Document And Entity Information [Abstract] Document And Entity Information [Abstract] Document Information [Table] Class of Stock [Axis] Class of Stock [Domain] Document Information [Line Items] Document Type Amendment Flag Document Period End Date Document Fiscal Year Focus Document Fiscal Period Focus Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date Entity Filer Category Trading Symbol Entity Common Stock, Shares Outstanding Statement of Financial Position [Abstract] Statement [Table] Series A Preferred Stock [Member] Series A Convertible Preferred stock [Member] Series A Convertible Preferred Stock [Member] Series B Preferred Stock [Member] Series B Convertible Preferred stock [Member] Series B Convertible Preferred Stock [Member] Statement [Line Items] Assets, Current [Abstract] Current Assets Available-for-sale Securities, Current Short-term investments Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Cash and Cash Equivalents, Beginning of Period Cash and Cash Equivalents, End of Period Prepaid Expense and Other Assets, Current Prepaid expenses and other assets Assets, Current Total Current Assets Property, Plant and Equipment, Net Property and equipment, net Other Assets, Noncurrent Long-term assets Assets Total Assets Liabilities, Current [Abstract] Current Liabilities Accounts Payable, Current Accounts payable Accrued Liabilities, Current Accrued expenses Accrued liabilities Liabilities, Current Total Current Liabilities Commitments and Contingencies Commitments and contingencies (Note 9) Stockholders' Equity Attributable to Parent [Abstract] Stockholders' Equity Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive loss Preferred Stock, Value, Issued Preferred stock, Value Common Stock, Value, Issued Common stock, $0.000041666 par value; 150,000,000 shares authorized, 92,741,672 and 73,164,914 shares issued and outstanding as of June 30, 2018 and December 31, 2017, respectively Additional Paid in Capital Additional paid-in capital Retained Earnings (Accumulated Deficit) Accumulated deficit Stockholders' Equity Attributable to Parent Total Stockholders' Equity Liabilities and Equity Total Liabilities and Stockholders' Equity Preferred Stock, Par or Stated Value Per Share Preferred Stock, Shares Authorized Preferred Stock, Shares Issued Preferred Stock, Shares Outstanding Common Stock, Par or Stated Value Per Share Common Stock, Shares Authorized Common Stock, Shares, Issued Common Stock, Shares, Outstanding Preferred Stock, Redemption Amount Income Statement [Abstract] Revenues Revenues Operating Expenses [Abstract] Costs and expenses Research and Development Expense Research and development expenses General and Administrative Expense General and administrative expenses Operating Expenses Total costs and expenses Operating Income (Loss) Loss from operations Nonoperating Income (Expense) [Abstract] Other income Investment Income, Interest Interest income, net Net Income (Loss) Attributable to Parent Net Loss Net Loss Net loss Earnings Per Share, Basic and Diluted Net Loss Per Common Share, Basic and Diluted Weighted Average Number of Shares Outstanding, Basic and Diluted Weighted Average Common Shares Outstanding, Basic and Diluted Statement of Comprehensive Income [Abstract] Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Other comprehensive loss: Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Unrealized loss on short-term investments Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive Loss Statement of Cash Flows [Abstract] Net Cash Provided by (Used in) Operating Activities [Abstract] Cash Flows from Operating Activities Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net loss to net cash used in operating activities: Depreciation, Depletion and Amortization, Nonproduction Depreciation and amortization Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Loss on disposal of assets Amortization of Debt Discount (Premium) Accretion and amortization of discounts and premiums on investments Share-based Compensation Stock-based compensation expense Increase (Decrease) in Operating Capital [Abstract] Changes in assets and liabilities: Increase (Decrease) in Prepaid Expense and Other Assets Prepaid expenses and other assets Increase (Decrease) in Accounts Payable Accounts payable Increase (Decrease) in Accrued Liabilities Accrued expenses Net Cash Provided by (Used in) Operating Activities Net cash used in operating activities Net Cash Provided by (Used in) Investing Activities [Abstract] Cash Flows from Investing Activities Payments to Acquire Available-for-sale Securities Purchase of short-term investments Proceeds from Sale and Maturity of Available-for-sale Securities Maturities of short-term investments Payments to Acquire Property, Plant, and Equipment Purchase of property and equipment Net Cash Provided by (Used in) Investing Activities Net cash (used in) provided by investing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Cash Flows from Financing Activities Payments Related to Tax Withholding for Share-based Compensation Tax payments related to shares withheld for vested restricted stock awards Proceeds from Warrant Exercises Proceeds from the issuance of common stock upon exercise of warrants Proceeds from Stock Options Exercised Proceeds from the issuance of common stock upon exercise of options Proceeds from Issuance of Common Stock Proceeds from the issuance of common stock, net Net Cash Provided by (Used in) Financing Activities Net cash provided by (used in) financing activities Cash and Cash Equivalents, Period Increase (Decrease) Net increase in cash and cash equivalents Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Supplemental disclosure of non-cash investing and financing activities: Conversion of Stock, Amount Converted Conversion of convertible preferred stock to common stock Unrealized Gain Loss on Short-Term Investments Unrealized loss on short-term investments Amount of unrealized (loss)gain on short-term investments. Leasehold Improvements Paid by Landlord Acquisitions of property and equipment included in accounts payable Future cash outflow to pay for leasehold improvements that have occurred. Organization, Consolidation and Presentation of Financial Statements [Abstract] Business Description