Equity [Abstract] Stockholders' Equity Stockholders' Equity Note Disclosure [Text Block] Leases [Abstract] Operating lease, weighted average remaining lease term Operating Lease, Weighted Average Remaining Lease Term Operating lease, weighted average discount rate, percent Operating Lease, Weighted Average Discount Rate, Percent Revenue from Contract with Customer [Abstract] Schedule of Changes in Contract Liabilities Contract with Customer, Asset and Liability [Table Text Block] Related Party Transactions [Abstract] Schedule of Related Party Transactions Schedule of Related Party Transactions [Table Text Block] 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] Sale of Stock [Axis] Sale of Stock [Axis] Sale of Stock [Domain] Sale of Stock [Domain] Public Stock Offering Public Stock Offering [Member] Public Stock Offering [Member] Over-Allotment Option Over-Allotment Option [Member] At-The-Market Offering At-The-Market Offering [Member] At-The-Market Offering [Member] 2017 PIPE 2017 PIPE [Member] 2017 PIPE [Member] Springer Purchase Agreement Springer Purchase Agreement [Member] Springer Purchase Agreement [Member] Exercise of common warrants Warrant [Member] IPO IPO [Member] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Common stock Common Stock [Member] Subsidiary, Sale of Stock [Line Items] Subsidiary, Sale of Stock [Line Items] Sale of stock, number of shares issued in transaction (in shares) Sale of Stock, Number of Shares Issued in Transaction Share price (in dollars per share) Sale of Stock, Price Per Share Sale common stock Sale of Stock, Consideration Received on Transaction Public securities offering, amount authorized Public Securities Offering, Amount Authorized Public Securities Offering, Amount Authorized Public stock offering, amount authorized Public Stock Offering, Amount Authorized Public Stock Offering, Amount Authorized Shares issued, value Proceeds from Issuance of Common Stock Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Stock issued (in shares) Stock Issued During Period, Shares, New Issues Exercise price (in dollars per share) Class of Warrant or Right, Exercise Price of Warrants or Rights Share price (in dollars per share) Class of Warrant or Right, Issued to Purchase Common Stock Class of Warrant or Right, Issued to Purchase Common Stock Proceeds from Initial Public Offering, net of underwriters' discounts and commissions Proceeds from Issuance Initial Public Offering Convertible preferred stock, shares issued upon conversion (in shares) Convertible Preferred Stock, Shares Issued upon Conversion Common stock, shares authorized (in shares) Common Stock, Shares Authorized Number of votes per share that common stockholders are entitled to Votes Per Share of Common Stock Votes Per Share of Common Stock Dividends declared or paid on common stock Dividends, Common Stock Share-based Payment Arrangement [Abstract] 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 [Axis] Award Type [Axis] Award Type [Domain] Award Type [Domain] Employee stock option grants Share-based Payment Arrangement [Member] Non-employee stock options Non Employee Stock Option [Member] An arrangement whereby a non-employee is entitled to receive in the future, subject to vesting and other restrictions, a number of shares in the entity at a specified price, as defined in the agreement. Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Dividend yield Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Expected term Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Expected volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Weighted-average fair value of common stock (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Weighted Average Fair Value Weighed-average fair value relating to the share-based payment award. Remaining performance obligation Revenue, Remaining Performance Obligation, Amount Remaining performance obligation, percentage Revenue, Remaining Performance Obligation, Percentage Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Spark License Agreement License Agreement Terms [Member] Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] License and Supply Obligation License And Supply Obligation [Member] License And Supply Obligation [Member] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Remaining performance obligation, period Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Investments, Debt and Equity Securities [Abstract] Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-sale [Table] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] U.S. government and agency securities US Treasury and Government [Member] Corporate bonds Corporate Bond Securities [Member] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-sale [Line Items] Amortized Cost Debt Securities, Available-for-sale, Amortized Cost Gross Unrealized Gains Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Gross Unrealized Losses Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Fair Value Debt Securities, Available-for-sale Statement of Stockholders' Equity [Abstract] Issuance costs Payments of Stock Issuance Costs Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Shares available for future stock incentive awards Restricted stock units Restricted Stock [Member] Unvested restricted stock units Restricted Stock Units (RSUs) [Member] Outstanding common stock options Share-based Payment Arrangement, Option [Member] Class of Stock [Line Items] Class of Stock [Line Items] Total (in shares) Common Stock, Capital Shares Reserved for Future Issuance Fair Value Disclosures [Abstract] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Measurement Frequency [Domain] Measurement Frequency [Domain] Recurring Fair Value, Recurring [Member] Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Domain] Cash and Cash Equivalents [Domain] Money market funds Money Market Funds [Member] Corporate bonds and commercial paper Corporate Bonds And Commercial Paper [Member] Corporate Bonds And Commercial Paper [Member] Commercial paper Commercial Paper [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] (Level 1) Fair Value, Inputs, Level 1 [Member] (Level 2) Fair Value, Inputs, Level 2 [Member] (Level 3) Fair Value, Inputs, Level 3 [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] Total cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Short-term investments: Investments, Fair Value Disclosure Investments maturity period Investments Maturity Period Represents information pertaining to US treasury obligations in investments maturity period. Goodwill and Intangible Assets Disclosure [Abstract] Technology License Agreements Technology License Agreements [Text Block] The entire disclosure for technology license agreements. Leases Lessee, Operating Leases [Text Block] Earnings Per Share [Abstract] 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 [Axis] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Stock options to purchase common stock Stock warrants to purchase common stock Potential common shares Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Total (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Statement of Cash Flows [Abstract] Statement [Table] Statement [Table] Statement [Line Items] Statement [Line Items] Cash flows from operating activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Net loss Net Income (Loss) Attributable to Parent 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 Depreciation Amortization of premiums (accretion of discounts) on investments Accretion (Amortization) of Discounts and Premiums, Investments Gain on disposal of property and equipment Gain (Loss) on Disposition of Property Plant Equipment Stock‑based compensation expense Share-based Payment Arrangement, Noncash Expense Non‑cash interest expense Paid-in-Kind Interest Loss on disposal of property and equipment Gain (Loss) on Disposition of Assets Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Prepaid expenses, deposits and other assets Increase (Decrease) in Prepaid Expense and Other Assets Accounts payable Increase (Decrease) in Accounts Payable Deferred revenue Increase (Decrease) in Contract with Customer, Liability Accrued expenses and other liabilities Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities Net cash used in operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Receipts from the maturity of short-term investments Proceeds from Maturities, Prepayments and Calls of Short-term Investments Purchases of short-term investments Payments to Acquire Short-term Investments Sale of short term investments Proceeds from Sale of Short-term Investments Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Proceeds from the sale of property and equipment Proceeds from Sale of Property, Plant, and Equipment Net cash provided by (used in) investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Net proceeds from issuance of common stock Proceeds from exercise of stock options Proceeds from Stock Options Exercised Proceeds from issuance of common stock under Employee Stock Purchase Plan 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 Effect of Exchange Rate on Cash and Cash Equivalents Net change 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 at beginning of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash, cash equivalents, and restricted cash at end of period Supplement cash flow information Supplemental Cash Flow Information [Abstract] Cash paid for interest Interest Paid, Excluding Capitalized Interest, Operating Activities Noncash investing and financing activities Noncash Investing and Financing Items [Abstract] Purchase of property and equipment not yet paid Capital Expenditures Incurred but Not yet Paid Equity offering costs in accrued liabilities Equity Offering Costs In Accrued Liabilities Equity Offering Costs In Accrued Liabilities Unrealized gain (loss) on marketable securities Marketable Securities, Unrealized Gain (Loss) Statement of Financial Position [Abstract] Preferred stock, par value (in dollars 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, shares authorized Common stock, shares issued Common Stock, Shares, Issued Common stock, shares outstanding Common Stock, Shares, Outstanding Accounting Policies [Abstract] Realized gains or losses on sale of investments Realized Investment Gains (Losses) Number of operating segments Number of Operating Segments Related-Party Transactions Related Party Transactions Disclosure [Text Block] Schedule of Authorized Shares of Common Stock for Future Issuance Schedule of Stock by Class [Table Text Block] Schedule of Cash and Cash Equivalents Schedule of Cash and Cash Equivalents [Table Text Block] Schedule of Restricted Cash and Cash Equivalents Restrictions on Cash and Cash Equivalents [Table Text Block] Components of Accumulated Other Comprehensive Income (Loss), Net of Tax Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] 2019 Follow-On Offering 2019 Follow-On Offering [Member] 2019 Follow-On Offering [Member] Title of Individual [Axis] Title of Individual [Axis] Title of Individual [Domain] Title of Individual [Domain] Director Director [Member] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Founders Founder [Member] Represents information pertaining to founder member. Related Party Transaction [Axis] Related Party Transaction [Axis] Related Party Transaction [Domain] Related Party Transaction [Domain] Quarterly payment Quarterly Payment [Member] Quarterly Payment [Member] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Related party transaction, amounts of transaction Related Party Transaction, Amounts of Transaction Options granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures Granted (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Consulting services expenses Related Party Transaction, Expenses from Transactions with Related Party Contract liabilities: Change In Contract With Customer, Liability [Roll Forward] Change In Contract With Customer, Liability [Roll Forward] Deferred revenue, beginning of period Contract with Customer, Liability, Deferred Revenue Contract with Customer, Liability, Deferred Revenue Other liabilities, beginning of period Contract with Customer, Liability, Other Contract with Customer, Liability, Other Contract liabilities, beginning of period Contract with Customer, Liability Deferred revenue, additions Contract with Customer, Liability, Deferred Revenue, Increase From Cash Receipts Contract with Customer, Liability, Deferred Revenue, Increase From Cash Receipts Other liabilities, additions Contract with Customer, Liability, Other, Increase From Cash Receipts Contract with Customer, Liability, Other, Increase From Cash Receipts Contract liabilities, additions Contract with Customer, Liability, Increase From Cash Receipts Contract with Customer, Liability, Increase From Cash Receipts Deferred revenue, deductions Contract with Customer, Liability, Deferred Revenue, Revenue Recognized Contract with Customer, Liability, Deferred Revenue, Revenue Recognized Other liabilities, deductions Contract with Customer, Liability, Other, Revenue Recognized Contract with Customer, Liability, Other, Revenue Recognized Contract liabilities, deductions Contract with Customer, Liability, Revenue Recognized Deferred revenue, end of period Other liabilities, end of period Contract liabilities, end of period Other liabilities, current portion Contract with Customer, Liability, Other, Current Contract with Customer, Liability, Other, Current Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Statistical Measurement [Axis] Statistical Measurement [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Restatement [Axis] Restatement [Axis] Restatement [Domain] Restatement [Domain] Restatement Adjustment Restatement Adjustment [Member] Adjustments for Error Corrections [Axis] Adjustments for Error Corrections [Axis] Adjustments for Error Correction [Domain] Adjustments for Error Correction [Domain] Error Recognized Upon the Initial Adoption of ASC 606 Error Recognized Upon the Initial Adoption of ASC 606 [Member] Error Recognized Upon the Initial Adoption of ASC 606 [Member] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Grant Revenue Grant [Member] Accumulated deficit Retained Earnings [Member] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] ASU 2014-09 Accounting Standards Update 2014-09 [Member] First Acquisition Right First Acquisition Right [Member] First Acquisition Right [Member] Skolkovo Russia Vased Development Fund Of New Technologies Development And Commercialization Center Grant Agreement [Member] Represents information pertaining to russi vased development fund of new technologies development and commercialization center grant agreement. Second Acquisition Right Second Acquisition Right [Member] Second Acquisition Right [Member] Spark Letter Agreement Spark Letter Agreement [Member] Spark Letter Agreement [Member] MIT Exclusive Patent License Agreement With Massachusetts Institute Of Technology [Member] Represents information pertaining to Exclusive patent license agreement with Massachusetts Institute of Technology. " Consideration for Promises Consideration For Promises [Member] Consideration For Promises [Member] Development Milestones Development Milestones [Member] Development Milestones [Member] Regulatory Milestones Regulatory Milestones [Member] Regulatory Milestones [Member] Commercial Milestones Commercial Milestones [Member] Commercial Milestones [Member] Discount on Option Obligation Discount On Option Obligation [Member] Discount On Option Obligation [Member] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Upfront cash payment License And Option Agreement, Upfront Cash Payment License And Option Agreement, Upfront Cash Payment Aggregate additional payments due within twelve months License And Option Agreement, Aggregate Additional Payments Due Within Twelve Months Of Contract Date License And Option Agreement, Aggregate Additional Payments Due Within Twelve Months Of Contract Date Term loan number of payments Term Loan Number of Payments Term Loan Number of Payments Two payments due within 12 months of contract date License And Option Agreement, Two Payments Due Within Twelve Months Of Contract Date License And Option Agreement, Two Payments Due Within Twelve Months Of Contract Date Number of additional targets License And Option Agreement, Number Of Additional Targets For Which Other Party May Exercise Options For Additional Licenses License And Option Agreement, Number Of Additional Targets For Which Other Party May Exercise Options For Additional Licenses Variable fee the Company is eligible to receive for each additional target option elected License And Option Agreement, Variable Fee To Be Received For Each Additional Target Option Elected License And Option Agreement, Variable Fee To Be Received For Each Additional Target Option Elected Election period to exercise additional targets License And Option Agreement, Period For Other Party To Exercise Options For Additional Licenses License And Option Agreement, Period For Other Party To Exercise Options For Additional Licenses Additional development and regulatory milestone payments License And Option Agreement, Additional Development