Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

v3.4.0.3
Document and Entity Information - shares
3 Months Ended
Mar. 31, 2016
May. 02, 2016
Document And Entity Information [Abstract]    
Entity Registrant Name XOMA Corp  
Entity Central Index Key 0000791908  
Current Fiscal Year End Date --12-31  
Entity Well-known Seasoned Issuer No  
Entity Filer Category Accelerated Filer  
Entity Common Stock, Shares Outstanding   120,367,541
Document Fiscal Year Focus 2016  
Document Fiscal Period Focus Q1  
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Mar. 31, 2016