Document And Entity Information (USD $)
12 Months Ended
Dec. 31, 2011
Feb. 01, 2012
Jun. 30, 2011
Document And Entity Information [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2011    
Document Fiscal Year Focus 2011    
Document Fiscal Period Focus FY    
Entity Registrant Name SANGAMO BIOSCIENCES INC    
Entity Central Index Key 0001001233    
Trading Symbol SGMO    
Entity Filer Category Accelerated Filer    
Current Fiscal Year End Date --12-31    
Entity Common Stock, Shares Outstanding   52,554,795  
Entity Well-known Seasoned Issuer No    
Entity Public Float     $ 294,045,039
Entity Current Reporting Status Yes    
Entity Voluntary Filers No