Accounting Policies [Abstract] Net loss Net Income (Loss) Attributable to Parent Weighted average number of common shares Weighted Average Number of Shares Outstanding, Basic Basic income (loss) per common share (in USD per share) Earnings Per Share, Basic Diluted income (loss) per common share (in USD per share) Earnings Per Share, Diluted Property, Plant and Equipment [Abstract] Schedule of property and equipment Property, Plant and Equipment [Table Text Block] Deferred Revenue Disclosure [Abstract] Collaborations, contracts and licensing agreements Collaborative Arrangement Disclosure [Text Block] Stockholders' Equity Note [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] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Arbutus Plans Arbutus Plans [Member] Arbutus Plans [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Balance - Number of optioned common shares (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Options reclassified to liability (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Reclassifications to Liability in Period Share-based Compensation Arrangement by Share-based Payment Award, Options, Reclassifications to Liability in Period Options granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Options exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Options forfeited, canceled or expired (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period Balance - Number of optioned common shares (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Balance - Weighted average exercise price (in CAD and USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Options reclassified liability - Weighted average exercise price (in CAD and USD per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Reclassifications to Liability in Period, Weighted Average Exercise Price Share-based Compensation Arrangements by Share-based Payment Award, Options, Reclassifications to Liability in Period, Weighted Average Exercise Price Options granted - Weighted average exercise price (in CAD and USD per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Options exercised - Weighted average exercise price (in CAD and USD per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Options forfeited, canceled or expired - Weighted average exercise price (in CAD and USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price Balance - Weighted average exercise price (in CAD and USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] Balance - Aggregate intrinsic value Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Options exercised, aggregate intrinsic value Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value Options reclassified - Aggregate intrinsic value Share-based Compensation Arrangement by Share-based Payment Award, Options, Reclassifications to Liability in Period Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Reclassifications to Liability in Period Intrinsic Value Balance - Aggregate intrinsic value Quarterly Financial Information Disclosure [Abstract] Interim financial data (unaudited) Quarterly Financial Information [Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Schedule of Indefinite-Lived Intangible Assets [Table] Schedule of Indefinite-Lived Intangible Assets [Table] Indefinite-lived Intangible Assets [Axis] Indefinite-lived Intangible Assets [Axis] Indefinite-lived Intangible Assets, Major Class Name [Domain] Indefinite-lived Intangible Assets, Major Class Name [Domain] IPR&D – Immune Modulators In Process Research and Development, Immune Modulators [Member] In Process Research and Development, Immune Modulators [Member] IPR&D – Antigen Inhibitors In Process Research and Development, Antigen Inhibitors [Member] In Process Research and Development, Antigen Inhibitors [Member] IPR&D – cccDNA Sterilizers In Process Research and Development, cccDNA Sterilizers [Member] In Process Research and Development, cccDNA Sterilizers [Member] Indefinite-lived Intangible Assets [Line Items] Indefinite-lived Intangible Assets [Line Items] Intangible assets Intangible Assets, Net (Excluding Goodwill) Statement of Cash Flows [Abstract] Statement [Table] Statement [Table] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Research, development, collaborations Research and Development Expense [Member] General and administrative expenses General and Administrative Expense [Member] Statement [Line Items] Statement [Line Items] OPERATING ACTIVITIES Net Cash Provided by (Used in) Operating Activities [Abstract] Net loss for the period Items not involving cash: Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Deferred income taxes Deferred Income Tax Expense (Benefit) Depreciation of property and equipment Depreciation Loss (gain) on sale of property and equipment Gain (Loss) on Disposition of Property Plant Equipment Stock-based compensation Share-based Compensation Unrealized foreign exchange gains Foreign Currency Transaction Gain (Loss), Unrealized Change in fair value of warrant liability Fair Value, Option, Changes in Fair Value, Gain (Loss) Change in fair value of contingent consideration Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability Impairment of intangible assets Impairment of Intangible Assets (Excluding Goodwill) Impairment of goodwill Goodwill, Impairment Loss Net change in non-cash operating items: Increase (Decrease) in Operating Capital [Abstract] Accounts receivable Increase (Decrease) in Accounts Receivable Accrued revenue Increase (Decrease) in Unbilled Receivables Deferred expenses IncreaseDecreaseOtherDeferredCostsNet The increase (decrease) during the reporting period in the amount of other deferred costs. Does not include deferred finance costs or deferred acquisition costs of insurance companies. Investment tax credits receivable Increase (Decrease) in Income Taxes Receivable Prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Accounts payable and accrued liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Deferred revenue Increase (Decrease) in Deferred Revenue 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] Disposition (acquisition) of investments Payments for (Proceeds from) Investments Acquisition of restricted investment Payments to Acquire Restricted Investments Cash acquired through acquisition Cash Acquired from Acquisition Proceeds from sale of property and equipment Proceeds from Sale of Property, Plant, and Equipment Acquisition of property and equipment Payments to Acquire Property, Plant, and Equipment Net cash provided by (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 loan payable Proceeds from Issuance of Long-term Debt Proceeds from issuance of common shares, net of issuance costs Proceeds from Issuance of Common Stock Issuance of common