cash						$ 9,200	$ 36,000		$ 2,100
Number of shares issued upon exercise of warrants						3,256,269	21,691,003		740,000
Exercise price of warrants						$ 2.82	$ 1.66		$ 2.84
Avenue \| Unregistered warrants
Share-based Compensation Arrangement by Share-based Payment Award
Net proceeds										$ 3,900
At the Market Offering
Share-based Compensation Arrangement by Share-based Payment Award
Stock offering, number of shares issued				3,750,000								500,000	1,800,000
Stock purchase, price per share												$ 1.94	$ 1.95
Stock offering, gross proceeds												$ 1,000	$ 3,500
At the Market Offering \| Journey
Share-based Compensation Arrangement by Share-based Payment Award
Stock offering, number of shares issued												1,800,000
Stock offering, gross proceeds												$ 10,900
At the Market Offering \| Mustang \| Founder agreement with Mustang)
Share-based Compensation Arrangement by Share-based Payment Award
Stock offering, number of shares issued												54,000
Sale of stock, net proceeds												$ 600
At the Market Offering \| Avenue \| Founder agreement with Mustang)
Share-based Compensation Arrangement by Share-based Payment Award
Stock offering, number of shares issued												23,474
Shares issued (in percent)												2.50%
At the Market Offering \| Avenue \| Unregistered warrants
Share-based Compensation Arrangement by Share-based Payment Award
Shares issued												900,000
Net proceeds												$ 2,100
Shelf Registration 2024 Statement
Share-based Compensation Arrangement by Share-based Payment Award
Amount available for future stock offerings												42,100
Shelf Registration 2024 Statement \| Mustang
Share-based Compensation Arrangement by Share-based Payment Award
Stock offering, aggregate offering permitted by the agreement												$ 34,200
Shelf Registration 2024 Statement \| Maximum \| Mustang
Share-based Compensation Arrangement by Share-based Payment Award
Stock offering, aggregate offering permitted by the agreement		$ 40,000
Post effective amendment of Shelf Registration 2024 \| Urica \| 8% Cumulative Convertible Class B Preferred Offering
Share-based Compensation Arrangement by Share-based Payment Award
Dividend rate percentage	8.00%
Post effective amendment of Shelf Registration 2024 \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award
Stock offering, number of shares issued	1,987,250
Post effective amendment of Shelf Registration 2024, November Prospectus
Share-based Compensation Arrangement by Share-based Payment Award
Number of share per unit issued	1
Number of warrants per unit issued	1
Post effective amendment of Shelf Registration 2024, November Prospectus \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award
Stock offering, number of shares issued	5,885,000
Post effective amendment of Shelf Registration 2024, December Prospectus
Share-based Compensation Arrangement by Share-based Payment Award
Number of share per unit issued	1
Number of warrants per unit issued	1
Post effective amendment of Shelf Registration 2024, December Prospectus \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award
Stock offering, number of shares issued	3,303,305
February 2025 Equity Offering \| Checkpoint \| Founder agreement with Mustang)
Share-based Compensation Arrangement by Share-based Payment Award
Stock offering, number of shares issued								127,140
Shares issued (in percent)								2.50%
February 2025 Equity Offering \| Mustang
Share-based Compensation Arrangement by Share-based Payment Award
Stock offering, number of shares issued								495,000
Stock purchase, price per share								$ 3.01
Exercise of warrants for cash					$ 7,100
Exercise price of warrants								$ 3.01
Number of warrants to purchase shares					2,900,000			2,162,807
Sale of stock, net proceeds								$ 6,800
Common Stock, par value								$ 0.0001
February 2025 Equity Offering \| Mustang \| Series C-1 warrants
Share-based Compensation Arrangement by Share-based Payment Award
Number of warrants to purchase shares								2,657,807
Warrant expiration term								5 years
February 2025 Equity Offering \| Mustang \| Series C-2 warrants
Share-based Compensation Arrangement by Share-based Payment Award
Number of warrants to purchase shares								2,657,807
Warrant expiration term								24 months
Warrants exercised, Number of shares					2,400,000
February 2025 Equity Offering \| Mustang \| Pre funded warrants
Share-based Compensation Arrangement by Share-based Payment Award
Stock purchase, price per share								$ 3.0099
Exercise price of warrants								$ 0.0001
Warrants exercised, Number of shares					500,000
Prior Oaktree Agreement \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award
Stock offering, number of shares issued	116,637