Document and Entity Information [Abstract] Document and Entity Information [Abstract] 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] Class of Stock [Axis] Class of Stock [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 Marketable securities 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 Total assets Assets, Noncurrent [Abstract] Long-term assets Property, Plant and Equipment, Net Property and equipment, net Property, and equipment, net Other Assets, Noncurrent Other assets Indefinite-lived Intangible Assets (Excluding Goodwill) Indefinite-lived intangible asset Goodwill Goodwill Operating Lease, Right-of-Use Asset Operating lease right-of-use 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 Operating Lease, Liability, Current Operating lease liabilities - short-term Liabilities, Noncurrent [Abstract] Long-term liabilities Deferred Tax Liabilities, Net, Current Deferred tax liabilities Deferred Revenue, Noncurrent Deferred revenue - long-term Deferred Rent Credit, Noncurrent Deferred rent Operating Lease, Liability, Noncurrent Operating lease liabilities - long-term 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; no shares issued or outstanding Common Stock, Value, Issued Common stock, $0.001 par value; 100,000,000 shares authorized as of March 31, 2019 and December 31, 2018; 25,549,757 and 25,495,425 shares issued and outstanding as of March 31, 2019 and December 31, 2018, respectively Additional Paid in Capital Additional paid-in capital Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive loss Retained Earnings (Accumulated Deficit) Accumulated deficit Stockholders' Equity Attributable to Parent Total stockholders' equity Balance Balance Liabilities and 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, Par or Stated Value Per Share Common stock, par value Common Stock, Shares Authorized Common stock, shares authorized Common Stock, Shares, Issued Common stock, shares issued Common Stock, Shares, Outstanding Common stock, shares outstanding Income Statement [Abstract] Product and Service [Axis] Product and Service [Domain] Operating Expenses [Abstract] Operating expenses: Research and Development Expense Research and development General and Administrative Expense General and administrative Operating 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 Other Operating Income (Expense), Net Other income (expense), net Nonoperating Income (Expense) Total other income Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Loss before income taxes Income Tax Expense (Benefit) Income tax benefit Net Income (Loss) Attributable to Parent Net loss Net loss Net (loss) income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Other comprehensive (loss) income Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax Unrealized gain (loss) on marketable securities, net of tax Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive loss Earnings Per Share, Basic and Diluted Net loss per share, basic and diluted Weighted Average Number of Shares Outstanding, Basic and Diluted Weighted average common shares outstanding, basic and diluted Revenues Collaboration revenue Statement of Cash Flows [Abstract] Restatement [Axis] Restatement [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, Depletion and Amortization Depreciation and amortization Share-based Compensation Stock-based compensation Deferred Income Tax Expense (Benefit) Deferred income tax benefit 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 Other Noncurrent Assets Other assets Increase Decrease In Deferred Rent Noncurrent Deferred rent Amount of increase (decrease) in noncurrent operating liabilities classified as deferred rent. Increase (Decrease) in Other Operating Liabilities Operating lease liabilities Gain (Loss) on Disposition of Assets Loss on disposal of fixed assets Other Noncash Income (Expense) Other Accretion and Amortization of Investments in Marketable Securities Net accretion and amortization of investments in marketable securities Amount of Accretion and Amortization of Investments in Marketable Securities. Noncash rent expense Non-cash rent expense Represent non cash rent expense. 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 Property, Plant, and Equipment Purchases of property and equipment Payments to Acquire Marketable Securities Purchases of marketable securities Proceeds from Sale and Maturity of Marketable Securities Proceeds from maturities of marketable securities Net Cash Provided by (Used in) Investing Activities Net cash provided by (used in) investing activities Proceeds from Sale of Held-to-maturity Securities Proceeds from sale of marketable securities Net Cash Provided by (Used in) Financing Activities [Abstract] Cash flows from financing activities Proceeds from Issuance Initial Public Offering Proceeds from the exercise of stock options Net Cash Provided by (Used in) Financing Activities Net cash provided by financing activities Cash and Cash Equivalents, Period Increase (Decrease) Net decrease in cash and cash equivalents 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) Options, Exercised Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Stock-based compensation Trading Securities, Change in Unrealized Holding Gain (Loss) Unrealized gain (loss) on marketable securities Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Issuance of shares for settlement of restricted stock units Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Issuance of shares for settlement of restricted stock units (in shares) Adjustments to Additional Paid in Capital, Share-based Compensation, Restricted Stock Unit or Restricted Stock Award, Requisite Service Period Recognition Reclassification of stock-based awards from equity to accrued expenses Organization, Consolidation and Presentation of Financial Statements [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] Investments in Marketable Securities Property, Plant and Equipment [Abstract] Property, Plant and Equipment Disclosure [Text Block] Property 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 Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Disclosure of Compensation Related Costs, Share-based Payments Collaboration Agreement [Abstract] Collaborative and License Arrangement Disclosure [Text Block] Collaboration Agreement Collaborative and License Arrangement Disclosure. Milestones and Research Agreements [Abstract] Milestones and Research Agreements [Text Block] Milestones and Research Agreements Lease, Cost [Abstract] Lessee, Operating Lease, Disclosure [Table Text Block] Basis of Accounting, Policy [Policy Text Block] Basis of presentation Use of Estimates, Policy [Policy Text Block] Use of Estimates Stock-based compensation [Policy Text Block] Stock-based Compensation Share based Compensation, Policy. Earnings Per Share, Policy [Policy Text Block] Net Loss per Share New Accounting Pronouncements, Policy [Policy Text Block] Recent Accounting Pronouncements Lessee, Leases [Policy Text Block] Leases Significant Accounting Policies [Policy Text Block] Significant Accounting Policies Disclosure of accounting policy for Significant Accounting Policies. 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 Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of Earnings Per Share, Basic and Diluted Schedule of Available-for-sale Securities Reconciliation [Table Text Block] Schedule of Available-for-sale Securities Reconciliation Fair Value Measurements, Recurring and Nonrecurring [Table Text Block] Property, Plant and Equipment [Table Text Block] Property and Equipment Schedule of Accrued Liabilities [Table Text Block] Schedule of Accrued Expenses Financial Instrument [Axis] Financial Instruments [Domain] Share-based Compensation, Stock Options, Activity [Table Text Block] Schedule Of Share Based Compensation Stock Options Activity Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Assumptions for Weighted Average Fair Value of Options Granted 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 Contract with Customer, Asset and Liability [Table Text Block] Contract with Customer, Asset and Liability Schedule of Collaboration revenue recognized with the period Schedule of Collaboration revenue recognized with the period Lessee, Operating Lease, Liability, Maturity [Table Text Block] Lessee, Operating Lease, Liability, Maturity Disclosure of quantitative information of operating leases [Table Text Block] Disclosure of quantitative information of operating leases Disclosure of quantitative information of operating lease Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Warrants To Purchase Common Stock [Member] Options To Purchase Common Stock [Member] Restricted stock units to purchase common stock [Member] RSUs Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Earnings Per Share Reconciliation [Abstract] Earnings Per Share [Abstract] Net (loss) income per share: Earnings Per Share, Basic Basic Earnings Per Share, Diluted Diluted Net Income (Loss) Attributable to Parent [Abstract] Numerator: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Denominator: Weighted Average Number of Shares Outstanding, Diluted Weighted average common shares outstanding for diluted net (loss) income per share Award Type [Axis] Equity Award [Domain] Plan Name [Axis] Plan Name [Domain] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain]