Supplemental cash flow information Supplemental Cash Flow Information [Abstract] Canadian federal and provincial income tax rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Net loss attributable to common shareholders per share Earnings Per Share, Policy [Policy Text Block] Weighted average number of common shares Weighted Average Number Of Common Shares [Abstract] Weighted average number of common shares Leasehold improvements Leasehold Improvements [Member] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Net loss Net loss Net loss Net Income (Loss) Attributable to Parent Total deferred tax assets Deferred Tax Assets (Liabilities), Gross Deferred Tax Assets (Liabilities), Gross Right of use asset Operating Lease, Right-of-Use Asset Scientific research and experimental development expenditures available for indefinite carry-forward Non-capital losses carryforwards Deferred Tax Assets, Operating Loss Carryforwards Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Income Statement Location [Axis] Income Statement Location [Axis] Range [Domain] Statistical Measurement [Domain] Liability Related To Future Royalties [Roll Forward] Liability Related To Future Royalties [Roll Forward] Liability Related To Future Royalties Segment information Segment Reporting, Policy [Policy Text Block] Security Exchange Name Security Exchange Name Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code License Agreement Milestone payment maximum License Agreement Milestone payment maximum License Agreement Milestone payment maximum Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] OMERS OMERS [Member] OMERS Weighted-average remaining lease term (years) Operating Lease, Weighted Average Remaining Lease Term Fair value of liability-classified options exercised in the period Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Fair Value Foreign currency translation and functional currency conversion Foreign Currency Transactions and Translations Policy [Policy Text Block] Liability classified stock options Employee Stock Option, Liability Classified [Member] Employee Stock Option, Liability Classified [Member] Other non-current assets Other Assets, Noncurrent Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Bona fide collaboration Percentage [Member] Bona fide collaboration Percentage Bona fide collaboration Percentage Investment, Name [Axis] Investment, Name [Axis] Royalty guarantees commitments percentage Royalty Guarantees Commitments Percentage Represents the royalty guarantees commitments percentage. Expected dividends Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Increase in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Entity File Number Entity File Number Expected volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Stock-based compensation APIC, Share-based Payment Arrangement, Increase for Cost Recognition Intrinsic value of options exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value Options forfeited, canceled or expired (in shares) Options forfeited, canceled or expired (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Deductible stock options Deferred Tax Assets, Tax Deferred Expense, Compensation And Benefits, Stock Options Deferred Tax Assets, Tax Deferred Expense, Compensation And Benefits, Stock Options Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Investment tax credit carryforward Investment Tax Credit Carryforward [Member] Variable lease payment Variable Lease, Cost Net deferred tax assets (liabilities) Deferred Tax Assets, Net Weighted average discount rate Operating Lease, Weighted Average Discount Rate, Percent Anti-dilutive common shares excluded from calculation of income per common share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Research and development Research and Development Expense [Member] Sale of Stock [Axis] Sale of Stock [Axis] Net equity investment loss Net equity investment gain or loss Net equity investment gain or loss Equity accounted for investment Deferred Tax Assets, Equity Method Investments Non-Vested Stock Options Nonvested [Member] Nonvested [Member] Arbutus Plans Arbutus Plans [Member] Arbutus Plans [Member] Business Acquisition [Axis] Business Acquisition [Axis] Title of Individual [Domain] Title of Individual [Domain] Equity Award [Domain] Award Type [Domain] Local Phone Number Local Phone Number Schedule of changes in fair value of contingent consideration Schedule of Business Acquisitions by Acquisition, Contingent Consideration [Table Text Block] Assets Assets [Abstract] Related Party Transactions [Abstract] Related Party Transactions [Abstract] Currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Portion Attributable to Noncontrolling Interest Products and Services [Table] Products and Services [Table] Investment tax credits available to reduce Canadian federal income taxes Deferred Tax Assets, Operating Loss Carryforwards, Domestic Income Taxes [Line Items] Income Taxes (Details) [Line Items] Cash equivalents Cash Equivalents [Member] Property and equipment Property, Plant and Equipment, Policy [Policy Text Block] Number of options outstanding (in shares) Balance - Number of optioned common shares (in shares) Balance - Number of optioned common shares (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Deficit Retained