Significant Accounting Policies (Policies)	6 Months Ended
Significant Accounting Policies (Policies)	Jun. 30, 2016
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Organizati on KemPharm, Inc. (the “ Company”) is a clinical-stage specialty pharmaceutical company engaged in the discovery and development of proprietary prodrugs. Through the use of its Ligand Activated Therapy (“LAT”) platform technology, the Company is able to initiate and pursue the development of improved versions of widely prescribed, approved drugs. The Company was formed on October 30, 2006, and incorporated in Iowa, and reorganized in Delaware on May 30, 2014. The Company has experienced recurring losses from operations and negative operating cash flows due to its ongoing research and development of its potential product candidates. The Company also has an accumulated deficit at June 30, 2016. Various internal and external factors will affect whether and when the candidates become approved drugs and how significant their market share will be. The length of time and cost of developing and commercializing these candidates and/or failure of them at any stage of the drug approval process will materially affect the Company’s financial condition and future operations. Based upon its current operating plan, the Company believes that its existing cash and cash equivalents, restricted cash, marketable securities and long-term investments will enable it to fund its operating expenses and capital expenditure requirements through at least the next 18 months. The accompanying unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of Americ a for interim financial information and with the instructions to Form 10-Q and Rule 8-03 of Regulation S-X. Accordingly, they do not include all of the information and related notes required by accounting principles generally accepted in the United States of America for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation have been included in the accompanying financial statements. Operating results for the three and six months ended June 30, 2016, are not necessarily indicative of the results that may be expected for the full year ending December 31, 2016. This interim information should be read in conjunction with the audited financial statements included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2015, filed with the Securities and Exchange Commission (“SEC”) on March 15, 2016.
Stockholders' Equity, Policy [Policy Text Block]	Reverse Stock Split On April 2, 2015, the Company effected a 1-for -7.5 reverse stock split of its issued common stock. All applicable share data, per share amounts and related information in the unaudited condensed financial statements and notes thereto have been adjusted retroactively to give effect to the 1-for-7.5 reverse stock split. Initial Public Offering In April 2015, the Company completed an initial public offering (“ IPO”) of its common stock. In connection with the initial closing of the IPO, the Company sold an aggregate of 5,090,909 shares of common stock at a price to the public of $11.00 per share. In May 2015, the underwriters in the IPO exercised their option to purchase additional shares pursuant to which the Company sold an additional 763,636 shares of common stock at a price equal to the public price of $11.00 per share. In the aggregate, net proceeds from the IPO, including net proceeds from the underwriters’ exercise of their option to purchase additional shares, were $59.9 million, after deducting underwriting discounts and commissions of $4.5 million. In addition, offering expenses totaled $2.8 million. Upon completion of the IPO, all outstanding shares of the Company’s redeemable convertible preferred stock were converted or reclassified into 5,980,564 shares of common stock and all outstanding warrants to acquire shares of the Company’s redeemable convertible preferred stock became warrants to acquire the Company’s common stock. In connection with the IPO, the Company amended and restated its Amended and Restated Certificate of Incorporation to change the authorized capital stock to 250,000,000 shares, designated as common stock, and 10,000,000 shares, designated as preferred stock, each with a par value of $0.0001 per share.
Reclassification, Policy [Policy Text Block]	Reclassifications During the first quarter of 2016 the Company adopted Accounting St andards Update (“ASU”) 2015-03, Interest – Imputation of Interest (Subtopic 835-30) (“ASU 2015-03”), which requires the debt issuance costs related to a recognized debt liability be presented in the balance sheet as direct deduction from the carrying amount of that debt liability, consistent with the presentation of debt discounts. The adoption of ASU 2015-03 reduced the Company’s assets and liabilities by the amount of the debt issuance costs, which were $4.0 million and $1.1 million at June 30, 2016 and December 31, 2015, respectively. This reclassification had no effect on reported net income (loss).
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of financial statements in conformity with accounting principles gen erally accepted in the United States of America requires the Company to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. On an ongoing ba sis, the Company evaluates its estimates, including those related to the useful lives of property and equipment, and assumptions used for purposes of determining stock-based compensation, income taxes, and the fair value of the derivative and warrant liability, among others. The Company bases its estimates on historical experience and on various other assumptions that it believes to be reasonable, the results of which form the basis for making judgments about the carrying value of assets and liabilities.
New Accounting Pronouncements, Policy [Policy Text Block]	Application of New or Revised Accounting Standards—Not Yet Adopted In May 2014, the FASB issued guidance codified in ASC Topic 606, Revenue Recognition—Revenue from Contracts with Customers ("ASC 606") , which amends the guidance in former ASC 605, Revenue Recognition , and becomes effective beginning January 1, 2018. The Company is currently evaluating the impact of the provisions of ASC 606 on its financial statements and disclosures. In August 2014, the FASB issued ASU No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”), which amends ASC Subtopic 205-40 to provide guidance about management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related disclosures. Specifically, the amendments (1) provide a definition of the term “substantial doubt,” (2) require an evaluation every reporting period, (3) provide principles for considering the mitigating effect of management’s plans, (4) require certain disclosures when substantial doubt is alleviated as a result of consideration of management’s plans, (5) require an express statement and other disclosures when substantial doubt is not alleviated and (6) require an assessment for a period of one year after the date that financial statements are issued. ASU 2014-15 is effective for fiscal years ending after December 15, 2016, and for annual periods and interim periods thereafter. The Company is currently evaluating the impact of the adoption of ASU 2014-15 on its financial statements and disclosures. In November 2015, the FASB issued ASU 2015-17, Income Taxes: Balance Sheet Classification of Deferred Taxes (Topic 740) (“ASU 2015-17”), which requires that deferred tax liabilities and assets be classified as noncurrent in a classified statement of financial position. This update applies to all entities that present a classified statement of financial position. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. The Company does not expect this standard to have a material impact on its financial statements upon adoption. In January 2016, the FASB issued ASU 2016-01, Financial Instruments Overall – Recognition and Measurement of Financial Assets and Liabilities (Topic 825-10) (“ASU 2016-01”), which provides several updates related to Topic 825-10. This update applies to all entities that hold financial assets or owe financial liabilities. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The Company does not expect this standard to have a material impact on its financial statements upon adoption. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) (“ASU 2016-02”), which requires lessees to recognize assets and liabilities for operating leases with lease terms greater than twelve months in the balance sheet. The update also requires improved disclosures to help users of financial statements better understand the amount, timing and uncertainty of cash flows arising from leases. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, with early adoption permitted. The Company is currently evaluating the impact of the adoption of ASU 2016-02 on its financial statements and disclosures. In March 2016, the FASB issued ASU 2016-06, Derivatives and Hedging (Topic 815), Contingent Put and Call Options in Debt Instruments (“ASU 2016-06”), which clarifies the requirements for assessing whether contingent call and put options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts. ASU 2016-06 is effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years, with early adoption permitted. The Company is currently evaluating the impact of the adoption of ASU 2016-06 on its financial statements and disclosures. In March 2016, the FASB issued ASU 2016-09, Compensation–Stock Compensation (Topic 718), Improvements to Employee Share-Based Payment Accounting (“ASU 2016-09”), which simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 is effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years, with early adoption permitted. The Company is currently evaluating the impact of the adoption of ASU 2016-09 on its financial statements and disclosures.