Document And Entity Information - USD ($)	12 Months Ended
Document And Entity Information - USD ($)	Dec. 31, 2016	Mar. 14, 2017	Jun. 30, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	Arbutus Biopharma Corp
Document Type	10-K
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		55,023,207
Entity Public Float			$ 190,692,659
Amendment Flag	false
Entity Central Index Key	0001447028
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Well-known Seasoned Issuer	No
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	FY

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 23,413	$ 166,779
Short-term investments	107,146	14,525
Accounts receivable	273	1,008
Accrued revenue	128	128
Investment tax credits receivable	293	246
Prepaid expenses and other assets	1,311	1,196
Total current assets	132,564	183,882
Restricted investment	12,601	0
Long-term investments	0	10,070
Property and equipment	17,683	12,912
Less accumulated depreciation	(10,738)	(9,729)
Property and equipment, net of accumulated depreciation	6,945	3,183
Intangible assets	99,445	352,642
Goodwill	24,364	162,514
Total assets	275,919	712,291
Current liabilities:
Accounts payable and accrued liabilities	9,910	8,827
Deferred revenue	15	868
Liability-classified options	553	0
Warrants	107	883
Total current liabilities	10,585	10,578
Deferred revenue, net of current portion	0	213
Loan payable	12,001	0
Contingent consideration	9,065	7,497
Deferred tax liability	41,263	146,324
Total liabilities	72,914	164,612
Stockholders’ equity:
Common shares, authorized - unlimited number with no par value, Issued and outstanding: 54,841,494 (December 31, 2015 - 54,570,691)	867,393	834,240
Additional paid-in capital	36,543	30,206
Deficit	(651,149)	(266,985)
Accumulated other comprehensive loss	(49,782)	(49,782)
Total stockholders' equity	203,005	547,679
Total liabilities and stockholders' equity	$ 275,919	$ 712,291

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Common shares, par value (in USD per share)	$ 0	$ 0
Common shares, shares issued	54,841,494	54,570,691
Common shares, shares outstanding	54,841,494	54,570,691

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenue
Collaborations and contracts	$ 229	$ 13,309	$ 11,738
Licensing fees, milestone and royalty payments	1,262	11,564	3,215
Total revenue	1,491	24,873	14,953
Expenses
Research, development, collaborations and contracts	61,253	51,505	38,713
General and administrative	39,438	26,438	8,683
Depreciation of property and equipment	1,092	589	529
Acquisition costs	0	9,656	462
Impairment of intangible assets	253,197	39,007	0
Impairment of goodwill	138,150	0	0
Total expenses	493,130	127,195	48,387
Loss from operations	(491,639)	(102,322)	(33,434)
Other income (losses)
Interest income	1,391	674	853
Foreign exchange gains	1,120	21,771	4,127
Gain on disposition of financial instrument	1,000	0	0
Decrease (increase) in fair value of warrant liability	530	3,341	(10,383)
Increase in fair value of contingent consideration	(1,568)	(770)	0
Total other income (losses)	2,473	25,016	(5,403)
Loss before income taxes	(489,166)	(77,306)	(38,837)
Deferred income tax recovery	105,002	16,185	0
Net loss	$ (384,164)	$ (61,121)	$ (38,837)
Loss per common share
Basic loss per common share (in USD per share)	$ (7.24)	$ (1.34)	$ (1.80)
Diluted loss per common share (in USD per share)	$ (7.24)	$ (1.34)	$ (1.80)
Weighted average number of common shares
Basic weighted average number of common shares (in shares)	53,074,401	45,462,324	21,603,136
Diluted weighted average number of common shares (in shares)	53,074,401	45,462,324	21,603,136
Other Comprehensive loss
Cumulative translation adjustment	$ 0	$ (27,469)	$ (6,489)
Comprehensive loss	$ (384,164)	$ (88,590)	$ (45,326)

Consolidated Statement of Stockholders’ Equity - USD ($) $ in Thousands	Total	Common Stock	Additional paid-in capital	Deficit	Accumulated other comprehensive loss
Balance (in shares) at Dec. 31, 2013		19,048,900
Balance at Dec. 31, 2013	$ 59,194	$ 216,702	$ 25,343	$ (167,027)	$ (15,824)
Stock-based compensation	3,283		3,283
Issuance of common shares pursuant to exercise of options (in shares)		648,506
Issuance of common shares pursuant to exercise of options	2,616	$ 5,034	(2,418)
Issuance of common shares pursuant to exercise of warrants (in shares)		615,763
Issuance of common shares pursuant to exercise of warrants	11,791	$ 11,791
Issuance of common shares in conjunction with the private offering, net of issuance costs (in shares)		2,125,000
Issuance of common shares in conjunction with the private offering, net of issuance costs	56,477	$ 56,477
Currency translation adjustment	(6,489)				(6,489)
Net loss	(38,837)			(38,837)
Balance (in shares) at Dec. 31, 2014		22,438,169
Balance at Dec. 31, 2014	88,035	$ 290,004	26,208	(205,864)	(22,313)
Stock-based compensation	22,093	$ 16,687	5,406
Issuance of common shares pursuant to exercise of options (in shares)		640,457
Issuance of common shares pursuant to exercise of options	1,651	$ 4,186	(2,535)
Issuance of common shares pursuant to exercise of warrants (in shares)		18,750
Issuance of common shares pursuant to exercise of warrants	371	$ 371
Issuance of common shares in conjunction with the private offering, net of issuance costs (in shares)		7,500,000
Issuance of common shares in conjunction with the private offering, net of issuance costs	142,177	$ 142,177
Increase of equity instruments in conjunction with the acquisition of Arbutus Inc. (in shares)		23,973,315
Increase of equity instruments in conjunction with the acquisition of Arbutus Inc.	381,942	$ 380,815	1,127
Currency translation adjustment	(27,469)				(27,469)
Net loss	(61,121)			(61,121)
Balance (in shares) at Dec. 31, 2015		54,570,691
Balance at Dec. 31, 2015	547,679	$ 834,240	30,206	(266,985)	(49,782)
Stock-based compensation	38,162	$ 31,986	6,176
Reclassification of equity to liability stock option awards	(3,243)		(3,243)
Certain fair value adjustments to liability stock option awards	3,621		3,621
Issuance of common shares pursuant to exercise of options (in shares)		100,303
Issuance of common shares pursuant to exercise of options	258	$ 475	(217)
Issuance of common shares pursuant to exercise of warrants (in shares)		170,500
Issuance of common shares pursuant to exercise of warrants	692	$ 692
Currency translation adjustment	0
Net loss	(384,164)			(384,164)
Balance (in shares) at Dec. 31, 2016		54,841,494
Balance at Dec. 31, 2016	$ 203,005	$ 867,393	$ 36,543	$ (651,149)	$ (49,782)

