Entity Central Index Key Document and entity information. Document And Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Document Type Document Type Trading Symbol Trading Symbol Document Period End Date Document Period End Date Amendment Flag Amendment Flag Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock Shares Outstanding Document Fiscal Period Focus Document Fiscal Period Focus Document Fiscal Year Focus Document Fiscal Year Focus Statement Of Financial Position [Abstract] ASSETS Assets [Abstract] Current assets: Assets Current [Abstract] Cash and cash equivalents Cash And Cash Equivalents At Carrying Value Accounts receivable Accounts Receivable Net Current Inventory Inventory Net Deposits on purchased inventory Advances On Inventory Purchases Deferred cost of revenue Deferred Costs Current Prepaid expenses and other current assets Prepaid Expense And Other Assets Current Total current assets Assets Current Property and equipment, net Property Plant And Equipment Net Restricted cash Restricted Cash And Cash Equivalents Noncurrent Intangible assets, net Finite Lived Intangible Assets Net Other assets Other Assets Noncurrent TOTAL ASSETS Assets Current liabilities: Liabilities Current [Abstract] Accounts payable Accounts Payable Current Accrued liabilities Accrued Liabilities Current Customer deposits Customer Deposits Current Deferred revenue, current portion Deferred Revenue Current Total current liabilities Liabilities Current Deferred revenue, net of current portion Deferred Revenue Noncurrent Long-term debt Long Term Debt Noncurrent Warrant liabilities Liabilities Fair Value Disclosure Recurring Other long-term liabilities Other Liabilities Noncurrent TOTAL LIABILITIES Liabilities Commitments and contingencies (Note 6) Commitments And Contingencies Stockholders’ equity: Stockholders Equity [Abstract] Convertible preferred stock, par value of $0.01 per share; 10,000,000 shares authorized at March 31, 2018 and December 31, 2017; 3,000,581 shares issued and outstanding at March 31, 2018 and no shares issued and outstanding at December 31, 2017 Preferred Stock Value Common stock, par value of $0.01 per share; 300,000,000 shares authorized at March 31, 2018 and December 31, 2017; 72,022,089 and 67,653,974 shares issued and outstanding at March 31, 2018 and December 31, 2017 Common Stock Value Additional paid-in capital Additional Paid In Capital Common Stock Accumulated deficit Retained Earnings Accumulated Deficit TOTAL STOCKHOLDERS’ EQUITY Stockholders Equity TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY Liabilities And Stockholders Equity Preferred stock, par 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 Common stock, par 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 Amortization of beneficial conversion feature. Net income loss available to common stock holders basic and diluted. Income Statement [Abstract] Revenue: Revenues [Abstract] Product Sales Revenue Goods Net Service Sales Revenue Services Net Distribution rights Revenue From Related Parties Total revenue Revenues Cost of revenue: Cost Of Revenue [Abstract] Product Cost Of Goods Sold Service Cost Of Services Total cost of revenue Cost Of Revenue Gross margin Gross Profit Operating expenses: Operating Expenses [Abstract] Research and development Research And Development Expense Selling and marketing Selling And Marketing Expense General and administrative General And Administrative Expense Total operating expenses Operating Expenses Loss from operations Operating Income Loss Interest income Investment Income Interest Interest expense Interest Expense Other income (expense), net Nonoperating Income Expense Loss before provision for income taxes Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest Provision for income taxes Income Tax Expense Benefit Net loss and comprehensive loss Net Income Loss Amortization of beneficial conversion feature related to Series A convertible preferred stock Amortization Of Beneficial Conversion Feature Net loss attributable to common stockholders, basic and diluted Net Income Loss Available To Common Stock Holders Basic And Diluted Net loss per share, basic and diluted Earnings Per Share Basic And Diluted Weighted-average common shares used to compute net loss per share attributable to common stockholders, basic and diluted Weighted Average Number Of Share Outstanding Basic And Diluted Fixed assets transferred from inventory and deferred cost of revenue. Statement Of Cash Flows [Abstract] Statement [Table] Statement [Table] Sale of Stock Subsidiary Sale Of Stock [Axis] Sale of Stock Sale Of Stock Name Of Transaction [Domain] Private