shares pursuant to exercise of options Proceeds from Stock Options Exercised Issuance of common shares pursuant to exercise of warrants Proceeds from Warrant Exercises Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Effect of foreign currency rate changes on cash and cash equivalents Effect of Exchange Rate on Cash and Cash Equivalents Increase in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents, beginning of period Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents, end of period Supplemental cash flow information Supplemental Cash Flow Information [Abstract] Acquisition of property and equipment not yet paid Capital Expenditures Incurred but Not yet Paid Fair value of warrants exercised on a cashless basis Fair Value of Warrants Exercised on a Cashless Basis Represents the fair value of warrants exercised on a cashless basis. Investment tax credits received Proceeds from Income Tax Refunds Acquisition of Arbutus Inc. net of cash acquired Noncash or Part Noncash Acquisition, Net Nonmonetary Assets Acquired (Liabilities Assumed) Organization, Consolidation and Presentation of Financial Statements [Abstract] Nature of business and future operations Nature of Operations [Text Block] Risks and Uncertainties [Abstract] Schedule of Intercompany Foreign Currency Balance [Table] Schedule of Intercompany Foreign Currency Balance [Table] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Foreign currency exposure Foreign Currency Exposure [Member] Represents the foreign currency exposure. Intercompany Foreign Currency Balance [Line Items] Intercompany Foreign Currency Balance [Line Items] Cash and cash equivalents and short-term investments Cash, Cash Equivalents, and Short-term Investments Accounts receivable Accounts Receivable, Net Accrued revenue Unbilled Receivables, Current Accounts payable and accrued liabilities Accounts Payable and Accrued Liabilities Exposure to Canadian dollar Exposure to Canadian Dollar Exposure to Canadian Dollar Schedule of interim financial data (unaudited) Quarterly Financial Information [Table Text Block] Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table] Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table] Exercise Price Range [Axis] Exercise Price Range [Axis] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] Range 1 Range 1 [Member] Represents range 1. Range 2 Range 2 [Member] Represents range 2. Range 3 Range 3 [Member] Represents range 3. Range 4 Range 4 [Member] Represents range 4. Range 5 Range 5 [Member] Represents range 5. Range 6 Range 6 [Member] Represents range 6. Range 7 Range 7 [Member] Represents range 7. Total Range Total Range [Member] Represents the total range. Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] Range of Exercise prices - Low (in USD per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit Range of Exercise prices - High (in USD per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit Number of options outstanding (in shares) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options Weighted average remaining contractual life (years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Options outstanding, Weighted average exercise price (in USD per share) Number of options exercisable (in shares) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Exercisable Options Weighted average exercise price (in USD per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price Schedule of assets and liabilities measured at fair value on a recurring basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Changes in fair value of warrants Changes In Fair Value Of Warrants [Table Text Block] Represents the tabular disclosure for the change in fair value of warrants. Changes in fair value of liability-classified stock options Changes In Fair Value of Liability Option [Table Text Block] Changes In Fair Value of Liability Option [Table Text Block] Changes in fair value of contingent consideration Schedule of Business Acquisitions by Acquisition, Contingent Consideration [Table Text Block] Property and equipment estimated useful lives Property, Plant and Equipment, Estimated Useful Lives [Table Text Block] Tabular disclosure of property, plant and equipment, estimated useful lives. Schedule of basic and diluted net income (loss) per common share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Commitments and Contingencies Disclosure [Abstract] Contingencies and Commitments [Table] Contingencies and Commitments [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Laboratory facilities and office space Laboratory Facilities and Office Space [Member] Laboratory Facilities and Office Space [Member] Products and Services [Axis] Products and Services [Axis] Products and Services [Domain] Products and Services [Domain] Marqibo Marqibo [Member] Marqibo Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Blumberg and Drexel Blumberg and Drexel [Member] Blumberg and Drexel [Member] Blumberg Blumberg [Member] Blumberg Cytos Cytos [Member] Cytos Litigation Case [Axis] Litigation Case [Axis] Litigation Case [Domain] Litigation Case [Domain] Arbitration with the University of British Columbia Arbitration With The University Of British Columbia [Member] Information related to arbitration with the University of British Columbia. Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Arbutus Inc. Arbutus Inc. [Member] Arbutus Inc. [Member] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Enantigen Enantigen [Member] Enantigen Contingencies and Commitments [Line Items] Contingencies and Commitments [Line Items] Area of property (in sq ft) Area of Real Estate Property Lease term Lessee Leasing Arrangements, Operating Leases, Term of Contract Lease extension option Lessee Leasing Arrangements, Operating Leases, Number of Renewal Options Lessee Leasing Arrangements, Operating Leases, Number of Renewal Options Lease extension term Lessee Leasing Arrangements, Operating Leases, Renewal Term Total facility commitment Operating Leases, Future Minimum Payments Due Lease expense Operating Leases, Rent Expense, Net Percent of costs funded by TPC Percent Of Costs Funded By T P C Represents the percent of costs funded by TPC. Maximum contribution for product Maximum Contribution For Product Represents the maximum contribution for the product. Cumulative contribution for product Cumulative Contribution for Product Represents the cumulative contribution for a product. Royalty guarantees commitments percentage Royalty Guarantees Commitments Percentage Represents the royalty guarantees commitments percentage. Royalty revenue Royalty Revenue Royalty payable Royalty Payable Represents the royalty payable. Royalties paid or accrued Royalties Paid Or Accrued The cumulative amount of royalties