Annual report pursuant to Section 13 and 15(d)

Non-Controlling Interests - Summary Of Components of Non-Controlling Interests in Loss of Consolidated Entities (Detail)

v3.6.0.2
Non-Controlling Interests - Summary Of Components of Non-Controlling Interests in Loss of Consolidated Entities (Detail) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Noncontrolling Interest [Line Items]                      
Non-controlling interests in loss of consolidated entities $ 3,871 $ 3,975 $ 3,911 $ 4,438 $ 3,039 $ 1,694 $ 243 $ 479 $ (16,195) $ (5,455) $ 0
Avenue [Member]                      
Noncontrolling Interest [Line Items]                      
Non-controlling interests in loss of consolidated entities                 $ (349) $ (567)  
Non-controlling ownership 10.20%       11.50%       10.20% 11.50%  
Coronado SO Co, Inc [Member]                      
Noncontrolling Interest [Line Items]                      
Non-controlling interests in loss of consolidated entities                 $ (19) $ (240)  
Non-controlling ownership 13.00%       13.00%       13.00% 13.00%  
Mustang Therapeutics, Inc [Member]                      
Noncontrolling Interest [Line Items]                      
Non-controlling interests in loss of consolidated entities                 $ (1,805) $ (373)  
Non-controlling ownership 26.70%       10.00%       26.70% 10.00%  
Checkpoint Therapeutics, Inc [Member]                      
Noncontrolling Interest [Line Items]                      
Non-controlling interests in loss of consolidated entities                 $ (11,733) [1] $ (3,855)  
Non-controlling ownership [1] 62.90%       62.30%       62.90% 62.30%  
JMC [Member]                      
Noncontrolling Interest [Line Items]                      
Non-controlling interests in loss of consolidated entities                 $ (355) $ (420)  
Non-controlling ownership 7.00%       8.80%       7.00% 8.80%  
Helocyte [Member]                      
Noncontrolling Interest [Line Items]                      
Non-controlling interests in loss of consolidated entities                 $ (1,155)    
Non-controlling ownership 20.50%               20.50%    
Cellvation [Member]                      
Noncontrolling Interest [Line Items]                      
Non-controlling interests in loss of consolidated entities                 $ (158)    
Non-controlling ownership 22.00%               22.00%    
National Holdings [Member]                      
Noncontrolling Interest [Line Items]                      
Non-controlling interests in loss of consolidated entities                 $ (621)    
Non-controlling ownership 43.40%               43.40%    
[1] Checkpoint is consolidated with Fortress’ operations because Fortress maintains voting control through its ownership of Checkpoint’s Class A Common Shares which provide super-majority voting rights.