Placement Private Placement [Member] At the market offering program. At The Market Offering Program At The Market Offering Program [Member] Direct registered offering. Direct Registered Offering Direct Registered Offering [Member] Statement [Line Items] Statement [Line Items] CASH FLOWS FROM OPERATING ACTIVITIES: Net Cash Provided By Used In Operating Activities Continuing Operations [Abstract] Net loss Adjustments to reconcile net loss to net cash used in operating activities: Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Depreciation and amortization Depreciation And Amortization Stock-based compensation Share Based Compensation Accretion on asset retirement obligation Accretion Expense Including Asset Retirement Obligations Change in fair value of warrant liabilities Fair Value Adjustment Of Warrants Loss on disposal of property and equipment Gain Loss On Sale Of Property Plant Equipment Amortization of debt discount and interest accrual Amortization Of Debt Discount Premium Changes in operating assets and liabilities: Increase Decrease In Operating Capital [Abstract] Accounts receivable Increase Decrease In Accounts Receivable Inventory Increase Decrease In Inventories Deposits on purchased inventory Increase Decrease In Deposits Outstanding Deferred cost of revenue Increase Decrease In Deferred Charges Prepaid expenses and other assets Increase Decrease In Prepaid Deferred Expense And Other Assets Accounts payable Increase Decrease In Accounts Payable Accrued expenses and other long-term liabilities Increase Decrease In Accrued Liabilities And Other Operating Liabilities Customer deposits and deferred revenue Increase Decrease In Deferred Revenue And Customer Advances And Deposits Net cash used in operating activities Net Cash Provided By Used In Operating Activities Continuing Operations CASH FLOWS FROM INVESTING ACTIVITIES: Net Cash Provided By Used In Investing Activities Continuing Operations [Abstract] Purchase of property and equipment Payments To Acquire Property Plant And Equipment Net cash used in investing activities Net Cash Provided By Used In Investing Activities Continuing Operations CASH FLOWS FROM FINANCING ACTIVITIES: Net Cash Provided By Used In Financing Activities Continuing Operations [Abstract] Proceeds from common stock private placement, gross Proceeds From Issuance Of Private Placement Payment of offering costs related to common stock issuance Payments Of Stock Issuance Costs Proceeds from offering of common stock, gross Proceeds From Issuance Of Common Stock Proceeds from the exercise of stock options Proceeds From Stock Options Exercised Net cash provided by financing activities Net Cash Provided By Used In Financing Activities Continuing Operations NET INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CASH, CASH EQUIVALENTS AND RESTRICTED CASH — BEGINNING OF PERIOD Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CASH, CASH EQUIVALENTS AND RESTRICTED CASH — END OF PERIOD SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION: Supplemental Cash Flow Information [Abstract] Cash paid for interest Interest Paid SUPPLEMENTAL NON-CASH INVESTING AND FINANCING ACTIVITIES: Cash Flow Noncash Investing And Financing Activities Disclosure [Abstract] Purchase of property and equipment in accounts payable and accrued expenses Capital Expenditures Incurred But Not Yet Paid Transfer of property and equipment from inventory and deferred cost of revenue Property And Equipment Transferred From Inventory And Deferred Cost Of Revenue Offering cost in accounts payable and accrued expenses Liabilities Assumed1 Organization Consolidation And Presentation Of Financial Statements [Abstract] Background and Organization Organization Consolidation And Presentation Of Financial Statements Disclosure [Text Block] Accounting Policies [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Balance Sheet Components Supplemental Balance Sheet Disclosures [Text Block] Fair Value Disclosures [Abstract] Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Debt Instruments [Abstract] Debt Long Term Debt [Text Block] Commitments And Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments And Contingencies Disclosure [Text Block] Distribution agreement. Related Party Transactions [Abstract] Distribution Agreement Distribution Agreement [Text Block] Equity financing. Equity [Abstract] Equity Financing Equity Financing [Text Block] Convertible Preferred Stock Preferred Stock [Text Block] The entire disclosure for stock warrant. Warrants Stock Warrant Disclosure [Text Block] Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] Stock-Based Compensation