Quarterly report pursuant to Section 13 or 15(d)

Capital Stock - Rights Offering 2019 (Details)

v3.20.1
Capital Stock - Rights Offering 2019 (Details) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 3 Months Ended 12 Months Ended
Dec. 02, 2019
Dec. 31, 2019
Mar. 31, 2020
Mar. 31, 2019
Dec. 31, 2019
Sale of stock          
Stock issuance costs     $ 166 $ 376  
Preferred stock, stated value (in dollars per share)   $ 0.05 $ 0.05   $ 0.05
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 | Xoma Corporation          
Sale of stock          
Ownership percentage on outstanding shares         55.60%
BVF | Common Stock | Xoma Corporation          
Sale of stock          
Ownership percentage on outstanding shares   27.10%     27.10%