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

Quarterly report pursuant to Section 13 or 15(d)

Licenses Acquired - license as recorded in the Condensed Consolidated Statements of Operations (Detail)

Licenses Acquired - license as recorded in the Condensed Consolidated Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Research and Development in Process		$ 0
Parent Company [Member]
Research and Development in Process	$ 3,706	300	$ 3,804	$ 3,394
Checkpoint Therapeutics, Inc [Member]
Research and Development in Process	1,000	0	1,000	400
Checkpoint Therapeutics, Inc [Member] \| Jubilant Biosys License CK-103 [Member]
Research and Development in Process	0	0	0	400
Checkpoint Therapeutics, Inc [Member] \| Dana Farber License CK-301 [Member]
Research and Development in Process	1,000	0	1,000	0
Mustang Therapeutics, Inc [Member]
Research and Development in Process	1,407	1,424	4,087	4,029
Mustang Therapeutics, Inc [Member] \| Parent Company [Member]
Research and Development in Process	1,000	300	1,075	2,375
Mustang Therapeutics, Inc [Member] \| City of Hope (COH) IL-13 License [Member]
Research and Development in Process	0	0	0	250
Mustang Therapeutics, Inc [Member] \| COH IV/ICV License [Member]
Research and Development in Process	0	0	0	125
Mustang Therapeutics, Inc [Member] \| COH HER2 License [Member]
Research and Development in Process	0	0	0	600
Mustang Therapeutics, Inc [Member] \| COH CS-1 License [Member]
Research and Development in Process	0	0	0	600
Mustang Therapeutics, Inc [Member] \| COH License for PSCA [Member]
Research and Development in Process	0	0	0	300
Mustang Therapeutics, Inc [Member] \| UCLA License for PSCA [Member]
Research and Development in Process	0	0	0	200
Mustang Therapeutics, Inc [Member] \| Fred Hutch CD20 [Member]
Research and Development in Process	0	300	0	300
Mustang Therapeutics, Inc [Member] \| X-SCID License – St. Jude's [Member]
Research and Development in Process	1,000	0	1,000	0
Mustang Therapeutics, Inc [Member] \| Manufacturing License [Member]
Research and Development in Process	$ 0	$ 0	$ 75	$ 0