Fortress Biotech, Inc. Annual report pursuant to Section 13 and 15(d)

Organization and Description of Business - Additional Information (Detail)

v3.19.1

Organization and Description of Business - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions				12 Months Ended
	Feb. 11, 2019	Nov. 14, 2018	Sep. 09, 2016	Dec. 31, 2018
Organization And Nature Of Business [Line Items]
Sale of Stock, Transaction Date	Feb. 11, 2019	Nov. 14, 2018
Sale of Stock, Number of Shares Issued in Transaction	4,000,000
National Holdings Corporation [Member]
Organization And Nature Of Business [Line Items]
Merger Agreement Minimum Percentage Of Shares In Tender Offer To Completed Merger			56.60%
Business Acquisition, Share Price			$ 3.25
Sale of Stock, Percentage of Ownership before Transaction		56.10%
Sale of Stock, Price Per Share		$ 3.25
Sale of Stock, Consideration Received on Transaction		$ 22.9
Sale of Stock, Consideration Received Per Transaction	$ 13.1	$ 9.8
Sale of Stock, Number of Shares Issued in Transaction	4.0	3.0
Sale of Stock, Percentage of Ownership after Transaction				32.10%
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares			7,000,000
Business Combination, Consideration Transferred			$ 22.9

- Definition

The minimum percentage of tender offer of shares has to be reached to complete the merger transaction.

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Number of shares of equity interests issued or issuable to acquire entity.

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Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

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Date the subsidiary or equity investee issued or sold stock, in CCYY-MM-DD format.

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