Disclosure Of Compensation Related Costs Share Based Payments [Text Block] Income Tax Disclosure [Abstract] Income Tax Income Tax Disclosure [Text Block] Earnings Per Share [Abstract] Net Loss per Share Earnings Per Share [Text Block] Related Party Transactions Related Party Transactions Disclosure [Text Block] Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Basis of Presentation Basis Of Accounting Policy Policy [Text Block] Significant accounting policies. Significant Accounting Policies Significant Accounting Policies Policy [Text Block] Recent Accounting Pronouncements New Accounting Pronouncements Policy Policy [Text Block] Recently adopted accounting pronouncements. Recently Adopted Accounting Pronouncements Recently Adopted Accounting Pronouncements Policy [Text Block] Schedule of Revenue Disaggregated by Types and Geography Disaggregation Of Revenue Table [Text Block] Balance Sheet Related Disclosures [Abstract] Schedule of Property and Equipment Property Plant And Equipment [Text Block] Summary of Intangible Assets Schedule Of Finite Lived Intangible Assets Table [Text Block] Summary of Estimated Future Amortization Expense Scheduleof Finite Lived Intangible Assets Future Amortization Expense Table [Text Block] Schedule of Accrued Liabilities Schedule Of Accrued Liabilities Table [Text Block] Schedule of Deferred Revenue Deferred Revenue By Arrangement Disclosure [Text Block] Schedule of Fair Value of Financial Liabilities Fair Value Liabilities Measured On Recurring Basis [Text Block] Summary of Changes in Fair Value of Level 3 Financial Liabilities Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Text Block] Schedule of Future Minimum Lease Payments Under Noncancelable Operating Lease Agreements Schedule Of Future Minimum Rental Payments For Operating Leases Table [Text Block] Summary of Assumptions using Black- Scholes Option Pricing Model to estimate fair value Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques Table [Text Block] Summary of Company's Stock Option Activity and Related Information Schedule Of Share Based Compensation Activity Table [Text Block] Schedule of Weighted-Average Assumptions Used in Black-Scholes Option-Pricing Model to Estimate Fair Value of Employee Stock Option at Grant Date Schedule Of Share Based Payment Award Stock Options Valuation Assumptions Table [Text Block] Summary of Stock-Based Compensation Expense Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Text Block] Anti-Dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Text Block] Net loss Net cash used from operations Remaining term of distribution agreement. Distribution revenue reclassified as deferred revenue. Significant accounting policies. Business And Summary Of Significant Accounting Policies [Table] Business And Summary Of Significant Accounting Policies [Table] Business And Summary Of Significant Accounting Policies [Table] Type of Arrangement and Non-arrangement Transactions Type Of Arrangement [Axis] Arrangements and Non-arrangement Transactions Arrangements And Nonarrangement Transactions [Member] Itochu Corporation agreement. Itochu Corporation Agreement Itochu Corporation Agreement [Member] Finite-Lived Intangible Assets by Major Class Finite Lived Intangible Assets By Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name Finite Lived Intangible Assets Major Class Name [Domain] Distribution Rights Distribution Rights [Member] Adjustments for New Accounting Pronouncements Adjustments For New Accounting Pronouncements [Axis] Type of Adoption Type Of Adoption [Member] ASU No. 2016-18 Accounting Standards Update201618 [Member] Significant Accounting Policies [Line Items] Significant Accounting Policies [Line Items] Distribution revenue reclassified as deferred revenue Distribution Revenue Reclassified As Deferred Revenue Remaining term of distribution agreement Remaining Distribution Agreement Term Disaggregation Of Revenue [Table] Disaggregation Of Revenue [Table] Geographical Statement Geographical [Axis] Geographical Segment Geographical [Domain] U.S. UNITED STATES Outside of U.S. ("OUS") Non Us [Member] Disaggregation Of Revenue [Line Items] Disaggregation Of Revenue [Line Items] Deferred revenue, recognized Deferred Revenue Revenue Recognized1 Operating leases future minimum payments due Operating Leases Future Minimum Payments Due Increase in beginning and ending cash and cash equivalents and restricted cash due to adoption of new accounting guidance. Increase in cash, cash equivalents and restricted cash Increase In Beginning And Ending Cash And Cash Equivalents And Restricted Cash Due To Adoption Of New Accounting Guidance