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

Collaboration Agreement (Narrative) (Details) $ in Thousands		3 Months Ended		9 Months Ended
	Feb. 24, 2021 USD ($) Milestone	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Collaboration revenue		$ 364	$ 1,446	$ 1,518	$ 4,646
Accumulated deficit		(607,090)		(607,090)		$ (547,463)
Cash and cash equivalents		208,351	252,721	208,351	252,721	$ 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		$ 400	$ 1,400	$ 1,500	$ 4,600
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