Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

v3.7.0.1
Document and Entity Information - shares
6 Months Ended
Jun. 30, 2017
Aug. 03, 2017
Document And Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2017  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q2  
Trading Symbol CBAY  
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   43,756,968