Schedule Of Property Plant And Equipment [Table] Schedule Of Property Plant And Equipment [Table] Property, Plant and Equipment, Type Property Plant And Equipment By Type [Axis] Property, Plant and Equipment, Type Property Plant And Equipment Type [Domain] Prototype. Prototype Prototype [Member] Machinery and Equipment Machinery And Equipment [Member] Leasehold Improvements Leasehold Improvements [Member] Software Software And Software Development Costs [Member] Furniture and Fixtures Furniture And Fixtures [Member] Property Plant And Equipment [Line Items] Property Plant And Equipment [Line Items] Property and equipment, gross Property Plant And Equipment Gross Less: accumulated depreciation and amortization Accumulated Depreciation Depletion And Amortization Property Plant And Equipment Property and equipment, net Depreciation and amortization Depreciation Depletion And Amortization Schedule Of Finite Lived Intangible Assets [Table] Schedule Of Finite Lived Intangible Assets [Table] License cost. License Cost License Cost [Member] Patents Patents [Member] Finite Lived Intangible Assets [Line Items] Finite Lived Intangible Assets [Line Items] Intangible assets, gross Finite Lived Intangible Assets Gross Accumulated amortization Finite Lived Intangible Assets Accumulated Amortization Intangible assets, net Amortization of intangible assets Amortization Of Intangible Assets The remainder of 2018 Finite Lived Intangible Assets Amortization Expense Remainder Of Fiscal Year 2019 Finite Lived Intangible Assets Amortization Expense Next Twelve Months 2020 Finite Lived Intangible Assets Amortization Expense Year Two 2021 Finite Lived Intangible Assets Amortization Expense Year Three 2022 Finite Lived Intangible Assets Amortization Expense Year Four 2023 Finite Lived Intangible Assets Amortization Expense Year Five Thereafter Finite Lived Intangible Assets Amortization Expense After Year Five Accrued payable. Payables And Accruals [Abstract] Accrued payroll and related benefits Employee Related Liabilities Current Accrued accounts payable Accrued Payable Accrued legal, accounting and governance fees Accrued Professional Fees Current Tax payable Taxes Payable Current Other Other Accrued Liabilities Current Total accrued liabilities Deferred Revenue Disclosure [Abstract] Deferred Revenue Arrangement By Type [Table] Deferred Revenue Arrangement By Type [Table] Products and Services Product Or Service [Axis] Products and Services Products And Services [Domain] Product Product [Member] Services. Services Services [Member] Distribution rights. Distribution Rights Distribution Right [Member] Deferred Revenue [Line Items] Deferred Revenue Arrangement [Line Items] Total deferred revenue Deferred Revenue Less: current portion of deferred revenue Noncurrent portion of deferred revenue Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Table] Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Table] Class of Warrant or Right Class Of Warrant Or Right [Axis] Class of Warrant or Right Class Of Warrant Or Right [Domain] 2016 and 2017 private placement warrants. Two Thousand Sixteen And Two Thousand Seventeen Private Placement Warrants Two Thousand Sixteen And Two Thousand Seventeen Private Placement Warrants [Member] Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] Change in fair value of Level 3 financial liabilities Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Earnings Transfers between Level 1 to Level 2 Fair Value Liabilities Level1 To Level2 Transfers Amount Transfers between Level 2 to Level 1 Fair Value Liabilities Level2 To Level1 Transfers Amount Transfers into or out of Level 3 Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Transfers Net Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Fair Value, Hierarchy Fair Value By Fair Value Hierarchy Level [Axis] Fair Value Hierarchy Fair Value Measurements Fair Value Hierarchy [Domain] Level 1 Fair Value Inputs Level1 [Member] Level 2 Fair Value Inputs Level2 [Member] Level 3 Fair Value Inputs Level3 [Member] 2017 private placement warrants. 2017 Placement Warrants Two Thousand And Seventeen Private Placement Warrants [Member] 2016 private placement warrants. 