Entity Central Index Key Document and entity information. Document And Entity Information [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol Entity Registrant Name Entity Registrant Name Entity Central Index Key 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 Carrying amount as of the balance sheet date, which is the fair value of the acquired in-process technology, adjusted for any amortization recognized after market feasibility has been achieved and for any impairment charges. Statement Of Financial Position [Abstract] Assets Assets [Abstract] Current assets: Assets Current [Abstract] Cash and cash equivalents Cash And Cash Equivalents At Carrying Value Prepaid expenses and other current assets Prepaid Expense And Other Assets Current Total current assets Assets Current Goodwill Goodwill In-process research and development In Process Research And Development Investment in joint venture Investments In Affiliates Subsidiaries Associates And Joint Ventures Property and equipment, net Property Plant And Equipment Net Other assets Other Assets Noncurrent Total assets Assets Liabilities and Stockholders’ Equity Liabilities And Stockholders Equity [Abstract] Current liabilities: Liabilities Current [Abstract] Accounts payable Accounts Payable Current Accrued expenses Accrued Liabilities Current Total current liabilities Liabilities Current Long-term deferred rent Deferred Rent Credit Noncurrent Deferred tax liability Deferred Tax Liabilities Noncurrent Long-term deferred revenue Deferred Revenue Noncurrent Total liabilities Liabilities Commitments and contingencies Commitments And Contingencies Stockholders’ equity: Stockholders Equity [Abstract] Common stock, $0.001 par value;100,000,000 shares authorized at June 30, 2018 and December 31, 2017; 41,879,073 and 36,452,893 shares issued and outstanding at June 30, 2018 and December 31, 2017, respectively Common Stock Value Additional paid-in capital Additional Paid In Capital Common Stock Accumulated other comprehensive loss Accumulated Other Comprehensive Income Loss Net Of Tax Accumulated deficit Retained Earnings Accumulated Deficit Total stockholders’ equity Stockholders Equity Total liabilities and stockholders' equity Liabilities And Stockholders Equity Common stock, par value 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 Research, development and patents expense. Income Statement [Abstract] Operating expenses: Operating Expenses [Abstract] Research, development and patents Research Development And Patents Expense General and administrative General And Administrative Expense Total operating expenses Operating Expenses Operating loss Operating Income Loss Interest Income Interest Income Other Other income (expense) Other Nonoperating Income Expense Loss before income taxes Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest Income taxes Income Tax Expense Benefit Net loss applicable to common stockholders Net Income Loss Basic and diluted net loss per common share Earnings Per Share Basic And Diluted Shares used to compute basic and diluted net loss per common share Weighted Average Number Of Share Outstanding Basic And Diluted Net loss applicable to common stockholders Other comprehensive loss, net of tax: Other Comprehensive Income Loss Net Of Tax Period Increase Decrease [Abstract] Foreign currency translation adjustments Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax Comprehensive loss Comprehensive Income Net Of Tax Stock issued during period shares under at-the-market equity distribution and sales agreements. Class of warrant or right, exercised in period. Warrant exercises. Statement Of Stockholders Equity [Abstract] Statement [Table] Statement [Table] Equity Components Statement Equity Components [Axis] Equity Component Equity Component [Domain] Common stock Common Stock [Member] Additional paid-in capital Additional Paid In Capital [Member] Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income [Member] Accumulated deficit Retained Earnings [Member] Statement [Line Items] Statement [Line Items] Beginning Balance Beginning Balance (in shares) Shares Outstanding Share-based compensation Stock Issued During Period Value Share Based Compensation Issuance of shares under an employee stock purchase plan (ESPP) Stock Issued During Period Value Employee Stock Purchase Plan Issuance of shares under an employee stock purchase plan (ESPP) (in shares) Stock Issued During Period Shares Employee Stock Purchase Plans Issuance of common stock, net of offering costs Stock Issued During Period Value New Issues Issuance of common stock, net of offering costs (in shares) Stock Issued During Period Shares Under At The Market Equity Distribution And Sales Agreements Issuance of common stock for option exercises Stock Issued During Period Value Stock Options Exercised Issuance of common stock for option exercises (in shares) Stock Issued During Period Shares Stock Options Exercised Exercise of warrants Warrant Exercises Exercise of warrants, shares Class Of Warrant Or Right Exercised In Period Net loss