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

Revenues from Contracts and Significant Customers - Company's product revenue (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Sales Revenue, Goods, Net	$ 5,168		$ 17,366
Total Revenue	63,693	$ 46,886	182,952	$ 142,265
Parent Company [Member]
Total Revenue	5,173	$ 2,520	17,891	$ 9,702
TGTX [Member]
Sales Revenue, Goods, Net	5		525
Targadox [Member]
Sales Revenue, Goods, Net	4,322		16,183
Other branded revenue [Member]
Sales Revenue, Goods, Net	$ 846		$ 1,183