Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events - Additional Information (Detail)

v3.19.1
Subsequent Events - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 1 Months Ended 3 Months Ended
May 08, 2019
Apr. 30, 2019
Mar. 31, 2018
Mar. 31, 2019
Mar. 29, 2019
Dec. 31, 2018
Subsequent Event [Line Items]            
Common Stock, Shares, Issued       63,126,521   57,845,447
Common Stock, Par or Stated Value Per Share       $ 0.001   $ 0.001
Adjustments To Additional Paid In Capital At Market Offering Costs     $ (6)      
Class of Warrant or Right, Exercise Price of Warrants or Rights         $ 3.47  
Subsequent Event [Member] | Mustang Bio, Inc [Member]            
Subsequent Event [Line Items]            
Common Stock Shares Available For Future Issuance Value $ 20,900          
Subsequent Event [Member] | Market Offering [Member]            
Subsequent Event [Line Items]            
Proceeds from issuance of Common stock $ 22,500          
Common Stock, Shares, Issued 3,500,000          
Common Stock, Par or Stated Value Per Share $ 6.42          
Adjustments To Additional Paid In Capital At Market Offering Costs $ 400          
Subsequent Event [Member] | Over-Allotment Option [Member] | Mustang Bio, Inc [Member]            
Subsequent Event [Line Items]            
Stock Issued During Period, Value, New Issues   $ 31,600        
Stock Issued During Period, Shares, New Issues   6,875,000        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights   1,031,250        
Class of Warrant or Right, Exercise Price of Warrants or Rights   $ 4.00