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 Entity Emerging Growth Company Entity Small Business Statement of Financial Position [Abstract] Statement [Table] Legal Entity [Axis] Entity [Domain] Statement [Line Items] Assets [Abstract] ASSETS Assets, Current [Abstract] Current assets Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Cash and cash equivalents at the beginning of the period Cash and cash equivalents at the end of the period Marketable Securities, Current, Total Marketable securities, at fair value Accounts Receivable, Net, Current Accounts receivable from collaboration Prepaid Expense and Other Assets, Current Prepaid expenses and other current assets Assets, Current Total current assets Assets, Noncurrent [Abstract] Long-term assets Marketable Securities, Noncurrent, Total Marketable securities, at fair value Property, Plant and Equipment, Net Property, plant and equipment, net Property, plant and equipment, net Security Deposit Security deposits Intangible Assets, Net (Excluding Goodwill) Intangible assets Goodwill Goodwill Assets, Noncurrent, Total Total long-term assets Assets Total assets Liabilities and Equity [Abstract] LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities, Current [Abstract] Current liabilities Accounts Payable Accounts payable Accrued Liabilities, Current Accrued expenses Total accrued expenses Deferred Revenue, Current Deferred revenue - short-term Liabilities, Current Total current liabilities Liabilities, Noncurrent [Abstract] Long-term liabilities Deferred Tax Liabilities, Net, Current Deferred tax liabilities Deferred Revenue, Noncurrent Deferred revenue - long-term Liabilities, Noncurrent, Total Total long-term liabilities Deferred Rent Credit, Noncurrent Deferred rent Liabilities Total liabilities Commitments and Contingencies Commitments and contingencies Stockholders' Equity Attributable to Parent [Abstract] Stockholders' equity Preferred Stock, Value, Issued Preferred stock, $0.001 par value; 5,000,000 shares authorized; 0 shares issued and outstanding Common Stock, Value, Issued Common stock, $0.001 par value; 100,000,000 and 50,000,000 shares authorized as of September 30, 2018 and December 31, 2017; 25,460,122 and 20,137,974 shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively Additional Paid in Capital Additional paid-in capital Accumulated Other Comprehensive Income (Loss), Net of Tax, Total Accumulated other comprehensive loss Retained Earnings (Accumulated Deficit) Accumulated deficit Stockholders' Equity Attributable To Parent Total stockholders' equity Balance Balance Liabilities and Stockholders Equity Total liabilities and stockholders' equity Preferred Stock Par Or Stated Value Per Share Preferred stock, par value Preferred Stock Shares Authorized Preferred stock, shares authorized Preferred Stock, Shares Issued Preferred stock, issued Preferred Stock, Shares Outstanding Preferred stock, shares outstanding Common Stock Shares Authorized Common stock, shares authorized Common Stock, Shares, Issued Common stock, shares issued Common Stock Shares Outstanding Common stock, shares outstanding Common Stock, Par or Stated Value Per Share Common stock, par value Common Stock, Par or Stated Value Per Share Income Statement [Abstract] Product and Service [Axis] Product and Service [Domain] Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Loss before income taxes Income Tax Expense (Benefit) Income tax benefit Revenues Collaboration revenue Operating Expenses [Abstract] Operating expenses: Research and Development Expense Research and development General and Administrative Expense General and administrative Costs and Expenses Total operating expenses Operating Income Loss Loss from operations Nonoperating Income (Expense) [Abstract] Other income (expenses) Interest Income, Other Interest and other income Marketable Securities, Realized Gain (Loss), Total Realized loss from marketable securities Nonoperating Income (Expense) Total other income Net Loss Net loss Net loss Net loss Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Other comprehensive (loss) income Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Reclassification Adjustments, Net of Tax Unrealized loss recognized in accumulated other comprehensive loss before reclassification, net of tax benefit of $50,664, $31,844, $44,192 and $89,281, respectively Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Reclassification adjustment of unrealized loss included in net loss, net of tax expense of $56,139, $37,987, $56,139 and $221,358, respectively Comprehensive Income (Loss), Net of Tax, Attributable to Parent, Total Comprehensive loss Basic and Diluted Net Loss Per Common Share (In Dollars Per Share) Net loss per share, basic and diluted Weighted Average Number of Shares Outstanding, Basic and Diluted Weighted average common shares outstanding, basic and diluted Other Comprehensive Income (Loss), Available-for-sale Securities, before Reclassification Adjustments, Tax Unrealized loss recognized in accumulated other comprehensive loss before reclassification, net of tax benefit Other Comprehensive Income (Loss), Securities, Available-for-sale, Tax Statement Of Cash Flows [Abstract] Scenario [Axis] Scenario, Unspecified [Domain] Related Party [Axis] Related Party [Domain] Debt Instrument [Axis] Debt Instrument, Name [Domain] Deferred Revenue Arrangement Type [Axis] Deferred Revenue [Domain] 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 Depreciation and amortization Share-based Compensation Stock-based compensation Share-based Compensation Increase Decrease In Operating Capital [Abstract] Changes in operating assets and liabilities: Increase (Decrease) in Accounts Receivable Accounts receivable from collaboration Increase (Decrease) in Prepaid Expense and Other Assets Prepaid expenses and other current assets Increase (Decrease) in Accounts Payable Accounts payable Increase (Decrease) in Accrued Liabilities Accrued expenses Increase (Decrease) in Deferred Revenue Deferred revenue Increase (Decrease) in Security Deposits Security deposits Increase Decrease in Deferred Rent Noncurrent Deferred rent Amount of increase (decrease) in noncurrent operating liabilities classified as deferred rent. Deferred Income Tax Expense (Benefit) Deferred income tax benefit Investment Income, Net, Amortization of Discount and Premium Amortization of premium (discount) on investment securities, net Net Cash Provided by (Used in) Operating Activities Net cash (used in) provided by operating activities Net Cash Provided by (Used in) Investing Activities [Abstract] Cash