paid or accrued of an entity. Contractual obligation Contractual Obligation Loss contingency, damages sought for allegedly unpaid royalties Loss Contingency, Damages Sought, Value Business combination, high end of payment upon achievement of certain triggering events Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High Business combination, regulatory, development and sales milestone payments estimated fair value Business Combination, Contingent Consideration, Liability Increase in fair value of contingent consideration Increase (Decrease) In Fair Value Of Contingent Consideration Liability Increase (Decrease) In Fair Value Of Contingent Consideration Liability Number of series of compounds Number of series of compounds Number of series of compounds License fee License Costs Development and regulatory milestones payment per licensed compound series, maximum License Agreement Maximum Development And Regulatory Milestone Payments Per License License Agreement, Maximum Development and Regulatory Milestone Payments Per License Sales performance milestones payment per licensed product, maximum License Agreement Maximum Sales Performance Milestone Payments Per License License Agreement, Maximum Sales Performance Milestone Payments Per License Research funding per year under research collaboration and funding agreement Contractual Obligation Amount Of Research Funding Per Year Contractual Obligation, Amount of Research Funding Per Year Research funding period Research Funding Period Research Funding Period Research funding period, renewable option Research Funding Period Renewable Option Research Funding Period Renewable Option Research funding agreement exclusive license upfront payment Research Funding Agreement Right To Obtain Exclusive License Upfront Payment Research Funding Agreement Right to Obtain Exclusive License Upfront Payment Research funding agreement exclusive license maximum development and regulatory milestone payments Research Funding Agreement Right To Obtain Exclusive License Maximum Development And Regulatory Milestone Payments Research Funding Agreement Right to Obtain Exclusive License Maximum Development and Regulatory Milestone Payments Research funding agreement license maximum commercialization milestone payments Research Funding Agreement Right To Obtain Exclusive License Maximum Commercialization Milestone Payments Research Funding Agreement Right to Obtain Exclusive License Maximum Commercialization Milestone Payments Research funding period, number of renewable options Research Funding Period, Number of Renewable Options Research Funding Period, Number of Renewable Options Income Statement [Abstract] Revenue Revenues [Abstract] Collaborations and contracts Contracts Revenue Licensing fees, milestone and royalty payments Licenses Revenue Total revenue Revenues Expenses Costs and Expenses [Abstract] Research, development, collaborations and contracts Research and Development Expense General and administrative General and Administrative Expense Acquisition costs Business Combination, Acquisition Related Costs Total expenses Operating Expenses Loss from operations Operating Income (Loss) Other income (losses) Nonoperating Income (Expense) [Abstract] Interest income Investment Income, Interest Foreign exchange gains Foreign Currency Transaction Gain (Loss), before Tax Gain on disposition of financial instrument Option Exercised Contractual Option, Revenue Amount Option Exercised Contractual Option, Revenue Amount Decrease (increase) in fair value of warrant liability Increase in fair value of contingent consideration Total other income (losses) Nonoperating Income (Expense) Loss before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Deferred income tax recovery Income Tax Expense (Benefit) Net loss Loss per common share Earnings Per Share, Basic and Diluted [Abstract] Basic loss per common share (in USD per share) Diluted loss per common share (in USD per share) Weighted average number of common shares Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic weighted average number of common shares (in shares) Diluted weighted average number of common shares (in shares) Weighted Average Number of Shares Outstanding, Diluted Other Comprehensive loss Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Cumulative translation adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Comprehensive loss Comprehensive Income (Loss), Net of Tax, Attributable to Parent Government Grants And Refundable Investment Tax Credits [Abstract] Government Grants and Refundable Investment Tax Credits [Table] Government Grants and Refundable Investment Tax Credits [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] ISARIC ISARIC [Member] Represents the International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC). Government Grants and Refundable Investment Tax Credits [Line Items] Government Grants and Refundable Investment Tax Credits [Line Items] Contracts revenue Revenue from government grants Revenue from Grants Investment tax credit Investment Tax Credit Basis of presentation Basis of Accounting, Policy [Policy Text Block] Foreign currency translation and functional currency conversion Foreign Currency Transactions and Translations Policy [Policy Text Block] Use of estimates Use of Estimates, Policy [Policy Text Block] Cash and cash equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Short-term and long-term investments Investment, Policy [Policy Text Block] Loan payable and restricted cash (investment) Debt and Restricted Cash (Investment) Policy [Policy Text Block] Debt and Restricted Cash (Investment) Policy Fair value of financial instruments Fair Value Measurement, Policy [Policy Text Block] Property and equipment Property, Plant and Equipment, Policy [Policy Text Block] Impairment of property and equipment Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Goodwill and intangible assets Goodwill and Intangible Assets, Policy [Policy Text Block] Revenue recognition Revenue Recognition, Policy [Policy Text Block] Leases and lease inducements Lease, Policy [Policy Text Block] Research and development costs Research, Development, and Computer Software, Policy [Policy Text Block] Income or loss per share Earnings Per Share, Policy [Policy Text Block] Government grants and refundable investment tax credits Government Grants And Refundable Investment Tax Credits [Policy Text Block] Represents the policy for the government grants and refundable investment tax credits. Deferred income taxes Income Tax, Policy [Policy Text Block] Equity and liability classified stock option awards Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] Replacement awards Replacement Awards [Policy Text Block] Replacement Awards [Policy Text