Ending Balance Ending Balance (in shares) Proceeds from issuance of common stock, exercise of common stock options and warrants, net of issuance costs. Statement Of Cash Flows [Abstract] Operating activities: Net Cash Provided By Used In Operating Activities [Abstract] 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] Non-cash stock-based compensation Share Based Compensation Depreciation and amortization Depreciation Depletion And Amortization Change in joint venture investment Income Loss From Equity Method Investments Changes in assets and liabilities: Increase Decrease In Operating Capital [Abstract] Prepaid expenses and other assets Increase Decrease In Prepaid Deferred Expense And Other Assets Accounts payable, accrued liabilities and other liabilities Increase Decrease In Operating Liabilities Net cash used in operating activities Net Cash Provided By Used In Operating Activities Investing activities: Net Cash Provided By Used In Investing Activities [Abstract] Acquisition of property and equipment Payments To Acquire Property Plant And Equipment Proceeds from dissolution of joint venture Proceeds From Divestiture Of Interest In Joint Venture Net cash used in investing activities Net Cash Provided By Used In Investing Activities Financing activities: Net Cash Provided By Used In Financing Activities [Abstract] Proceeds from issuance of common stock, exercise of common stock options and warrants, net of issuance costs Proceeds From Issuance Of Common Stock Exercise Of Common Stock Options And Warrants Net Of Issuance Costs Proceeds from issuance of equity awards under ESPP Proceeds From Stock Plans Net cash provided by financing activities Net Cash Provided By Used In Financing Activities Effect of exchange rate changes on cash and cash equivalents Effect Of Exchange Rate On Cash And Cash Equivalents Net increase in cash and cash equivalents Cash And Cash Equivalents Period Increase Decrease Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Supplemental disclosures of cash flow information: Supplemental Cash Flow Information [Abstract] Income taxes paid Income Taxes Paid Quarterly Financial Information Disclosure [Abstract] Interim Financial Information Quarterly Financial Information [Text Block] Revenue Recognition [Abstract] Revenue Recognition Deferred Revenue Disclosure [Text Block] Fair Value Disclosures [Abstract] Fair Value Measurements Fair Value Measurement Inputs Disclosure [Text Block] Equity Method Investments And Joint Ventures [Abstract] Joint Venture Equity Method Investments Disclosure [Text Block] Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] Stock-based Compensation Disclosure Of Compensation Related Costs Share Based Payments [Text Block] Equity [Abstract] Stockholders' Equity Stockholders Equity Note Disclosure [Text Block] Earnings Per Share [Abstract] Net Loss Per Share Earnings Per Share [Text Block] Accounting Policies [Abstract] Basis of Presentation Basis Of Accounting Policy Policy [Text Block] Research development and patents expense. Research, Development and Patents Research Development And Patents Expense Policy [Text Block] Use of Estimates Use Of Estimates Recently Issued Accounting Pronouncements New Accounting Pronouncements Policy Policy [Text Block] Revenue Recognition Policy Revenue Recognition Policy [Text Block] Summary of Stock Option Activity and Related Information Schedule Of Share Based Compensation Stock Options Activity Table [Text Block] Schedule of share based payment award stock options and employee stock purchase plan valuation assumptions. Schedule of Assumptions Used in Estimating Fair Value of Options Granted and Performance-Based Stock Options Schedule Of Share Based Payment Award Stock Options And Employee Stock Purchase Plan Valuation Assumptions Table [Text Block] Securities Excluded from Diluted Net Loss Per Common Share Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Text Block] Quarterly financial information disclosure. Quarterly financial information disclosure. Quarterly Financial Information Disclosure [Table] Quarterly Financial Information Disclosure [Table] Product and Service Product Or Service [Axis] Product and Service Products And Services [Domain] License License [Member] Quarterly Financial Information Disclosure [Line Items] Quarterly Financial Information Disclosure [Line Items] Research and development Research And Development Expense Patent-related expenses Cost Of Goods And Services Sold Revenue Recognition Milestone Method [Table] Revenue Recognition Milestone Method [Table] Related Party Related Party Transactions By Related Party [Axis] Related Party Related Party [Domain] Kissei Pharmaceutical Co., Ltd. Kissei Pharmaceutical Co., Ltd Kissei Pharmaceutical Co Ltd [Member] Revenue Recognition Milestone Method [Line Items] Revenue Recognition Milestone Method [Line Items] Deferred revenue related to research and development services Revenue relating to research and development services Research And Development Arrangement Contract To Perform For Others Compensation