Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2013
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates.
Segment Reporting	Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business in one operating segment operating in the United States.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less from the date of purchase to be cash equivalents. Cash and cash equivalents include cash in readily available checking and savings accounts.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts of accounts payable and accrued expenses are considered to be representative of their respective fair values because of the short-term nature of those instruments. Based on the borrowing rates currently available to the Company for loans with similar terms, the Company believes that the fair value of long-term debt approximates its carrying value. The carrying amount of the warrant liability represents fair value.
Concentrations of Risk	Concentrations of Risk Financial instruments that potentially subject the Company to significant credit risk consist primarily of cash and cash equivalents. The Company maintains deposits in a federally insured financial institution in excess of federally insured limits. The Company has established guidelines designed to maintain safety and liquidity, has not experienced any losses in such accounts and believes the exposure to significant risk to the cash balance is minimal. In addition, the Company relies on third-party manufacturers for the production of its drug candidate. If the third-party manufacturers are unable to continue manufacturing the Company’s drug candidate, or if the Company loses one of its sole source suppliers used in its manufacturing processes, the Company may not be able to meet clinical trial supply demand for its product candidate and the development of the product candidate could be materially and adversely affected.
Preferred Stock Warrant Liability	Preferred Stock Warrant Liability Warrants for shares that are puttable and warrants for shares that are contingently redeemable are classified as liabilities on the accompanying balance sheets and carried at their estimated fair value. At the end of each reporting period, any changes in fair value are recorded as a component of other income (expense). At the completion of the IPO, the Company adjusted the carrying value of the warrants and reclassified the liability to additional paid-in capital.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation expense is recorded at the estimated fair value of the award as of the grant date and is recognized as expense on a straight-line basis over the employee’s requisite service period, which is generally the vesting period of the award. Stock-based compensation expense is based on awards ultimately expected to vest, and therefore, the recorded expense includes an estimate of future forfeitures. Forfeitures are to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Prior to the IPO, the Company granted stock options to purchase common stock to employees with exercise prices equal to the value of the underlying stock, as determined by the board of directors on the date the equity award was granted. The board of directors determined the fair value of the underlying common stock by considering a number of factors, including historical and projected financial results, the risks the Company faced at the time, the preferences of the Company’s preferred stockholders and the lack of liquidity of the Company’s common stock. Subsequent to the IPO, the exercise price of the stock options granted to employees and members of the board of directors of the Company was determined by the Company’s closing market price on the date the stock options were granted. The fair value of each option award is estimated on the date of grant using the Black-Scholes valuation model using the appropriate risk-free interest rate, expected term and volatility assumptions. The expected life of options was calculated using the simplified method, which calculates the life as the average of the contractual term of the stock option and the vesting period of the option. Due to the Company’s limited historical data as a public company, the estimated volatility is calculated based upon the historical volatility of the Company and comparable companies whose share prices are publicly available for a sufficient period of time. The risk-free interest rate is based upon U.S. Treasury securities with remaining terms similar to the expected term of the stock award being valued. The Company granted 501,500 options in 2013 and no options in 2012.
Research and Development Expenses	Research and Development Expenses Research and development costs are expensed as incurred and primarily include compensation and related benefits, stock-based compensation expense, costs paid to third-party contractors to perform research, conduct clinical trials and develop drug materials and delivery devices. The Company expenses costs relating to the purchase and production of pre-approval inventories as research and development expense in the period incurred until FDA approval is received. The Company bases its expense accruals related to clinical studies on estimates of the services received and efforts expended pursuant to contracts with multiple research institutions and clinical research organizations , or CROs, that conduct and manage clinical studies on our behalf. The financial terms of these agreements vary from contract to contract and may result in uneven payment flows. Payments under some of these contracts depend on factors, such as the successful enrollment of patients, site initiation and the completion of clinical study milestones. Service providers invoice us monthly in arrears for services performed. In accruing service fees, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. If the Company does not identify costs that have begun to be incurred, or if the Company underestimates or overestimates the level of services performed or the costs of these services, actual expenses could differ from estimates. To date, the Company has not experienced significant changes in estimates of accrued research and development expenses after a reporting period. However, due to the nature of estimates, no assurance can be made that changes to the estimates will not be made in the future as the Company becomes aware of additional information about the status or conduct of clinical studies and other research activities. We do not own or operate manufacturing facilities for the production of EVK-001, nor do we have plans to develop our own manufacturing operations in the foreseeable future. We currently depend on third-party contract manufacturers for all of our required raw materials, drug substance and finished product for our preclinical research and clinical trials. We do not have any current contractual relationships for the manufacture of commercial supplies of EVK-001. If EVK-001 is approved by any regulatory agency, we intend to enter into agreements with third-party contract manufacturers for the commercial production at that time. We currently utilize a third-party consultant, which we engage on an as-needed, hourly basis, to manage our manufacturing contractors.
Income Taxes	Income Taxes The Company accounts for income taxes in accordance with ASC 740, Income Taxes. Under ASC 740, deferred tax assets and liabilities reflect the future tax consequences of the differences between the financial reporting and tax basis of assets and liabilities using current enacted tax rates. The Company provides a valuation allowance against net deferred tax assets unless, based upon the available evidence, it is more likely than not that the deferred tax assets will be realized. The Company’s policy related to accounting for uncertainty in income taxes prescribes a recognition threshold and measurement attributed criteria for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more likely than not to be sustained upon examination by taxing authorities.
Comprehensive Income (Loss)	Comprehensive Income (Loss) ASC 220, Comprehensive Income, defines comprehensive income (loss) as a change in equity during a period from transactions and other events and circumstances from non-owner sources. Net loss and comprehensive loss were the same for all periods presented.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for common stock equivalents and adjusted for the weighted-average number of common shares outstanding that are subject to repurchase. The Company has excluded 103,750, 118,750 and 140,125 weighted-average shares subject to repurchase from the weighted-average number of common shares outstanding for the year ended December 31, 2013, 2012 and 2011, respectively. Diluted net loss per share is calculated by dividing the net loss by the weighted-average number of common share equivalents outstanding for the period determined using the treasury-stock method. Dilutive common stock equivalents are comprised of convertible preferred stock, warrants for the purchase of convertible preferred stock, warrants for the purchase of common stock, and options outstanding under the Company’s equity incentive plans. For the periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the Company’s net loss position.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In February 2013, the Financial Accounting Standards Board issued an accounting standard update to require reclassification adjustments from other comprehensive income to be presented either in the financial statements or in the notes to the financial statements. This accounting standard became effective for the Company beginning in the first quarter of 2013, and its adoption did not have any impact on the Company’s financial statements. In July 2013, the FASB issued Accounting Standards Update No. 2013-11, presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists (“ASU 2013-11”). The guidance is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2013, with an option for early adoption. The Company intends to adopt this guidance during the first quarter of 2014, and does not believe the adoption of this standard will have a material impact on the Company’s consolidated financial statements.