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
OPERATING ACTIVITIES
Net loss for the period	$ (384,164)	$ (61,121)	$ (38,837)
Items not involving cash:
Deferred income taxes	(105,061)	(16,185)	0
Depreciation of property and equipment	1,092	589	529
Loss (gain) on sale of property and equipment	174	0	(80)
Unrealized foreign exchange gains	(1,003)	(21,966)	(4,218)
Change in fair value of warrant liability	(530)	(3,341)	10,383
Change in fair value of contingent consideration	1,568	770	0
Impairment of intangible assets	253,197	39,007	0
Impairment of goodwill	138,150	0	0
Net change in non-cash operating items:
Accounts receivable	735	628	(1,887)
Accrued revenue		349	(360)
Deferred expenses	0	0	167
Investment tax credits receivable	(47)	(188)	(52)
Prepaid expenses and other assets	(115)	159	(773)
Accounts payable and accrued liabilities	26	(2,489)	6,253
Deferred revenue	(1,066)	(13,090)	13,171
Net cash used in operating activities	(57,885)	(54,785)	(12,421)
INVESTING ACTIVITIES
Disposition (acquisition) of investments	(82,551)	9,645	(41,982)
Acquisition of restricted investment	(12,601)	0	0
Cash acquired through acquisition	0	324	0
Proceeds from sale of property and equipment	25	0	80
Acquisition of property and equipment	(3,996)	(2,287)	(1,056)
Net cash provided by (used in) investing activities	(99,123)	7,682	(42,958)
FINANCING ACTIVITIES
Proceeds from loan payable	12,001	0	0
Proceeds from issuance of common shares, net of issuance costs	0	142,177	56,477
Issuance of common shares pursuant to exercise of options	192	1,651	2,616
Issuance of common shares pursuant to exercise of warrants	445	42	1,583
Net cash provided by financing activities	12,638	143,870	60,676
Effect of foreign currency rate changes on cash and cash equivalents	1,004	(2,175)	(1,827)
Increase in cash and cash equivalents	(143,366)	94,592	3,470
Cash and cash equivalents, beginning of period	166,779	72,187	68,717
Cash and cash equivalents, end of period	23,413	166,779	72,187
Supplemental cash flow information
Acquisition of property and equipment not yet paid	1,057	0	0
Fair value of warrants exercised on a cashless basis	0	0	(116)
Investment tax credits received	0	24	0
Acquisition of Arbutus Inc. net of cash acquired	0	381,618	0
Research, development, collaborations
Items not involving cash:
Stock-based compensation	11,155	7,869	2,343
General and administrative expenses
Items not involving cash:
Stock-based compensation	$ 28,004	$ 14,224	$ 940

Nature of Business and Future Operations	12 Months Ended
Nature of Business and Future Operations	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of business and future operations	Nature of business and future operations Arbutus Biopharma Corporation (the “Company” or “Arbutus”) is a biopharmaceutical business dedicated to discovering, developing, and commercializing a cure for patients suffering from chronic hepatitis B infection, a disease of the liver caused by the hepatitis B virus (“HBV”). The Company is also developing a pipeline focused on advancing novel RNA interference therapeutics ("RNAi") leveraging the Company’s expertise in Lipid Nanoparticle ("LNP") technology. The success of the Company is dependent on obtaining the necessary regulatory approvals to bring its products to market and achieve profitable operations. The continuation of the research and development activities and the commercialization of its products are dependent on the Company’s ability to successfully complete these activities and to obtain adequate financing through a combination of financing activities and operations. It is not possible to predict either the outcome of future research and development programs or the Company’s ability to continue to fund these programs in the future.

Significant Accounting Policies

12 Months Ended

Dec. 31, 2016

Accounting Policies [Abstract]

Significant accounting policies

Basis of presentation

Arbutus Biopharma Corporation was incorporated in Canada on October 6, 2005 as an inactive wholly owned subsidiary of Inex Pharmaceuticals Corporation (Inex). Pursuant to a “Plan of Arrangement” effective April 30, 2007, the business and substantially all of the assets and liabilities of Inex were transferred to the Company. The consolidated financial statements for all periods presented herein include the consolidated operations of Inex until April 30, 2007 and the operations of the Company thereafter.

The Company has two wholly-owned subsidiaries as at December 31, 2016: Arbutus Biopharma, Inc. (Arbutus Inc. formerly OnCore Biopharma, Inc.) and Protiva Biotherapeutics Inc. ("Protiva"). Protiva was acquired on May 30, 2008. Arbutus Inc. was acquired by way of a Merger Agreement on March 4, 2015.

In addition to Arbutus Inc. and Protiva, the Company's former wholly-owned subsidiary, Protiva Agricultural Development Company Inc. ("PADCo"), was previously recorded by the Company using the equity method. On March 4, 2016, Monsanto exercised its option to acquire 100% of the outstanding shares of PADCo, as described in note 4(b).

These consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, Arbutus Inc. and Protiva. All intercompany transactions and balances have been eliminated on consolidation.

Foreign currency translation and functional currency conversion

Prior to January 1, 2016, the Company's functional currency was the Canadian dollar. Translation gains and losses from the application of the U.S. dollar as the reporting currency while the Canadian dollar was the functional currency are included as part of cumulative currency translation adjustment, which is reported as a component of shareholders' equity under accumulated other comprehensive loss.

The Company re-assessed its functional currency and determined as at January 1, 2016, its functional currency changed from the Canadian dollar to the U.S. dollar based on management's analysis of changes in the primary economic environment in which the Company operates. The change in functional currency is accounted for prospectively from January 1, 2016 and financial statements prior to and including the period ended December 31, 2015 have not been restated for the change in functional currency.

For periods prior to January 1, 2016, the effects of exchange rate fluctuations on translating foreign currency monetary assets and liabilities into Canadian dollars were included in the statement of operations and comprehensive loss as foreign exchange gain/loss. Revenue and expense transactions were translated into the U.S. dollar reporting currency at the balance sheet date at average exchange rates during the period, and assets and liabilities were translated at end of period exchange rates, except for equity transactions, which were translated at historical exchange rates. Translation gains and losses from the application of the U.S. dollar as the reporting currency while the Canadian dollar was the functional currency are included as part of the cumulative foreign currency translation adjustment, which is reported as a component of shareholders’ equity in accumulated other comprehensive loss.

For periods commencing January 1, 2016, monetary assets and liabilities denominated in foreign currencies are translated into U.S. dollars using exchange rates in effect at the balance sheet date. Opening balances related to non-monetary assets and liabilities are based on prior period translated amounts, and non-monetary assets and non-monetary liabilities incurred after January 1, 2016 are translated at the approximate exchange rate prevailing at the date of the transaction. Revenue and expense transactions are translated at the approximate exchange rate in effect at the time of the transaction. Foreign exchange gains and losses are included in the statement of operations and comprehensive loss as foreign exchange gains.

Use of estimates

The preparation of the consolidated financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions about future events that affect the reported amounts of assets, liabilities, revenue, expenses, contingent assets and contingent liabilities as at the end or during the reporting period. Actual results could significantly differ from those estimates. Significant areas requiring the use of management estimates relate valuation of intangible assets and goodwill, recognition of revenue, stock-based compensation, and financial instruments, and the amounts recorded as accrued liabilities, contingent consideration, and income tax recovery.