And Regulatory Milestone Payments That May Be Received License And Option Agreement, Additional Development And Regulatory Milestone Payments That May Be Received Commercialization milestone payments License And Option Agreement, Commercialization Milestone Payments That May Be Received License And Option Agreement, Commercialization Milestone Payments That May Be Received Sales milestone payments License And Option Agreement, Sales Milestone Payments That May Be Received License And Option Agreement, Sales Milestone Payments That May Be Received Number of obligations Revenue, Number Of Performance Obligations Revenue, Number Of Performance Obligations Period after first commercial sale when the Company is eligible to receive royalties Eligible Period To Receive Royalties Eligible Period To Receive Royalties Period for prior written notice to terminate license Period For Prior Written Notice To Terminate License Represents information pertaining to period for prior written notice to terminate license. Premium of average daily VWAP (as a percent) Premium Of Average Daily Volume Weighted Average Price Of Common Stock, Percent Premium Of Average Daily Volume Weighted Average Price Of Common Stock, Percent Deferred revenue related to agreement Increase (decrease) in deferred revenue Deferred revenue, current portion Contract with Customer, Liability, Current Deferred revenue, net of current portion Contract with Customer, Liability, Noncurrent Consecutive calendar days leading up to and ending on the day prior to the Contract Date Consecutive Calendar Days Leading Up To Contract Date Consecutive Calendar Days Leading Up To Contract Date Aggregate purchase price Aggregate Purchase Price Aggregate Purchase Price Aggregate price of shares Spark will have the right to purchase Stock Purchase Agreement, Authorized Amount Of Stock To Sell Stock Purchase Agreement, Authorized Amount Of Stock To Sell Number of shares authorized to be issued pursuant to the Stock Purchase Agreement (in shares) Stock Purchase Program, Number Of Shares Authorized To Be Sold Stock Purchase Program, Number Of Shares Authorized To Be Sold License and option agreement, additional sub-license payment received liability License And Option Agreement, Additional Sub-License Payment Received Liability License And Option Agreement, Additional Sub-License Payment Received Liability License and option agreement, payments made relative to calculated premium paid for initial equity investment made under the purchase agreement License And Option Agreement, Calculated Premium Paid For Equity Investment Under Purchase Agreement License And Option Agreement, Calculated Premium Paid For Equity Investment Under Purchase Agreement Number of agreements combined and evaluated into a single agreement Number Of Agreements Combined Into Single Agreement For Evaluation Number Of Agreements Combined Into Single Agreement For Evaluation Fair value of initial purchase of common stock combined with the embedded future stock Acquisition Rights Stock Issued During Period, Value, Purchase of Assets Performance obligation per each option Revenue, Remaining Performance Obligation, Each Option Revenue, Remaining Performance Obligation, Each Option Incremental costs of obtaining a contract Capitalized Contract Cost, Net Percentage of sublicense income Percentage Of Sublicense Income Represents information pertaining to percentage of sublicense income. Current assets Assets, Current Long-term assets Assets, Noncurrent Accumulated deficit Retained Earnings (Accumulated Deficit) Revenue recognized Aggregate purchase price per share (in dollar per share) Stock Purchase Program, Aggregate Purchase Price Per Share Stock Purchase Program, Aggregate Purchase Price Per Share Payments received Increase Decrease In Contingently Repayable Grant Funding The increase (decrease) during the reporting period in contingently repayable grant funding that are used in an entity's business. Adoption of new accounting principle Cumulative Effect of New Accounting Principle in Period of Adoption Grants from entities, unused grant funds Grants From Entities Unused Grant Funds Grants From Entities Unused Grant Funds Overspent costs Overspent Costs Overspent Costs Grant and collaboration revenue Revenue from Contract with Customer, Excluding Assessed Tax Reimbursement invoices Reimbursement Invoice Reimbursement Invoice Other liabilities Current liabilities Liabilities, Current Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Research and development Research And Development [Member] Represents the information pertaining to research and development expenses included in the income statement. General and administrative General and Administrative Expense [Member] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Total stock-based compensation expense Share-based Payment Arrangement, Expense Additional paid-In Capital Additional Paid-in Capital [Member] Accumulated other comprehensive loss AOCI Attributable to Parent [Member] Increase (Decrease) in Stockholders' Equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning balance (in shares) Beginning balance Stockholders' Equity Attributable to Parent Issuance of common stock under Employee Stock Purchase Plan (in shares) Stock Issued During Period, Shares, Employee Stock Purchase Plans Issuance of common stock under Employee Stock Purchase Plan Stock Issued During Period, Value, Employee Stock Purchase Plan Issuance of common stock upon exercise of options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Issuance of common stock upon exercise of options Stock Issued During Period, Value, Stock Options Exercised Issuance of common stock, net of issuance costs (in shares) Issuance of common