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 Title of 12(b) Security Trading Symbol Security Exchange Name Entity Current Reporting Status Entity Interactive Data Current Entity Filer Category Entity Small Business Entity Emerging Growth Company Entity Shell Company Entity Common Stock, Shares Outstanding Current Fiscal Year End Date Document Fiscal Year Focus Document Fiscal Period Focus Entity Central Index Key Amendment Flag Condensed Consolidated Balance Sheets Statement [Table] Statement [Line Items] Company's equity incentive plans Assets, Current [Abstract] Current Assets Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Cash and cash equivalents Short-term Investments Short-term investments 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 Operating Lease, Right-of-Use Asset Operating lease right-of-use assets Restricted Cash Restricted cash Restricted cash (included in non-current assets on the condensed consolidated balance sheets) Other Assets, Noncurrent Long-term assets Assets Total Assets Liabilities, Current [Abstract] Current Liabilities Accounts Payable, Current Accounts payable Accrued Liabilities, Current Accrued liabilities Accrued expenses Operating Lease, Liability, Current Operating lease liabilities - current Current portion included in current liabilities Liabilities, Current Total Current Liabilities Liabilities, Noncurrent [Abstract] Non-Current Liabilities Operating Lease, Liability, Noncurrent Operating lease liabilities - noncurrent Long-term portion included in non-current liabilities Other Liabilities, Noncurrent Other liabilities Liabilities, Noncurrent Total Non-Current Liabilities Liabilities Total Liabilities Commitments and Contingencies Commitments and contingencies (Notes 8 and 9) Condensed Consolidated Statements of Stockholders' Equity Stockholders' Equity Preferred Stock, Value, Issued Preferred stock, Value Common Stock, Value, Issued Common stock, $0.000041666 par value; 300,000,000 shares authorized, 126,823,156 and 126,411,808 shares issued and outstanding as of March 31, 2020 and December 31, 2019, respectively Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive income Additional Paid in Capital Additional paid-in capital Retained Earnings (Accumulated Deficit) Retained earnings Accumulated deficit Stockholders' Equity Attributable to Parent Ending Balance Beginning Balance Total Stockholders' Equity Liabilities and Equity Total Liabilities and Stockholders' Equity Class of Stock [Axis] Class Of Stock [Domain] Class of Stock [Domain] Series A Preferred Stock [Member] Series A Convertible Preferred Stock Series B Preferred Stock [Member] Series B Convertible Preferred Stock Preferred Stock, Par or Stated Value Per Share Preferred stock, par or stated value per share Preferred Stock, Shares Authorized Preferred stock, shares authorized Preferred Stock, Shares Issued Preferred Stock, Shares Issued Preferred Stock, Shares Outstanding Preferred stock, shares outstanding Preferred Stock, Liquidation Preference, Value Preferred Stock, Liquidation Preference, Value Common Stock, Par or Stated Value Per Share Common stock, par or stated value per share 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 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 loss Net loss 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 Condensed Consolidated Statements of Comprehensive Loss Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Other comprehensive income: Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax Unrealized gain on short-term investments Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive Loss Shares, Outstanding Ending Balance (in Shares) Beginning Balance (in Shares) Cumulative Effect of New Accounting Principle in Period of Adoption Adoption of ASU 2018-07 Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Stock-based compensation expense Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Vesting of restricted shares issued for services Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Vesting of restricted shares issued for services (in shares) Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net Tax payments related to shares withheld for vested restricted stock units Stock Issued During Period, Value, Stock Options Exercised Common stock issued upon exercise of stock options Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Exercised Common stock issued upon exercise of stock options (in shares) Amount of cancellation shares from settlement of dispute. Stock Cancelled During Period Shares Of Common Stock Cancellation of common shares from settlement of dispute Amount of cancellation shares from settlement of dispute. Cancellation of common shares from settlement of dispute (In Shares) Cancellation of common shares from settlement of dispute (In Shares) 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: Share-based Compensation Stock-based compensation expense Share-based Compensation Amount of Noncash lease expense. Non Cash Lease Expense Noncash lease expense Amortization of Debt Discount (Premium) Amortization of premiums on investments Depreciation, Depletion and Amortization, Nonproduction Depreciation and amortization Gain (Loss) Related to Litigation Settlement Gain on settlement of dispute Increase (Decrease) in Operating Capital [Abstract] Changes in assets and liabilities: Increase (Decrease) in Prepaid Expense and Other Assets Prepaid expenses, other assets, and long-term assets Amount of operating lease liabilities. Increase Decrease in operating Lease Right of Use Asset Operating lease liabilities (Right-of-use assets) Increase (Decrease) in Accounts Payable Accounts payable Increase (Decrease) in Accrued Liabilities Accrued expenses and other liabilities Net Cash Provided by (Used in) Operating Activities Net cash used in operating activities Net cash used in operating activities Net Cash Provided by (Used in) Investing Activities [Abstract] Cash Flows from Investing Activities Proceeds from Sale and Maturity of Debt Securities, Available-for-sale Maturities of short-term investments Payments to Acquire Available-for-sale Securities Purchase 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 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 Stock Options Exercised Proceeds from the issuance