Quarterly report pursuant to Section 13 or 15(d)

Capital Stock - Rights Offering 2019 (Details)

v3.20.2
Capital Stock - Rights Offering 2019 (Details) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 9 Months Ended 12 Months Ended
Dec. 02, 2019
Dec. 31, 2019
Sep. 30, 2020
Sep. 30, 2019
Dec. 31, 2019
Feb. 29, 2020
Sale of stock            
Stock issuance costs     $ 231 $ 377    
Preferred stock, stated value (in dollars per share)   $ 0.05 $ 0.05   $ 0.05  
Series Y Preferred Stock | BVF            
Sale of stock            
Beneficial ownership limitation (as a percent)           50.00%
2019 Rights Offering            
Sale of stock            
Aggregate gross proceeds from issuance of common stock and preferred stock $ 22,000 $ 22,000        
Stock issuance costs   200        
Net proceeds from issuance of stock   $ 21,800        
2019 Rights Offering | BVF            
Sale of stock            
Legal fees and expenses         $ 18  
2019 Rights Offering | Common Stock            
Sale of stock            
Total number of shares issued   1,000,000        
2019 Rights Offering | Common Stock | BVF            
Sale of stock            
Total number of shares issued   845,463        
Purchase price (in dollars per share)   $ 22.00     $ 22.00  
BVF | Common Stock | Xoma Corporation            
Sale of stock            
Ownership percentage on outstanding shares     37.90%      
Ownership interest, if shares are converted (as a percent)     57.30%