2016 Placement Warrants Two Thousand And Sixteen Private Placement Warrants [Member] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] Placement Warrants Liability Fair value, beginning of period Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value Issuance of Placement Warrants Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Issues Change in fair value of Level 3 financial liabilities Fair value, end of period Interest payment end date. The minimum value of the Company after the Investment has been made Minimum gross revenue. Debt instrument cash interest rate percentage. Deferred payment in-kind interest rate percentage. Debt Disclosure [Abstract] Debt Instrument [Table] Debt Instrument [Table] MRIdian system. MRIdian System M R Idian System [Member] Debt Instrument, Redemption, Period Debt Instrument Redemption Period [Axis] Debt Instrument, Redemption, Period Debt Instrument Redemption Period [Domain] First 12 Months Debt Instrument Redemption Period One [Member] After Year 1 but on or Before Year 2 Debt Instrument Redemption Period Two [Member] After Year 2 but on or Before Year 3 Debt Instrument Redemption Period Three [Member] Debt instrument redemption after period three. After Year 3 Thereafter Until Maturity Debt Instrument Redemption After Period Three [Member] Loan Restructuring Modification Loan Restructuring Modification [Axis] Loan Restructuring Modification Loan Restructuring Modification [Domain] Milestone one. Milestone One Milestone One [Member] Milestone two. Milestone Two Milestone Two [Member] Range Range [Axis] Range Range [Member] Maximum Maximum [Member] Minimum Minimum [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Maximum borrowing capacity Line Of Credit Facility Maximum Borrowing Capacity Current borrowing capacity Line Of Credit Facility Current Borrowing Capacity Remaining borrowing capacity Line Of Credit Facility Remaining Borrowing Capacity Proceeds from initial public offering Proceeds From Issuance Initial Public Offering Post Money Valuation Minimum Amount Post Money Valuation Minimum Amount Required minimum gross revenue Minimum Gross Revenue Debt drawn Proceeds From Lines Of Credit Debt maturity date Debt Instrument Maturity Date Interest payment end date Interest Payment End Date Frequency of periodic payment Debt Instrument Frequency Of Periodic Payment Debt instrument cash interest rate percentage Debt Instrument Interest Rate Stated Percentage Debt instrument cash interest rate percentage Debt Instrument Cash Interest Rate Percentage Deferred payment in-kind interest rate Deferred Payment In Kind Interest Rate Debt instrument prepayment penalty percentage on outstanding balance. Prepayment penalty Debt Instrument Prepayment Penalty Facility fee Line Of Credit Facility Commitment Fee Percentage Term loan first amendment description. Term loan first amendment description Term Loan First Amendment Description Change in line of credit facility commitment fee percentage. Debt instrument existing capacity extended expiration date. Debt instrument additional capacity extended expiration date. Term loan second amendment description. Line of credit facility additional borrowing capacity. Term loan second amendment description Term Loan Second Amendment Description Additional borrowing capacity Line Of Credit Facility Additional Borrowing Capacity Existing capacity extended expiration date Debt Instrument Existing Capacity Extended Expiration Date Additional capacity extended expiration date Debt Instrument Additional Capacity Extended Expiration Date Increase in facility fee Change In Line Of Credit Facility Commitment Fee Percentage Term loan third amendment description. Term loan fourth amendment description. Term loan third amendment description Term Loan Third Amendment Description Term loan fourth amendment description Term Loan Fourth Amendment Description Deferred payment in-kind interest. Amount outstanding under the agreement Debt Instrument Carrying Amount Deferred payment in-kind interest Deferred Payment In Kind Interest Operating Leases Future Minimum Payments Due [Abstract] The remainder of 2018 Operating Leases Future Minimum Payments Remainder Of Fiscal Year 2019 Operating Leases Future Minimum Payments Due Current Total future minimum payments Purchase commitments Purchase Obligation Payment for distribution fees. Number of installments. Distribution agreement term. Other Industries [Abstract] Marketing agreement. Marketing Agreement [Table] Marketing Agreement [Table] Marketing Agreement [Table] Transaction Type Transaction Type [Axis] Transaction Transaction [Domain] First installment. First Installment First Installment [Member] Second installment. Second Installment Second Installment [Member] Third installment. Third Installment Third Installment [Member] First and second installment. First and Second Installment First And Second Installment [Member] Marketing Agreement [Line Items] Marketing Agreement [Line Items] Distribution agreement term Distribution Agreement Term Distribution fees Distribution Fees Number of installments Number Of Installments Distribution fees payment Payment For Distribution Fees Distribution fee reclassified to deferred revenue Distribution rights revenue Subsidiary Or Equity Method Investee Sale Of Stock By Subsidiary Or Equity Investee [Table] Subsidiary Or Equity Method Investee Sale Of Stock By Subsidiary Or Equity Investee [Table] At The Market Offering Program 2016 Placement Warrants 2017 Placement Warrants Equity Components Statement Equity Components [Axis] Equity Component Equity Component [Domain] Common Stock Common Stock [Member] 2016 private placement. 