Mustang Bio, Inc. Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

Stockholders Equity (Common Stock and Equity Offerings) (Narrative) (Details)

Stockholders Equity (Common Stock and Equity Offerings) (Narrative) (Details)					12 Months Ended
	May 24, 2021 USD ($)	Dec. 04, 2019 USD ($)	Jul. 26, 2016 shares	Jul. 22, 2016	Dec. 31, 2022 USD ($) item $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 04, 2020 shares	Nov. 11, 2020 $ / shares shares	Nov. 10, 2020 shares	Jul. 13, 2018	Dec. 31, 2016 USD ($) shares
Stockholders' Equity
Common stock, shares authorized					200,000,000	150,000,000	125,000,000	125,000,000	85,000,000
Common stock par value (in dollars per share) \| $ / shares					$ 0.0001	$ 0.0001		$ 0.0001
Preferred stock, shares authorized					2,000,000	2,000,000
Preferred stock, shares issued					250,000	250,000
Aggregate value of shares subscribed \| $					$ 1,109,000	$ 4,329,000
Common stock, shares issuable					2,807,008	2,536,607
Shares available for future sale					413,990
Fortress Biotech, Inc [Member]
Stockholders' Equity
Issuance of common shares - Founders Agreement (in shares)					196,952	576,157
Sale of Stock aggregate offering price - Founders Agreement \| $					$ 6,600,000	$ 71,900,000
Percentage of fully diluted equity					2.50%	2.50%
Common shares issuable recorded - Founders Agreement						51,295
Expenses from related party transaction \| $					$ 1,000,000.0	$ 500,000
Aggregate value of shares subscribed \| $											$ 900
Common stock, shares issuable						51,295
Proceeds from issuance of common shares \| $					$ 6,600,000	$ 71,900,000
Stock dividend (as a percent)			2.50%
At the Market Offering [Member]
Stockholders' Equity
Agent commission (as a percent)										3.00%
Issuance of common shares (in shares)					7,900,000	19,400,000
Shares issued, price per share \| $ / shares					$ 0.84	$ 3.70
Proceeds from issuance of common shares \| $					$ 6,600,000	$ 71,900,000
Aggregate fees of stock issuance \| $					100,000	1,300,000
Proceeds from issuance of Common Stock, net of offering costs \| $					$ 6,500,000	$ 70,600,000
At the Market Offering [Member] \| Fortress Biotech, Inc [Member]
Stockholders' Equity
Issuance of common shares (in shares)					196,952	576,157
Shares issued, price per share \| $ / shares						$ 3.70
Registration Statements [Member]
Stockholders' Equity
Shelf Registration statement, value of securities authorized to be sold \| $		$ 100,000,000.0
Shares available for future issuance - Founders Agreement \| $					$ 8,000,000.0
Registration Statements [Member] \| Maximum
Stockholders' Equity
Shelf Registration statement, value of securities authorized to be sold \| $	$ 200,000,000.0
Common Stock [Member]
Stockholders' Equity
Number of votes per share \| item					1
Common Stock [Member] \| Fortress Biotech, Inc [Member]
Stockholders' Equity
Common stock, shares issuable											2,000,000
Class A Common Shares [Member]
Stockholders' Equity
Common stock, shares authorized						1,000,000
Director appointment right, period					10 years
Common stock, shares issued					845,385	845,385
Class B Common Shares [Member]
Stockholders' Equity
Number of votes per share \| item					1.1
Class B Common Shares [Member] \| Fortress Biotech, Inc [Member]
Stockholders' Equity
Number of shares converted			7,250,000
Common stock, shares issuable											7,000,000
Preferred Class A [Member]
Stockholders' Equity
Preferred stock, shares issued						250,000
Preferred Class A [Member] \| Fortress Biotech, Inc [Member]
Stockholders' Equity
Percentage of fully diluted equity				2.50%
Number of shares issued in conversion			250,000
General and administrative [Member] \| Fortress Biotech, Inc [Member]
Stockholders' Equity
Expenses from related party transaction \| $					$ 200,000	$ 1,900,000