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Payment One-Time Upfront Cash Payment [Member] One-Time Upfront Cash Payment Cash equivalents Cash Equivalents [Member] Other Liabilities Disclosure [Line Items] Other Liabilities Disclosure [Line Items] Other Liabilities Disclosure [Line Items] Revenue, Remaining Performance Obligation, Amount Revenue, Remaining Performance Obligation, Amount Investments in marketable securities, non-current Debt Securities, Available-for-sale, Noncurrent Purchase of investments Payments to Acquire Investments Gross proceeds from sale of royalty interest. before advisory fees Gross Proceeds From Royalty Interest Sold Gross Proceeds From Royalty Interest Sold Royalty Interest Sold, Annual Revenue Threshold Of Highest Tier Annual Revenue Threshold Annual Revenue Threshold Jefferies LLC Jefferies LLC [Member] Jefferies LLC Investments in marketable securities, current Debt Securities, Available-for-sale Disposition of investments Proceeds from Sale, Maturity and Collection of Investments Deficit Retained 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[Member] Assembly Biosciences, Inc. 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Other accrued liabilities Other Accrued Liabilities, Current Costs related to collaboration Other Cost and Expense, Operating Investments, Debt and Equity Securities [Abstract] Fair value measurements Fair Value Disclosures [Text Block] Depreciation Depreciation, Depletion and Amortization Additional paid-in capital Additional Paid in Capital Arbutus Plans Arbutus Plans [Member] Arbutus Plans [Member] 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] Liabilities and stockholders’ equity Liabilities and Equity [Abstract] Accumulated Other Comprehensive Loss AOCI Attributable to Parent [Member] Accounts payable and accrued liabilities Accounts payable and accrued liabilities Accounts Payable and Accrued Liabilities, Current Convertible Preferred Stock Convertible Preferred Stock [Member] Marketable Securities [Table] Marketable Securities [Table] Common shares, shares outstanding (in shares) Common Stock, Shares, Outstanding Income from services (less than) Related Party Transaction, Other Revenues from Transactions with Related Party Investments in marketable securities, non-current Long-term Investments Financial Instruments [Domain] Financial Instruments [Domain] Operating expenses Operating Expenses [Abstract] Ownership interest in equity method investment (as a percentage) Equity Method Investment, Ownership Percentage Entity Interactive Data Current Entity Interactive Data Current Revenue Revenues [Abstract] 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] Document Period End Date Document Period End Date Change in fair value of contingent consideration Increase (decrease) in fair value of contingent consideration Increase in fair value of liability Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability Entity Central Index Key Entity Central Index Key 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 Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Liability classified stock options Employee Stock Option, Liability Classified [Member] Employee Stock Option, Liability Classified [Member] Income Statement Location [Domain] Income Statement Location [Domain] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Investments in marketable securities, Gross Unrealized Gain Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Short-term investments Investments, Fair Value Disclosure Entity Address, State or Province Entity Address, State or Province Jan 2020 Registration Stmt [Member] Jan 2020 Registration Stmt [Member] Jan 2020 Registration Stmt Loss contingency, damages sought for allegedly unpaid royalties Loss Contingency, Damages Sought, Value Property and equipment, net of accumulated depreciation of $10,132 (December 31, 2021: $9,374) Property, Plant and Equipment, Net Total operating expenses Operating Expenses Jan 2020 Oct 2020 and Nov 2021 Registration Stmts Jan 2020 Oct 2020 and Nov 2021 Registration Stmts [Member] Jan 2020 Oct 2020 and Nov 2021 Registration Stmts [Member] Entitlement of royalties to be received Royalty Interest Sold, Maximum Royalties For Buyer Royalty Interest Sold, Maximum Royalties For Buyer Preferred shares dividends accrued Dividends, Preferred Stock, Cash Current liabilities: Liabilities, Current [Abstract] Issuance of common shares pursuant to the Open Market Sale Agreement Issuance of common shares pursuant to the agreement Stock Issued During Period, Value, New Issues General and administrative General and Administrative Expense Trading Symbol Trading Symbol Acuitas Therapeutics, Inc. Acuitas Therapeutics Inc. [Member] Acuitas Therapeutics Inc. Loss per share Earnings Per Share [Abstract] Level 3 Fair Value, Inputs, Level 3 [Member] Accounts payable and accrued liabilities Accounts Payable and Accrued Liabilities Disclosure [Text Block] Related Party Transaction [Domain] Related Party Transaction [Domain] Accounting Policies [Abstract] Revenues Revenues 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 Document Transition Report Document Transition Report Changes in fair value of liability option Changes In Fair Value of Liability Option [Table Text Block] Changes In Fair Value of Liability Option [Table Text Block] Foreign exchange (loss) gain Foreign Currency Transaction Gain (Loss), before Tax Issued and outstanding: 148,794,262 (December 31, 2021: 144,987,736) Common Stock, Value, Issued Dividend accretion of convertible preferred shares. 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[Member] Qilu Pharmaceutical Co, LTD. [Member] Qilu Pharmaceutical Co, LTD. 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Open Market Sale Agreement Mar 2021 Trade accounts payable Accounts Payable, Trade, Current Ownership [Domain] Ownership [Domain] Current Fiscal Year End Date Current Fiscal Year End Date Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Income Taxes Paid Income Taxes Paid Marketable securities Marketable Securities [Table Text Block] Issuance of common shares pursuant to ESPP Proceeds from Stock Plans Other liabilities Increase (Decrease) in Other Operating Liabilities Statement [Table] Statement [Table] Recent accounting pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Acquisition of property and equipment Payments to Acquire Property, Plant, and Equipment Registration Statement [Domain] Registration Statement [Domain] Registration Statement [Domain] Maximum Maximum [Member] Range [Axis] Statistical Measurement [Axis] X-Chem, Inc. and Proteros [Member] X-Chem, Inc. and Proteros [Member] X-Chem, Inc. and Proteros Liability Related To Sale Of Future Royalties [Roll Forward] Liability Related To Sale Of Future Royalties [Roll Forward] Liability Related To Sale Of Future Royalties [Roll Forward] Sale of future royalties Liabilities Related To Sale Of Future Royalties [Text Block] Liabilities Related To Sale Of Future Royalties Summary of collaborations Collaborative Arrangement and Arrangement Other than Collaborative [Table Text Block] Total liabilities Liabilities Stockholders' Equity Note [Abstract] March 2022 Prospectus Supplement [Member] March 2022 Prospectus Supplement [Member] March 2022 Prospectus Supplement Premium on closing stock price (as a percent) Premium on Closing Stock Price Premium on Closing Stock Price Award Type [Axis] Award Type [Axis] Preferred Shares Preferred Stock [Member] Weighted average exercise price (in USD per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Aug 2020 Prospectus Supplement Aug 2020 Prospectus Supplement [Member] Aug 2020 Prospectus Supplement FINANCING ACTIVITIES Net Cash Provided by (Used in) Financing Activities [Abstract] Arbutus Inc. Arbutus Inc. [Member] Arbutus Inc. 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