Earned 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 and NAV Fair Value By Fair Value Hierarchy Level [Axis] Fair Value Hierarchy and NAV Fair Value Measurements Fair Value Hierarchy [Domain] Fair Value Measurements Using Level 1 Fair Value Inputs Level1 [Member] Cash and Cash Equivalents Cash And Cash Equivalents [Axis] Cash and Cash Equivalents Restricted Cash And Cash Equivalents Cash And Cash Equivalents [Member] Money Market Funds Money Market Funds [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] Cash and cash equivalents fair value Cash And Cash Equivalents Fair Value Disclosure Schedule Of Equity Method Investments [Table] Schedule Of Equity Method Investments [Table] Investment, Name Schedule Of Equity Method Investment Equity Method Investee Name [Axis] Investment, Name Equity Method Investee Name [Domain] Zhejiang Sunmy Bio Medical Co Ltd. Zhejiang Sunmy Bio Medical Co Ltd Zhejiang Sunmy Bio Medical Co Ltd [Member] Investment Issuer Investment Issuer [Axis] Investment Issuer Investment Issuer [Domain] Beijing Medfron Medical Technologies Co Ltd. Beijing Medfron Medical Technologies Co Ltd Beijing Medfron Medical Technologies Co Ltd [Member] Schedule Of Equity Method Investments [Line Items] Schedule Of Equity Method Investments [Line Items] Investment in joint venture, percentage Equity Method Investment Ownership Percentage Proceed from dissolution of joint venture and liquidation of investments Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Plan Name Plan Name [Axis] Plan Name Plan Name [Domain] Two thousand thirteen equity incentive plan. 2013 Plan Two Thousand Thirteen Equity Incentive Plan [Member] Two thousand four plan. 2004 Plan Two Thousand Four Plan [Member] Award Type Award Type [Axis] Equity Award Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain] Stock Option Employee Stock Option [Member] Range Range [Axis] Range Range [Member] Minimum Minimum [Member] Maximum Maximum [Member] Sale of Stock Subsidiary Sale Of Stock [Axis] Sale of Stock Sale Of Stock Name Of Transaction [Domain] 2007 Employee Stock Purchase Plan Employee Stock [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Common stock reserved for future issuance Common Stock Capital Shares Reserved For Future Issuance Shares available for future grant Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant Options granted expiration term Sharebased Compensation Arrangement By Sharebased Payment Award Expiration Period Stock option, vesting period Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Period1 Number of Option Shares Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Roll Forward Stock Options, Beginning Balance Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number Stock Options, Granted Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross Stock Options, Exercised Stock Options, Cancelled Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures And Expirations In Period Stock Options, Ending Balance Stock Options, Exercisable at June 30, 2018 Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number 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, Granted Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price Weighted Average Exercise Price, Exercised Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price Weighted Average Exercise Price, Cancelled Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures And Expirations In Period Weighted Average Exercise Price Weighted Average Exercise Price, Ending Balance Weighted Average Exercise Price, Exercisable at June 30, 2018 Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price Stock options exercised Gross proceed from stock options exercised Proceeds From Stock Options Exercised Stock issuance limit under employee stock purchase plan description. Annual increase in shares reserved for issuance. Annual increase in shares reserved for issuance as percentage of outstanding shares of common stock. Employee stock purchase plan offering period. Shares reserved, description Stock Issuance Limit Under Employee Stock Purchase Plan Description Increase in shares reserved for issuance Annual Increase In Shares Reserved For Issuance Increase in shares reserved for issuance as percentage of outstanding shares Annual Increase In Shares Reserved For Issuance As Percentage Of Outstanding Shares Of Common Stock Percentage of employee compensation for purchase of common stock under ESPP Share Based Compensation Arrangement By Share Based Payment Award Maximum Employee Subscription Rate Common stock fair market value, percentage Sharebased Compensation Arrangement By Sharebased Payment Award Purchase Price Of Common Stock Percent Employee stock purchase plan offering period Employee Stock Purchase Plan Offering Period Shares issued under ESPP Stock-based compensation expense Employee Stock Purchase Plan Weighted-average assumptions for stock options and ESPP Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Abstract] Risk-free interest rate Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate