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]

License Agreements (Narrative) (Details)

License Agreements (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions		1 Months Ended	12 Months Ended
	Feb. 28, 2023	Dec. 31, 2021	Dec. 31, 2024	Dec. 31, 2023
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payments of milestones			$ 0.7	$ 0.5
Avenue \| AnnJi Pharmaceutical Co
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Royalty expense	$ 3.0
Common shares issued (in shares)	11,089
Expenses recognized	$ 0.9
Stock offering, price per share	$ 2.1
Research and development expense	$ 0.9
Avenue \| AnnJi Pharmaceutical Co \| Additional Indication Milestones
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Common shares issued (in shares)	3,688
Avenue \| AnnJi Pharmaceutical Co \| Drug development milestones
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payments of milestones	$ 27.5
Avenue \| AnnJi Pharmaceutical Co \| Additional Sales Milestone Payments
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payments of milestones	165.0
Avenue \| Minimum \| AnnJi Pharmaceutical Co \| Additional Sales Milestone Payments
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Net sales milestones	75.0
Avenue \| Maximum \| AnnJi Pharmaceutical Co \| First Indication Milestones
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payments of milestones	10.8
Avenue \| Maximum \| AnnJi Pharmaceutical Co \| Additional Sales Milestone Payments
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Net sales milestones	750.0
Avenue \| Maximum \| DFD Agreement \| AnnJi Pharmaceutical Co \| Additional Indication Milestones
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payments of milestones	$ 14.5
Urica \| Licensing Agreements \| Fuji Yakuhin Co. Ltd
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payments of milestones		$ 3.0
One-time amendment payment				$ 0.3