Fortress Biotech, Inc. Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

Debt and Interest (Narrative) (Details)

Debt and Interest (Narrative) (Details)						1 Months Ended					12 Months Ended
Debt and Interest (Narrative) (Details)	Dec. 31, 2025 USD ($)	Apr. 11, 2023 USD ($)	Dec. 27, 2022 USD ($) $ / shares shares	Aug. 27, 2020 USD ($) shares	Dec. 27, 2003 USD ($)	Feb. 28, 2026	Nov. 30, 2023 USD ($) $ / shares shares	Oct. 31, 2023 USD ($) shares	Aug. 31, 2022 USD ($)	Jan. 31, 2022 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Jun. 13, 2023 $ / shares	Mar. 31, 2021 USD ($)	Aug. 29, 2020 $ / shares shares
Debt Instrument [Line Items]
Sale of stock, net proceeds							$ 8,900,000	$ 10,000,000.0
Total notes payable											$ 60,856,000	$ 91,730,000
Unamortized debt discount fees											4,144,000	9,320,000
Debt instrument, interest expense											11,915,000	10,417,000
Repayments of debt											50,375,000	0
Letter of credit, amount outstanding											2,400,000	2,700,000
Number of shares called by warrants \| shares							1
Exercise price of warrants \| $ / shares							$ 1.70						$ 8.136
Fair Value Adjustment of Warrants											(4,424,000)	(1,129,000)
Amortization of Debt Issuance Costs											3,400,000	2,065,000
Warrant expiration term							5 years
Amortization of debt discount											3,032,000	2,065,000
Loss on extinguishment of debt											$ (2,796,000)	0
Debt Instrument, Repayment Period from February 2027 If Total Revenue Measured on Trailing Twelve Month Basis is Greater than Threshold Revenue as of December 31, 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Percentage of Principal Amount						15.00%
Debt Instrument, Threshold Revenue Considered for No Periodic Payment	$ 70,000,000.0
IDB Note Payable
Debt Instrument [Line Items]
Percent of Outstanding Loan Principal Amount for Calculation of Repayment Change											7.50%
Interest expense											$ 300,000
IDB Note Payable \| Letter of Credit
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage											2.00%
Oaktree Note
Debt Instrument [Line Items]
Debt instrument face amount				$ 60,000,000.0
Debt instrument, interest expense											$ 5,561,000	5,561,000
Debt Instrument, Interest Rate, Stated Percentage				11.00%							11.00%
Debt maturity date				Aug. 27, 2025
Percentage of upfront commitment fee				3.00%
Upfront Commitment Fee				$ 1,800,000
Debt issuance fees											$ 8,700,000
Agency fees payment				35,000
Payment of expenses to third parties				$ 2,500,000
Exercise price of warrants \| $ / shares															$ 48.00
Warrants issued \| shares				116,624
Warrants, fair value				$ 4,400,000
Amortization of Debt Issuance Costs											2,073,000	1,532,000
Amortization of debt discount											$ 2,100,000	1,500,000
Oaktree Note \| Minimum
Debt Instrument [Line Items]
Warrants issued \| shares															100,000
EWB Term Loan
Debt Instrument [Line Items]
Amount outstanding														$ 10,000,000
Proceeds from debt									$ 5,000,000	$ 15,000,000
Debt instrument face amount														$ 20,000,000.0
Debt Instrument, Interest Rate, Stated Percentage											10.20%
Repayments of debt											$ 20,000,000
Interest expense											$ 2,800,000
Runway Note
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage											13.80%
Partner company notes payable
Debt Instrument [Line Items]
Debt instrument, interest expense											$ 4,856,000	4,021,000
Amortization of Debt Issuance Costs											$ 492,000	$ 533,000
SWK Term Loan [Member]
Debt Instrument [Line Items]
Debt, effective interest rate											15.10%
Debt Instrument, Interest Rate, Stated Percentage											15.10%
Maximum borrowing capacity					$ 20,000,000.0
Proceeds from Lines of Credit					15,000,000
Debt Instrument, Percentage of Exit Fees											5.00%
Payments of Debt Issuance Costs											$ 200,000
Amortization of Debt Issuance Costs											$ 200,000
Remaining borrowing capacity					$ 5,000,000.0
SWK Term Loan [Member] \| Debt Instrument, Repayment Period from February 2027 If Total Revenue Measured on Trailing Twelve Month Basis is Greater than Threshold Revenue as of December 31, 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Percentage of Principal Amount						7.50%
SWK Term Loan [Member] \| If Debt Insturment Prepaid Prior To First Anniversary Of Closing Date [Member]
Debt Instrument [Line Items]
Debt Instrument, Percentage of Prepayment Premium											2.00%
SWK Term Loan [Member] \| If Debt Instrument Prepaid On Or After First Anniversary But Prior To Second Anniversary Of Closing Date [Member]
Debt Instrument [Line Items]
Debt Instrument, Percentage of Prepayment Premium											1.00%
SWK Term Loan [Member] \| If Debt Instrument Prepaid After Second Anniversary Of Closing Date [Member]
Debt Instrument [Line Items]
Debt Instrument, Percentage of Prepayment Premium											0.00%
SWK Term Loan [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Debt Instrument [Line Items]
Debt Instrument, Floor Rate					5
Basis spread on variable rate					7.75%
Interest Expense
Debt Instrument [Line Items]
Fair Value Adjustment of Warrants											$ 300,000
Mustang
Debt Instrument [Line Items]
Common shares issued (in shares) \| shares								920,000
Stock offering, aggregate fees paid								$ 500,000
Mustang \| Maximum
Debt Instrument [Line Items]
Warrant expiration term								5 years 6 months
Mustang \| Runway Note
Debt Instrument [Line Items]
Term Loan payoff amount		$ 30,400,000
Urica \| Placement Agent Warrants
Debt Instrument [Line Items]
Fair Value Adjustment of Warrants											$ 52,000
Urica \| 8% Cumulative Convertible Class B Preferred Offering
Debt Instrument [Line Items]
Warrants, fair value			$ 100,000
Stock offering, number of shares issued \| shares			135,494
Stock offering, gross proceeds			$ 3,400,000
Stock offering, aggregate fees paid			$ 500,000
Stock offering, price per share \| $ / shares			$ 25.00
Preferred Stock, dividend rate percentage			8.00%
Aggregate gross proceeds from convertible preferred stock			$ 20,000,000
Percentage of discounted price			20.00%
Percentage of placement agents fees			10.00%
Percentage of number of securities into which warrants converted			10.00%
Percentage of common stock which can be exchanged for preferred stock			10.00%