Block] Warrants Warrants [Policy Text Block] The accounting policy for the warrants. Segment information Segment Reporting, Policy [Policy Text Block] Recent accounting pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Dividend yield Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate 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 average option term Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Research, development, collaborations and contracts expenses Stock-based compensation expense Allocated Share-based Compensation Expense Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Laboratory equipment Laboratory Equipment [Member] Represents the laboratory equipment. Computer and office equipment Computer Equipment [Member] Furniture and fixtures Furniture and Fixtures [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Useful lives Property, Plant and Equipment, Useful Life Impairment evaluations for intangible assets and goodwill Goodwill and Intangible Assets Disclosure [Text Block] Financial obligations, period to pay Threshold Period To Pay Accounts Payables Threshold Period To Pay Accounts Payables Fair Value, Liabilities Measured on Recurring Basis [Roll Forward] Fair Value, Liabilities Measured on Recurring Basis [Roll Forward] Fair Value, Liabilities Measured on Recurring Basis [Roll Forward] Liability at beginning of the period Warrants Not Settleable in Cash, Fair Value Disclosure Fair value of warrants exercised in the period Fair Value Of Warrants Exercised In The Period Represents the fair value of warrants exercised in the period. Increase (decrease) in fair value of warrants Increase (decrease) in value of warrants Represents the increase decrease in value of warrants. Foreign exchange loss Fair Value Warrants Foreign Exchange (Gain) Loss The amount of gains and losses from changes in foreign exchanges. Liability at end of the period Schedule of minimum rent and estimated operating cost commitment, net of lease inducements Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Equivalent number of Company common shares Equivalent Number Of Company Common Shares [Member] Represents the equivalent number of company common shares. Protiva Share Options Protiva Share Options [Member] Represents the Protiva share options. Options forfeited, canceled or expired (in shares) Class of Warrant or Right [Table] Class of Warrant or Right [Table] Class of Warrant or Right [Line Items] Class of Warrant or Right [Line Items] Class Of Warrant Or Right Number Of Securities Called By Warrants Or Rights [Roll Forward] Class Of Warrant Or Right Number Of Securities Called By Warrants Or Rights [Roll Forward] Class Of Warrant Or Right Number Of Securities Called By Warrants Or Rights [Roll Forward] Balance, Common shares purchasable upon exercise of warrants (in shares) Class of Warrant or Right, Number of Securities Called by Warrants or Rights Exercised, Common shares purchasable upon exercise of warrants (in shares) Class Of Warrant Or Right Exercised During Period Represents the class of warrant or right, exercised during period. Expired, Common shares purchasable upon exercise of warrants (in shares) Class of Warrant or Right, Expired Class of Warrant or Right, Expired Balance, Common shares purchasable upon exercise of warrants (in shares) Balance, Weighted average exercise price (in CAD and USD per share) Class of Warrant or Right, Exercise Price of Warrants or Rights Exercised, Weighted average exercise price (in CAD and USD per share) Class Of Warrant Or Right Exercised During Period Exercise Price Exercise price per share of warrants or rights exercised during period. Expired, Weighted average exercise price (in CAD and USD per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price Balance, Weighted average exercise price (in CAD and USD per share) Balance, Range of exercise prices (in CAD and USD per share) Balance, Range of exercise prices Represents the range of prices for outstanding warrants or rights. Exercised, Range of exercise prices (in CAD and USD per share) Class Of Warrants Or Rights Excercised Price Range Represents the price range for warrants or rights exercised during the period. Expired, Range of exercise prices (in CAD and USD per share) Class of Warrants or Rights Expired Price Range Class of Warrants or Rights Expired Price Range Balance, Range of exercise prices (in CAD and USD per share) Balance, Weighted average remaining contractual life Balance, Weighted average remaining contractual life Represents the class of warrant or right price of warrants or rights contractual term. Balance, Aggregate intrinsic value Class Of Warrant Or Right Price Of Warrants Or Rights Intrinsic Value Represents the class of warrant or right price of warrants or rights intrinsic value. Statement of Financial Position [Abstract] Common shares, par value (in USD per share) Common Stock, No Par Value Common shares, shares issued Common Stock, Shares, Issued Common shares, shares outstanding Common Stock, Shares, Outstanding Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions [Table] Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions [Table] DoD Do D [Member] Represents the department of defense. Monsanto Monsanto [Member] Represents the company Monsanto. BMS BMS [Member] Represents Bristol Myers Squibb. Dicerna Dicerna [Member] Represents Dicerna pharmaceuticals. Other Other Milestone and Royalty Payments [Member] Other Milestone and Royalty Payments [Member] Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] Collaborations and contracts Collaborations And Contracts [Abstract] Collaborations and contracts Licensing fees, milestone and royalty payments Licensing Fees Milestone And Royalty Payments [Abstract] Licensing fees, milestone and royalty payments Liability classified stock options Employee Stock Option, Liability Classified [Member] Employee Stock Option, Liability Classified [Member] Contingencies and commitments Commitments and Contingencies Disclosure [Text Block] Schedule of Research and Development Arrangement, Contract to Perform for Others [Table] Schedule of Research and Development Arrangement, Contract to Perform for Others [Table] PADCo. PADCo. [Member] PADCo. [Member] Contract Modifications [Axis] Contract Modifications [Axis] Contract Modifications [Axis] Contract Modifications [Domain] Contract Modifications [Domain] [Domain] for Contract Modifications [Axis] Increase to support development plans Increase To Support Development Plans [Member] Represents the increase funding potential to support development plans that integrate recent advancements in lipid nanoparticle (“LNP”) formulation and manufacturing technologies. Increased funding for stage one Increased Funding For Stage