Stockholders' Equity	3 Months Ended
Mar. 31, 2019
Equity [Abstract]
Stockholders' Equity	NOTE 9—STOCKHOLDERS’ EQUITY Common Stock In April 2018, Sangamo completed an underwritten public offering of its common stock, in which the Company sold an aggregate of 14.2 million shares of its common stock at a public offering price of $16.25 per share. The net proceeds to Sangamo from the sale of shares in this offering, after deducting underwriting discounts and commissions and other estimated offering expenses, were approximately $215.8 million. At-the-Market Offering Agreements On December 7, 2016, the Company entered into an “at-the-market” offering agreement with Cowen and Company, LLC (“Cowen”), pursuant to which the Company may issue and sell from time to time up to $75.0 million of the Company’s common stock through the bank as the sales agent (the “ATM Agreement”). In May 2017, the Company entered into an amended and restated sales agreement with Cowen pursuant to which the Company may offer and sell, in its sole discretion, shares of common stock having an aggregate offering price of up to $75.0 million through Cowen acting as the sales agent (the “ATM Facility”). Sales of the Company’s common stock, if any, will be made at market prices by any method that is deemed to be an “at-the-market offering” as defined in Rule 415 under the Securities Act of 1933, as amended. The Company has not sold any common stock under the ATM Facility. As of March 31, 2019, the full $75.0 million provided for under the ATM Facility remained available for sale, subject to certain conditions as specified in the agreement.

Stockholders' Equity

3 Months Ended

Mar. 31, 2019

NOTE 9—STOCKHOLDERS’ EQUITY

Common Stock

In April 2018, Sangamo completed an underwritten public offering of its common stock, in which the Company sold an aggregate of 14.2 million shares of its common stock at a public offering price of $16.25 per share. The net proceeds to Sangamo from the sale of shares in this offering, after deducting underwriting discounts and commissions and other estimated offering expenses, were approximately $215.8 million.

At-the-Market Offering Agreements

On December 7, 2016, the Company entered into an “at-the-market” offering agreement with Cowen and Company, LLC (“Cowen”), pursuant to which the Company may issue and sell from time to time up to $75.0 million of the Company’s common stock through the bank as the sales agent (the “ATM Agreement”).

In May 2017, the Company entered into an amended and restated sales agreement with Cowen pursuant to which the Company may offer and sell, in its sole discretion, shares of common stock having an aggregate offering price of up to $75.0 million through Cowen acting as the sales agent (the “ATM Facility”). Sales of the Company’s common stock, if any, will be made at market prices by any method that is deemed to be an “at-the-market offering” as defined in Rule 415 under the Securities Act of 1933, as amended. The Company has not sold any common stock under the ATM Facility. As of March 31, 2019, the full $75.0 million provided for under the ATM Facility remained available for sale, subject to certain conditions as specified in the agreement.