Cash and cash equivalents

Cash and cash equivalents are all highly liquid instruments with an original maturity of three months or less when purchased. Cash equivalents are recorded at cost plus accrued interest. The carrying value of these cash equivalents approximates their fair value.

Short-term and long-term investments

Short-term investments have original maturities exceeding three months, and have remaining maturities less than one year. Long-term investments have remaining maturities exceeding twelve months. Short-term and long-term investments accrue interest daily based on a fixed interest rate for the term. The carrying value of these investments are recorded at cost plus accrued interest, which approximates their fair value. All investments are governed by the Board approved Investment Policy for the Company.

Loan payable and restricted cash (investment)

The Company obtained a loan from Wells Fargo for the purpose of financing its operations, including the expansion of laboratory facilities for its U.S. operations. The loan accrues interest daily based on an interest rate with a variable and fixed component. The variable component is the one-month London Interbank Offered Rate (LIBOR), and the fixed component is a margin based on the amount of collateral cash the Company maintains with the lender - see note 9. The loan is due December 2019. The loan is recorded at amortized cost.

The Company must maintain a cash or investment balance as collateral for the loan payable to Wells Fargo. The cash or investment is restricted from the Company's use until the loan is repaid. The Company does not expect to repay the loan within twelve months of the balance sheet date so has classified the restricted cash as a long-term asset. The restricted cash balance has been used to purchase a two year investment maturing on December 23, 2018 and accruing interest at a fixed interest rate of 1.25%. The carrying value of the restricted cash is recorded at cost plus any accrued interest not yet received, which approximates its fair value.

Fair value of financial instruments

We measure certain financial instruments and other items at fair value.

To determine the fair value, we use the fair value hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available. Observable inputs are inputs market participants would use to value an asset or liability and are developed based on market data obtained from independent sources. Unobservable inputs are inputs based on assumptions about the factors market participants would use to value an asset or liability. The three levels of inputs that may be used to measure fair value are as follows:


•	Level 1 inputs are quoted market prices for identical instruments available in active markets.


•	Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability either directly or indirectly. If the asset or liability has a contractual term, the input must be observable for substantially the full term. An example includes quoted market prices for similar assets or liabilities in active markets.


•	Level 3 inputs are unobservable inputs for the asset or liability and will reflect management’s assumptions about market assumptions that would be used to price the asset or liability.

Assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurements. Changes in the observability of valuation inputs may result in a reclassification of levels for certain securities within the fair value hierarchy.

The Company’s financial instruments consist of cash and cash equivalents, short-term, long-term and restricted investments, accounts receivable, accounts payable and accrued liabilities, warrants, and loan payable . Long-term and restricted investments approximate fair value due to the interest rates being at prevailing market rates.

The carrying values of cash and cash equivalents, short-term investments, accounts receivable and accounts payable and accrued liabilities approximate their fair values due to the immediate or short-term maturity of these financial instruments.

As quoted prices for the warrants are not readily available, the Company has used a Black-Scholes pricing model, as described in note 6, to estimate fair value. These are level 3 inputs as defined above.

To determine the fair value of the contingent consideration, the Company uses a probability weighted assessment of the likelihood the milestones would be met and the estimated timing of such payments, and then the potential contingent payments were discounted to their present value using a probability adjusted discount rate that reflects the early stage nature of the development program, time to complete the program development, and overall biotech indices, as detailed in note 10. The Company determined the fair value of the contingent consideration was $9,065,000 and the increase of $1,568,000 has been recorded in other losses in the statement of operations and comprehensive loss for the year ended December 31, 2016. The assumptions used in the discounted cash flow model are level 3 inputs as defined above.

The following tables present information about the Company’s assets and liabilities that are measured at fair value on a recurring basis, and indicates the fair value hierarchy of the valuation techniques used to determine such fair value:



	Level 1		Level 2	Level 3		December 31, 2016
Assets
Cash and cash equivalents	$	23,413	—	—		$	23,413
Short-term investments	107,146		—	—		107,146
Restricted investment	12,601		—	—		12,601
Total	$	143,160	—	—		$	143,160
Liabilities
Warrants	—		—	$	107	$	107
Liability-classified stock option awards	—		—	553		553
Contingent consideration	—		—	9,065		9,065
Total	—		—	9,725		$	9,725



	Level 1		Level 2	Level 3		December 31, 2015
Assets
Cash and cash equivalents	$	166,779	—	—		$	166,779
Guaranteed investment certificates	14,525		—	—		14,525
Term deposit	10,070		—	—		10,070
Total	$	191,374	—	—		$	191,374
Liabilities
Warrants	—		—	$	883	$	883
Contingent consideration	—		—	7,497		7,497
Total	—		—	$	8,380	$	8,380

The following table presents the changes in fair value of the Company’s warrants:



	Liability at beginning of the period		Fair value of warrants exercised in the period			Increase (decrease) in fair value of warrants			Foreign exchange loss			Liability at end of the period
Year ended December 31, 2014	$	5,379	$	(10,208	)	$	10,383		$	(455	)	$	5,099
Year ended December 31, 2015	$	5,099	$	(334	)	$	(3,341	)	$	(541	)	$	883
Year ended December 31, 2016	$	883	$	(247	)	$	(529	)	$	—		$	107

The following table presents the changes in fair value of the Company’s liability-classified stock option awards:



	Reclassification of equity to liability ⁽¹⁾		Fair value of liability-classified stock option awards exercised in the period			Increase (decrease) in fair value of liability			Liability at end of the period
Year ended December 31, 2016	$	1,909	$	(54	)	$	(1,302	)	$	553

(1) Upon functional currency conversion on January 1, 2016 - see functional currency conversion above.

The following table presents the changes in fair value of the Company’s contingent consideration:



	Contingent consideration at beginning of the period		Increase in fair value of contingent consideration		Contingent consideration at end of the period
Year ended December 31, 2015⁽¹⁾	$	6,727	$	770	$	7,497
Year ended December 31, 2016	$	7,497	$	1,568	$	9,065

(1) As at acquisition date of March 4, 2015.

Property and equipment

Property and equipment is recorded at cost less impairment losses, accumulated depreciation, related government grants and investment tax credits. The Company records depreciation using the straight-line method over the estimated useful lives of the capital assets as follows:



	Useful life (years)
Laboratory equipment		5
Computer and office equipment	2	—	5
Furniture and fixtures		5

Leasehold improvements are depreciated over their estimated useful lives but in no case longer than the lease term, except where lease renewal is reasonably assured.

If there is a major event indicating that the carrying value of property and equipment may be impaired then management will perform an impairment test and if the carrying value exceeds the recoverable value, based on undiscounted future cash flows, then such assets are written down to their fair values.

Goodwill and intangible assets

The costs incurred in establishing and maintaining patents for intellectual property developed internally are expensed in the period incurred.

Intangible assets consist of in-process research and development arising from the Company’s acquisition of Arbutus Inc. in 2015. In-process research and development (IPR&D) intangible assets are classified as indefinite-lived and are not amortized. IPR&D becomes definite-lived upon the completion or abandonment of the associated research and development efforts. Intangible assets with finite useful lives are amortized on a straight-line basis over their estimated useful lives, which are the respective patent terms. Amortization begins when intangible assets with finite lives are put into use. If there is a major event indicating that the carrying value of intangible assets may be impaired, then management will perform an impairment test in an interim period and if the carrying value exceeds the recoverable value, based on discounted future cash flows, then such assets are written down to their fair values.

The Company reviews the recoverable amount of intangible assets and goodwill on an annual basis, and the annual evaluation is performed as of December 31 each year. In addition, the Company evaluates for events or changes in the business that could indicate impairment and earlier testing. Such indicators include, but are not limited to, on an ongoing basis: (a) industry and market considerations such as increased competitive environment or adverse change in legal factors including an adverse assessment by regulators; (b) an accumulation of costs significantly in excess of the amount originally expected for the development of the asset; (c) current period operating or cash flow loss combined with a history of operating or cash flow losses or a projection or forecast that demonstrates continuing losses associated with the use of the asset; (d) adverse research and development program results; and (e) if applicable, a sustained decrease in share price.

Goodwill represents the excess of purchase price over the value assigned to the net tangible and identifiable intangible assets of Arbutus Inc. - see note 3. Goodwill has an indefinite accounting life and is therefore not amortized. Instead, goodwill is subject to a two-step impairment test on an annual basis, unless the Company identifies impairment indicators that would require earlier testing. The first step compares the fair value of the reporting unit to its carrying amount, which includes the goodwill. When the fair value of a reporting unit exceeds its carrying amount, goodwill of the reporting unit is considered not to be impaired, and the second step of the impairment test is unnecessary. If the carrying amount exceeds the fair value of the reporting unit, the second step measures the amount of the impairment loss. In the second step of the impairment test, the amount of impairment loss is calculated to the extent that the implied fair value of goodwill exceeds the carrying value of goodwill assigned to the Company's single reporting unit based on a hypothetical purchase price allocation.

Revenue recognition

The Company earns revenue from research and development collaboration and contract services, licensing fees, milestone and royalty payments. In arrangements with multiple deliverables, the delivered item or items is considered a separate unit of accounting if: (1) the delivered item has value to the customer on a standalone basis; and (2) if the arrangement includes a general right of return relative to the delivered item, delivery or performance of the undelivered item is considered probably and substantially in the Company's control. If the elements of the arrangement do not meet both of the criteria above, they are recognized as a single unit of accounting. If the elements do meet the criteria above, arrangement consideration is allocated to the separate units of accounting based on their relative selling price. Non-refundable payments received under collaborative research and development agreements are recorded as revenue as services are performed and related expenditures are incurred. Non-refundable upfront license fees from collaborative licensing and development arrangements are recognized as the Company fulfills its obligations related to the various elements within the agreements, in accordance with the contractual arrangements with third parties and the term over which the underlying benefit is being conferred. If non-refundable license fees have values to the customer on a standalone basis, separate from the undelivered performance obligations, they are recognized upon delivery. To date, the Company has not recognized any non-refundable license fees upon delivery.

The Company evaluates new arrangements for any substantive milestones by considering: whether substantive uncertainty exists upon execution of the arrangement; if the event can only be achieved based in whole or in part on the Company’s performance, or occurrence of a specific outcome resulting from the Company’s performance; any future performance required, and payment is reasonable relative to all deliverables; and, the payment terms in the arrangement. Payments received upon the achievement of substantive milestones are recognized as revenue in their entirety. Payments received upon the occurrence of milestones that are non-substantive are deferred and recognized as revenue over the estimated period of performance applicable to the associated collaborative agreement.

Revenue earned under research and development manufacturing collaborations where the Company bears some or all of the risk of a product manufacturing failure is recognized when the purchaser accepts the product and there are no remaining rights of return.

Revenue earned under research and development collaborations where the Company does not bear any risk of product manufacturing failure is recognized in the period the work is performed. For contracts where the manufacturing amount is specified, revenue is recognized as product is manufactured in proportion to the total amount specified under the contract.

Revenue and expenses under the contract with the United States Government Department of Defense (“DoD”) were being recorded using the percentage-of-completion method. Contract progress was based on costs incurred to date. Expenses under the contract were recorded in the Company’s consolidated statement of operations and comprehensive income (loss) as they were incurred. Government contract revenues related to expenses incurred under the contract were recorded in the same period as those expenses. Expenses accrued under the contract but not yet invoiced were recorded in the Company’s balance sheet as accrued liabilities and accrued revenues. Equipment purchased under the contract was recorded on the Company’s balance sheet as deferred expense and deferred revenue and amortized, on a straight-line basis, over the life of the contract.

Cash or other compensation received in advance of meeting the revenue recognition criteria is recorded on the balance sheet as deferred revenue. Revenue meeting recognition criteria but not yet received or receivable is recorded on the balance sheet as accrued revenue.

Leases and lease inducements

Leases entered into are classified as either capital or operating leases. Leases which substantially transfer all benefits and risks of ownership of property to the Company are accounted for as capital leases. At the time a capital lease is entered into, an asset is recorded together with its related long-term obligation to reflect the purchase and financing.

All other leases are accounted for as operating leases wherein rental payments are expensed as incurred.

Lease inducements represent leasehold improvement allowances and reduced or free rent periods and are amortized on a straight-line basis over the term of the lease and are recorded as a reduction of rent expense.

Research and development costs

Research and development costs, including acquired in-process research and development expenses for which there is no alternative future use, are charged as an expense in the period in which they are incurred.

Income or loss per share

Income or loss per share is calculated based on the weighted average number of common shares outstanding. Diluted loss per share does not differ from basic loss per share for the years ended December 31, 2016, 2015 and 2014, since the effect of the Company’s stock options and warrants is anti-dilutive.

The following table sets out the computation of basic and diluted net income (loss) per common share:



	For the year ended December 31
	2016			2015			2014
Numerator:
Net loss	$	(384,164	)	$	(61,121	)	$	(38,837	)
Denominator:
Weighted average number of common shares	53,074,401			45,462,324			21,603,136
Basic income (loss) per common share	$	(7.24	)	$	(1.34	)	$	(1.80	)
Diluted income (loss) per common share	$	(7.24	)	$	(1.34	)	$	(1.80	)

For the year ended December 31, 2016, potential common shares of 4,645,864 were excluded from the calculation of income per common share because their inclusion would be anti-dilutive (December 31, 2015 – 2,899,331; December 31, 2014 – 2,221,233).

Government grants and refundable investment tax credits

Government grants and tax credits provided for current expenses is included in the determination of income or loss for the year, as a reduction of the expenses to which it relates. Government grants and tax credits towards the acquisition of property and equipment is deducted from the cost of the related property and equipment.