stock, net of issuance costs of $344.1 Stock Issued During Period, Value, New Issues Stock‑based compensation expense APIC, Share-based Payment Arrangement, Increase for Cost Recognition Currency translation adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Unrealized gains (losses) on securities Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax Adoption of new accounting principle Issuance of common stock, license agreement Issuance of common stock through at-the-market offering, net (in shares) Stock Issued During Period, Shares, Other Issuance of common stock through at-the-market offering, net Stock Issued During Period, Value, Other Ending balance (in shares) Ending balance Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Schedule of Lease, Cost Lease, Cost [Table Text Block] Schedule of Lessee, Operating Lease, Liability, Maturity Lessee, Operating Lease, Liability, Maturity [Table Text Block] Principles of Consolidation Consolidation, Policy [Policy Text Block] Foreign Currency Foreign Currency Transactions and Translations Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Segment Information Segment Reporting, Policy [Policy Text Block] Cash Equivalents, Short-term Investments and Restricted Cash Cash Equivalents And Short Term Investments [Policy Text Block] Disclosure of accounting policy for cash equivalents and short term investments. Concentrations of Credit Risk and Off-Balance Sheet Risk Concentration Risk, Credit Risk, Policy [Policy Text Block] Fair Value of Financial Instruments Fair Value of Financial Instruments, Policy [Policy Text Block] Property and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Impairment of Long-Lived Assets Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Debt Issuance Costs Debt, Policy [Policy Text Block] Accumulated Other Comprehensive Income (Loss) Comprehensive Income, Policy [Policy Text Block] Revenue Recognition Revenue from Contract with Customer [Policy Text Block] Research and Development Costs Research and Development Expense, Policy [Policy Text Block] Clinical Trial Costs Clinical Trial Costs [Policy Text Block] Disclosure of accounting policy for clinical trial costs. Income Taxes Income Tax, Policy [Policy Text Block] Warrants Warrants [Policy Text Block] Disclosure of accounting policy for warrants. Stock-Based Compensation Share-based Payment Arrangement [Policy Text Block] Net Loss Per Share Earnings Per Share, Policy [Policy Text Block] Contingent Liabilities Contingent Liability Reserve Estimate, Policy [Policy Text Block] Leases Lessee, Leases [Policy Text Block] Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Summary of Assets Measured at Fair Value on a Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] The 2008 Plan and the 2016 Plan The 2008 Plan And The 2016 Plan [Member] The 2008 Plan And The 2016 Plan [Member] 2008 Plan Stock Incentive Plan2008 [Member] Represents the information pertaining to the 2008 stock incentive plan, which provides for the granting of stock based awards to employees, directors, and consultants under terms and provisions established by the board of directors. 2016 Plan Stock Incentive Plan2016 [Member] Represents the information pertaining to the 2016 stock incentive plan, which provides for the granting of stock based awards to employees, directors, and consultants under terms and provisions established by the board of directors. Employment Inducement Incentive Award Plan Employment Inducement Incentive Award Plan [Member] Employment Inducement Incentive Award Plan [Member] ESPP Employee Stock Purchase Plan2016 [Member] Represent information pertaining to the 2016 Employee Stock Purchase Plan. Vesting [Axis] Vesting [Axis] Vesting [Domain] Vesting [Domain] Tranche One Share-based Payment Arrangement, Tranche One [Member] Tranche Two Share-based Payment Arrangement, Tranche Two [Member] Executive Officer Executive Officer [Member] Number of shares authorized for grants (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Automatic increase in the number of shares that may be issued (as a percent) Employee Stock Purchase Plan Maximum Percentage Of Shares Reserved Based On Shares Outstanding The maximum percentage increase in the shares reserved for future issuance each year based on the number of common stock outstanding at the last day of the year. Number of shares authorized, increase (in shares) Share-Based Compensation Arrangement By Share-Based Payment Award, Number Of Shares Available For Grant, Increase (Decrease) Share-Based Compensation Arrangement By Share-Based Payment Award, Number Of Shares Available For Grant, Increase (Decrease) Common stock authorized and reserved for future issuance (in shares) Exercise price of incentive stock options (not less than) Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent Combined voting power of participants (as a percent) Share-based Compensation Arrangement By Share-based Payment Award, Voting Rights of Common Stock, Holding Percentage Represents the percentage of voting rights of all classes of stock held by the employees. Award vesting term Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Award expiration term Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period Grants in period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Reserved for issuance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Period Increase (Decrease) Grants in period (in dollars 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 Estimated forfeitures rate Share-based Compensation Arrangement By Share-based Payment Award Forfeitures Rate Represents the percentage of forfeitures rate of the stock options based on the historical trends. Weighted average grant date fair value of stock options (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Aggregate intrinsic value of stock options exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value Unrecognized compensation expense related to unvested employee stock options Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount Weighted average period for recognition Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Vested and expected to vest (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares Vested and expected to vest, exercisable (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Number Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Unrecognized compensation expense related to unvested non-employee stock options Share-Based Goods And Non Employee Services Transaction, Compensation Not Yet Recognized, Stock Options Share-Based Goods And Non Employee Services Transaction, Compensation Not Yet Recognized, Stock Options Unrecognized compensation expense related to unvested non-employee stock options, period Share-Based Goods And Non Employee Services Transaction, Compensation Not Yet Recognized, Stock Options, Period Share-Based Goods And Non Employee Services Transaction, Compensation Not Yet Recognized, Stock Options, Period Stock‑based compensation expense Shares issued (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period Shares issued (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Shares issued, value Unrecognized compensation expense Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount Organization, Consolidation and Presentation of Financial Statements [Abstract] Nature of the Business and Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Collaborative Arrangement and Arrangement Other than Collaborative [Table] Collaborative Arrangement and Arrangement Other than Collaborative [Table] Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] Contractual payments defined in the Exclusive Patent License agreement License And Option Agreement, Contractual Payments Made License And Option Agreement, Contractual Payments Made Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Summary of Available-for-Sale Marketable Securities Debt Securities, Available-for-sale [Table Text Block] Schedule of Fair Values and Amortized Cost of Marketable Debt Securities by Contractual Maturity Investments Classified by Contractual Maturity Date [Table Text Block] Number of offering periods under the ESPP Number Of Offering Periods Number Of Offering Periods Term of each offering period Offering Period Offering Period Eligible compensation withheld for use (up to) (as a percent) Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate Purchase price of shares (not less than) (as a percent) Number of shares of common stock outstanding (as a percent) Shares of common stock issued to employees under the ESPP (in shares) Stock-based compensation expense Schedule of Cash and Cash Equivalents [Table] Schedule of Cash and Cash Equivalents [Table] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] Russian subsidiary RUSSIAN FEDERATION Unrestricted cash Unrestricted Cash [Member] Unrestricted Cash [Member] Cash and Cash Equivalents [Line Items] Cash and Cash Equivalents [Line Items] Short-term deposits and investments Short-term Investments Cash, cash equivalents, and restricted cash Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Timothy A. Springer, Ph.D. Timothy A. Springer, Ph.D. [Member] Timothy A. 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Employer contribution made Defined Contribution Plan, Cost Cover page. 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Average Remaining Contractual Term Share-based Compensation Arrangement By Share-based Payment Award, Options, Vested, Outstanding, Weighted Average Remaining Contractual Term Vested and expected to vest, term Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term Aggregate intrinsic value Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value [Abstract] n/a Outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Vested Share-based Compensation Arrangement By Share-based Payment Award, Options, Vested, Outstanding, Intrinsic Value Share-based Compensation Arrangement By Share-based Payment Award, Options, Vested, Outstanding, Intrinsic Value Vested and expected to vest Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Fair Value Measurements Fair Value Disclosures [Text Block] Schedule of Future Minimum Payments on the Term Loans Schedule of Maturities of Long-term Debt [Table Text Block] MEE License Agreement With Massachusetts Eye And Ear Infirmary And Schepens Eye Research Institute Inc. [Member] Represents information pertaining to License agreement with Massachusetts Eye and Ear Infirmary and The Schepens Eye Research Institute, Inc. License fees due under agreement Initial License Fee Paid Initial License Fee Paid Accrued license fees Accrued Professional Fees Stock Incentive Plans Share-based Payment Arrangement [Text Block] Statement of Comprehensive Income [Abstract] Operating expenses: Cost of Revenue [Abstract] Research and development Research and Development Expense General and administrative General and Administrative Expense Total operating expenses Operating Expenses Loss from operations Operating Income (Loss) Investment income Investment Income, Net Foreign currency transaction (loss), net Foreign Currency Transaction Gain (Loss), before Tax Interest expense Interest Expense Other (expense), net Other Nonoperating Income (Expense) Net loss Other comprehensive loss: Other Comprehensive Income (Loss), Tax [Abstract] Foreign currency translation adjustment Unrealized gain on securities Total comprehensive loss Comprehensive Income (Loss), Net of Tax, Attributable to Parent Net