Convertible Preferred Stock	12 Months Ended
Dec. 31, 2017
Equity [Abstract]
Convertible Preferred Stock	6. Convertible Preferred Stock On March 10, 2015, the Company converted from a Delaware limited liability company into a Delaware corporation and changed the Company’s name from Aeglea BioTherapeutics Holdings, LLC to Aeglea BioTherapeutics, Inc. In connection with the LLC Conversion, all of the Company’s outstanding common shares and convertible preferred shares were converted into shares of common stock and convertible preferred stock. No distributions were declared or paid by the Company prior to the LLC Conversion. Further, the outstanding Common B share awards were converted into a combination of vested and unvested restricted common stock and vested and unvested stock options with no changes to the vesting provisions (see Note 9). Upon the LLC Conversion, each then-outstanding Series A convertible preferred share was converted into one share of Series A convertible preferred stock, par value $0.0001 per share. The Company determined that the LLC Conversion resulted in a deemed dividend from stockholders of common stock to stockholders of Series A convertible preferred stock of $0.11 per share of Series A convertible preferred stock. The Company recorded $228,000 as an increase in the carrying amount of the Series A convertible preferred stock and as a reduction of additional paid-in capital. Such dividend was determined by comparing the fair value of the Series A convertible preferred shares immediately prior to the conversion to the fair value of the Series A convertible preferred stock issued in the conversion. Also on March 10, 2015, the Company issued 4,929,948 shares of Series B convertible preferred stock, par value $0.0001 per share, at an issuance price equal to $8.93 per share and received gross proceeds of $44.0 million. In connection with the financing, the Company incurred total offering costs of $321,000. On April 12, 2016, immediately prior to the closing of the IPO, all of the Company’s outstanding convertible preferred stock was automatically converted, at a ratio of one share of common stock for each share of convertible preferred stock, into an aggregate total of 7,172,496 shares of common stock with the related carrying value of $58.3 million reclassified to common stock and additional paid-in capital. As of December 31, 2017, there were no shares of preferred stock outstanding.

6. Convertible Preferred Stock

On March 10, 2015, the Company converted from a Delaware limited liability company into a Delaware corporation and changed the Company’s name from Aeglea BioTherapeutics Holdings, LLC to Aeglea BioTherapeutics, Inc. In connection with the LLC Conversion, all of the Company’s outstanding common shares and convertible preferred shares were converted into shares of common stock and convertible preferred stock. No distributions were declared or paid by the Company prior to the LLC Conversion. Further, the outstanding Common B share awards were converted into a combination of vested and unvested restricted common stock and vested and unvested stock options with no changes to the vesting provisions (see Note 9). Upon the LLC Conversion, each then-outstanding Series A convertible preferred share was converted into one share of Series A convertible preferred stock, par value $0.0001 per share. The Company determined that the LLC Conversion resulted in a deemed dividend from stockholders of common stock to stockholders of Series A convertible preferred stock of $0.11 per share of Series A convertible preferred stock. The Company recorded $228,000 as an increase in the carrying amount of the Series A convertible preferred stock and as a reduction of additional paid-in capital. Such dividend was determined by comparing the fair value of the Series A convertible preferred shares immediately prior to the conversion to the fair value of the Series A convertible preferred stock issued in the conversion.

Also on March 10, 2015, the Company issued 4,929,948 shares of Series B convertible preferred stock, par value $0.0001 per share, at an issuance price equal to $8.93 per share and received gross proceeds of $44.0 million. In connection with the financing, the Company incurred total offering costs of $321,000.

On April 12, 2016, immediately prior to the closing of the IPO, all of the Company’s outstanding convertible preferred stock was automatically converted, at a ratio of one share of common stock for each share of convertible preferred stock, into an aggregate total of 7,172,496 shares of common stock with the related carrying value of $58.3 million reclassified to common stock and additional paid-in capital. As of December 31, 2017, there were no shares of preferred stock outstanding.