2016 Private Placement Two Thousand And Sixteen Private Placement [Member] 2017 private placement. 2017 Private Placement Two Thousand And Seventeen Private Placement [Member] Two thousand and seventeen direct registered offering. 2017 Direct Registered Offering Two Thousand And Seventeen Direct Registered Offering [Member] Two thousand eighteen direct registered offering. 2018 Direct Registered Offering Two Thousand Eighteen Direct Registered Offering [Member] Series a convertible preferred stock. Series A Convertible Preferred Stock Series A Convertible Preferred Stock [Member] Subsidiary Sale Of Stock [Line Items] Subsidiary Sale Of Stock [Line Items] Private placement, common shares Sale Of Stock Number Of Shares Issued In Transaction Warrants to purchase common stock, shares Class Of Warrant Or Right Number Of Securities Called By Warrants Or Rights Common stock warrants expiry term. Warrant exercise price Class Of Warrant Or Right Exercise Price Of Warrants Or Rights1 Proceed from private placement and equity issuances, gross Proceeds From Issuance Or Sale Of Equity Warrant expiration period Common Stock Warrants Expiry Term Class of warrants or rights expiry date. Warrant exercisable date Class Of Warrant Or Righst Date From Which Warrants Or Rights Exercisable Warrant expiration date Class Of Warrants Or Rights Expiry Date Stock issued during period Stock Issued During Period Shares New Issues Aggregate gross proceeds from issuance of common stock Liabilities and stockholders equity authorized offering value. Common stock authorized value. Maximum aggregate offering price Liabilities And Stockholders Equity Authorized Offering Value Maximum common stock saleable shares, value Common Stock Authorized Value Compensation percentage pertaining to gross sales price per share sold. Compensation percentage pertaining to gross sales price per share sold Compensation Percentage Pertaining To Gross Sales Price Per Share Sold Average market price per share Shares Issued Price Per Share Convertible preferred stock beneficial conversion feature. Convertible preferred stock. Convertible preferred stock. Convertible Preferred Stock [Table] Convertible Preferred Stock [Table] Class of Stock Statement Class Of Stock [Axis] Class of Stock Class Of Stock [Domain] Two thousand and eighteen direct registered offering. 2018 Direct Registered Offering Two Thousand And Eighteen Direct Registered Offering [Member] Subsequent Event Type Subsequent Event Type [Axis] Subsequent Event Type Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Convertible Preferred Stock [Line Items] Convertible Preferred Stock [Line Items] Convertible preferred stock, shares issued Stock price Convertible preferred stock, beneficial conversion feature Convertible Preferred Stock Beneficial Conversion Feature Preferred stock conversion percentage. Preferred stock conversion rate Preferred Stock Conversion Percentage Convertible preferred stock converted to common stock Stock Issued During Period Shares Conversion Of Convertible Securities Common stock warrant expiration date. Common stock warrants. Schedule of common stock warrants. Schedule Of Common Stock Warrants [Table] Schedule Of Common Stock Warrants [Table] Common stock warrant. Common Stock Warrants Common Stock Warrant [Member] 2015 placement common stock warrants. 2015 Placement Common Stock Warrants Two Thousand And Fifteen Placement Common Stock Warrants [Member] Related Party Related Party Transactions By Related Party [Axis] Related Party Related Party [Domain] Insiders. Insiders Insiders [Member] Two thousand and eighteen offering warrants. 