Deferred income taxes

Income taxes are accounted for using the asset and liability method of accounting. Deferred income taxes are recognized for the future income tax consequences attributable to differences between the carrying values of assets and liabilities and their respective income tax bases and for loss carry-forwards. Deferred income tax assets and liabilities are measured using enacted income tax rates expected to apply to taxable income in the periods in which temporary differences are expected to be recovered or settled. The effect on deferred income tax assets and liabilities of a change in tax laws or rates is included in earnings in the period that includes the enactment date. When realization of deferred income tax assets does not meet the more-likely-than-not criterion for recognition, a valuation allowance is provided.

Equity classified stock option awards

The Company grants stock options to employees, directors and consultants pursuant to share incentive plans described in note 6. Compensation expense is recorded for issued stock options using the fair value method with a corresponding increase in additional paid-in capital. Any consideration received on the exercise of stock options is credited to share capital.

The fair value of equity classified stock options is measured at the grant date and amortized on a straight-line basis over the vesting period.

Liability-classified stock option awards

The Company accounts for liability-classified stock option awards ("liability options") under ASC 718 - Compensation - Stock Compensation ("ASC 718"), under which awards of options that provide for an exercise price that is not denominated in: (a) the currency of a market in which a substantial portion of the Company's equity securities trades, (b) the currency in which the employee's pay is denominated, or (c) the Company's functional currency, are required to be classified as liabilities. Due to the change in functional currency as of January 1, 2016, certain stock option awards with exercise prices denominated in Canadian dollars changed from equity classification to liability classification. As such, the historic equity classification of these stock option awards changed to liability classification effective January 1, 2016. The change in classification resulted in reclassification of these awards from additional paid-in capital to liability-classified options.

Liability options are re-measured to their fair values at each reporting date with changes in the fair value recognized in share-based compensation expense or additional paid-in capital until settlement or cancellation. Under ASC 718, when an award is reclassified from equity to liability, if at the reclassification date the original vesting conditions are expected to be satisfied, then the minimum amount of compensation cost to be recognized is based on the grant date fair value of the original award. Fair value changes below this minimum amount are recorded in additional paid-in capital.

Replacement awards

Replacement awards are share-based payment awards exchanged for awards held by employees of Arbutus Inc. As part of the Company’s acquisition of Arbutus Inc., Arbutus shares were exchanged for Arbutus Inc.’s shares subject to repurchase rights held by Arbutus Inc.’s employees.

As at the date of acquisition of Arbutus Inc., the Company determined the total fair value of replacement awards and attributed a portion of the replacement awards to pre-combination service as part of the total acquisition consideration, and a portion to post-combination service, which is recognized as compensation expense over the expiry period of repurchase provision rights subsequent to the acquisition date.

The replacement awards consist of common shares that were issued at acquisition. Accordingly, as stock compensation expense related to these awards is recognized, share capital is increased by a corresponding amount. Replacement awards are excluded in the calculation of basic net income (loss) per share until the repurchase rights have expired.

Warrants

The Company accounts for the warrants under the authoritative guidance on accounting for derivative financial instruments indexed to, and potentially settled in, a company’s own stock, on the understanding that in compliance with applicable securities laws, the registered warrants require the issuance of registered securities upon exercise and do not sufficiently preclude an implied right to net cash settlement. The Company classifies warrants in its consolidated balance sheet as a liability which is revalued at each balance sheet date subsequent to the initial issuance. The Company uses the Black-Scholes pricing model to value the warrants. Determining the appropriate fair-value model and calculating the fair value of registered warrants requires considerable judgment. A small change in the estimates used may cause a relatively large change in the estimated valuation. The estimated volatility of the Company’s common stock at the date of issuance, and at each subsequent reporting period, is based on historic fluctuations in the Company’s stock price. The risk-free interest rate is based on the Government of Canada rate for bonds with a maturity similar to the expected remaining life of the warrants at the valuation date. The expected life of the warrants is based on the historical pattern of exercises of warrants.

Segment information

The Company operates in a single reporting segment. Substantially all of the Company’s revenues to date were earned from customers or collaborators based in the United States. Substantially all of the Company’s premises, property and equipment are located in Canada and the United States.

Recent accounting pronouncements

From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (FASB) or other standard setting bodies that are adopted by the Company as of the specified effective date. Unless otherwise discussed, we believe that the impact of recently issued standards that are not yet effective will not have a material impact on our financial position or results of operations upon adoption.

In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (ASC 606). The standard, as subsequently amended (ASU 2015-14, ASU 2016-08, ASU 2016-10, ASU 2016-12, ASU 2016-20), is intended to clarify the principles for recognizing revenue and to develop a common revenue standard for U.S. GAAP and IFRS by creating a new Topic 606, Revenue from Contracts with Customers. This guidance supersedes the revenue recognition requirements in ASC 605, Revenue Recognition, and supersedes some cost guidance included in Subtopic 605-35, Revenue Recognition – Construction-Type and Production-Type Contracts. The core principle of the accounting standard is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those good or services. The amendments should be applied by either (1) retrospectively to each prior reporting period presented; or (2) retrospectively with the cumulative effect of initially applying this ASU recognized at the date of initial application. The new guidance would be effective for fiscal years beginning after December 15, 2017, which for the Company means January 1, 2018. The Company has begun its evaluation and, at this time, does not expect adoption of this guidance to materially impact its financial statements.

In March 2016, the FASB issued ASU 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The update is intended to simplify several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification of the statement of cash flows. Under this update, there are five simplifications for public companies. All excess tax benefits and tax deficiencies should be recognized as income tax expense or benefit in the income statement and the tax effects of exercised or vested awards should be treated as discrete items in the reporting period in which they occur. Excess tax benefits should be classified along with other tax cash flows as an operating activity. An entity can make an entity-wide accounting policy election to either estimate the number of awards that are expected to vest (current GAAP) or account for forfeitures when they occur. Cash paid by an employee when directly withholding shares for tax withholding purposes should be classified as financing activity. The amendments in this update would be effective for annual periods beginning after December 15, 2016, which for the Company means January 1, 2017. Early application is permitted in any interim period or annual period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. The Company has early adopted all provisions of this update effective October 1, 2016 and elected an entity-wide accounting policy to recognize forfeitures as they occur. The impact of this adoption was immaterial and has been reflected in the Company's statement of operations and comprehensive loss for the year ended December 31, 2016. The remaining provisions did not have a material impact on the Company's financial statements.

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842): Recognition and Measurement of Financial Assets and Financial Liabilities. The update supersedes Topic 840, Leases and requires the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous GAAP. Topic 842 retains a distinction between finance leases and operating leases, with cash payments from operating leases classified within operating activities in the statement of cash flows. The amendments in this update are effective for fiscal years beginning after December 15, 2018 for public business entities, which for the Company means January 1, 2019. The Company does not plan to early adopt this update. The extent of the impact of this adoption has not yet been determined.

