Subsequent Event	3 Months Ended
Mar. 31, 2017
Subsequent Events [Abstract]
Subsequent Event	NOTE 10—SUBSEQUENT EVENT On May 10, 2017, Sangamo entered into a Collaboration and License Agreement (the “Pfizer Agreement”) with Pfizer Inc. (“Pfizer”), pursuant to which Sangamo and Pfizer established a collaboration for the research, development and commercialization of SB-525, Sangamo’s gene therapy product candidate for Hemophilia A, and closely related products. Under the Pfizer Agreement, Sangamo will be responsible for conducting the Phase 1/2 clinical trial and certain manufacturing activities for SB-525, while Pfizer will be responsible for subsequent worldwide development, manufacturing, marketing and commercialization of SB-525. Sangamo and Pfizer may also collaborate in the research and development of additional adeno-associated virus (“AAV”)-based gene therapy products for Hemophilia A. Under the Pfizer Agreement, Sangamo will receive an upfront fee of $70.0 million from Pfizer. In addition, Sangamo is eligible to receive development milestone payments contingent on the achievement of specified clinical development, intellectual property, regulatory and first commercial sale milestones for SB-525 and potentially other products. The total amount of potential clinical development, intellectual property, regulatory, and first commercial sale milestone payments, assuming the achievement of all specified milestones in the Pfizer Agreement, is $475.0 million, which includes up to $300.0 million for SB-525 and up to $175.0 million for other products that may be developed under the Pfizer Agreement, subject to reduction on account of payments made under certain licenses for third party intellectual property. In addition, Pfizer agrees to pay Sangamo royalties for each potential licensed product developed under the Pfizer Agreement that are an escalating tiered, double-digit percentage of the annual net sales of such product and are subject to reduction due to patent expiration, entry of biosimilar products to the market and payment made under certain licenses for third party intellectual property. Subject to the terms of the Pfizer Agreement, Sangamo will grant Pfizer an exclusive, worldwide, royalty-bearing license, with the right to grant sublicenses, to use certain technology controlled by Sangamo for the purpose of developing, manufacturing and commercializing SB-525 and related products. Under the Pfizer Agreement, Pfizer will grant Sangamo a non-exclusive, worldwide, royalty free, fully paid license, with the right to grant sublicenses, to use certain manufacturing technology developed under the Pfizer Agreement and controlled by Pfizer to manufacture Sangamo’s products that utilize the AAV delivery system. During a specified period, neither Sangamo nor Pfizer will be permitted to clinically develop or commercialize, outside of the collaboration, certain AAV-based gene therapy products for Hemophilia A.

NOTE 10—SUBSEQUENT EVENT

On May 10, 2017, Sangamo entered into a Collaboration and License Agreement (the “Pfizer Agreement”) with Pfizer Inc. (“Pfizer”), pursuant to which Sangamo and Pfizer established a collaboration for the research, development and commercialization of SB-525, Sangamo’s gene therapy product candidate for Hemophilia A, and closely related products.

Under the Pfizer Agreement, Sangamo will be responsible for conducting the Phase 1/2 clinical trial and certain manufacturing activities for SB-525, while Pfizer will be responsible for subsequent worldwide development, manufacturing, marketing and commercialization of SB-525. Sangamo and Pfizer may also collaborate in the research and development of additional adeno-associated virus (“AAV”)-based gene therapy products for Hemophilia A.

Under the Pfizer Agreement, Sangamo will receive an upfront fee of $70.0 million from Pfizer. In addition, Sangamo is eligible to receive development milestone payments contingent on the achievement of specified clinical development, intellectual property, regulatory and first commercial sale milestones for SB-525 and potentially other products. The total amount of potential clinical development, intellectual property, regulatory, and first commercial sale milestone payments, assuming the achievement of all specified milestones in the Pfizer Agreement, is $475.0 million, which includes up to $300.0 million for SB-525 and up to $175.0 million for other products that may be developed under the Pfizer Agreement, subject to reduction on account of payments made under certain licenses for third party intellectual property. In addition, Pfizer agrees to pay Sangamo royalties for each potential licensed product developed under the Pfizer Agreement that are an escalating tiered, double-digit percentage of the annual net sales of such product and are subject to reduction due to patent expiration, entry of biosimilar products to the market and payment made under certain licenses for third party intellectual property.

Subject to the terms of the Pfizer Agreement, Sangamo will grant Pfizer an exclusive, worldwide, royalty-bearing license, with the right to grant sublicenses, to use certain technology controlled by Sangamo for the purpose of developing, manufacturing and commercializing SB-525 and related products. Under the Pfizer Agreement, Pfizer will grant Sangamo a non-exclusive, worldwide, royalty free, fully paid license, with the right to grant sublicenses, to use certain manufacturing technology developed under the Pfizer Agreement and controlled by Pfizer to manufacture Sangamo’s products that utilize the AAV delivery system. During a specified period, neither Sangamo nor Pfizer will be permitted to clinically develop or commercialize, outside of the collaboration, certain AAV-based gene therapy products for Hemophilia A.