Fortress Biotech, Inc. Quarterly report pursuant to Section 13 or 15(d)

Collaboration Agreement (Narrative) (Details) $ in Thousands		3 Months Ended		6 Months Ended
	Feb. 24, 2021 USD ($) Milestone	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Collaboration revenue		$ 577	$ 2,400	$ 1,154	$ 3,200
Accumulated deficit		(584,579)		(584,579)		$ (547,463)
Cash and cash equivalents		248,771	274,992	248,771	274,992	$ 305,744
Cyprium [Member] \| Sentynl Therapeutics, Inc [Member]
Upfront fees payment	$ 8,000
Payments of milestones	$ 12,000
Percentage of ownership over any FDA priority review voucher	100.00%
Number of net sales milestones \| Milestone	5
Collaboration revenue		$ 600	$ 2,400	$ 1,200	$ 3,200
FDA approval of the NDA [Member] \| Cyprium [Member] \| Sentynl Therapeutics, Inc [Member]
Payments of milestones	$ 9,000
Achievement of Certain Sales Milestones [Member] \| Cyprium [Member] \| Sentynl Therapeutics, Inc [Member]
Payments of milestones	255,000
Completion of Clinical Development Milestones [Member] \| Cyprium [Member] \| Sentynl Therapeutics, Inc [Member]
Payments of milestones	$ 3,000