loss attributable to common stockholders Net Income (Loss) Available to Common Stockholders, Basic Net loss per share: Earnings Per Share, Basic and Diluted [Abstract] Net loss per share attributable to common stockholders—basic and diluted (in dollars per share) Earnings Per Share, Basic and Diluted Weighted average common shares outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic and diluted (in shares) Weighted Average Number of Shares Outstanding, Basic and Diluted Computation of Basic and Diluted Net Loss Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of Potential Common Shares Issuable Upon Conversion of Warrants Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] 3SBio License License Agreement With Shenyang Sunshine Pharmaceutical Company Limited [Member] Represents information pertaining to License agreement with Shenyang Sunshine Pharmaceutical co., ltd. Aggregate amount of upfront and milestone-based payments Aggregate Amount Of Upfront And Milestone Based Payments Paid Aggregate Amount Of Upfront And Milestone Based Payments Paid Net Loss Per Share Earnings Per Share [Text Block] Operating cash flows from operating leases Operating Lease, Payments Income Tax Holiday [Table] Income Tax Holiday [Table] Income Tax Authority [Axis] Income Tax Authority [Axis] Income Tax Authority [Domain] Income Tax Authority [Domain] Domestic And State Tax Authority Domestic And State Tax Authority [Member] Domestic And State Tax Authority [Member] Income Tax Holiday [Line Items] Income Tax Holiday [Line Items] Operating loss carryforwards, subject to expiration Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration Unrecognized tax benefits Unrecognized Tax Benefits Debt securities, available-for-sale, number of positions Available-for Sale Debt Securities, Number Of Positions Available-for Sale Debt Securities, Number Of Positions Debt securities, available-for-sale, continuous unrealized loss position, 12 months or longer, number of positions Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions Schedule of Weighted Average Assumptions Used Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Summary of Activity Under the 2008 Plan and the 2016 Plan Share-based Payment Arrangement, Option, Activity [Table Text Block] Disclosure of Share-based Compensation Arrangements by Share-based Payment Award Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block] Schedule of Stock-Based Compensation Expense Related to Stock Options and Restricted Common Stock Share-based Payment Arrangement, Cost by Plan [Table Text Block] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Restricted cash Restricted Cash and Cash Equivalents, Current Restricted cash included in other assets Restricted Cash and Cash Equivalents, Noncurrent Total cash, cash equivalents, and restricted cash shown in the consolidated statement of cash flows Numerator: Net Income (Loss) Available to Common Stockholders, Basic [Abstract] Denominator: Weighted‑average common shares outstanding—basic and diluted (in shares) Schedule of Operating Leased Assets [Table] Schedule of Operating Leased Assets [Table] Accounting Standards Update 2016-02 [Member] Accounting Standards Update 2016-02 [Member] Lease Arrangement, Type [Axis] Lease Arrangement, Type [Axis] Lease Arrangement, Type [Domain] Lease Arrangement, Type [Domain] Laboratory and office space Laboratory And Office Space [Member] Represents information pertaining to laboratory and office space member. Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Letter of credit Letter of Credit [Member] Lease Arrangement [Axis] Lease Arrangement [Axis] Lease Arrangement [Axis] Lease Arrangement [Domain] Lease Arrangement [Domain] [Domain] for Lease Arrangement [Axis] 75 North Beacon, Watertown, MA 75 North Beacon, Watertown, MA [Member] 75 North Beacon, Watertown, MA [Member] Operating Leased Assets [Line Items] Operating Leased Assets [Line Items] Right of use asset, net (Note 8) Operating Lease, Right-of-Use Asset Lease liabilities Deferred rent and incentives Deferred Rent Credit Operating lease, remaining lease term Operating Lease, Remaining Lease Term Operating Lease, Remaining Lease Term Discount rate Lessee, Operating Lease, Discount Rate Term of contract Lessee, Operating Lease, Term of Contract Renewal term Lessee, Operating Lease, Renewal Term Tenant improvement allowance Restricted cash Restricted Cash Area of additional office space leased Area of Real Estate Property Rent expense Operating Leases, Rent Expense Fair Value Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract] Less than one year Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value Amortized Cost Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract] Less than one year Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost Payroll and employee related expenses Employee-related Liabilities, Current Current portion of deferred rent and lease incentive Accrued Rent And Lease Incentive Payable Current " Carrying value as of the balance sheet date of obligations incurred through that date and payable for contractual rent under lease arrangements and an incentive or inducement contractually stipulated between parties to a lease whereby the lessor has committed to provide the entity (lessee) with a cash payment as inducement to enter the lease. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer)." Collaboration and licensing Accrued Collaboration and Licensing Accrued Collaboration and Licensing Accrued patent fees Accrued Patent Fees Current Carrying value as of the balance sheet date of patent fees. Accrued external research and development costs Accrued Research And Development Costs Current Carrying value as of the balance sheet date of research and development costs. Accrued professional and consulting services Accrued Audit Fees, Current Accrued Audit Fees, Current Accrued grant refund Accrued Grant Refund, Current Accrued Grant Refund, Current Accrued interest Interest Payable, Current Other Other Accrued Liabilities, Current Accrued expenses Accrued Liabilities, Current Subsequent Event [Table] Subsequent Event [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Lessee, rentable area Lessee, Rentable Area Lessee, Rentable Area Lessee, base rent per month Lessee, Base Rent Per Month Lessee, Base Rent Per Month Lessee, base rent per sqft Lessee, Base Rent Per Square Foot Annually Lessee, Base Rent Per Square Foot Annually Expected annual increase in rental rate percentage Expected Annual Increase In Rental Rate Expected Annual Increase In Rental Rate Assets Assets [Abstract] Current assets: Assets, Current [Abstract] Cash, cash equivalents, and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Current Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Current Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Total current assets Property and equipment, net Restricted cash and other assets Restricted Cash and Investments, Noncurrent Total assets Assets Liabilities and stockholders’ equity Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Accrued expenses Loan payable, current portion Loans Payable, Current Lease liability, current portion (Note 8) Total current liabilities Non‑current liabilities: Other Liabilities, Noncurrent [Abstract] Deferred rent and lease incentive Deferred Rent Credit, Noncurrent Other long‑term liabilities Other Liabilities, Noncurrent Total liabilities Liabilities Commitments and contingencies (Note 17) Commitments and Contingencies Stockholders’ equity (deficit): Stockholders' Equity Attributable to Parent [Abstract] Preferred stock, $0.0001 par value; 10,000,000 shares authorized; no shares issued and outstanding at June 30, 2019 and December 31, 2018, respectively Preferred Stock, Value, Issued Common stock, $0.0001 par value; 200,000,000 shares authorized; 44,952,951 and 22,471,776 shares issued and outstanding as of June 30, 2019 and December 31, 2018, respectively Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Accumulated deficit Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total stockholders’ equity (deficit) Total liabilities and stockholders’ equity (deficit) Liabilities and Equity Line of Credit Facility [Table] Line of Credit Facility [Table] 2017 Term Loans 2017 Term Loans [Member] 2017 Term Loans [Member] Term Loans Term Loan [Member] Represents information pertaining to term loan member. Debt Covenant Period [Axis] Debt Covenant Period [Axis] Debt Covenant Period [Axis] Debt Covenant Period [Domain] Debt Covenant Period [Domain] [Domain] for Debt Covenant Period [Axis] Prepaid after to first anniversary but before second Term Loan Prepaid After First Anniversary But Before Second Anniversary [Member] Represents information pertaining to prepayment of term loan after first anniversary but prior to second anniversary. Prepaid after second anniversary Term Loan Prepaid After Second Anniversary [Member] Represents information pertaining to prepayment of term loan after second anniversary. Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] Base Rate Base Rate [Member] Outstanding Balances Outstanding Balances [Member] Outstanding Balances [Member] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Term loan facility Long-term Line of Credit Repayments of debt Repayments of Lines of Credit Loss on extinguishment of debt Gain (Loss) on Extinguishment of Debt Debt issuance costs, line of credit arrangements (less than) Debt Issuance Costs, Line of Credit Arrangements, Net Debt instrument, basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate Prepayment fee (as a percent) Early Extinguishment Of Debt, Prepayment Fee Percentage Percentage of fee payable on early extinguishment of debt. Interest rate per annum Line of Credit Facility, Interest Rate During Period Minimum assets trigger Debt Instrument, Event Of Default, Minimum Assets Trigger Debt Instrument, Event Of Default, Minimum Assets Trigger Minimum amount in excess of indebtedness trigger Debt Instrument, Event Of Default, Minimum Amount In Excess Of Indebtedness Trigger Debt Instrument, Event Of Default, Minimum Amount In Excess Of Indebtedness Trigger Final payment fee (as a percent) Final Payment Fee Percentage Percentage of final fee payment payable on aggregate principal amounts borrowed. Final payment fee Debt Instrument, Periodic Payment Terms, Balloon Payment to be Paid Interest expense related to the Term Loan Year ended December 31, Long-term Debt, Fiscal Year Maturity [Abstract] 2019 Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year 2020 Long-term Debt, Maturities, Repayments of Principal in Year Two 2021 Long-term Debt, Maturities, Repayments of Principal in Year Three 2022 Long-term Debt, Maturities, Repayments of Principal in Year Four Total minimum debt payments Long-term Debt Less: Amount representing interest Debt Instrument Interest Portion The interest portion of gross outstanding debt. Less: Debt discount and deferred charges Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Less: Current portion of loan payable Long-term Debt, Current Maturities Loan payable, net of current portion Long-term Debt, Excluding Current Maturities Accrued Expenses Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block] Available-for-Sale Marketable Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Schedule of Property and Equipment Property, Plant and Equipment [Table Text Block] Defined Contribution Plan Pension and Other Postretirement Benefits Disclosure [Text Block]