Nature of the Business and Basis of Presentation	9 Months Ended
Sep. 30, 2015
Accounting Policies [Abstract]
Nature of the Business and Basis of Presentation	1. Nature of the Business and Basis of Presentation Dimension Therapeutics, Inc. (the “Company”) was incorporated in Delaware on June 20, 2013. The Company is a gene therapy platform company focused on discovering and developing new therapeutic products for people living with rare diseases associated with the liver and caused by genetic mutations. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. As of September 30, 2015 and December 31, 2014, the Company had an accumulated deficit of $42,166 and $16,138, respectively. The Company expects to continue to generate operating losses in the foreseeable future. On October 27, 2015 the Company completed an initial public offering (“IPO”) of its common stock, which resulted in the issuance and sale of 5,500,000 shares of its common stock at a public offering price of $13.00 per share, resulting in net proceeds of approximately $63,445 after deducting underwriting discounts and other estimated offering costs. Upon the closing of the IPO, all outstanding shares of the Company’s Convertible Preferred Stock were automatically converted into 15,286,968 shares of the Company’s common stock. On November 25, 2015, the underwriters of the Company’s IPO exercised their over-allotment option to purchase an additional 104,775 shares of common stock at the initial public offering price of $13.00 per share, resulting in net proceeds of approximately $1,250, after deducting underwriting discounts and other estimated offering costs. The Company may seek additional funding through public or private financings, debt financing, collaboration agreements or government grants. The Company may not be able to obtain financing on acceptable terms, or at all, and the Company may not be able to enter into additional collaboration arrangements or obtain government grants. If the Company is unable to obtain funding, the Company could be forced to delay, reduce or eliminate its research and development programs, product portfolio expansion or commercialization efforts, which could adversely affect its business prospects. Although management continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all. The condensed financial statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”).

1. Nature of the Business and Basis of Presentation

Dimension Therapeutics, Inc. (the “Company”) was incorporated in Delaware on June 20, 2013. The Company is a gene therapy platform company focused on discovering and developing new therapeutic products for people living with rare diseases associated with the liver and caused by genetic mutations.

The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales.

As of September 30, 2015 and December 31, 2014, the Company had an accumulated deficit of $42,166 and $16,138, respectively. The Company expects to continue to generate operating losses in the foreseeable future. On October 27, 2015 the Company completed an initial public offering (“IPO”) of its common stock, which resulted in the issuance and sale of 5,500,000 shares of its common stock at a public offering price of $13.00 per share, resulting in net proceeds of approximately $63,445 after deducting underwriting discounts and other estimated offering costs. Upon the closing of the IPO, all outstanding shares of the Company’s Convertible Preferred Stock were automatically converted into 15,286,968 shares of the Company’s common stock. On November 25, 2015, the underwriters of the Company’s IPO exercised their over-allotment option to purchase an additional 104,775 shares of common stock at the initial public offering price of $13.00 per share, resulting in net proceeds of approximately $1,250, after deducting underwriting discounts and other estimated offering costs. The Company may seek additional funding through public or private financings, debt financing, collaboration agreements or government grants.

The Company may not be able to obtain financing on acceptable terms, or at all, and the Company may not be able to enter into additional collaboration arrangements or obtain government grants. If the Company is unable to obtain funding, the Company could be forced to delay, reduce or eliminate its research and development programs, product portfolio expansion or commercialization efforts, which could adversely affect its business prospects. Although management continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all.

The condensed financial statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”).