Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

v2.4.0.8
Document and Entity Information
9 Months Ended
Sep. 30, 2014
Oct. 31, 2014
Document And Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2014  
Document Fiscal Year Focus 2014  
Document Fiscal Period Focus Q3  
Trading Symbol CYMA  
Entity Registrant Name CymaBay Therapeutics, Inc.  
Entity Central Index Key 0001042074  
Current Fiscal Year End Date --12-31  
Entity Filer Category Smaller Reporting Company  
Entity Common Stock, Shares Outstanding   14,686,969