Significant accounting policies | Significant accounting policies Basis of presentation These unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial statements and accordingly, do not include all disclosures required for annual financial statements. These statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto for the year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 (the “2018 Form 10-K”). These unaudited condensed consolidated financial statements reflect, in the opinion of management, all adjustments and reclassifications necessary to fairly present the Company's financial position as of June 30, 2019 and the Company's results of operations and cash flows for the three and six months ended June 30, 2019 and 2018. The results of operations for the three and six months ended June 30, 2019 and 2018, respectively, are not necessarily indicative of the results for the full year. These unaudited condensed consolidated financial statements follow the same significant accounting policies as those described in the notes to the audited consolidated financial statements of the Company for the year ended December 31, 2018 , except as described below under Recent Accounting Pronouncements. Principles of consolidation These unaudited condensed consolidated financial statements include the accounts of the Company and its two wholly-owned subsidiaries, Arbutus Biopharma Inc. ("Arbutus Inc.") and Arbutus Biopharma US Holdings, Inc. All intercompany transactions and balances have been eliminated in consolidation. Income or loss per share The Company follows the two-class method when computing net loss attributable to common shareholders per share as the Company has issued Series A participating convertible preferred shares (the "Preferred Shares"), as further described in note 9, that meet the definition of participating securities. The Preferred Shares entitle the holders to participate in dividends but do not require the holders to participate in losses of the Company. Accordingly, if the Company reports a net loss attributable to holders of the Company's common shares, net losses are not allocated to holders of the Preferred Shares. Net loss attributable to common shareholders per share is calculated based on the weighted average number of common shares outstanding. Diluted net loss attributable to common shareholders per share does not differ from basic net loss attributable to common shareholders per share since the effect of the Company’s stock options was anti-dilutive. During the six months ended June 30, 2019 , potential common shares of approximately 28 million ( six months ended June 30, 2018 – approximately 24 million), consisting of the as-if converted number of Preferred Shares and outstanding stock options, were excluded from the calculation of net loss per common share because their inclusion would be anti-dilutive. The following table sets out the computation of basic and diluted net income (loss) attributable to common shareholders per share: (Expressed in thousands of U.S. dollars, except share and per share amounts) Three months ended Six months ended June 30, 2019 June 30, 2019 Numerator: Allocation of distributable earnings $ — $ — Allocation of undistributed loss (26,077 ) (52,043 ) Allocation of income (loss) attributed to shareholders $ (26,077 ) $ (52,043 ) Denominator: Weighted average number of shares - basic and diluted 56,805,583 56,275,795 Weighted average number of shares - diluted 56,805,583 56,275,795 Basic and diluted net income (loss) attributable to shareholders per share $ (0.46 ) $ (0.92 ) Equity method investment The Company accounts for its investment in associated companies in accordance with the Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") 323, Investments - Equity Method and Joint Ventures ("ASC 323"). In accordance with ASC 323, associated companies are accounted for as equity method investments. Results of associated companies are presented on a one-line basis. Investments in, and advances to, associated companies are presented on a one-line basis in the caption “Investment in Genevant” in the Company's Condensed Consolidated Balance Sheets, net of allowance for losses, which represents the Company's best estimate of probable losses inherent in such assets. The Company's proportionate share of any associated companies' net income or loss is presented on a one-line basis in the caption "Equity investment (loss)" in the Company's Condensed Consolidated Statement of Operations. Transactions between the Company and any associated companies are eliminated on a basis proportional to the Company's ownership interest. Financial results of Genevant Sciences Ltd. ("Genevant") are recorded on a one-quarter lag basis. Revenue recognition The Company recognizes the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers under a five-step model: (i) identify contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when or as a performance obligation is satisfied. The Company generates revenue primarily through collaboration agreements and license agreements. Such agreements may require the Company to deliver various rights and/or services, including intellectual property rights or licenses and research and development services. Under such agreements, the Company is generally eligible to receive non-refundable upfront payments, funding for research and development services, milestone payments, and royalties. In contracts where the Company has more than one performance obligation to provide its customer with goods or services, each performance obligation is evaluated to determine whether it is distinct based on whether (i) the customer can benefit from the good or service either on its own or together with other resources that are readily available and (ii) the good or service is separately identifiable from other promises in the contract. The consideration under the contract is then allocated between the distinct performance obligations based on their respective relative stand-alone selling prices. The estimated stand-alone selling price of each deliverable reflects the Company's best estimate of what the selling price would be if the deliverable was regularly sold on a stand-alone basis and is determined by reference to market rates for the good or service when sold to others or by using an adjusted market assessment approach if the selling price on a stand-alone basis is not available. The consideration allocated to each distinct performance obligation is recognized as revenue when control is transferred to the customer for the related goods or services. Consideration associated with at-risk substantive performance milestones, including sales-based milestones, is recognized as revenue when it is probable that a significant reversal of the cumulative revenue recognized will not occur. Sales-based royalties received in connection with licenses of intellectual property are subject to a specific exception in the revenue standards, whereby the consideration is not included in the transaction price and recognized in revenue until the customer’s subsequent sales or usages occur. Segment information The Company operates as a single segment. Recent accounting pronouncements From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that are adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on the Company's financial position or results of operations upon adoption. The Company adopted ASU No. 2016-02, Leases (Topic 842), as of January 1, 2019, using the modified retrospective approach with the effective date transition method (note 8). Accordingly, all periods prior to adoption are presented in accordance with legacy accounting and the Company recorded no retrospective adjustments to the comparative periods presented. In addition, the Company elected the package of practical expedients permitted under the transition guidance within ASC 842, which among other things, allowed the Company to carry forward its historical lease classification. In addition, the Company elected the short term exemption, which allows entities to not capitalize their leases with a term of 12 months or less. Adoption of the new standard resulted in the recording of operating lease right-of-use assets (“ROU assets”) and lease liabilities of approximately $3.2 million and $4.1 million , respectively, as of January 1, 2019. The standard did not materially impact the Company’s consolidated statements of operations and statements of cash flow. In November 2018, the FASB issued targeted amendments to ASU No. 2018-18, Collaborative Arrangements (Topic 808), and ASU No. 2016-10, Revenue from Contracts with Customers (Topic 606), to clarify that certain transactions between parties to collaborative arrangements should be accounted for in accordance with FASB revenue guidance when the counterparty is a customer. This guidance also prohibits the presentation of collaborative arrangements as revenues from contracts with customers if the counterparty is not a customer. This guidance, which is required to be applied retrospectively and is effective for interim and annual periods beginning after December 15, 2019, with early adoption permitted, is not expected to have a material impact on the Company’s consolidated financial statements. |