Fortress Biotech, Inc. Annual report [Section 13 and 15(d), not S-K Item 405]

Annual report [Section 13 and 15(d), not S-K Item 405]

Asset Purchase and Merger Agreements (Narrative) (Details)

Asset Purchase and Merger Agreements (Narrative) (Details)						1 Months Ended			12 Months Ended
	Nov. 05, 2025 USD ($)	Jul. 28, 2025 USD ($)	May 13, 2025	Jul. 15, 2024 USD ($)	Feb. 24, 2021 USD ($)	Sep. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2023 D	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Nov. 30, 2025 USD ($)	Jul. 31, 2022 USD ($)
Business Combination [Line Items]
Gain from deconsolidation of subsidiary									$ 27,127,000	$ 0
Number of days to dispose of assets purchased			180 days
Collaboration revenue										1,500,000
Other									3,146,000	4,915,000
Assets held for sale									$ 0	1,165,000
Baergic
Business Combination [Line Items]
Gain from deconsolidation of subsidiary	$ 200,000
Disposal group, not discontinued operations \| Baergic
Business Combination [Line Items]
Upfront payment receivable											$ 300,000
Percentage of expected receivables to all future payments and royalties payable											74.00%
Crystalys Therapeutics, Inc
Business Combination [Line Items]
Capitalization in equity securities				$ 150,000,000
Crystalys Therapeutics, Inc \| UBriGene
Business Combination [Line Items]
Percentage of royalty on future net sales				3.00%
Urica's equity position									15.00%
Assets Sold under Agreements to Repurchase, Accretion Expense										700,000
Maximum \| Disposal group, not discontinued operations \| Baergic
Business Combination [Line Items]
Milestone payments receivable											$ 79,000,000
Mustang
Business Combination [Line Items]
Other									$ 1,300,000	1,300,000
Mustang \| UBriGene
Business Combination [Line Items]
Consideration transferred		$ 6,000,000					$ 4,700,000
Repurchased assets on relative fair value basis							2,200,000
Purchase price							1,400,000
Gain on sale of asset		1,400,000
Expenses related to transactions having to do with sale of assets.		$ 300,000
Upfront payment							100,000
Subsequent amount							$ 1,300,000
Subsequent payment due period							12 months
Asset acquisition consideration, threshold net assets considered for delay in subsequent payment							$ 20,000,000
Interest rate on outstanding liability							5.00%
Fair value of supplies received by partner company expensed to research and development							$ 2,500,000
Subsequent payment extended due period							6 months
Cyprium \| Development and Asset Purchase Agreement w/Sentynl
Business Combination [Line Items]
Consideration received					$ 8,000,000
Number of days to assume control over development of CUTX-101 in the event that CUTX-101 NDA approval has not been obtained					45			45
Collaboration revenue									1,500,000	4,500,000
Development and regulatory milestone payments receivable					$ 128,000,000
Urica
Business Combination [Line Items]
Percentage of equity to be held				35.00%
Repurchase option liability						$ 2,600,000
Urica \| Asset Purchase, Royalty And Related Agreements With Crystalis
Business Combination [Line Items]
Consideration transferred				$ 6,400,000
Reimbursement for clinical costs				600,000
Amount of minimum qualified financing required				$ 120,000,000
Urica \| Crystalys Therapeutics, Inc
Business Combination [Line Items]
Royalty Income									0	0
Urica's equity position				15.00%
Assets Sold under Agreements to Repurchase, Accretion Expense									1,300,000
Avenue \| Avenue Share Repurchase Agreement
Business Combination [Line Items]
Total payments made									1,400,000
Avenue \| InvaGen \| Avenue Share Repurchase Agreement
Business Combination [Line Items]
Percentage of contingent fee payable												7.50%
Contingent fee payable from proceeds of future financing												$ 4,000,000
Contingent fees paid										$ 700,000
Payments of milestones									$ 200,000
Annual net sales up to $75 million \| Cyprium \| Development and Asset Purchase Agreement w/Sentynl
Business Combination [Line Items]
Percentage of royalty on future net sales					3.00%
Annual net sales up to $75 million \| Cyprium \| Maximum \| Development and Asset Purchase Agreement w/Sentynl
Business Combination [Line Items]
Annual net sales as basis for milestone payments					$ 75,000,000
Annual net sales between $75 million and $100 million \| Cyprium \| Development and Asset Purchase Agreement w/Sentynl
Business Combination [Line Items]
Percentage of royalty on future net sales					8.75%
Annual net sales between $75 million and $100 million \| Cyprium \| Minimum \| Development and Asset Purchase Agreement w/Sentynl
Business Combination [Line Items]
Annual net sales as basis for milestone payments					$ 75,000,000
Annual net sales between $75 million and $100 million \| Cyprium \| Maximum \| Development and Asset Purchase Agreement w/Sentynl
Business Combination [Line Items]
Annual net sales as basis for milestone payments					$ 100,000,000
Annual net sales in excess of $100 million \| Cyprium \| Development and Asset Purchase Agreement w/Sentynl
Business Combination [Line Items]
Percentage of royalty on future net sales					12.50%
Annual net sales in excess of $100 million \| Cyprium \| Minimum \| Development and Asset Purchase Agreement w/Sentynl
Business Combination [Line Items]
Annual net sales as basis for milestone payments					$ 100,000,000
Upon occurrence of development and regulatory events \| Disposal group, not discontinued operations \| Baergic
Business Combination [Line Items]
Milestone payments receivable											2,500,000
Each indication after occurrence of development and regulatory events \| Disposal group, not discontinued operations \| Baergic
Business Combination [Line Items]
Milestone payments receivable											$ 1,500,000