Document And Entity Information [Abstract] Document And Entity Information [Abstract] Document Information [Table] Document Information [Line Items] Document Type Document Quarterly Report Document Transition Report Document Period End Date Entity File Number Entity Registrant Name Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Address, Address Line One Entity Address, City or Town Entity Address, State or Province Entity Address, Postal Zip Code City Area Code Local Phone Number Amendment Flag Document Fiscal Year Focus Document Fiscal Period Focus Entity Central Index Key Current Fiscal Year End Date Entity Current Reporting Status Entity Interactive Data Current Entity Filer Category Trading Symbol Security Exchange Name Title of 12(b) Security Entity Common Stock, Shares Outstanding Entity Shell Company Entity Emerging Growth Company Entity Small Business CONDENSED CONSOLIDATED BALANCE SHEETS Statement [Table] Statement [Line Items] Assets [Abstract] ASSETS Assets, Current [Abstract] Current assets Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents 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 Property, Plant and Equipment, Net. Property, plant and equipment, net Property, plant and equipment, net Operating lease, right-of-use asset Operating lease right-of-use assets Other Assets, Noncurrent Other assets Indefinite-lived Intangible Assets (Excluding Goodwill) Indefinite-lived intangible asset Goodwill Goodwill Assets Total assets Liabilities and Equity [Abstract] LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities, Current [Abstract] Current liabilities Accounts Payable Accounts payable Accrued Liabilities, Current Total accrued expenses Accrued expenses Deferred Revenue, Current Deferred revenue - short-term Operating Lease, Liability, Current Operating lease liabilities - short-term Liabilities, Current Total current liabilities Liabilities, Noncurrent [Abstract] Long-term liabilities Deferred Rent Credit, Noncurrent Deferred rent Deferred Income Tax Liabilities, Net Deferred tax liabilities Deferred Revenue, Noncurrent Deferred revenue - long-term 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 June 30, 2019 and December 31, 2018; 25,646,783 and 25,495,425 shares issued and outstanding as of June 30, 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 Balance Balance Total stockholders' equity 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, shares 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 CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS Revenue from Contract with Customer, Including Assessed Tax Collaboration revenue 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 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 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 CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS 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 Amount of Accretion and Amortization of Investments in Marketable Securities. Accretion and Amortization of Investments in Marketable Securities Net accretion and amortization of investments in marketable securities Represent non cash rent expense. Noncash rent expense Non-cash rent expense Deferred Income Tax Expense (Benefit) Deferred income tax benefit Gain (Loss) on Disposition of Assets Loss on disposal of fixed assets Other Noncash Income (Expense) Other 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 Other Noncurrent Assets Other 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 Deferred Rent Noncurrent Deferred rent Increase (Decrease) in Other Operating Liabilities Operating lease liabilities 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 Proceeds from Sale of Held-to-maturity Securities Proceeds from sale of marketable securities Net Cash Provided by (Used in) Investing Activities Net cash provided by investing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Cash flows from financing activities Proceeds from Issuance Initial Public Offering Net proceeds from issuance of common stock through equity plans Net Cash Provided by (Used in) Financing Activities Net cash provided by financing activities Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect Net decrease in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash and cash equivalents at the end of the period Cash and cash equivalents at the beginning of the period CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY Shares, Outstanding Balance (in shares) Balance (in shares) Stock Issued During Period, Value, Stock Options Exercised Issuance of common stock upon exercise of stock options Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Option, Exercised Issuance of common stock upon exercise of stock options ( in shares ) Stock Issued During Period, Value, Employee Stock Ownership Plan Issuance of common stock under Employee Stock Purchase Plan (ESPP) Stock Issued During Period, Shares, Employee Stock Ownership Plan Issuance of common stock under Employee Stock Purchase Plan (ESPP) ( in shares ) Issuance of common stock under employee stock purchase plan ( in shares ) Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Issuance of shares of common stock for settlement of restricted stock units (RSUs) Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Issuance of shares of common stock for settlement of restricted stock units (RSUs)(in shares) Reclassification of stock-based awards from equity to accrued expenses Trading Securities, Change in Unrealized Holding Gain (Loss) Unrealized gain (loss) on marketable securities, net of tax Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Stock-based compensation Nature of Business Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Nature of Business Summary of Significant Accounting Policies and Recent Accounting Pronouncements Significant Accounting Policies [Text Block] Summary of Significant Accounting Policies and Recent Accounting Pronouncements Investments in Marketable Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Investments in Marketable Securities Property and Equipment, net Property, Plant and Equipment Disclosure [Text Block] Property and Equipment, net Accrued Expenses Accounts Payable and Accrued Liabilities Disclosure [Text Block] Accrued Expenses Stock-Plans and Stock-Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Stock Plans and Stock-Based Compensation Collaboration Agreement Collaborative and License Arrangement Disclosure. Collaborative and License Arrangement Disclosure [Text Block] Collaboration Agreement Milestones and Research Agreements Milestones and Research Agreements [Text Block] Milestones and Research Agreements Leases Leases. Leases Basis of Accounting, Policy [Policy Text Block] Basis of Presentation Use of Estimates, Policy [Policy Text Block] Use of Estimates Disclosure of accounting policy for Significant Accounting Policies. Significant Accounting Policies [Policy Text Block] Significant Accounting Policies Stock-based compensation [Policy Text Block] Stock-Based Compensation Lessee, Leases [Policy Text Block] Leases Earnings Per Share, Policy [Policy Text Block] Net Loss per Share 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 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 Schedule of fair value of financial assets Property, Plant and Equipment [Table Text Block] Schedule of Property and Equipment Schedule of Accrued Liabilities [Table Text Block] Schedule of Accrued Expenses Share-based Compensation, Stock Options, Activity [Table Text Block] Schedule of Stock Options Activity Nonvested Restricted Stock Shares Activity [Table Text Block] Schedule of RSU's Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Assumptions for Weighted Average Fair Value of Options Granted Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block] Schedule of Stock-Based Compensation Expense Contract with Customer, Asset and Liability [Table Text Block] Schedule of changes in contract liabilities Schedule of Collaboration revenue recognized with the period Schedule of Collaboration revenue recognized with the period Disclosure of quantitative information of operating lease Disclosure of quantitative information of operating leases [Table Text Block] Schedule of quantitative information- operating leases Lessee, Operating Lease, Liability, Maturity [Table Text Block] Schedule of operating lease maturities Number of Operating Segments Operating segments (in segments) Represents the number of approved products. FDA approved products (in products) Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities Name [Domain] Antidilutive Securities, Name [Domain] Warrant [Member] Warrants Employee Stock Option [Member] Options Employee Stock [Member] Common stock subject to purchase under ESPP Restricted Stock Units R S U [Member] RSUs Antidilutive Securities Excluded from Computation of Earnings Per Share Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive securities excluded from computation of earnings (loss) 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 per share Earnings Per Share [Abstract] Net loss per share: Earnings Per Share, Basic Basic Earnings Per Share, Diluted Diluted Lessee, operating lease, term of contract Operating lease, liability Operating lease liabilities