Statement of Financial Position [Abstract] Assets Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Short-term investments (note 2) Short-term Investments Accounts receivable Accounts Receivable, Net, Current Accrued revenue Unbilled Receivables, Current Investment tax credits receivable Income Taxes Receivable, Current Prepaid expenses and other assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current Restricted investment (notes 2 and 6) Restricted Investments, Noncurrent 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 (note 3) Intangible Assets, Net (Excluding Goodwill) Goodwill (note 3) Goodwill Total assets Assets Liabilities and stockholders' equity Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable and accrued liabilities (note 5) Accounts Payable and Accrued Liabilities, Current Deferred revenue (note 4) Deferred Revenue, Current Liability-classified options (note 2) Employee Stock Options, Liability Classified, Outstanding Employee Stock Options, Liability Classified, Outstanding Warrants (note 2) Warrants and Rights Outstanding Total current liabilities Liabilities, Current Deferred revenue, net of current portion (note 4) Deferred Revenue, Noncurrent Loan payable (notes 2 and 6) Loans Payable, Noncurrent Contingent consideration (note 7) Business Combination, Contingent Consideration, Liability, Noncurrent Deferred tax liability Deferred Tax Liabilities, Net, Noncurrent Total liabilities Liabilities Stockholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Common shares, issued and outstanding: 55,024,545 (December 31, 2016 - 54,841,494) 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 Deferred Revenue Disclosure [Abstract] Schedule of Research and Development Arrangement, Contract to Perform for Others [Table] Schedule of Research and Development Arrangement, Contract to Perform for Others [Table] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Alexion Alexion [Member] Alexion [Member] Dicerna Dicerna [Member] Represents Dicerna pharmaceuticals. Talon Talon Therapeutics [Member] Represents the Talon Therapeutics. Marqibo Marqibo [Member] Marqibo Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] PADCo. PADCo. [Member] PADCo. [Member] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Monsanto Monsanto [Member] Represents the company Monsanto. 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] Marqibo Commercial Sales Marqibo Commercial Sales [Member] Represents the Marqibo commercial sales. Research and Development Arrangement, Contract to Perform for Others [Line Items] Research and Development Arrangement, Contract to Perform for Others [Line Items] License upfront payment License Upfront Payment License Upfront Payment Potential milestone payments Potential Contract Funding Amount Represents the potential contract funding amount. Total deferred revenue Deferred Revenue Milestone payment Milestone Payment Represents a milestone payment. Licensing fees, milestone and royalty payments Licenses Revenue Business acquisition, percentage of outstanding shares acquired Business Acquisition, Percentage of Voting Interests Acquired Optional exercised contractual option, amount Optional Exercised Contractual Option, Amount Represents the amount of an option exercise that was embedded in a contract. Number of chemotherapy products with worldwide licenses Number Of Chemotherapy Products With Worldwide Licenses Number Of Chemotherapy Products With Worldwide Licenses Collaborations and contracts Contracts Revenue Royalty revenue Royalty Revenue Royalties percentage Accrued Contract Revenue Percentage Represents the percentage of revenue from accrued contracts. 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] Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions [Table] Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions [Table] Other milestone and royalty payments 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 Total revenue Revenues Accounting Policies [Abstract] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Equity Interest Type [Axis] Equity Interest Type [Axis] Equity Interest Issued or Issuable, Type [Domain] Equity Interest Issued or Issuable, Type [Domain] Common shares issued subject to repurchase provisions Common Shares Issued Subject to Repurchase Provision [Member] Common Shares Issued Subject to Repurchase Provision Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Wholly-owed subsidiaries Wholly Owned Subsidiaries Included in Financial Statements Represents the number of wholly owned subsidiaries included in the reporting of the financial statements. Anti-dilutive common shares excluded from calculation of loss per common share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Loan Payable [Abstract] Loan Payable [Abstract] Loan Payable Debt 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] Liability at beginning of the period Increase in fair value of Contingent Consideration Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability Liability at end of the period Common shares, no par value (in USD per share) Common Stock, No Par Value Common shares, shares issued (in shares) Common Stock, Shares, Issued Common shares, shares outstanding (in shares) Common Stock, Shares, Outstanding Organization, Consolidation and Presentation of Financial Statements [Abstract] Nature of business and future operations Nature of Operations [Text Block] Document and Entity Information [Abstract] Document and Entity Information [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Current Reporting Status Entity Current Reporting Status Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Significant accounting policies Significant Accounting Policies [Text Block] 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 investment, term Restricted Investment, Term Restricted Investment, Term Basis of presentation Basis of Accounting, Policy [Policy Text Block] Principles of Consolidation Consolidation, Policy [Policy Text Block] Income or loss per share Earnings Per Share, Policy [Policy Text Block] Fair value of financial instruments Fair Value Measurement, Policy [Policy Text Block] Revenue recognition Revenue Recognition, Policy [Policy Text Block] Recent accounting pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Payables and Accruals [Abstract] Schedule of accounts payable and accrued liabilities Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] Trade accounts payable Accounts Payable, Trade, Current Research and development accruals Accrued Research And Development Research and development accruals License fee accruals Accrued License Fee Accruals License fee accruals 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 Collaborations, contracts and licensing agreements Collaborative Arrangement Disclosure [Text Block] Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] 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] Statement [Line Items] Statement [Line Items] Beginning balance (in shares) Shares, Issued Beginning balance Stock-based compensation Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition 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) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period 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 Net loss Net Income (Loss) Attributable to Parent Ending balance (in shares) Ending balance Goodwill and Intangible Assets Disclosure [Abstract] Intangible assets and goodwill Goodwill and Intangible Assets Disclosure [Text Block] Deferred Revenue Arrangement, by Type [Table] Deferred Revenue Arrangement, by Type [Table] DoD Do D [Member] Represents the department of defense. Deferred Revenue Arrangement [Line Items] Deferred Revenue Arrangement [Line Items] Deferred revenue, current portion Deferred revenue, long-term portion Total deferred revenue 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. Liability at end of the period Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Cashless exercise provision Cashless Exercise Provision [Member] Represents the cashless exercise provision. Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Warrants exercised (in shares) Warrants Exercised (in Shares) Represents the warrants exercised. Warrants and rights outstanding Proceeds from warrant exercises Proceeds from Warrant Exercises Class of warrant expired (in shares) Class of Warrant or Rights Expired Class of Warrant or Rights, Expired Income Statement [Abstract] Revenue Revenues [Abstract] Licensing fees, milestone and royalty payments Expenses Operating Expenses [Abstract] Research, development, collaborations and contracts Research and Development Expense General and administrative General and Administrative Expense Depreciation of property and equipment Depreciation Total expenses Operating Expenses Loss from operations Operating Income (Loss) Other income (losses) Nonoperating Income (Expense) [Abstract] Interest income Investment Income, Interest Interest expense Interest Expense Foreign exchange gains (losses) Foreign Currency Transaction Gain (Loss), before Tax Gain on disposition of financial instrument (note 4) Option Exercised Contractual Option, Revenue Amount Option Exercised Contractual Option, Revenue Amount Decrease in fair value of warrant liability (note 2) Fair Value, Option, Changes in Fair Value, Gain (Loss) Increase in fair value of contingent consideration (note 7) Increase (Decrease) In Fair Value Of Contingent Consideration Liability Increase (Decrease) In Fair Value Of Contingent Consideration Liability Total other income (losses) Nonoperating Income (Expense) Net loss Loss per common share Earnings Per Share [Abstract] Loss per common share basic and diluted (in USD per share) Earnings Per Share, Basic and Diluted Weighted average number of common shares Weighted Average Number Of Common Shares [Abstract] Weighted average number of common shares Weighted average number of common shares basic and diluted (in shares) Weighted Average Number of Shares Outstanding, Basic and Diluted Risks and Uncertainties [Abstract] Accounts receivable Accounts Receivable, Net 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 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 option Changes In Fair Value of Liability Option [Table Text Block] Changes In Fair Value of Liability Option [Table Text Block] Schedule of changes in fair value of contingent consideration Schedule of Business Acquisitions by Acquisition, Contingent Consideration [Table Text Block] Statement of Cash Flows [Abstract] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Research, development, collaborations and contracts expenses Research and Development Expense [Member] General and administrative expenses General and Administrative Expense [Member] 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] Depreciation of property and equipment Stock-based compensation Share-based Compensation Unrealized foreign exchange (gains) losses Foreign Currency Transaction Gain (Loss), Unrealized Change in fair value of warrant liability Change in fair value of contingent consideration Net change in non-cash operating items: Increase (Decrease) in Operating Capital [Abstract] Accounts receivable Increase (Decrease) in Accounts Receivable 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 short and long-term investments, net Payments for (Proceeds from) Investments 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] Issuance of common shares pursuant to exercise of options Proceeds from Stock Options Exercised Issuance of common shares pursuant to exercise of warrants Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Effect of foreign exchange rate changes on cash and cash equivalents Effect of Exchange Rate on Cash and Cash Equivalents (Decrease) Increase in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Supplemental cash flow information Supplemental Cash Flow Information [Abstract] Non-cash transactions: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Acquired property and equipment in trade payables Capital Expenditures Incurred but Not yet Paid Concentrations of credit risk Concentration Risk Disclosure [Text Block] 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] Level 1 Fair Value, Inputs, Level 1 [Member] 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 Investments, Fair Value Disclosure Restricted investment Restricted Investments, at Fair Value Total Assets Assets, Fair Value Disclosure Liabilities Liabilities, Fair Value Disclosure [Abstract] Warrants Liability-classified options Employee Stock Options, Liability Classified, Outstanding, Fair Value Disclosure Employee Stock Options, Liability Classified, Outstanding, Fair Value Disclosure Contingent consideration Total Liabilities Liabilities, Fair Value Disclosure, Recurring Summary of carrying values, net of impairment of the intangible assets Schedule of Indefinite-Lived Intangible Assets [Table Text Block] Commitments and Contingencies Disclosure [Abstract] Contingencies and commitments Commitments and Contingencies Disclosure [Text Block] Accounts payable and accrued liabilities Accounts Payable and Accrued Liabilities Disclosure [Text Block] Contingencies and Commitments [Table] Contingencies and Commitments [Table] Products and Services [Axis] Products and Services [Axis] Products and Services [Domain] Products and Services [Domain] Blumberg and Drexel Blumberg and Drexel [Member] Blumberg and Drexel [Member] Blumberg Blumberg [Member] Blumberg Arbutus Inc. Arbutus Inc. [Member] Arbutus Inc. [Member] 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. Enantigen Enantigen [Member] Enantigen Contingencies and Commitments [Line Items] Contingencies and Commitments [Line Items] 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 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 Milestone payment 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 Programs in pre-clinical development Programs In Pre-Clinical Development Programs In Pre-Clinical Development Business combination, regulatory, development and sales milestone payments estimated fair value Business Combination, 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 Goodwill impairment charge Goodwill, Impairment Loss Subsequent Events [Abstract] Subsequent event Subsequent Events [Text Block] Liability classified stock options Employee Stock Option, Liability Classified [Member] Employee Stock Option, Liability Classified [Member] Liability at beginning of 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