of common stock upon exercise of options Net Cash Provided by (Used in) Financing Activities Net cash provided by / (used in) financing activities Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect Net increase / (decrease) in cash, cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash, Cash Equivalents, and Restricted Cash, End of Period (Note 2) Cash, Cash Equivalents, and Restricted Cash, Beginning of Period Total cash, cash equivalents and restricted cash Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Supplemental disclosure of non-cash investing and financing activities: Amount of unrealized gain (loss) on short-term investments. Unrealized Gain Loss On Short Term Investments Net unrealized gain on short-term investments Future cash outflow to pay for leasehold improvements that have occurred. Leasehold Improvements Paid by Landlord Acquisitions of property and equipment included in accounts payable and accrued expenses GENERAL ORGANIZATION AND BUSINESS Business Description and Basis of Presentation [Text Block] GENERAL ORGANIZATION AND BUSINESS SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Significant Accounting Policies [Text Block] SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS Cash, Cash Equivalents, and Short-term Investments [Text Block] CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS BALANCE SHEET COMPONENTS Supplemental Balance Sheet Disclosures [Text Block] BALANCE SHEET COMPONENTS STOCKHOLDERS' EQUITY Stockholders' Equity Note Disclosure [Text Block] STOCKHOLDERS' EQUITY STOCK BASED COMPENSATION Disclosure of Compensation Related Costs, Share-based Payments [Text Block] STOCK BASED COMPENSATION LICENSES AND AGREEMENTS The entire disclosure for licenses and agreements. Licenses And Agreements Disclosure [Text Block] LICENSES AND AGREEMENTS LEGAL PROCEEDINGS Contingencies Disclosure [Text Block] LEGAL PROCEEDINGS LEASES Lessee, Operating Leases [Text Block] LEASES RELATED PARTY TRANSACTIONS Related Party Transactions Disclosure [Text Block] RELATED PARTY TRANSACTIONS Cash and Cash Equivalents, Policy [Policy Text Block] Cash, Cash Equivalents, and Short-term Investments 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 Income Tax, Policy [Policy Text Block] Income Taxes Lessee, Leases [Policy Text Block] Leases 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 The accounting policy for all convertible instruments issued by the entity. Convertible Instruments Policy [Text Block] Convertible Instruments New Accounting Pronouncements, Policy [Policy Text Block] Recent Accounting Standards Subsequent Events, Policy [Policy Text Block] Subsequent Event Reclassification, Policy [Policy Text Block] Reclassifications Tabular disclosure of the components of cash, cash equivalents and Restricted Cash. Schedule of Cash and Cash Equivalents and Restricted Cash [Table Text Block] Schedule of cash and cash equivalents and restricted cash 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 Fair Value, Assets Measured on Recurring Basis [Table Text Block] Schedule of assets measured at fair value 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 Cash, Cash Equivalents and Investments [Table Text Block] Schedule of cash, money market funds and short-term investments Unrealized Gain (Loss) on Investments [Table Text Block] Schedule of cost and fair value of cash equivalents and short-term investments Schedule of Accrued Liabilities [Table Text Block] Schedule of accrued liabilities 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 Tabular disclosure of supplemental balance sheet information related to leases Supplemental Balance Sheet Information Related To Leases [Table Text Block] Schedule of balance sheet classification of the Company's right-of-use asset and lease liabilities Lease, Cost [Table Text Block] Schedule of components of lease expenses Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Schedule of maturities of the Company's operating lease liabilities Cash, Cash Equivalents, and Short-term Investments Cash, cash equivalents and short-term investments Cash includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the customer may deposit additional funds at any time and effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid Investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Short-term investments, exclusive of cash equivalents, generally consist of marketable securities intended to be sold within one year (or the normal operating cycle if longer) and may include trading securities, available-for-sale securities, or held-to-maturity securities (if maturing within one year), as applicable. ash, Cash Equivalents, and Short-term Investments, and Restricted Cash, Total cash equivalents, short-term investments, and restricted cash Disclosure of information about significant accounting policies. Accounting Policies [Table] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Security Deposit Security deposit Represents the security deposit for the benefit of the landlord for its commercial manufacturing facility. Security Deposit For Benefit Of Landlord For Commercial Manufacturing Facility Security deposit for the benefit of the landlord for its commercial manufacturing facility Represents the security deposit for the benefit of utilities service provider. Security Deposit For Benefit Of Utilities Service Provider Security deposit for the benefit of utilities service provider Letters of Credit Outstanding, Amount Letter of credit Antidilutive Securities [Axis] Antidilutive Securities Name [Domain] Antidilutive Securities, Name [Domain] Employee Stock Option [Member] Stock option Restricted Stock Units R S U [Member] Restricted stock units Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive securities excluded from calculation of net loss per share Fair Value Hierarchy and NAV [Axis] Fair Value Measurements Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Fair Value Inputs Level1 [Member] Level 1 Financial Instrument [Axis] Transfers And Servicing Of Financial Instruments Types Of Financial Instruments [Domain] Financial Instruments [Domain] U S Treasury Securities [Member] US treasury securities U S Government Corporations And Agencies Securities [Member] US government agency securities Assets, Fair Value Disclosure Total