In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. The update addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice. Under this update, the classification of cash receipts and payments that have aspects of more than one class of cash flows should be determined first by applying specific guidance in GAAP. In the absence of specific guidance, an entity should determine each separately identifiable source or use within the cash receipts and cash payments on the basis of the nature of the underlying cash flows. An entity should then classify each separately identifiable source or use within the cash receipts and payments on the basis of their nature in financing, investing, or operating activities. In situations in which cash receipts and payments have aspects of more than one class of cash flows and cannot be separated by source or use, the appropriate classification should depend on the activity that is likely to be the predominant source or use of cash flows for the item. The amendments in this update are effective for public business entities for fiscal years beginning after December 31, 2017, which for the Company means January 1, 2018, and interim periods within those fiscal years. Early adoption is permitted. The amendments in this update should be applied using a retrospective transition method to each period presented. If it is impracticable to apply the amendments retrospectively for some of the issues, the amendments for those issues would be applied prospectively as of the earliest date practicable. The Company is currently evaluating the extent of the impact of this adoption.

In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Statement of Cash Flows: Restricted Cash. The update requires the statement of cash flows to explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The amendments in this update are effective for public business entities for fiscal years beginning after December 15, 2017, which for the Company means January 1, 2018. Early adoption is permitted, including adoption in an interim period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that included that interim period. The amendments in this update should be applied using a retrospective transition method to each period presented. The Company is currently evaluating the extent of the impact of this adoption.

In January 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. The update simplifies the subsequent measurement of goodwill by eliminating Step 2 from the goodwill impairment test. In computing the implied fair value of goodwill under Step 2, an entity had to perform procedures to determine the fair value at impairment testing date of its assets and liabilities following the procedure that would be required in determining the fair value of assets required and liabilities assumed in a business combination. Instead, under the amendments in this Update, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. The amendments in this update are effective for public business entities should be adopted for its annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019, which for the Company means January 1, 2020. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company is currently evaluating the extent of the impact of this adoption.

Impairment Evaluations For Intangible Assets and Goodwill

12 Months Ended

Dec. 31, 2016

Goodwill and Intangible Assets Disclosure [Abstract]

Impairment evaluations for intangible assets and goodwill

During the year ended December 31, 2016, the Company recognized a cumulative impairment charge of $391,347,000 against intangible assets and goodwill, as detailed below. The change in the estimated discount rate and the resulting impairment charge did not impact liquidity, cash runway, or cash flow from operations.

All in-process research and development (IPR&D) acquired is currently classified as indefinite-lived and is not currently being amortized. IPR&D becomes definite-lived upon the completion or abandonment of the associated research and development efforts, and will be amortized from that time over an estimated useful life based on respective patent terms. The Company evaluates the recoverable amount of intangible assets on an annual basis and performs an annual evaluation of goodwill as of December 31 each year, unless there is an event or change in the business that could indicate a requirement to test at an interim period.

Impairment of intangible assets

During the year-ended December 31, 2016, the Company recorded a total impairment charge of $253,197,000 and a corresponding income tax benefit of $105,002,000 against its identified intangible assets. The total impairment charge included $156,324,000 for the discontinuance of the ARB-1598 program in the Immune Modulator drug class, as well as a delay in the Company's research and development of its cccDNA Sterilizer drug class recorded during the quarter ended June 30, 2016. An additional charge of $96,873,000 resulted from the Company's impairment assessment performed at December 31, 2016.

At December 31, 2016, the Company re-assessed the discount rate used in its valuation models used to assess the carrying value of goodwill and intangible assets for impairment as a result of the sustained discrepancy between the Company’s market capitalization compared to carrying values and management’s assessment of fair values. As a result, the Company adjusted its company-specific risk premium to its market-derived weighted average cost of capital, which has increased the discount rate used in the annual impairment assessment at December 31, 2016. Following the process prescribed by the standard, intangible assets are first tested before assessing goodwill for impairment. The change in discount rate has resulted in an impairment charge of $96,873,000 to the Company’s intangible assets at December 31, 2016.

The following table summarizes the carrying values, net of impairment of the intangible assets as at December 31, 2016:



Year ended December 31	2016		2015
IPR&D – Immune Modulators	40,798		183,103
IPR&D – Antigen Inhibitors	14,811		36,437
IPR&D – cccDNA Sterilizers	43,836		133,102
Total IPR&D	$	99,445	$	352,642

Annual impairment evaluation of goodwill

On December 31, the Company conducted its annual impairment evaluation of goodwill. Goodwill was recorded as a result of the acquisition of Arbutus Inc. as described in note 2. As part of the evaluation of the recoverability of goodwill, the Company has identified only one reporting unit to which the total carrying amount of goodwill has been assigned.

The Company determines the fair value of the reporting unit each reporting period using accepted valuation methods, including the use of discounted cash flows supplemented by market-based assessments of fair value.

The income approach is used in step one of the impairment assessment to estimate the fair value of the reporting unit, which requires estimating future cash flows and risk-adjusted discount rates in the Company's discounted cash flow model. The overall market outlook and cash flow projections of our reporting unit involve the use of key assumptions, including cash flows, discount rates and probability of success. Due to uncertainties in the estimates that are inherent to our industry, actual results could differ significantly from the estimates made.

As at December 31, 2016, the Company re-assessed the discount rate used in the calculation of fair value, consistent with the change to the discount rate used in the intangible assets impairment assessment (described above). As a result of the increased discount rate, the carrying value of the reporting unit determined in step one of the impairment assessment exceeded the fair value of the reporting unit, and as such the Company proceeded to the second step of the impairment test, which measures the amount of an impairment charge. In the second step, the carrying value of goodwill is compared to the fair value of goodwill that is implied by performing a hypothetical purchase price allocation based on identifiable assets at the date of the assessment. The remaining implied goodwill of $24,364,000 is the result of deferred taxes in the hypothetical purchase price allocation. As a result, the Company has recorded an impairment for $138,150,000 against goodwill.

Many key assumptions in the cash flow projections are interdependent on each other. A change in any one or combination of these assumptions could impact the estimated fair value of the reporting unit. See note 2 for additional discussion of the Company's policy for accounting for goodwill.

- Definition

The entire disclosure for the aggregate amount of goodwill and a description of intangible assets, which may include (a) for amortizable intangible assets (also referred to as finite-lived intangible assets), the carrying amount, the amount of any significant residual value, and the weighted-average amortization period, (b) for intangible assets not subject to amortization (also referred to as indefinite-lived intangible assets), the carrying amount, and (c) the amount of research and development assets acquired and written off in the period, including the line item in the income statement in which the amounts written off are aggregated, if not readily apparent from the income statement. Also discloses (a) for amortizable intangibles assets in total and by major class, the gross carrying amount and accumulated amortization, the total amortization expense for the period, and the estimated aggregate amortization expense for each of the five succeeding fiscal years, (b) for intangible assets not subject to amortization the carrying amount in total and by major class, and (c) for goodwill, in total and for each reportable segment, the changes in the carrying amount of goodwill during the period (including the aggregate amount of goodwill acquired, the aggregate amount of impairment losses recognized, and the amount of goodwill included in the gain (loss) on disposal of a reporting unit). If any part of goodwill has not been allocated to a reportable segment, discloses the unallocated amount and the reasons for not allocating. For each impairment loss recognized related to an intangible asset (excluding goodwill), discloses: (a) a description of the impaired intangible asset and the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method for determining fair value, (c) the caption in the income statement or the statement of activities in which the impairment loss is aggregated, and (d) the segment in which the impaired intangible asset is reported. For each goodwill impairment loss recognized, discloses: (a) a description of the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method of determining the fair value of the associated reporting unit, and (c) if a recognized impairment loss is an estimate not finalized and the reasons why the estimate is not final. May also disclose the nature and amount of any significant adjustments made to a previous estimate of an impairment loss.