One [Member] Represents the increased funding for phase one of the clinical trials. Stage one Stage One [Member] Represents the first stage of the contract and is aligned with phase one of the clinical trials. Contract extension Contract Extension [Member] Represents the contract extension. Marqibo Commercial Sales Marqibo Commercial Sales [Member] Represents the Marqibo commercial sales. Talon Therapeutics Talon Therapeutics [Member] Represents the Talon Therapeutics. Research and Development Arrangement, Contract to Perform for Others [Line Items] Research and Development Arrangement, Contract to Perform for Others [Line Items] Potential contract funding amount Potential Contract Funding Amount Represents the potential contract funding amount. Optional exercised contractual option, amount Optional Excercised Contractual Option, Amount Represents the amount of an option exercise that was embedded in a contract. Approximate option period Approximate Option Period Represents the approximate period of the option agreement. Maximum potential transaction value Maximum Potential Transaction Value Represents the maximum potential transaction value. Option period extension Option Period Extension Option period extension Payments from inception of contract Near Term Contract Payments Represents the payments for the near term as part of the contract. Revenue Business acquisition, percentage of outstanding shares acquired Business Acquisition, Percentage of Voting Interests Acquired Deferred revenue Deferred Revenue Length of agreement with Bristol-Myers Squibb Length Of Agreement With Bristol-Myers Squibb Length Of Agreement With Bristol-Myers Squibb Milestone payment Milestone Payment Represents a milestone payment. Number of chemotherapy products with worldwide licenses Number Of Chemotherapy Products With Worldwide Licenses Number Of Chemotherapy Products With Worldwide Licenses Accrued royalties Accrued Royalties Income Tax Disclosure [Abstract] Schedule of effective income tax rate reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of components of deferred tax assets Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Property and equipment Property, Plant and Equipment Disclosure [Text Block] Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration Fair Value, Liability [Roll Forward] Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration Fair Value, Liability [Roll Forward] Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration Fair Value, Liability [Roll Forward] Contingent consideration at beginning of the period Business Combination, Contingent Consideration, Liability, Noncurrent Increase in fair value of contingent consideration Contingent consideration at end of the period Payables and Accruals [Abstract] Supplementary information Supplemental Balance Sheet Disclosures [Text Block] Year ended December 31, 2017 Operating Leases, Future Minimum Payments Due, Next Twelve Months Year ended December 31, 2018 Operating Leases, Future Minimum Payments, Due in Two Years Year ended December 31, 2019 Operating Leases, Future Minimum Payments, Due in Three Years Year ended December 31, 2020 Operating Leases, Future Minimum Payments, Due in Four Years Year ended December 31, 2021 and after Operating Leases, Future Minimum Payments, Due Thereafter Future minimum rent and estimated operating cost commitment, net of lease inducements Subsequent Events [Abstract] Subsequent events Subsequent Events [Text Block] Immune Modulator and cccDNA Sterilizer drug classes Cyclophilin Drug Candidate, OCB-030 [Member] Cyclophilin Drug Candidate, OCB-030 [Member] Cumulative impairment charge against intangible assets and goodwill Goodwill and Intangible Asset Impairment Impairment charge Income tax benefit on impairment charge Number of reporting units Number of Reporting Units Goodwill Goodwill Goodwill impairment charge Debt Disclosure [Abstract] Loan Payable Debt Disclosure [Text Block] Income taxes Income Tax Disclosure [Text Block] Wholly-owned subsidiaries Wholly Owned Subsidiaries Included in Financial Statements Represents the number of wholly owned subsidiaries included in the reporting of the financial statements. Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Line Items] Business Acquisition [Line Items] Restricted investment, term Restricted Investment, Term Restricted Investment, Term Interest rate on restricted investment Investment Interest Rate Fair value of contingent consideration Anti-dilutive common shares excluded from calculation of income per common share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Computed taxes (recoveries) at Canadian federal and provincial tax rates Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount Permanent and other differences Effective Income Tax Rate Reconciliation, Other Adjustments, Amount Change in valuation allowance - other Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount Difference due to income taxed at foreign rates Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount Stock-based compensation Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Amount Impairment of goodwill Effective Income Tax Rate Reconciliation, Nondeductible Expense, Impairment Losses, Amount Deferred income tax recovery Protiva Option Plan Protiva Option Plan [Member] Protiva Option Plan [Member] OnCore Option Plan OnCore Option Plan [Member] OnCore Option Plan [Member] Schedule of warrant activity Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block] Schedule of weighted average Black-Scholes option-pricing assumptions and resultant fair values Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Schedule of stock option activity for the Arbutus Plans Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] Summary of stock options outstanding by exercise price range Temporal Diagram of Share Based Compensation Shares Authorized Under Stock Option Plans by Exercise Price Range [Table Text Block] Represents the schedule of share based compensation for the shares authorized under the stock option plan. Schedule of non-vested stock option activity Schedule of Nonvested Share Activity [Table Text Block] Schedule of weighted average option pricing assumptions and the resultant fair values Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value [Table Text Block] Schedule of option activity Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding and Exercisable [Table Text Block] Schedule of allocation of stock-based compensation Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block] Schedule of accounts payable and accrued liabilities Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] Subsequent Event [Table] Subsequent Event [Table] Alexion Alexion [Member] Alexion [Member] 