Nature of Operations and Basis of Presentation	9 Months Ended
Sep. 30, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Operations and Basis of Presentation	1. Nature of Operations and Basis of Presentation Discussion of the Business CoLucid Pharmaceuticals, Inc. (the “Company”) is a Phase 3 clinical-stage biopharmaceutical company that is developing an innovative and proprietary small molecule for the acute treatment of migraine headaches. The Company’s product candidates utilize the first new mechanism of action under development in the last twenty years that could address the unmet needs of migraine patients, including those with cardiovascular risk factors or stable cardiovascular disease and those who are dissatisfied with existing therapies. Lasmiditan, the Company’s lead product candidate, is an oral tablet for the acute treatment of migraine headaches in adults which is not expected to have the clinical limitations associated with the most commonly used therapies. The Company is also developing intravenous lasmiditan (“IV lasmiditan”) for the acute treatment of unspecified non-traumatic primary headache pain in adults in emergency room and other urgent care settings, another significant unmet medical need. The Company is conducting its first pivotal Phase 3 randomized, double-blind, placebo-controlled clinical trial of lasmiditan, under a special protocol assessment (“SPA”) agreement with the U.S. Food and Drug Administration with top-line data expected in the third quarter of 2016. The Company believes it has sufficient cash and cash equivalents to enable it to complete its two planned Phase 3 pivotal clinical trials, and initiate its long-term, open-label study of lasmiditan. The Company also estimates that such funds will support its operating expenses and capital expenditure requirements into mid-2017. The Company has never been profitable and has incurred net losses in each year since inception. The Company’s net losses were $3.0 million and $2.2 million for the years ended December 31, 2014 and 2013, respectively, and $19.5 million for the nine months ended September 30, 2015, and as of September 30, 2015 its accumulated deficit was $75.9 million. These net losses resulted primarily from research and development programs, including preclinical development activities and clinical trials, and general and administrative costs associated with operations. The Company expects to continue to incur significant expenses and increasing operating losses for at least the next several years. These net losses and negative operating cash flows have had, and will continue to have, an adverse effect on stockholders’ equity and working capital. Because of the numerous risks and uncertainties associated with pharmaceutical product development, the Company is unable to accurately predict the timing or amount of increased expenses or when, or if, it will be able to achieve or maintain profitability. The Company was incorporated on August 31, 2005 in the state of Delaware, with its current headquarters at 222 Third Street, Suite 1320 in Cambridge, Massachusetts. Initial Public Offering In connection with preparing for its initial public offering (“IPO”), the Company’s Board of Directors and stockholders approved a one-for-40.7 reverse stock split of the Company’s common stock. The reverse stock split became effective in April 2015. All share and per share amounts in these condensed interim financial statements and notes thereto have been retroactively adjusted for all periods presented to give effect to this reverse stock split, including reclassifying an amount equal to the reduction in par value of common stock to additional paid-in capital. On May 11, 2015, the Company closed an IPO of its common stock, which resulted in the sale of 5,500,000 shares of its common stock at a public offering price of $10.00 per share. The Company received net proceeds from the IPO of approximately $49.8 million, after deducting underwriting discounts and approximately $1.3 million of expenses paid by the Company. In connection with the closing of the IPO, all of the Company’s outstanding redeemable convertible preferred stock automatically converted to common stock on May 5, 2015, resulting in an additional 9,489,659 shares of common stock of the Company becoming outstanding. At September 30, 2015, the Company does not have any redeemable convertible preferred stock issued or outstanding. The significant increase in common stock outstanding in connection with the IPO is expected to impact the year-over-year comparability of the Company’s net loss per share calculations in future periods.

1. Nature of Operations and Basis of Presentation

Discussion of the Business

CoLucid Pharmaceuticals, Inc. (the “Company”) is a Phase 3 clinical-stage biopharmaceutical company that is developing an innovative and proprietary small molecule for the acute treatment of migraine headaches. The Company’s product candidates utilize the first new mechanism of action under development in the last twenty years that could address the unmet needs of migraine patients, including those with cardiovascular risk factors or stable cardiovascular disease and those who are dissatisfied with existing therapies. Lasmiditan, the Company’s lead product candidate, is an oral tablet for the acute treatment of migraine headaches in adults which is not expected to have the clinical limitations associated with the most commonly used therapies. The Company is also developing intravenous lasmiditan (“IV lasmiditan”) for the acute treatment of unspecified non-traumatic primary headache pain in adults in emergency room and other urgent care settings, another significant unmet medical need.

The Company is conducting its first pivotal Phase 3 randomized, double-blind, placebo-controlled clinical trial of lasmiditan, under a special protocol assessment (“SPA”) agreement with the U.S. Food and Drug Administration with top-line data expected in the third quarter of 2016.

The Company believes it has sufficient cash and cash equivalents to enable it to complete its two planned Phase 3 pivotal clinical trials, and initiate its long-term, open-label study of lasmiditan. The Company also estimates that such funds will support its operating expenses and capital expenditure requirements into mid-2017.

The Company has never been profitable and has incurred net losses in each year since inception. The Company’s net losses were $3.0 million and $2.2 million for the years ended December 31, 2014 and 2013, respectively, and $19.5 million for the nine months ended September 30, 2015, and as of September 30, 2015 its accumulated deficit was $75.9 million. These net losses resulted primarily from research and development programs, including preclinical development activities and clinical trials, and general and administrative costs associated with operations. The Company expects to continue to incur significant expenses and increasing operating losses for at least the next several years. These net losses and negative operating cash flows have had, and will continue to have, an adverse effect on stockholders’ equity and working capital. Because of the numerous risks and uncertainties associated with pharmaceutical product development, the Company is unable to accurately predict the timing or amount of increased expenses or when, or if, it will be able to achieve or maintain profitability.

The Company was incorporated on August 31, 2005 in the state of Delaware, with its current headquarters at 222 Third Street, Suite 1320 in Cambridge, Massachusetts.

Initial Public Offering

In connection with preparing for its initial public offering (“IPO”), the Company’s Board of Directors and stockholders approved a one-for-40.7 reverse stock split of the Company’s common stock. The reverse stock split became effective in April 2015. All share and per share amounts in these condensed interim financial statements and notes thereto have been retroactively adjusted for all periods presented to give effect to this reverse stock split, including reclassifying an amount equal to the reduction in par value of common stock to additional paid-in capital.

On May 11, 2015, the Company closed an IPO of its common stock, which resulted in the sale of 5,500,000 shares of its common stock at a public offering price of $10.00 per share. The Company received net proceeds from the IPO of approximately $49.8 million, after deducting underwriting discounts and approximately $1.3 million of expenses paid by the Company.

In connection with the closing of the IPO, all of the Company’s outstanding redeemable convertible preferred stock automatically converted to common stock on May 5, 2015, resulting in an additional 9,489,659 shares of common stock of the Company becoming outstanding. At September 30, 2015, the Company does not have any redeemable convertible preferred stock issued or outstanding. The significant increase in common stock outstanding in connection with the IPO is expected to impact the year-over-year comparability of the Company’s net loss per share calculations in future periods.