and Basis of Presentation [Text Block] GENERAL ORGANIZATION AND BUSINESS Accounting Policies [Abstract] Significant Accounting Policies [Text Block] SUMMARY OF SIGNIFICANT ACCOUNTING PRACTICES Cash, Cash Equivalents, and Short-term Investments [Abstract] Cash, Cash Equivalents, and Short-term Investments [Text Block] CASH AND CASH EQUIVALENTS Supplemental Balance Sheet Disclosures [Text Block] BALANCE SHEET COMPONENTS Stockholders' Equity Note [Abstract] Stockholders' Equity Note Disclosure [Text Block] STOCKHOLDERS' EQUITY Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Disclosure of Compensation Related Costs, Share-based Payments [Text Block] STOCK BASED COMPENSATION Licenses And Agreements [Abstract] Licenses And Agreements Disclosure [Text Block] LICENSES AND AGREEMENTS The entire disclosure for licenses and agreements. Loss Contingency [Abstract] Contingencies Disclosure [Text Block] LEGAL PROCEEDINGS Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Text Block] COMMITMENTS AND CONTINGENCIES Related Party Transactions [Abstract] Related Party Transactions Disclosure [Text Block] RELATED PARTY TRANSACTIONS Earnings Per Share, Policy [Policy Text Block] Loss per Share Fair Value Measurement, Policy [Policy Text Block] Fair Value Measurements Use of Estimates, Policy [Policy Text Block] Use of Estimates Consolidation, Policy [Policy Text Block] Principles of Consolidation Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] Stock-Based Compensation Stockholders' Equity Note, Redeemable Preferred Stock, Issue, Policy [Policy Text Block] Preferred Stock Convertible Instruments Policy [Text Block] Convertible Instruments The accounting policy for all convertible instruments issued by the entity. New Accounting Pronouncements, Policy [Policy Text Block] Recent Accounting Standards Subsequent Events, Policy [Policy Text Block] Subsequent Events Reclassification, Policy [Policy Text Block] Reclassifications Cash Cash Equivalents and Shortterm Investments [Policy Text Block] Cash, Cash Equivalents, and Short-term Investments The policy disclosure of the components of cash, cash equivalents, and short-term investments. Short-term investments may include current marketable securities. Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block] Schedule of Stock-Based Compensation Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block] Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan Fair Value, Assets Measured on Recurring Basis [Table Text Block] Schedule of Assets Measured at Fair Value Unrealized Gain (Loss) on Investments [Table Text Block] Cash, Cash Equivalents and Investments [Table Text Block] Schedule of Cash, Money Market Funds and Short-Term Investments Property, Plant and Equipment [Abstract] Schedule of Accrued Liabilities [Table Text Block] Schedule of Accrued Liabilities Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block] Schedule of Stockholders' Equity Note, Warrants or Rights Share-based Compensation, Stock Options, Activity [Table Text Block] Schedule of Status of Stock Options Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Schedule of Future Minimum Rental Payments for Operating Leases Equity Components [Axis] Equity Component [Domain] Sale of Stock [Axis] Sale of Stock [Domain] IPO [Member] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Investment Type [Axis] Investments [Domain] Proceeds from Stock Options and Warrants Exercised Amount of cash inflow from exercise of stock options granted under share-based compensation arrangement. Stock Issued During Period, Shares, New Issues Shares Issued, Price Per Share Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Exercised Stock Issued During Period, Value, New Issues Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Employee Stock Option [Member] Warrant [Member] Restricted Stock Awards [Member] Restricted Stock [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Assets, Fair Value Disclosure Financial Instrument [Axis] Financial Instruments [Domain] US Government Debt Securities [Member] US Government agency securities [Member] US Treasury Securities [Member] US Treasury Securities [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 3 [Member] Income Statement Location [Axis] Income Statement Location [Domain] Research and Development Expense [Member] General and Administrative Expense [Member] Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost, Total Equity-Based Arrangements, Individual Contracts, Type of Deferred Compensation [Axis] Equity-Based Arrangements, Individual Contracts, Type of Deferred Compensation [Domain] Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Domain] Demand Deposits [Member] Money Market Funds [Member] US Government Corporations and Agencies Securities [Member] Short-term Investments [Abstract] Short-term Investments Cash Equivalents, at Carrying Value Cash, Cash Equivalents, and Short-term Investments Securities or Other Assets Sold under Agreements to Repurchase [Axis] Assets Sold under Agreements to Repurchase, Type [Domain] Trading SecuritiesAccretion Accretion Value of accretion of trading securities during the period. Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain Gross Unrealized Gains Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss Gross Unrealized Losses Held-to-maturity Securities, Current Amortized Cost Investment Owned, at Fair Value Fair Value Accrued Employee Benefits, Current Accrued payroll and employee related expenses Legal And Related Services Current Legal and related services Carrying value as of the balance sheet date of obligations incurred through that date and payable for legal and related services. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Clinical Related Expenses Current Clinical related Carrying value as of the balance sheet date of obligations incurred through that date and payable for clinical and related services. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Manufacturing Related Expenses Current Manufacturing related Carrying value as of the balance sheet date of obligations incurred through that date and payable for manufacturing of the entity's goods and services. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Accrued Rent, Current Deferred rent