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

Sponsored Research and Clinical Trial Agreements - summary of Mustang’s expense related to its sponsored research agreements (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Research And Development In Process	$ 1	$ 1,800	$ 98	$ 3,094
Mustang Therapeutics Inc [Member]
Research And Development In Process	1,290	2,076	2,680	2,605
COH CAR T [Member] \| Mustang Therapeutics Inc [Member]
Research And Development In Process	500	500	1,000	1,000
COH - CD123 [Member] \| Mustang Therapeutics Inc [Member]
Research And Development In Process	114	575	264	595
COH - IL13Ra2 [Member] \| Mustang Therapeutics Inc [Member]
Research And Development In Process	143	1,001	503	1,010
City of Hope - Manufacturing [Member] \| Mustang Therapeutics Inc [Member]
Research And Development In Process	115	0	229	0
Fred Hutch - CD20 [Member] \| Mustang Therapeutics Inc [Member]
Research And Development In Process	$ 418	$ 0	$ 684	$ 0