2018 Offering Warrants Two Thousand And Eighteen Offering Warrants [Member] 2016 Private Placement Common Stock Warrants [Line Items] Common Stock Warrants [Line Items] Warrants issued Exercise price Common stock warrants, expiration date Common Stock Warrants Expiration Date Common stock warrants, expiry term Fair value of warrant liability upon issuance. Fair value of warrants upon issuance Fair Value Of Warrant Liability Upon Issuance Expected term (in years) Fair Value Assumptions Expected Term Expected volatility Fair Value Assumptions Expected Volatility Rate Risk-free interest rate Fair Value Assumptions Risk Free Interest Rate Expected dividend yield Fair Value Assumptions Expected Dividend Rate Proceeds from offering warrants Proceeds From Issuance Of Warrants (Gain) loss related to change in fair value Fair value of warrants Fair Value Inputs Liabilities Quantitative Information [Table] Fair Value Inputs Liabilities Quantitative Information [Table] Fair Value Inputs Liabilities Quantitative Information [Line Items] Fair Value Inputs Liabilities Quantitative Information [Line Items] Placement warrants outstanding Class Of Warrant Or Right Outstanding Common stock warrants, expiry date Share-based compensation arrangement by share-based payment award number of shares available for grant. Shares Available for Grant Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant [Abstract] Shares Available for Grant, Beginning balance Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant Shares Available for Grant, Additional options authorized Share Based Compensation Arrangement By Share Based Payment Award Number Of Additional Shares Authorized Shares Available for Grant, Options granted Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross Shares Available for Grant, Options canceled Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period Shares Available for Grant, Ending balance Number of Stock Options Outstanding Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Roll Forward Number of Stock Options Outstanding, Beginning balance Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number Number of Stock Options Outstanding, Options granted Number of Stock Options Outstanding, Options exercised Stock Issued During Period Shares Stock Options Exercised Number of Stock Options Outstanding, Options canceled Number of Stock Options Outstanding, Ending balance Number of Stock Options Outstanding, Vested and exercisable Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number Number of Stock Options Outstanding, Vested and expected to vest Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Exercisable Number Weighted- Average Exercise Price Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price Rollforward Weighted- Average Exercise Price, Beginning balance Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price Weighted- Average Exercise Price, Options granted Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price Weighted- Average Exercise Price, Options exercised Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price Weighted- Average Exercise Price, Options canceled Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price Weighted- Average Exercise Price, Ending balance Weighted- Average Exercise Price, Vested and exercisable Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price Weighted- Average Exercise Price, Vested and expected to vest Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Exercisable Weighted Average Exercise Price Share-based compensation arrangement by share-based payment award options weighted average remaining contractual term. Weighted- Average Remaining Contractual Life (Years) Share Based Compensation Arrangement By Share Based Payment Award Options Weighted Average Remaining Contractual Term [Abstract] Options Outstanding, Weighted- Average Remaining Contractual Life (Years) Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 Weighted- Average Remaining Contractual Life (Years), Vested and exercisable Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 Weighted- Average Remaining Contractual Life (Years), Vested and expected to vest Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested And Expected To Vest Exercisable Weighted Average Remaining Contractual Term1 Share based compensation arrangement by share based payment award options aggregate intrinsic value. Aggregate Intrinsic Value Share Based Compensation Arrangement By Share Based Payment Award Options Aggregate Intrinsic Value [Abstract] Aggregate Intrinsic Value Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value Aggregate Intrinsic Value, Vested and exercisable Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 Aggregate Intrinsic Value, Vested and expected to vest Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Aggregate Intrinsic Value Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Award Type Award Type [Axis] Equity Award Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain] Restricted Stock Units (RSUs) Restricted Stock Units R S U [Member] Title of