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				3 Months Ended
	Apr. 01, 2025	Jun. 12, 2024	May 31, 2024	May 05, 2023	Dec. 30, 2022	Mar. 31, 2025	Feb. 28, 2025	Jan. 31, 2025	May 31, 2024	Mar. 31, 2025	Mar. 31, 2024	Mar. 09, 2025	Dec. 31, 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock offering, number of shares issued					4,900,000
Exercise of warrants for cash										$ 17	$ 30
Sale of stock, net proceeds					$ 150,000
Common Stock, par value					$ 0.0001	$ 0.001				$ 0.001			$ 0.001
Warrants exercised, Number of shares										10,000
Stock-based compensation expense										$ 6,289	4,857
Net proceeds from private placement										1,009	894
Pre funded warrants
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Warrants issued							2,162,807
Journey
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock-based compensation expense										1,323	1,406
Checkpoint
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Exercise price of warrants												$ 3.62
Number of warrants to purchase shares												5,853,659
Stock-based compensation expense										$ 1,956	709
Checkpoint \| Founder agreement with Mustang)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
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 [Line Items]
Exercise of warrants for cash						$ 36,000		$ 2,100
Number of shares issued upon exercise of warrants						21,691,003		740,000
Exercise price of warrants						$ 1.66		$ 2.84		$ 1.66
Mustang
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock-based compensation expense										$ 38	77
Avenue
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock-based compensation expense										185	191
Avenue \| Unregistered warrants
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Net proceeds									$ 3,900
Long-Term Incentive Program
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock-based compensation expense										$ 2,500	$ 1,700
At the Market Offering
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock offering, number of shares issued										500,000	500,000
Stock offering, price per share						$ 1.94				$ 1.94	$ 1.99
Stock offering, gross proceeds										$ 1,000	$ 900
At the Market Offering \| Journey
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock offering, number of shares issued										800,000
Stock offering, gross proceeds										$ 4,100
Number of Shares issuable for At-the-Market offering										1.8
At the Market Offering \| Avenue \| Founder agreement with Mustang)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock offering, number of shares issued			54,000							23,474
Shares issued (in percent)										2.50%
Sale of stock, net proceeds			$ 600
At the Market Offering \| Avenue \| Unregistered warrants
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares issued										900,000
Net proceeds										$ 2,100
Shelf Registration 2023 Statement \| Checkpoint
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Amount available for future stock offerings						$ 65,700				65,700
Shelf Registration 2023 Statement \| Maximum [Member] \| Checkpoint
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock offering, aggregate offering permitted by the agreement				$ 150,000
Shelf Registration 2024 Statement
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Amount available for future stock offerings						$ 42,100				42,100
Shelf Registration 2024 Statement \| Mustang
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock offering, aggregate offering permitted by the agreement										$ 34,200
Shelf Registration 2024 Statement \| Maximum [Member] \| Mustang
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
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 \| Subsequent events
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Dividend rate percentage	8.00%
Post effective amendment of Shelf Registration 2024 \| Maximum [Member] \| Subsequent events
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock offering, number of shares issued	1,987,250
Post effective amendment of Shelf Registration 2024, November Prospectus \| Subsequent events
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of share per unit issued	1
Number of warrants per unit issued	1
Post effective amendment of Shelf Registration 2024, November Prospectus \| Maximum [Member] \| Subsequent events
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock offering, number of shares issued	5,885,000
Post effective amendment of Shelf Registration 2024, December Prospectus \| Subsequent events
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of share per unit issued	1
Number of warrants per unit issued	1
Post effective amendment of Shelf Registration 2024, December Prospectus \| Maximum [Member] \| Subsequent events
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
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 [Line Items]
Stock offering, number of shares issued							67,806
Shares issued (in percent)							2.50%
February 2025 Equity Offering \| Mustang
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock offering, number of shares issued							495,000
Stock offering, price per share							$ 3.01
Exercise price of warrants							$ 3.01
Number of warrants to purchase shares							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 [Line Items]
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 [Line Items]
Number of warrants to purchase shares							2,657,807
Warrant expiration term							24 months
February 2025 Equity Offering \| Mustang \| Pre funded warrants
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock offering, price per share							$ 3.0099
Number of shares issued upon exercise of warrants							670,000
Exercise price of warrants							$ 0.0001
Prior Oaktree Agreement \| Maximum [Member] \| Subsequent events
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock offering, number of shares issued	116,637