Quarterly report pursuant to Section 13 or 15(d)

Licensing and Other Arrangements - Novartis - Additional Information (Details)

v3.8.0.1
Licensing and Other Arrangements - Novartis - Additional Information (Details)
$ / shares in Units, € in Millions
 3 Months Ended 12 Months Ended
Aug. 24, 2017
USD ($)
Agreement
Obligation
$ / shares
shares
Aug. 24, 2017
EUR (€)
Agreement
Obligation
shares
Sep. 30, 2015
Mar. 31, 2018
USD ($)
Jun. 30, 2017
USD ($)
Dec. 31, 2017
USD ($)
Dec. 31, 2015
USD ($)
Novartis Pharma AG [Member]              
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]              
Upfront payment received $ 25,700,000            
Common stock aggregate fair value 4,800,000            
Common stock premium $ 200,000            
Number of license agreements | Agreement 2 2          
Number of performance obligations | Obligation 2 2          
License agreement transaction price $ 40,200,000            
Contract liabilities       $ 0   $ 0  
Contract assets       0   0  
Revenue recognize       0      
Capitalized contract costs       0      
Novartis Pharma AG [Member] | Licenses and Related Materials, Process and Know-How and Filings to Regulatory Authority [Member]              
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]              
Recognized the entire transaction price as revenue upon completion of delivery           40,200,000  
Novartis Pharma AG [Member] | Common Stock [Member]              
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]              
Cash received from sale of shares $ 5,000,000            
Number of shares sold | shares 539,131 539,131          
Sale of stock price per share | $ / shares $ 9.2742            
Common stock closing price | $ / shares $ 8.93            
Novartis Pharma AG [Member] | Les Laboratories Servier [Member]              
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]              
Repayments of debt $ 14,300,000 € 12.0          
Novartis Pharma AG [Member] | XOMA-052 License Agreement [Member]              
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]              
License agreement consideration received 30,000,000            
Upfront payment received 15,700,000            
Eligible milestone payments receivable upon achievement of development, regulatory and commercial milestones $ 438,000,000            
Agreement termination prior written notice period 6 months 6 months          
Novartis Pharma AG [Member] | IL-1 Target License Agreement [Member]              
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]              
Upfront payment received $ 10,000,000            
Novartis International [Member]              
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]              
Cash received from sale of shares $ 5,000,000            
Number of shares sold | shares 539,131 539,131          
Common stock aggregate fair value $ 4,800,000            
Common stock closing price | $ / shares $ 8.93            
Common stock premium $ 200,000            
Novartis International [Member] | License Agreement [Member]              
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]              
Eligible milestone payments receivable upon achievement of development, regulatory and commercial milestones       470,000,000      
Contract liabilities       0   0  
Contract assets       0   $ 0  
Revenue recognize       0      
Capitalized contract costs       $ 0      
Agreement termination notice period     180 days        
Upfront payment recognized as revenue             $ 37,000,000
Milestone received under the collaboration agreement         $ 10,000,000