Earnings [Member] Prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Qilu Qilu [Member] Qilu Other Liabilities Disclosure [Abstract] Other Liabilities Disclosure [Abstract] Contingencies and commitments Commitments and Contingencies Disclosure [Text Block] Currency translation adjustment Translation Adjustment Functional to Reporting Currency, Net of Tax, Period Increase (Decrease) Conversion of Preferred Shares into Common Shares Stock Issued During Period, Value, Conversion of Convertible Securities Adjustment to prior year Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount Cash payment for collaborations Proceeds from Collaborators Related Party [Axis] Related Party [Axis] Accounts receivable Increase (Decrease) in Accounts Receivable Schedule of components of deferred tax assets Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Percent of costs funded by TPC Percent Of Costs Funded By T P C Represents the percent of costs funded by TPC. Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Basic (in USD per share) Basic net loss attributable to common shareholders per share (in USD per share) Earnings Per Share, Basic Deferred tax assets, operating loss carryforwards, subject to expiration Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration Assembly Assembly Biosciences, Inc. [Member] Assembly Biosciences, Inc. Operating lease expense Operating Lease, Expense 2024 Lessee, Operating Lease, Liability, to be Paid, Year Three Non-cash royalty revenue Non-Cash Royalty [Member] Non-Cash Royalty Laboratory equipment Lab equipment Laboratory Equipment [Member] Represents the laboratory equipment. Federal R&E credits Deferred Tax Assets, Tax Credit Carryforwards Administrative and transitional services Administrative And Transitional Services [Member] Administrative And Transitional Services [Member] 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 Cash paid for amounts included in the measurement of lease liabilities Operating Lease, Payments Preferred dividend percentage Preferred Stock, Dividend Rate, Percentage Talon Therapeutics Talon Therapeutics [Member] Represents the Talon Therapeutics. Entity Voluntary Filers Entity Voluntary Filers US government bonds US Government Bonds [Member] US Government Bonds [Member] Plan Name [Axis] Plan Name [Axis] Assets Assets, Fair Value Disclosure [Abstract] Outstanding debt Long-term Debt Total Assets, Fair Value Disclosure Level 1 Fair Value, Inputs, Level 1 [Member] INVESTING ACTIVITIES Net Cash Provided by (Used in) Investing Activities [Abstract] Unrealized foreign exchange gains Foreign Currency Transaction Gain (Loss), Unrealized Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Effective annual interest rate of royalty liability Effective Annual Interest Rate Of Royalty Liability Effective Annual Interest Rate Of Royalty Liability Entity Small Business Entity Small Business Marqibo Commercial Sales Marqibo Commercial Sales [Member] Represents the Marqibo commercial sales. 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. Discount rate on shares Common Stock, Discount On Shares, Percentage Common Stock, Discount On Shares, Percentage Conversion of Preferred Shares into Common Shares (in shares) Conversion of Stock, Shares Converted Items applicable to preferred shares Preferred Stock Dividends and Other Adjustments [Abstract] Total liabilities and stockholders' equity Liabilities and Equity Other accrued liabilities Other Accrued Liabilities, Current Investments, Debt and Equity Securities [Abstract] Investments, Debt and Equity Securities [Abstract] 2026 Lessee, Operating Lease, Liability, to be Paid, Year Five 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 Additional paid-in capital Additional Paid in Capital Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Liabilities and stockholders' equity Liabilities and Equity [Abstract] Accounts payable and accrued liabilities Accounts payable and accrued liabilities Accounts Payable and Accrued Liabilities, Current Ownership interest in equity method investment (as a percent) Equity Method Investment, Ownership Percentage Entity Interactive Data Current Entity Interactive Data Current Cash and Cash Equivalents [Domain] Cash and Cash Equivalents [Domain] Issuance of common shares pursuant to exercise of options Stock Issued During Period, Value, Stock Options Exercised Minimum Minimum [Member] OnCore Option Plan OnCore Option Plan [Member] OnCore Option Plan [Member] Change in fair value of contingent consideration Increase in fair value of contingent consideration Increase in fair value of liability Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability 2023 Lessee, Operating Lease, Liability, to be Paid, Year Two Effect of foreign exchange rate changes on cash and cash equivalents Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Total Financial and Nonfinancial Liabilities, Fair Value Disclosure 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 Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Income Tax Authority [Domain] Income Tax Authority [Domain] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Royalty interest sold, maximum royalties for buyer Royalty Interest Sold, Maximum Royalties For Buyer Royalty Interest Sold, Maximum Royalties For Buyer Gross Unrealized Gain Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Entity Address, State or Province Entity Address, State or Province Loss contingency, damages sought for allegedly unpaid royalties Loss Contingency, Damages Sought, Value Current liabilities: Liabilities, Current [Abstract] Schedule of stock options vested and outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding and Exercisable [Table Text Block] Issuance of common shares pursuant to the Open Market Sales Agreement Issuance of common shares in conjunction with the private offering, net of issuance costs Stock Issued During Period, Value, New Issues General and administrative General and Administrative Expense Audit Information [Abstract] Audit Information Number of wholly-owned subsidiaries Number Of Wholly-Owned Subsidiaries Number Of Wholly-Owned Subsidiaries Payroll accruals Accrued Payroll Current Accrued Payroll Current Stock-based compensation Share-based Payment Arrangement [Text Block] Level 3 Fair Value, Inputs, Level 3 [Member] Leases Lessee, Leases [Policy Text Block] Collaborations and licenses Collaboration And Contracts [Member] Collaboration And Contracts [Member] Accounting Policies [Abstract] Accounting Policies [Abstract] Weighted-average term remaining Weighted-average term remaining of vested stock options Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Contractual obligation Contractual Obligation Issuance of common shares pursuant to the Open Market Sales Agreement (in shares) Stock Issued During Period, Shares, New Issues Professional fee accruals Accrued Professional Fees, Current Present value of lease payments Operating Lease, Liability Document Transition Report Document Transition Report Foreign exchange gain (loss) Foreign Currency Transaction Gain (Loss), before Tax Common shares, Authorized: unlimited number without par value, Issued and outstanding: 144,987,736 (December 31, 2020: 89,678,722) Common Stock, Value, Issued Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Dividend accretion of convertible preferred shares Preferred Stock Dividends and Other Adjustments Total other loss Nonoperating Income (Expense) Unearned compensation expense, recognition period Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Fixed lease payment Fixed Lease, Cost Fixed Lease, Cost Basis of presentation Basis of Accounting, Policy [Policy Text Block] Performance shares Performance Shares [Member] Leases Lessee, Operating Leases [Text Block] Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Emerging Growth Company Entity Emerging Growth Company ICFR Auditor Attestation Flag ICFR Auditor Attestation Flag 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] Ownership [Axis] Ownership [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Investments in marketable securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Contingencies and Commitments [Line Items] Contingencies and Commitments [Line Items] Legal Entity [Axis] Legal Entity [Axis] Auditor Name Auditor Name Cover [Abstract] Class of Stock [Axis] Class of Stock [Axis] Impairment of goodwill Effective Income Tax Rate Reconciliation, Nondeductible Expense, Impairment Losses, Amount Transaction costs related to sale of future royalties Transaction Costs Related To Sale Of Future Royalties Transaction Costs Related To Sale Of Future Royalties Cash and cash equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Less: interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Income Tax Authority [Axis] Income Tax Authority [Axis] Allocation of undistributable loss Undistributed Earnings (Loss) Available to Common Shareholders, Basic Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] Share-based Payment Arrangement, Option, Exercise Price Range [Line Items] Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Income from related party (less than) Revenue from Related Parties Offices Located at 626 Jacksonville Rd., Warminster, Pennsylvania Offices Located at 626 Jacksonville Rd., Warminster, Pennsylvania [Member] Offices Located at 626 Jacksonville Rd., Warminster, Pennsylvania Financial Instrument [Axis] Financial Instrument [Axis] Sale of future royalties Liabilities Related To Sale Of Future Royalties [Text Block] Liabilities Related To Sale Of Future Royalties Entity [Domain] Entity [Domain] Noncontrolling interest, ownership percentage by owners after conversion Noncontrolling Interest, Ownership Percentage By Noncontrolling Owners After Conversion Noncontrolling Interest, Ownership Percentage By Noncontrolling Owners After Conversion Stock Option Stock options Stock Options Share-based Payment Arrangement, Option [Member] Equity [Abstract] Equity [Abstract] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Comprehensive loss Comprehensive Income, Policy [Policy Text Block] Number of chemotherapy products with worldwide licenses Number Of Chemotherapy Products With Worldwide Licenses Number Of Chemotherapy Products With Worldwide Licenses Common Shares Common Stock [Member] Interest income Investment Income, Interest Federal and Provincial ITCs applied Effective Income Tax Rate Reconciliation, Tax Credit, Investment, Amount US government agency bonds US Government Agency Bonds [Member] US Government Agency Bonds [Member] Pre-tax foreign losses Income (Loss) from Continuing Operations before Income Taxes, Foreign Loss from operations Operating Income (Loss) Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-sale [Line Items] Lease liability, current Operating Lease, Liability, Current Alnylam Pharmaceuticals, Inc. Alnylam Pharmaceuticals, Inc [Member] Alnylam Pharmaceuticals, Inc Gross Unrealized Loss Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Collaborations and royalty entitlements Collaborative Arrangement Disclosure [Text Block] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Document Fiscal Year Focus Document Fiscal Year Focus Liability options Employee Stock Options, Liability Classified, Outstanding Employee Stock Options, Liability Classified, Outstanding Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Abstract] Stock-based compensation expense Share-based Payment Arrangement, Noncash Expense Additional paid-in capital Additional Paid-in Capital [Member] Cash and cash equivalents Cash Equivalents, Amortized Cost Cash and Cash Equivalents, at Carrying Value Depreciation Depreciation Depreciation Investment in Genevant Equity Method Investments [Policy Text Block] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Decrease in fair value of liability Increase (Decrease) in Fair Value of Liability Classified Options Increase (Decrease) in Fair Value of Liability Classified Options Difference due to change in tax rate on opening deferred taxes Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount Stock-based compensation Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Payment Arrangement, Amount Lease liabilities Increase (Decrease) in Other Operating Liabilities Legal Fees Legal Fees Acquisition of property and equipment Payments to Acquire Property, Plant, and Equipment Schedule of 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] Maximum Maximum [Member] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Share-based Payment Arrangement [Abstract] Schedule of estimated useful lives of property and equipment Property, Plant and Equipment, Estimated Useful Lives [Table Text Block] Tabular disclosure of property, plant and equipment, estimated useful lives. Schedule of revenue recognized under collaborations, contracts and licensing agreements Collaborative Arrangement and Arrangement Other than Collaborative [Table Text Block] Total liabilities Liabilities Award Type [Axis] Award Type [Axis] 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 FINANCING ACTIVITIES Net Cash Provided by (Used in) Financing Activities [Abstract] Intrinsic value of stock options Intrinsic value of vested stock options Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Schedule of lease maturity Lessee, Operating Lease, Liability, Maturity [Table Text Block] Total stockholders' equity Beginning balance Ending balance Stockholders' Equity Attributable to Parent Premium percentage on closing stock price Premium on Closing Stock Price Premium on Closing Stock Price Net operating losses Operating Loss Carryforwards Common shares, shares issued (in shares) Common Stock, Shares, Issued Equity method investment, percentage or revenue entitled Equity Method Investment, Percentage Of Revenue Entitled Equity Method Investment, Percentage Of Revenue Entitled Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued City Area Code City Area Code Components of Deferred Tax Assets [Table] Components of Deferred Tax Assets [Table] Accounts payable and accrued liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Royalty, percentage of interest sold Royalty, Percentage of Interest Sold Royalty, Percentage of Interest Sold Investment in Genevant Equity Method Investments and Joint Ventures Disclosure [Text Block] 2016 and 2011 Plans 2016 And 2011 Plans [Member] 2016 And 2011 Plans Entity Address, City or Town Entity Address, City or Town Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Useful lives Property, Plant and Equipment, Useful Life Number of renewal options Lessee, Operating Lease, Number Of Renewal Options Lessee, Operating Lease, Number Of Renewal Options Stockholders' equity Stockholders' Equity Attributable to Parent [Abstract] Concentrations of Credit Risk Concentration Risk, Credit Risk, Policy [Policy Text Block] Accretion of accumulated dividends on Preferred Shares Preferred Stock, Accretion of Redemption Discount Lease liability, non-current Operating Lease, Liability, Noncurrent Fair Value, Measurement Frequency [Domain] Measurement Frequency [Domain] Interest expense Interest Expense Shares price (in USD per share) Share Price Deficit Retained Earnings (Accumulated Deficit) Royalty interest sold, percentage of sales, annual revenue threshold of highest tier Royalty Interest Sold, Percentage Of Sales, Annual Revenue Threshold Of Highest Tier Royalty Interest Sold, Percentage Of Sales, Annual Revenue Threshold Of Highest Tier Research and development costs Research, Development, and Computer Software, Policy [Policy Text Block] Litigation Case [Domain] Litigation Case [Domain] Equivalent number of Company common shares Equivalent Number Of Company Common Shares [Member] Represents the equivalent number of company common shares. US treasury bills US Treasury Bill Securities [Member] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Issuance of common shares pursuant to exercise of ESPP options (in shares) Stock Issued During Period, Shares, Employee Stock Purchase Plans Entity Filer Category Entity Filer Category Research and development accruals Accrued Research and Development, Current Accrued Research and Development, Current Gritstone Oncology, Inc. Gritstone [Member] Gritstone [Member] Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Equity method investments Equity Method Investments Income Statement [Abstract] Income Statement [Abstract] Entity Registrant Name Entity Registrant Name Royalty payable Royalty Payable Represents the royalty payable. Other Liabilities Disclosure [Line Items] Other Liabilities Disclosure [Line Items] Other Liabilities Disclosure [Line Items] One-Time Upfront Cash Payment One-Time Upfront Cash Payment [Member] One-Time Upfront Cash Payment 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 Proceeds from Stock Options Exercised Investments in marketable securities, current Short-term Investments Related Party Transaction [Axis] Related Party Transaction [Axis] Income tax expense (recovery) Income Tax Expense (Benefit) Accounts receivable Accounts Receivable, after Allowance for Credit Loss, Current Amendment Flag Amendment Flag Equity Components [Axis] Equity Components [Axis] Entity Tax Identification Number Entity Tax Identification Number Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Document Fiscal Period Focus Document Fiscal Period Focus Total current assets Assets, Current Sale of Stock [Domain] Sale of Stock [Domain] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Total lease payments Lessee, Operating Lease, Liability, to be Paid Change in valuation allowance - other Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Stock-based compensation Share-based Payment Arrangement [Policy Text Block] Equity Method Investments and Joint Ventures [Abstract] Equity Method Investments and Joint Ventures [Abstract] 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] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Thereafter Lessee, Operating Lease, Liability, to be Paid, after Year Five Stock-based compensation expense related to ESPP Employee Stock Ownership Plan (ESOP), Compensation Expense Contingent consideration Fair value of contingent consideration Contingent consideration Liability at beginning of the period Liability at end of the period Business Combination, Contingent Consideration, Liability, Noncurrent Fair value measurements Fair Value Measurement, Policy [Policy Text Block] Product and Service [Axis] Product and Service [Axis] Property, Plant and Equipment, Type [Domain] Long-Lived Tangible Asset [Domain] Vested Stock Options Vested [Member] Vested [Member] Grantee Status [Axis] Grantee Status [Axis] Preferred stock, par value (in USD per share) Preferred Stock, Par or Stated Value Per Share Non-cash royalty revenue Liability From Sale Of Future Royalties, Non Cash Royalty Income Liability From Sale Of Future Royalties, Non Cash Royalty Income Entity Public Float Entity Public Float 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. Documents Incorporated by Reference Documents Incorporated by Reference [Text Block] Genevant Genevant Genevant Sciences Corporation [Member] Genevant Sciences Corporation [Member] Equity Component [Domain] Equity Component [Domain] Unrealized (loss) gain on available-for-sale securities Debt Securities, Available-for-sale, Unrealized Gain (Loss) 2022 Lessee, Operating Lease, Liability, to be Paid, Year One Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Proceeds from equity investment Proceeds from (Repurchase of) Equity Schedule of Research and Development Arrangement, Contract to Perform for Others [Table] Schedule of Research and Development Arrangement, Contract to Perform for Others [Table] Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Renewal term Lessor, Operating Lease, Renewal Term Non-cash interest expense Liability From Sale Of Future Royalties, Non Cash Expense Liability From Sale Of Future Royalties, Non Cash Expense Statement [Line Items] Statement [Line Items] Litigation Case [Axis] Litigation Case [Axis] Grantee Status [Domain] Grantee Status [Domain] Weighted average exercise price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Purchase of investments in marketable securities Payments to Acquire Investments United States Federal Domestic Tax Authority [Member] Fair Value Debt Securities, Available-for-sale Disposition of investments in marketable securities Proceeds from Sale, Maturity and Collection of Investments Counterparty Name [Domain] Counterparty Name [Domain] 2025 Lessee, Operating Lease, Liability, to be Paid, Year Four Litigation settlement interest Litigation Settlement Interest Level 2 Fair Value, Inputs, Level 2 [Member] 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. Property, Plant and Equipment, Type [Axis] Long-Lived Tangible Asset [Axis] Valuation allowance Deferred Tax Assets, Valuation Allowance Auditor Location Auditor Location Amortized Cost Debt Securities, Available-for-sale, Amortized Cost Consideration on sale of stock transaction Sale of Stock, Consideration Received Per Transaction Use of estimates Use of Estimates, Policy [Policy Text Block] Options granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Schedule of computation of basic and diluted net loss per common share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Document Annual Report Document Annual Report Schedule of allocation of stock-based compensation Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Royalties paid or accrued Royalties Paid Or Accrued The cumulative amount of royalties paid or accrued of an entity. Title of 12(b) Security Title of 12(b) Security Issuance of common shares pursuant to the Open Market Sales Agreement Proceeds from issuance of common stock Proceeds from Issuance of Common Stock Total assets Assets Investment, Name [Domain] Investment, Name [Domain] Plan Name [Domain] Plan Name [Domain] Maximum royalty payment License Agreement Maximum Development And Regulatory Milestone Payments Per Royalty License Agreement Maximum Development And Regulatory Royalty Payment per Royalty Title of Individual [Axis] Title of Individual [Axis] Net loss attributable to common shares Net loss attributable to common shares Net Income (Loss) Available to Common Stockholders, Basic Document Type Document Type Research and development Research and Development Expense Product and Service [Domain] Product and Service [Domain] Accounts payable and accrued liabilities Supplemental Balance Sheet Disclosures [Text Block] Collier Plan Collier Plan [Member] Collier Plan [Domain] March 2021 Prospectus Supplement March 2021 Prospectus Supplement [Member] March 2021 Prospectus Supplement Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Non-cash royalty revenue Non-cash royalty revenue Non Cash Royalty Revenue Related To Sale Of Future Royalties Non Cash Royalty Revenue Related To Sale Of Future Royalties Business combination, regulatory, development and sales milestone payments estimated fair value Business Combination, Contingent Consideration, Liability Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Significant accounting policies Significant Accounting Policies [Text Block] Measurement Frequency [Axis] Measurement Frequency [Axis] Net cash used in operating activities Net Cash Provided by (Used in) Operating Activities Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table] Share-based Payment Arrangement, Option, Exercise Price Range [Table] Activity related to net liability Liabilities Related To Sale Of Future Royalties Roll Forward [Table Text Block] Liabilities Related To Sale Of Future Royalties Roll Forward Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Furniture and fixtures Furniture and Fixtures [Member] Schedule of lease cost Lease, Cost [Table Text Block] Tax Credit Carryforward [Axis] Tax Credit Carryforward [Axis] Lease Contractual Term [Domain] Lease Contractual Term [Domain] Basic (in shares) Weighted average number of common shares - basic (in shares) Weighted Average Number of Shares Outstanding, Basic Diluted (in USD per share) Diluted net loss attributable to common shareholders per share (in USD per share) Earnings Per Share, Diluted Provincial State and Local Jurisdiction [Member] Non-cash interest expense Non Cash Interest Expense Related To Sale Of Future Royalties Non Cash Interest Expense Related To Sale Of Future Royalties Investments Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Difference due to income taxed at foreign rates Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount Comprehensive loss Comprehensive Income (Loss), Net of Tax, Attributable to Parent Investments in marketable securities Investment, Policy [Policy Text Block] Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Related Party Transaction [Line Items] Related Party Transaction [Line Items] Option vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Equity investment loss Gain (loss) on investments Income (Loss) from Equity Method Investments 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] Conversion of Preferred Shares into Common Shares (in shares) Stock Issued During Period, Shares, Conversion of Convertible Securities Vaccitech Vaccitech [Member] Vaccitech Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Costs related to collaboration Other Cost and Expense, Operating Schedule of effective income tax rate reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Fair value measurements Fair Value Disclosures [Text Block] 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 Site consolidation Restructuring Charges 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] Accumulated other comprehensive loss AOCI Attributable to Parent [Member] Options vested (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. Arbutus Inc. Arbutus Inc. [Member] Arbutus Inc. [Member] Convertible Preferred Stock Convertible Preferred Stock [Member] Common shares, shares outstanding (in shares) Common Stock, Shares, Outstanding Investments in marketable securities, non-current Long-term Investments Financial Instruments [Domain] Financial Instruments [Domain] Acuitas Therapeutics, Inc. Acuitas Therapeutics Inc. [Member] Acuitas Therapeutics Inc. Revenue Revenues [Abstract] Blumberg and Drexel Blumberg and Drexel [Member] Blumberg and Drexel [Member] Document Period End Date Document Period End Date Common shares reserved for issuance Employee Stock Ownership Plan (ESOP), Shares in ESOP Lease Contractual Term [Axis] Lease Contractual Term [Axis] Entity Central Index Key Entity Central Index Key Number of optioned common shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Schedule of property and equipment Property, Plant and Equipment [Table Text Block] Research and development credits Deferred Tax Assets, Tax Credit Carryforwards, Research Income Statement Location [Domain] Income Statement Location [Domain] Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-sale [Table] Investments in marketable securities Investments, Fair Value Disclosure Preferred Shares Stockholders' Equity Note, Redeemable Preferred Stock, Issue, Policy [Policy Text Block] Number of additional shares authorized (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Property and equipment, net of accumulated depreciation Net book value Property, Plant and Equipment, Net Property and equipment Property, Plant and Equipment Disclosure [Text Block] Total operating expenses Operating Expenses October 2021 Prospectus Supplement October 2021 Prospectus Supplement [Member] October 2021 Prospectus Supplement Preferred shares dividends accrued Dividends, Preferred Stock, Cash Employee Share-based Payment Arrangement, Employee [Member] Liability related to sale of future royalties Net liability related to sale of future royalties - beginning balance Net liability related to sale of future royalties - ending balance Liability Related To Sale Of Future Royalties, Noncurrent Liability Related To Sale Of Future Royalties, Noncurrent Permanent and other differences Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount Trading Symbol Trading Symbol Equity Method Investee Equity Method Investee [Member] Cost Property, Plant and Equipment, Gross Related Party Transaction [Domain] Related Party Transaction [Domain] Revenues Revenues Liability-classified options Liability at beginning of the period Liability at end of the period Employee Stock Options, Liability Classified, Outstanding, Fair Value Disclosure Employee Stock Options, Liability Classified, Outstanding, Fair Value Disclosure Balance - Weighted average exercise price (in CAD and USD per share) Balance - Weighted average exercise price (in CAD and USD per share) Options outstanding, Weighted average exercise price (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Operating expenses Costs and Expenses [Abstract] Non-cash royalty revenue Potential Contract Funding Amount Represents the potential contract funding amount. Percent of Costs related to Collaboration Percent of Costs related to Collaboration Percent of Costs related to Collaboration Liabilities Liabilities, Fair Value Disclosure [Abstract] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Stock-based compensation expense Share-based Payment Arrangement, Expense Aggregate share sales price Common Stock, Value, Subscriptions Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Research tax credit carryforward Research Tax Credit Carryforward [Member] Entity Current Reporting Status Entity Current Reporting Status Acrotech Biopharma, LLC Acrotech Biopharma, LLC [Member] Acrotech Biopharma, LLC Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Loss per share Earnings Per Share, Basic and Diluted [Abstract] Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Outstanding preferred shares that converted to common shares (in shares) Convertible Preferred Stock, Shares Issued upon Conversion Net accretion and amortization of investments in marketable securities Accretion (Amortization) of Discounts and Premiums, Investments Counterparty Name [Axis] Counterparty Name [Axis] Payables and Accruals [Abstract] Payables and Accruals [Abstract] Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Beginning balance (in shares) Ending balance (in shares) Shares, Issued Tax Credit Carryforward, Name [Domain] Tax Credit Carryforward, Name [Domain] Number of shares issued under agreement Sale of Stock, Number of Shares Issued in Transaction Sub-licensing revenue, percentage Sub-licensing revenue Percentage Sub-licensing revenue Percentage Current assets: Assets, Current [Abstract] Research and Development Arrangement, Contract to Perform for Others [Line Items] Research and Development Arrangement, Contract to Perform for Others [Line Items] Number of shares remaining for issuance Common Stock, Capital Shares Reserved for Future Issuance Roivant Roivant Sciences Ltd [Member] Roivant Sciences Ltd [Member] Leases [Abstract] Leases [Abstract] Deferred income taxes Income Tax, Policy [Policy Text Block] Impairment of property and equipment Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Number of operating leases Lessee, Operating Lease, Number of Leases Lessee, Operating Lease, Number of Leases Cash and cash equivalents Cash Equivalents, Fair Value Cash and Cash Equivalents, Fair Value Disclosure Entity Address, Postal Zip Code Entity Address, Postal Zip Code Schedule of accounts payable and accrued liabilities Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] Revenue from collaborations and licenses Revenue from Contract with Customer [Policy Text Block] Issuance of common shares pursuant to exercise of options (in shares) Options exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Diluted (in shares) Weighted average number of common shares - diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Pre-tax domestic losses Income (Loss) from Continuing Operations before Income Taxes, Domestic Unrealized loss on available-for-sale securities Other Comprehensive Income (Loss), Net of Tax Fair Value, Measurements, Recurring Fair Value, Recurring [Member] Income taxes Income Tax Disclosure [Text Block] Cash, cash equivalents and short-term investments Cash, Cash Equivalents, and Short-term Investments Related Party [Domain] Related Party [Domain] Schedule of stock option activity Share-based Payment Arrangement, Option, Activity [Table Text Block] Shareholders' equity Stockholders' Equity Note Disclosure [Text Block] Gross proceeds from royalty interest sold Gross Proceeds From Royalty Interest Sold Gross Proceeds From Royalty Interest Sold Investment tax credits Deferred Tax Assets, Investments Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Other income (loss) Nonoperating Income (Expense) [Abstract] Auditor Firm ID Auditor Firm ID Discount rate Lessee, Operating Lease, Discount Rate Investment in Genevant Payments to Acquire Equity Method Investments Class of Stock [Line Items] Class of Stock [Line Items] Royalty Royalty [Member] Entity Address, Address Line One Entity Address, Address Line One Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Net change in operating items: Increase (Decrease) in Operating Capital [Abstract] Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Issuance of common shares pursuant to exercise of ESPP options Stock Issued During Period, Value, Employee Stock Purchase Plan OPERATING ACTIVITIES Net Cash Provided by (Used in) Operating Activities [Abstract] Research and development deductions Deferred Tax Assets, in Process Research and Development General and administrative General and Administrative Expense [Member] Principles of consolidation Consolidation, Policy [Policy Text Block] Entity Shell Company Entity Shell Company Components of Deferred Tax Assets [Line Items] Components of Deferred Tax Assets [Line Items] Expected life Expected average option term Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Total current liabilities Liabilities, Current Class of Stock [Domain] Class of Stock [Domain] Contingencies and Commitments [Table] Contingencies and Commitments [Table] Trade accounts payable Accounts Payable, Trade, Current Money market fund Money Market Funds [Member] Collaborations and contracts Contracts revenue Revenue from Contract with Customer, Including Assessed Tax Directors and Executives Directors And Executives [Member] Directors And Executives Ownership [Domain] Ownership [Domain] Current Fiscal Year End Date Current Fiscal Year End Date Payments for legal settlements Payments for Legal Settlements Enantigen Enantigen [Member] Enantigen Investments in marketable securities Marketable Securities [Table Text Block] Issuance of common shares pursuant to exercise of ESPP options Proceeds from Stock Plans Statement [Table] Statement [Table] Recent accounting pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Other Deferred Tax Assets, Other Unearned compensation expense Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Preferred shares, Authorized: unlimited number without par value, Issued and outstanding: 0 (December 31, 2020: 1,164,000) Preferred Stock, Including Additional Paid in Capital, Net of Discount Range [Axis] Statistical Measurement [Axis] Jefferies LLC Jefferies LLC [Member] Jefferies LLC Computed taxes (benefits) at Canadian federal and provincial tax rates Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount Subsequent event Subsequent Event [Member] Options vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares Income Taxes [Table] Income Taxes [Table] Convertible Preferred Shares Preferred Stock [Member] Sale Agreement Open Market Sale Agreement [Member] Open Market Sale Agreement Maximum contribution for product Maximum Contribution For Product Represents the maximum contribution for the product. Number of options outstanding (in shares) Share-based Payment Arrangement, Option, Exercise Price Range, Shares Outstanding Number of royalty entitlements Alnylam Entitlements Alnylam Entitlements License License [Member] Investment tax credits available to reduce provincial income taxes Deferred Tax Assets, Operating Loss Carryforwards, State and Local Organization Nature of Operations [Text Block] Book amortization in excess of tax Book amortization in excess of tax Represents the deferred tax asset book amortization in excess of tax. Subsequent Event Type [Axis] Subsequent Event Type [Axis] Cumulative contribution for product Cumulative Contribution for Product Represents the cumulative contribution for a product. Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Axis] Computer and office equipment Computer hardware and software Computer Equipment [Member] Related party transactions Related Party Transactions Disclosure [Text Block] Corporate Headquarters Located 701 Veterans Circle, Warminster, Pennsylvania Corporate Headquarters Located 701 Veterans Circle, Warminster, Pennsylvania [Member] Corporate Headquarters Located 701 Veterans Circle, Warminster, Pennsylvania Proteros X-Chem and Proteros [Member] X-Chem and Proteros Non-cash items: Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]