Description of Business	9 Months Ended
Description of Business	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business On June 4, 1999, NewLink Genetics Corporation (NewLink) was incorporated as a Delaware corporation. NewLink was formed to develop treatments for patients with cancer and other diseases. NewLink initiated operations in April 2000. NewLink and its subsidiaries (the Company) have historically devoted substantially all of their efforts toward research and development. The Company has never earned revenue from commercial sales of its drugs. The accompanying condensed consolidated financial statements as of September 30, 2019 and for the three and nine months ended September 30, 2019 have been prepared assuming the Company will continue as a going concern. The Company’s cash and cash equivalents as of September 30, 2019 are expected to be adequate to satisfy the Company’s liquidity requirements through 2021. If available liquidity becomes insufficient to meet the Company’s operating obligations as they come due, the Company’s plans include selling additional shares of common stock, alternative funding arrangements and/or reducing expenditures as necessary to meet the Company’s cash requirements. However, there is no assurance that, if required, the Company will be able to raise additional capital or reduce discretionary spending to provide the required liquidity. Failure by the Company to successfully execute its plans or otherwise address its liquidity needs may have a material adverse effect on its business and financial position and may materially affect the Company’s ability to continue as a going concern. Proposed Merger with Lumos Pharma On September 30, 2019, the Company, Cyclone Merger Sub, Inc., a wholly-owned subsidiary of the Company (Merger Sub), and Lumos Pharma, Inc., a privately-held Delaware corporation (Lumos), entered into an Agreement and Plan of Merger and Reorganization (the Merger Agreement), pursuant to which, among other things, subject to the satisfaction or waiver of the conditions set forth in the Merger Agreement, Merger Sub will merge with and into Lumos, with Lumos surviving as a wholly-owned subsidiary of NewLink (the Merger). Following the Merger, NewLink will change its name to “Lumos Pharma, Inc.” and Lumos will change its name to a name mutually agreed upon by the Company and Lumos. At the effective time of the Merger (Effective Time), each share of Lumos capital stock outstanding immediately prior to the Effective Time (excluding shares of Lumos capital stock held as treasury stock or held or owned by Lumos or Merger Sub prior to the Effective Time and shares held by Lumos stockholders who have exercised and perfected appraisal rights in accordance with Delaware law) shall be automatically converted solely into the right to receive a number of shares of NewLink’s common stock equal to the amount determined pursuant to a charter amendment to Lumos’ certificate of incorporation that will be filed prior to the Effective Time, at exchange ratios applicable to each type of Lumos capital stock. Pursuant to such conversion, immediately following the Merger, former Lumos stockholders will own approximately 50% of the aggregate number of shares of Company common stock issued and outstanding following the consummation of the Merger (the Post-Closing Shares), and the stockholders of the Company as of immediately prior to the Merger are expected to own approximately 50% of the aggregate number of Post-Closing Shares. Outstanding options to purchase Lumos common stock will be assumed by NewLink and converted into options to purchase a number of shares of NewLink’s common stock at the exchange ratio applicable to exchanging shares of Lumos common stock for NewLink’s common stock. The Merger Agreement includes customary representations, warranties and covenants made by the Company and Lumos, including covenants relating to the Company's and Lumos' conduct of their respective businesses between the date of signing the Merger Agreement and the closing of the Merger. Consummation of the Merger is subject to certain closing conditions, including, among other things, approval by the stockholders of the Company and Lumos. Lumos stockholders approved the Merger in September 2019. The Merger Agreement contains certain termination rights for both the Company and Lumos, and further provides that, upon termination of the Merger Agreement under specified circumstances, the Company or Lumos, as applicable, may be required to pay the other party a termination fee of $2.0 million. The Merger Agreement contemplates that the Company will also seek approval from its stockholders to effect a reverse stock split, with the split ratio to be mutually agreed to by the Company and Lumos immediately prior to the Effective Time. The Merger is expected to close in the first quarter of 2020.