+ References + Details

Collaborations, Contracts and Licensing Agreements

12 Months Ended

Dec. 31, 2016

Deferred Revenue Disclosure [Abstract]

Collaborations, contracts and licensing agreements

The following tables set forth revenue recognized under collaborations, contracts and licensing agreements:



	Year ended December 31
	2016		2015		2014
Collaborations and contracts
DoD (a)	$	—	$	6,764	$	8,407
Monsanto (b)	—		4,725		1,080
BMS (c)	—		—		1,741
Dicerna (d)	229		1,820		510
Total research and development collaborations and contracts	229		13,309		11,738
Licensing fees, milestone and royalty payments
Monsanto licensing fees and milestone payments (b)	—		10,256		2,744
Dicerna licensing fee (d)	1,066		1,053		131
Other milestone and royalty payments (e)	196		255		340
Total licensing fees, milestone and royalty payments	1,262		11,564		3,215
Total revenue	$	1,491	$	24,873	$	14,953

The following table sets forth deferred collaborations and contracts revenue:



	December 31, 2016		December 31, 2015
DoD (a)	$	15	$	15
Monsanto current portion (b)	—		—
Dicerna current portion (d)	—		853
Deferred revenue, current portion	15		868
Monsanto long-term portion (b)	—		—
Dicerna long-term portion (d)	—		213
Total deferred revenue	$	15	$	1,081

(a) Contract with United States Government’s Department of Defense (“DoD”) to develop TKM-Ebola

On July 14, 2010, the Company signed a contract with the DoD to advance TKM-Ebola, an RNAi therapeutic utilizing the Company’s lipid nanoparticle technology to treat Ebola virus infection.

In the initial phase of the contract, funded as part of the Transformational Medical Technologies program, the Company was eligible to receive up to $34,700,000. This initial funding was for the development of TKM-Ebola including completion of preclinical development, filing an Investigational New Drug application with the United States Food and Drug Administration (“FDA”) and completing a Phase 1 human safety clinical trial. On May 8, 2013, the Company announced that the contract had been modified to support development plans that integrate recent advancements in lipid nanoparticle (“LNP”) formulation and manufacturing technologies. The contract modification increased the stage one targeted funding by an additional $6,970,000. On April 22, 2014, the Company and the DoD signed a contract modification to further increase the stage one targeted funding by $2,100,000 to $43,819,000. The additional funding was to compensate the Company for unrecovered overheads related to the temporary stop-work period that occurred in 2012 and to provide additional overhead funding should it be required.

The DoD had the option of extending the contract beyond the initial funding period to support the advancement of TKM-Ebola through to the completion of clinical development and FDA approval. Based on the contract’s budget this would have provided the Company with up to $140,000,000 in funding for the entire program. In December 2014, the DoD exercised an option valued at $7,000,000 to manufacture TKM-Ebola-Guinea, developed by the Company targeting the Ebola-Guinea strain responsible for the current outbreak in West Africa.

Under the contract, the Company is reimbursed for costs incurred, including an allocation of overhead costs, and is paid an incentive fee. At the beginning of the fiscal year, the Company estimates its labor and overhead rates for the year ahead. At the end of the year the actual labor and overhead rates are calculated and revenue is adjusted accordingly. The Company’s actual labor and overhead rates will differ from its estimated rates based on actual costs incurred and the proportion of the Company’s efforts on contracts and internal products versus indirect activities. Within minimum and maximum collars, the amount of incentive fee the Company can earn under the contract varies based on costs incurred versus budgeted costs. During the contractual period, incentive fee revenue and total costs are impacted by management’s estimate and judgments which are continuously reviewed and adjusted as necessary using the cumulative catch-up method. For the years ended December 31, 2015 and 2016, the Company believes it can reliably estimate the final contract costs so has recognized the portion of expected incentive fee which has been earned to date.

On October 1, 2015, the Company received formal notification from the DoD that, due to the unclear development path for TKM-Ebola and TKM-Ebola-Guinea, the Ebola-Guinea Manufacturing and the Ebola-Guinea IND submission statements of work had been terminated, subject to the completion of certain post-termination obligations. The TKM-Ebola portion of the contract was completed in November 2015. The Company is currently conducting contract close out procedures with the DoD.

(b) Option and Services Agreements with Monsanto Company (“Monsanto”)

On January 13, 2014, the Company and Monsanto signed an Option Agreement and a Services Agreement (together, the “Agreements”). Under the Agreements, Monsanto has an option to obtain a license to use the Company’s proprietary delivery technology and related intellectual property for use in agriculture. Over the option period, which is expected to be approximately four years, the Company will provide lipid formulations for Monsanto’s research and development activities, and Monsanto will make certain payments to the Company to maintain its option rights. The maximum potential value of the transaction is $86,200,000 following the successful completion of milestones.

In May 2015, the arrangement was amended to extend the option period by approximately five months, with payments up to $2,000,000 for the extension period. From inception of the contract to December 31, 2015, the Company had received $19,300,000 from Monsanto. The amounts received relate to research services and use of the Company’s technology over the option period, and are recognized as revenue on a straight-line basis over the extended option period.

Following the completion of the Phase A extension period in October 2015, no further research activities were conducted under the arrangement, as Monsanto did not elect to proceed to Phase B of the research plan. As such, the Company revised its estimate of the option period, over which payments received from Monsanto is recognized as revenue, to be from inception to December 31, 2015 as the Company believes it no longer has any further obligations to provide future research activities to Monsanto. This resulted in the full release of Monsanto deferred revenue and a recognition of $14,981,000 in Monsanto revenue for the year ended December 31, 2015.

Under the Agreements, the Company has established a wholly-owned subsidiary, PADCo. The Company has determined that PADCo is a variable interest entity (“VIE”); however, Monsanto is the primary beneficiary of the arrangement. PADCo was established to perform research and development activities, which have been funded by Monsanto in return for a call option to acquire the equity or all of the assets of PADCo. On March 4, 2016, Monsanto exercised its option to acquire 100% of the outstanding shares of PADCo and paid the Company an option exercise fee of $1,000,000. From the acquisition of PADCo, Monsanto received a worldwide, exclusive right to use the Company’s proprietary delivery technology in the field of agriculture. The Company recorded the exercise fee received as a gain on disposition of a financial instrument in its consolidated statement of operations and comprehensive loss for the year ended December 31, 2016.