Individual Title Of Individual [Axis] Relationship to Entity Title Of Individual With Relationship To Entity [Domain] Board of Directors Director [Member] Executive Officers Executive Officer [Member] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Grant date fair value of options granted, per share Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value Grant date fair value of options vested Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested In Period Fair Value1 Aggregate intrinsic value of option exercised Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value Unrecognized compensation cost Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Stock Options Weighted average period for recognition of compensation costs Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1 Expected term (in years) Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 Expected volatility% Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate Risk-free interest rate% Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate Expected dividend yield% Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate RSUs Granted Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Grant date fair value of RSUs, per share Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value RSUs Released Share Based Compensation Arrangement By Share Based Payment Award Shares Issued In Period Stock based compensation expenses Allocated Share Based Compensation Expense Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Table] Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Table] Income Statement Location Income Statement Location [Axis] Income Statement Location Income Statement Location [Domain] Research and Development Research And Development Expense [Member] Selling and Marketing Selling And Marketing Expense [Member] General and Administrative General And Administrative Expense [Member] Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] Stock-based compensation expense Stock-based compensation expense capitalized Employee Service Share Based Compensation Allocation Of Recognized Period Costs Capitalized Amount Income tax expense Federal statutory tax rate Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate Federal and state effective tax rate Effective Income Tax Rate Continuing Operations Unrecognized tax benefits Unrecognized Tax Benefits Accrued interest and penalties related to uncertain tax positions Unrecognized Tax Benefits Income Tax Penalties And Interest Expense Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Antidilutive Securities Antidilutive Securities Excluded From Computation Of Earnings Per Share By Antidilutive Securities [Axis] Antidilutive Securities, Name Antidilutive Securities Name [Domain] Series A Convertible Preferred Stock (If Converted) Options To Purchase Common Stock Employee Stock Option [Member] Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Anti-dilutive securities excluded from calculation of diluted net loss per share Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount Percentage of royalty rate payable on sales. Schedule Of Related Party Transactions By Related Party [Table] Schedule Of Related Party Transactions By Related Party [Table] University of Florida research foundation. University Of Florida Research Foundation University Of Florida Research Foundation [Member] Licensing Agreements Licensing Agreements [Member] Related Party Transaction Related Party Transaction [Axis] Related Party Transaction Related Party Transaction [Domain] Sales consulting agreement. Sales Consulting Agreement [Member] Sales Consulting Agreement [Member] Investment manager of investment company. Investment Manager of Investment Company Investment Manager Of Investment Company [Member] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Common Stock granted in exchange for licensing Stock Issued During Period Shares Issued For Services Percentage of royalty payment based on sale Percentage Of Royalty Rate Payable On Sales Royalty payment per quarter Payments For Royalties Term of related party transaction. Related party, agreement term Related Party Transaction Term Related party, total consideration Due To Related Parties Current Subsequent Event [Table] Subsequent Event [Table] Lease Agreement Lease Agreements [Member] Mountain View, California CALIFORNIA Subsequent Event [Line Items] Subsequent Event [Line Items] Additional office space Area Of Real Estate Property Lease agreement, term of contract Lessee Leasing Arrangements Operating Leases Term Of Contract Lease agreement, renewal term Lessee Leasing Arrangements Operating Leases Renewal Term