Annual report pursuant to Section 13 and 15(d)

Significant Accounting Policies - Additional information (Details)

v3.20.1
Significant Accounting Policies - Additional information (Details)
$ in Thousands
 1 Months Ended 12 Months Ended
Jan. 01, 2020
shares
Jan. 01, 2019
shares
Jul. 31, 2016
Jul. 31, 2016
shares
Dec. 31, 2019
USD ($)
segment
shares
Dec. 31, 2018
USD ($)
shares
Dec. 31, 2017
USD ($)
Class of Stock [Line Items]              
Number of operating segments | segment         1    
Number of reportable segments | segment         1    
Certificates of deposit         $ 0 $ 27,600  
Estimated useful life         5 years    
Property, plant and equipment, gross         $ 9,826 7,490  
Stock dividend (as a percent) 2.50% 2.00% 2.50%        
Research and development - licenses acquired         $ 6,273 $ 3,360  
Common stock dividend (in shares) | shares 1,206,667 709,314          
Common Stock, Shares, Issued | shares         39,403,519 26,610,183  
Restricted cash         $ 1,000 $ 500  
License Agreements [Member]              
Class of Stock [Line Items]              
Research and development - licenses acquired         $ 4,900 $ 2,100  
License Agreements [Member] | Fortress Biotech, Inc              
Class of Stock [Line Items]              
Research and development - licenses acquired             $ 9,600
Class A Preferred Shares              
Class of Stock [Line Items]              
Shares issued for services (in shares) | shares       250,000 0 0  
Stock Issued During Period, Shares, New Issues | shares         0    
Class A Common Shares              
Class of Stock [Line Items]              
Shares issued for services (in shares) | shares         0 0  
Common Stock, Shares, Issued | shares         845,385 1,000,000  
Stock Issued During Period, Shares, New Issues | shares         0    
Construction in Process              
Class of Stock [Line Items]              
Property, plant and equipment, gross         $ 1,157 $ 393  
Cash and Cash Equivalents [Member]              
Class of Stock [Line Items]              
Certificates of deposit           10,000  
Short-term Investments [Member]              
Class of Stock [Line Items]              
Certificates of deposit         $ 17,600 $ 17,600