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] Upfront payment License Upfront Payment License Upfront Payment Subsequent payments Summary of carrying values, net of impairment of the intangible assets Schedule of Indefinite-Lived Intangible Assets [Table Text Block] Significant accounting policies Significant Accounting Policies [Text Block] Income Taxes [Table] Income Taxes [Table] Tax Credit Carryforward [Axis] Tax Credit Carryforward [Axis] Tax Credit Carryforward, Name [Domain] Tax Credit Carryforward, Name [Domain] Investment tax credit carryforward Investment Tax Credit Carryforward [Member] Research tax credit carryforward Research Tax Credit Carryforward [Member] Income Taxes [Line Items] Income Taxes (Details) [Line Items] Canadian federal and provincial income tax rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Investment tax credits available to reduce Canadian federal income taxes Deferred Tax Assets, Operating Loss Carryforwards, Domestic Investment tax credits available to reduce provincial income taxes Deferred Tax Assets, Operating Loss Carryforwards, State and Local Research and development credits Deferred Tax Assets, Tax Credit Carryforwards, Research Scientific research and experimental development expenditures available for indefinite carry-forward Deferred Tax Assets, Operating Loss Carryforwards Deferred tax assets, operating loss carryforwards, subject to expiration Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration Patent tax refund percentage Patent Tax Refund Percentage Represents the patent tax refund percentage. Income tax refund maximum from patents 2007 Plan 2007 Plan [Member] 2007 Plan [Member] 2011 Plan 2011 Plan [Member] 2011 Plan [Member] Designated Plans Designated Plans [Member] Represents the Designated Plans. Cashless Exercise Provision Cashless Exercise Provision [Member] Represents the cashless exercise provision. Revised new common shares Revised New Common Shares [Member] Represents the revised new common shares. Unexpired repurchase rights on shares issued to Arbutus Inc. Unexpired Repurchase Rights On Shares Issued to Arbutus Inc. [Member] Unexpired Repurchase Rights On Shares Issued to Arbutus Inc. [Member] Expired repurchase rights on shares issued to Arbutus Inc. Expired Repurchase Rights On Shares Issued to Arbutus Inc. [Member] Expired Repurchase Rights On Shares Issued to Arbutus Inc. [Member] Class of Warrant or Right [Axis] Class of Warrant or Right [Axis] Class of Warrant or Right [Domain] Class of Warrant or Right [Domain] Stock issued during underwritten public offering (in shares) Stock Issued During Period, Shares, New Issues Stock price at public offering (in USD per share) Sale of Stock, Price Per Share Gross proceeds from issuance of stock Period for option to purchase additional shares Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period Number of additional shares authorized (in shares) Number of Additional Shares Authorized (in Shares) The number of additional shares authorized in which underwriters have the option to purchase. Potential proceeds of additional shares authorized Potential Proceeds of Additional Shares Authorized The potential cash inflow from the additional capital contribution to the entity if an option is exercised. Payments of stock issuance costs, including commissions and professional fees Payments of Stock Issuance Costs Proceeds from issuance of common stock, net Proceeds From Issuance Of Common Stock Net Proceeds from issuance of common stock net. Warrants exercised (in shares) Warrants Exercised (in Shares) Represents the warrants exercised. Proceeds from warrant exercises Common shares issued from warrants exercise (in shares) Stock Issued During Period, Shares, Conversion of Convertible Securities Warrants expired (in shares) Decrease in fair value of warrant liability Number of share-based compensation plans Number of Share-Based Compensation Plans Number of Share-Based Compensation Plans Expected average term (years) Option vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Number of stock-based compensation awards approved to be issued (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Number of additional shares authorized (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Number of executive officers granted options with new appointments Number Of Executive Officers Granted Options With New Appointments Number Of Executive Officers Granted 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intrinsic value of option expected to vest Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value Total fair value of options that vested during period Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value Risk-free interest rate Fair Value Assumptions, Risk Free Interest Rate Number of exercisable liability options (in shares) Weighted average exercise price (in CAD and USD per share) Shares reserved for future exercise (in shares) Common Stock, Capital Shares Reserved for Future Issuance Option exercise price (in CAD per share) Investment Options, Exercise Price Conversion of stock, shares converted (in shares) Conversion of Stock, Shares Converted Fair value of consideration issued Business Acquisition, Equity Interest Issued or Issuable, Value Assigned Expected volatility Fair Value Assumptions, Expected Volatility Rate Dividend yield Fair Value Assumptions, Expected Dividend Rate Expected average term (years) Fair Value Assumptions, Expected Term Business acquisition, fair value amount attributed as pre-combination service and included as part of acquisition consideration Business Acquisition Equity Interest Issued Or Issuable Value Assigned Attributed As Pre Combination Service And Included As Part Of Total Purchase Price Business Acquisition Equity Interest Issued Or Issuable Value Assigned Attributed As Pre Combination Service And Included As Part Of Total Purchase Price Business acquisition, post-combination attribution recognized as compensation expense Business Acquisition Equity Interest Issued Or Issuable Value Assigned Attributed As Post Combination Service And Not Included As Part Of Total Purchase Price Business Acquisition Equity Interest Issued Or Issuable Value Assigned Attributed As Post Combination Service And Not Included As Part Of Total Purchase Price Options exercisable weighted average exercise price (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Unearned compensation expense Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Unearned compensation expense, recognition period Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Number of options outstanding (in shares) Accelerated compensation expense recognized in each subsequent period Business Combination Acceleration Of Share Based Compensation Expense Per Quarter Business Combination Acceleration Of Share Based Compensation Expense Per Quarter Number of shareholders whose departure accelerated compensation expense Number of Shareholders Whose Departure Accelerated Compensation Expense Number of Shareholders Whose Departure Accelerated Compensation Expense Number of shareholders subject to repurchase provision Number of Shareholders Subject to Repurchase Provision Number of Shareholders Subject to Repurchase Provision Unrecognized compensation expense related to expiry of repurchase provisions Common Shares Attributed to Post Acquisition Period Compensation Cost Not Yet Recognized Over Expiry Period of Repurchase Provision Rights Common Shares Attributed to Post Acquisition Period Compensation Cost Not Yet Recognized Over Expiry Period of Repurchase Provision Rights Net liquidity Net Liquidity Disclosure [Table Text Block] Represents the full tabular disclosure for the net liquidity. Schedule of exposure to US dollar currency expressed in Canadian dollars Schedule of Intercompany Foreign Currency Balances [Table Text Block] Loss from operations Net loss Basic and diluted net loss per share (in USD per share) Earnings Per Share, Basic and Diluted Liability at beginning of the period Employee Stock Options, Liability Classified, Outstanding, Fair Value Disclosure Employee Stock Options, Liability Classified, Outstanding, Fair Value Disclosure Fair value of liability-classified stock option awards exercised in the period Increase (decrease) in fair value of liability Increase (Decrease) in Fair Value of Liability Classified Options Increase (Decrease) in Fair Value of Liability Classified Options Liability at end of the period Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Fair value, inputs, Level 1 Fair Value, Inputs, Level 1 [Member] Fair value, inputs, Level 3 Fair Value, Inputs, Level 3 [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Assets Assets, Fair Value Disclosure [Abstract] Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Short-term investments and guaranteed investment certificates Investments, Fair Value Disclosure Restricted investment Restricted Investments, at Fair Value Term deposit Long-term Investments Total Assets Assets, Fair Value Disclosure Liabilities Liabilities, Fair Value Disclosure [Abstract] Warrants Liability-classified stock option awards Contingent consideration Total Liabilities Liabilities, Fair Value Disclosure, Recurring Deferred Revenue Arrangement, by Type [Table] Deferred Revenue Arrangement, by Type [Table] Deferred Revenue Arrangement [Line Items] Deferred Revenue Arrangement [Line Items] Deferred revenue, current portion Deferred Revenue, Current Deferred revenue, long-term portion Deferred Revenue, Noncurrent Total deferred revenue Statement of Stockholders' Equity [Abstract] Issuance of common shares in conjunction with private offering, issuance costs Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward] Non-vested, beginning balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares Options vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares Non-vested options forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Options Forfeited, Number of Shares Non-vested, ending balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Non-vested, beginning balance, weighted average fair value (in CAD and USD per share) Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Options Nonvested Weighted Average Fair Value Represents the share based compensation arrangement for the share based payment award for the fair value of equity instruments. Options vested (in CAD and USD per share) Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Options Vested In Period Weighted Average Fair Value Represents the share based compensation arrangement concerning the fair value of options vested. Non-vested options forfeited (in CAD and USD per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Non-vested, ending balance, weighted average fair value (in CAD and USD per share) Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Wells Fargo Wells Fargo [Member] Wells Fargo [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] LIBOR London Interbank Offered Rate (LIBOR) [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Loans payable Loans Payable [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Promissory note with Wells Fargo Promissory Note [Member] Promissory Note [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Loan payable Debt Instrument, Face Amount Fixed component of interest rate Debt Instrument, Basis Spread on Variable Rate Restricted investment Restricted Investments, Noncurrent Range 3 Range of Exercise prices - Low (in USD per share) Range of Exercise prices - High (in USD per share) Options reclassified to liability-options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Reclassification to Liability, Number of Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Reclassification to Liability, Number of Shares Options reclassified to liability (in CAD and USD per share) Share Based Compensation,Arrangement By Share Based Payment Award, Equity Instruments, Options, Reclassification to Liability, Nonvested, Weighted Average Fair Value Share Based Compensation,Arrangement By Share Based Payment Award, Equity Instruments, Options, Reclassification to Liability, Nonvested, Weighted Average Fair Value Options granted (in CAD and USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Components of Deferred Tax Assets [Table] Components of Deferred Tax Assets [Table] Income Tax Authority [Axis] Income Tax Authority [Axis] Income Tax Authority [Domain] Income Tax Authority [Domain] Federal Domestic Tax Authority [Member] Provincial State and Local Jurisdiction [Member] Components of Deferred Tax Assets [Line Items] Components of Deferred Tax Assets [Line Items] Non-capital loss carryforwards Research and development deductions Deferred Tax Assets, in Process Research and Development Book amortization in excess of tax Book amortization in excess of tax Represents the deferred tax asset book amortization in excess of tax. Share issue costs Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost Revenue recognized for tax purposes in excess of revenue recognized for accounting purposes Revenue recognized for tax purposes in excess of revenue recognized for accounting purposes Represents the deferred tax asset revenue recognized for tax purpose in excess of revenue recognized for accounting purposes. Tax value in excess of accounting value in lease inducements Tax value in excess of accounting value in lease inducements Represents the deferred tax asset tax value in excess of accounting value in lease inducements. Investment