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

Quarterly report pursuant to Section 13 or 15(d)

Partner Company Convertible Preferred Shares (Narrative) (Details)

Partner Company Convertible Preferred Shares (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended	6 Months Ended
	Jul. 31, 2021	Mar. 31, 2021	Mar. 31, 2021	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Stock offering, aggregate fees paid				$ 0	$ 793
Unamortized debt discount fees				7,737		$ 8,323
Journey [Member]
Stock offering, gross proceeds	$ 4,600
Stock offering, aggregate fees paid	500
Sale of stock, net proceeds	$ 4,200
Journey [Member] \| Contingent Payment Warrant [Member]
Change in fair value of warrants				200
Unamortized debt discount fees				$ 400
8% Cumulative Convertible Class A Preferred Stock [Member] \| Journey [Member]
Preferred Stock, dividend rate percentage		8.00%		8.00%
Number of common shares issuable as Preferred stock dividend				300,000
Common stock's average 10-day trading price discount percentage		7.50%
Stock offering, sales agreement termination date			Jul. 18, 2021
Stock offering, number of shares issued				573,280
Sale of stock, price per share				$ 25.00
Stock offering, gross proceeds				$ 14,300
Stock offering, aggregate fees paid				1,400
Payments of other stock issuance costs				300
Sale of stock, net proceeds				12,600
Partner company share-settled notes				14,300
Unamortized debt discount fees				$ 1,800
8% Cumulative Convertible Class A Preferred Stock [Member] \| Journey [Member] \| National Securities Corporation ("NSC") [Member]
Placement agent fee as a percentage of gross proceeds				10.00%
Percentage of common stock into which the Journey Preferred A converts				5.00%
8% Cumulative Convertible Class A Preferred Stock [Member] \| Journey [Member] \| Preferred Stock has not been Converted into Journey Common Stock [Member]
Preferred stock offering, aggregate proceeds		$ 25,000
8% Cumulative Convertible Class A Preferred Stock [Member] \| Journey [Member] \| Sale of Journey or a Qualified Financing [Member] \| National Securities Corporation ("NSC") [Member]
Percentage of common stock for which the Preferred A is exchanged				5.00%
8% Cumulative Convertible Class A Preferred Stock [Member] \| Journey [Member] \| Maximum [Member]
Preferred stock offering, aggregate proceeds		$ 30,000
8% Cumulative Convertible Class A Preferred Stock [Member] \| Journey [Member] \| Minimum [Member]
Preferred stock offering, aggregate proceeds			$ 12,500