| Document and Entity Information | Jun. 18, 2020 |
| Cover [Abstract] | |
| Entity Registrant Name | SANGAMO THERAPEUTICS, INC |
| Amendment Flag | true |
| Amendment Description | Amendment 1 |
| Entity Central Index Key | 0001001233 |
| Document Type | 8-K/A |
| Document Period End Date | Jun. 18, 2020 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 000-30171 |
| Entity Tax Identification Number | 68-0359556 |
| Entity Address, Address Line One | 7000 Marina Blvd |
| Entity Address, City or Town | Brisbane |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94005 |
| City Area Code | (510) |
| Local Phone Number | 970-6000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, $0.01 par value per share |
| Trading Symbol | SGMO |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