tax credits Deferred Tax Assets, Investments In-process research and development Deferred Tax Liabilities, Deferred Expense, Capitalized Research and Development Costs Upfront license fees Deferred Tax Asset, Upfront License Fees Deferred Tax Asset, Upfront License Fees Other Deferred Tax Assets, Other Total deferred tax assets Deferred Tax Assets, Gross Total deferred tax (liabilities) Deferred Tax Liabilities, Gross Valuation allowance Deferred Tax Assets, Valuation Allowance Net deferred tax assets (liabilities) Deferred Tax Liabilities, Net Concentrations of business risk Concentration Risk Disclosure [Text Block] Schedule of revenue recognized under collaborations, contracts and licensing agreements Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions [Table Text Block] Schedule of deferred collaborations and contracts revenue Deferred Revenue, by Arrangement, Disclosure [Table Text Block] Assets Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Short-term investments Short-term Investments Accounts receivable Accounts Receivable, Net, Current Accrued revenue Investment tax credits receivable Income Taxes Receivable, Current Prepaid expenses and other assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current Long-term investments Property and equipment Property, Plant and Equipment, Gross Less accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Property and equipment, net of accumulated depreciation Property, Plant and Equipment, Net Intangible assets Total assets Assets Liabilities and stockholders' equity Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable and accrued liabilities Accounts Payable and Accrued Liabilities, Current Deferred revenue Liability-classified options Employee Stock Options, Liability Classified, Outstanding Employee Stock Options, Liability Classified, Outstanding Warrants Warrants and Rights Outstanding Total current liabilities Liabilities, Current Deferred revenue, net of current portion Loan payable Loans Payable, Noncurrent Deferred tax liability Deferred Tax Liabilities, Net, Noncurrent Total liabilities Liabilities Stockholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Common shares, authorized - unlimited number with no par value, Issued and outstanding: 54,841,494 (December 31, 2015 - 54,570,691) Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Deficit Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total stockholders' equity Stockholders' Equity Attributable to Parent Total liabilities and stockholders' equity Liabilities and Equity Trade accounts payable Accounts Payable, Trade, Current Research and development accruals Accrued Research and Development, Current Accrued Research and Development, Current Professional fee accruals Accrued Professional Fees, Current Deferred lease inducements Lease Incentive, Payable, Current Payroll accruals Accrued Payroll Current Accrued Payroll Current Other accrued liabilities Other Accrued Liabilities, Current Accounts payable and accrued liabilities Document and Entity Information [Abstract] Document and Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Document Type Document Type Current Fiscal Year End Date Current Fiscal Year End Date Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Public Float Entity Public Float Amendment Flag Amendment Flag Entity Central Index Key Entity Central Index Key Entity Current Reporting Status Entity Current Reporting Status Entity Voluntary Filers Entity Voluntary Filers Entity Filer Category Entity Filer Category Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Asset impairment charges Asset Impairment Charges Fair value of warrants outstanding (in USD per share) Fair Value Of Warrants Outstanding Per Warrant Represents the fair value of the warrants outstanding. Aggregate fair value of warrants outstanding Number of warrants outstanding (in shares) Class of Warrant or Right, Outstanding Cash, cash equivalents and short-term investments Less: Accounts payable and accrued liabilities Net liquidity Net Liquidity Net liquidity Government grants and refundable investment tax credits Government Grants And Refundable Investment Tax Credits [Text Block] The entire disclosure for information about government grants and investment tax credits netted against expenses in the statement of operations. Lab equipment Leasehold improvements Leasehold Improvements [Member] Computer hardware and software Assets under construction Construction in Progress [Member] Cost Accumulated depreciation Dividend yield Expected volatility Risk-free interest rate Fair value of liability options outstanding (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Fair Value Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Fair Value Price Fair value of vested liability-classified options (in thousands) Share capital Stockholders' Equity Note Disclosure [Text Block] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock Common Stock [Member] Additional paid-in capital Additional Paid-in Capital [Member] Deficit Retained Earnings [Member] Accumulated other comprehensive loss AOCI Attributable to Parent [Member] Balance (in shares) Shares, Issued Balance Stock-based compensation Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Reclassification of equity to liability stock option awards Adjustments to Additional Paid in Capital, Reclassification of Equity to Liability Stock Option Awards Adjustments to Additional Paid in Capital, Reclassification of Equity to Liability Stock Option Awards Certain fair value adjustments to liability stock option awards Adjustments to Additional Paid in Capital, Certain Fair Value Adjustments to Liability Stock Option Awards Adjustments to Additional Paid in Capital, Certain Fair Value Adjustments to Liability Stock Option Awards Issuance of common shares pursuant to exercise of options (in shares) Issuance of common shares pursuant to exercise of options Stock Issued During Period, Value, Stock Options Exercised Issuance of common shares pursuant to exercise of warrants (in shares) Stock Issued During Period, Shares, Other Issuance of common shares pursuant to exercise of warrants Stock Issued During Period, Value, Other Issuance of common shares in conjunction with the private offering, net of issuance costs (in shares) Issuance of common shares in conjunction with the private offering, net of issuance costs Stock Issued During Period, Value, New Issues Increase of equity instruments in conjunction with the acquisition of Arbutus Inc. (in shares) Stock Issued During Period, Shares, Acquisitions Increase of equity instruments in conjunction with the acquisition of Arbutus Inc. Stock Issued During Period, Value, Acquisitions Currency translation adjustment Balance (in shares) Balance