flows from investing activities Payments To Acquire Property Plant and Equipment Purchases of fixed assets Payments to Acquire Marketable Securities Purchases of marketable securities Proceeds from Sale and Maturity of Marketable Securities Redemptions of marketable securities Net Cash Provided by (Used in) Investing Activities Net cash used in investing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Cash flows from financing activities Accrued Offering Cost Related to Issuance of Common Stock Proceeds from the exercise of stock options The amount of offering cost related to the issuance of common stock that were incurred during a noncash or partial noncash transaction. Net Cash Provided by (Used in) Financing Activities Net cash provided by financing activities Proceeds from Issuance or Sale of Equity Proceeds from common stock sold, net of underwriters' discounts and cost Cash and Cash Equivalents Period Increase Decrease Net increase (decrease) in cash and cash equivalents Noncash Investing and Financing Items [Abstract] Supplemental disclosure of cash flow information: Marketable Securities Available for Sale Change in Before Tax Change in unrealized gain on marketable securities available-for-sale, before tax expense The change in unrealized holding gain (loss), net of tax, on available-for-sale securities included in a separate component of shareholders' equity during the period. Stock Issued Shares issued for option exercise - receivable Statement of Stockholders' Equity [Abstract] Equity Components [Axis] Equity Component [Domain] Common Stock [Member] Additional Paid-in Capital [Member] AOCI Attributable to Parent [Member] Accumulated Other Comprehensive Loss [Member] Retained Earnings [Member] Accumulated Deficit [Member] Shares, Outstanding Balance (in Shares) Balance (in Shares) Stock Issued During Period, Value, Stock Options Exercised Proceeds from the exercise of stock options Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Proceeds from the exercise of stock options (in shares) Option, Exercised Trading Securities, Change in Unrealized Holding Gain (Loss) Change in unrealized gain on marketable securities, net of income tax expense of $11,947 Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Stock-based compensation Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Settlement of restricted stock units into common stock Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Settlement of restricted stock units into common stock (in shares) Stock Issued During Period, Value, New Issues Proceeds from common stock sold, net of underwriters' discounts and cost Stock Issued During Period, Shares, New Issues Proceeds from common stock sold, net of underwriters' discounts and cost (in shares) Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax Change in unrealized gain on marketable securities, net of income tax expense Organization, Business and Basis Of Presentation [Abstract] Organization Consolidation and Presentation Of Financial Statements Disclosure [Text Block] Nature of Business Accounting Policies [Abstract] Significant Accounting Policies [Text Block] Summary of Significant Accounting Policies and Recent Accounting Pronouncements Investments, Debt and Equity Securities [Abstract] Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Marketable Securities Property, Plant and Equipment [Abstract] Property, Plant and Equipment Disclosure [Text Block] Property, Plant and Equipment, Net Payables and Accruals [Abstract] Accounts Payable and Accrued Liabilities Disclosure [Text Block] Accrued Expenses Equity [Abstract] Stockholders' Equity Note Disclosure [Text Block] Stockholders' Equity Collaborative Arrangement Disclosure [Text Block] Collaboration Agreement Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Text Block] Commitments and Contingencies Basis of Accounting, Policy [Policy Text Block] Basis of presentation Use of Estimates, Policy [Policy Text Block] Use of Estimates Significant Accounting Policies [Policy Text Block] Significant Accounting Policies Disclosure of accounting policy for Significant Accounting Policies. Earnings Per Share, Policy [Policy Text Block] Loss per Share of Common Stock Revenue Recognition, Policy [Policy Text Block] Revenue Recognition New Accounting Pronouncements, Policy [Policy Text Block] Recent Accounting Pronouncements 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 Available-for-sale Securities Reconciliation [Table Text Block] Schedule of Available-for-sale Securities Reconciliation Schedule Of Available For Sale Securities Fair Value Measurement Categories [Table Text Block] Schedule Of Available For Sale Securities Fair Value Measurement Categories Tabular disclosure of fair value of marketable securities was classified into fair value measurement categories Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Table Text Block] Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value Property, Plant and Equipment [Table Text Block] Property, Plant and Equipment Schedule of Accrued Liabilities [Table Text Block] Schedule Accrued Expenses Financial Instrument [Axis] Financial Instruments [Domain] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Stockholders' Transactions [Abstract] Disclosure Of Share-Based Compensation Arrangements By Share-Based Payment Award [Table Text Block] Disclosure of Share-based Compensation Arrangements by Share-based Payment Award Schedule Of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Assumptions for Weighted Average Fair Value of Options Granted Schedule Of Unrecognized Compensation Cost, Nonvested Awards [Table Text Block] Estimated Future Stock Based Expenses Relating to Unvested Stock Options Nonvested Restricted Stock Shares Activity [Table Text Block] Schedule of Restricted Stock Number of units Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs Overview [Table] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Allergan Pharmaceuticals International Limited [Member] Overview [Line Items] Development Milestone Payments Development Milestone Payments Commercial Milestone Payments Defines Commercial Milestone Payments. Agreed To Share Maximum Amount Development Cost This element represent the maximum amount of development cost agreed by company. Revenue Recognition, Milestone Method, Description Sale of Stock, Price Per Share Proceeds from Issuance Initial Public Offering Additional Shares of Common Stock Issued Total number of common shares of an entity that have been sold or granted to underwriters. License [Member] Sale of Stock [Axis] Sale of Stock [Domain]