On May 10, 2010 the Company announced the expansion of its research collaboration with BMS. Under the new agreement, BMS uses small interfering RNA (“siRNA”) molecules formulated by the Company in LNP technology to silence target genes of interest. BMS is conducting the preclinical work to validate the function of certain genes and share the data with the Company. The Company can use the preclinical data to develop RNAi therapeutic drugs against the therapeutic targets of interest. The Company received $3,000,000 from BMS concurrent with the signing of the agreement and recorded the amount as deferred revenue. The Company is required to provide a pre-determined number of LNP batches over the four-year agreement. BMS has a first right to negotiate a licensing agreement on certain RNAi products developed by the Company that evolve from BMS validated gene targets.

Revenue from the May 10, 2010 agreement with BMS is being recognized as the Company produces the related LNP batches.

Revenue earned for the year ended December 31, 2014 relates to batches shipped to BMS during the period. In August 2014, the agreement expired and both companies' obligations under the agreement ended.

(d) License and Development and Supply Agreement with Dicerna Pharmaceuticals, Inc. (“Dicerna”)

On November 16, 2014, the Company signed a License Agreement and a Development and Supply Agreement (together, the “Agreements”) with Dicerna related to development, manufacture, and commercialization of products directed to the treatment of Primary Hyperoxaluria 1 (“PH1”). In consideration for the rights granted under the Agreements, Dicerna paid the Company an upfront cash payment of $2,500,000. The Company is also entitled to receive payments from Dicerna on the manufacturing and services provided, as well as further payments with the achievement of development and regulatory milestones of $22,000,000 in aggregate, and potential commercial royalties. Further, under the Agreements, a joint development committee has been established to provide guidance and direction on the progression of the collaboration.

The Company determined the deliverables under the Agreements included the rights granted, participation in the joint development committee, materials manufactured and other services provided, as directed under the joint development committee. The license and participation in the joint development committee have been determined by the Company to not have standalone value due to the uniqueness of the subject matter under the Agreements. Therefore, these deliverables are treated as one unit of accounting and recognized as revenue over the performance period. In September 2016, Dicerna announced the discontinuation of their DCR-PH1 program using the Company's technology. As such, the Company revised the completion date of performance period from March 2017 to September 30, 2016, at which time the Company had no further remaining performance obligations. This resulted in the recognition of $1,066,000 in Dicerna license fee revenue for the year ended December 31, 2016.

The Company has determined that manufacturing services and other services provided have standalone value, as a separate statement of work is executed and invoiced for each manufacturing or service work order. The relative fair values are determined as a batch price or fee is estimated upon the execution of each work order, with actual expenditures charged at comparable market rates with embedded margins on each work order.

Manufacturing work orders are invoiced at the time of execution of the work order, at the initiation of manufacture, and at the release of materials. The Company has deferred the recognition of revenue on all cash deposit payments received for manufacturing work orders until acceptance of inventory. Revenue from service work orders is recognized as the services are performed.

The Company believes the development and regulatory milestones are substantive, due to the existence of substantive uncertainty upon the execution of the arrangement, and that the achievement of the development and regulatory events are based in part on the Company’s performance and the occurrence of a specific outcome resulting from performance. The Company has not received any milestone payments to date.

(e) Agreements with Spectrum Pharmaceuticals, Inc. (“Spectrum”)

On May 6, 2006, the Company signed a number of agreements with Talon Therapeutics, Inc. (“Talon”, formerly Hana Biosciences, Inc.) including the grant of worldwide licenses (the “Talon License Agreement”) for three of the Company’s chemotherapy products, Marqibo®, Alocrest ™ (Optisomal Vinorelbine) and Brakiva ™ (Optisomal Topotecan).

On August 9, 2012, the Company announced that Talon had received accelerated approval for Marqibo from the FDA for the treatment of adult patients with Philadelphia chromosome negative acute lymphoblastic leukemia in second or greater relapse or whose disease has progressed following two or more anti-leukemia therapies. Marqibo is a liposomal formulation of the chemotherapy drug vincristine. In the year ended December 31, 2012, the Company received a milestone of $1,000,000 based on the FDA’s approval of Marqibo and will receive royalty payments based on Marqibo’s commercial sales. There are no further milestones related to Marqibo but the Company is eligible to receive total milestone payments of up to $18,000,000 on Alocrest and Brakiva.

Talon was acquired by Spectrum in July 2013. The acquisition did not affect the terms of the license between Talon and the Company. On September 3, 2013, Spectrum announced that they had shipped the first commercial orders of Marqibo. In the year ended December 31, 2016, the Company recorded $212,000 in Marqibo royalty revenue (2015 - $240,000, 2014 -$190,000). In the year ended December 31, 2016, the Company accrued $5,000 in royalties due to TPC in respect of the Marqibo royalty earned by the Company (see note 10).

Property and Equipment

12 Months Ended

Dec. 31, 2016

Property, Plant and Equipment [Abstract]

Property and equipment



December 31, 2016	Cost		Accumulated depreciation			Net book value
Lab equipment	$	7,894	$	(4,305	)	$	3,589
Leasehold improvements	4,928		(4,454		)	474
Computer hardware and software	2,103		(1,665		)	438
Furniture and fixtures	374		(314		)	60
Assets under construction	$	2,384	$	—		$	2,384
	$	17,683	$	(10,738	)	$	6,945



December 31, 2015	Cost		Accumulated depreciation			Net book value
Lab equipment	$	5,910	$	(3,748	)	$	2,162
Leasehold improvements	4,681		(4,189		)	492
Computer hardware and software	2,014		(1,487		)	527
Furniture and fixtures	307		(305		)	2
	$	12,912	$	(9,729	)	$	3,183

As at December 31, 2016, all of the Company’s property and equipment are currently in use and no impairment has been recorded.

Share Capital

12 Months Ended

Dec. 31, 2016

Stockholders' Equity Note [Abstract]

Share capital

(a) Financing

On March 26, 2014, the Company completed an underwritten public offering of 2,125,000 common shares, at a price of $28.50 per share, representing gross proceeds of $60,562,000. The Company also granted the underwriters a 30-day option to purchase an additional 318,750 shares for an additional $9,084,000 to cover any over-allotments. The underwriters did not exercise the option. The cost of financing, including commissions and professional fees, was $4,085,000, resulting in net proceeds of $56,477,000.

On March 25, 2015, the Company announced that it had completed an underwritten public offering of 7,500,000 common shares, at a price of $20.25 per share, representing gross proceeds of $151,875,000. The Company also granted the underwriters a 30-day option to purchase an additional 1,125,000 shares for an additional $22,781,000 to cover any over-allotments. The underwriters did not exercise the option. The cost of financing, including commissions and professional fees, was $9,700,000, resulting in net proceeds of $142,177,000.

(b) Authorized share capital

The Company’s authorized share capital consists of an unlimited number of common and preferred shares without par value.

During the year ended December 31, 2016, there were 170,500 warrants exercised for $445,000 in cash (December 31, 2015 – 18,750 warrants for $42,000) and no warrants were exercised using the cashless exercise provision (December 31, 2015 – 0 warrants for 0 common shares). In June 2016, 8,000 of the Company's warrants expired. The decrease in fair value from the previous balance sheet date relating to the expired warrants has been included in the total decrease in fair value of warrant liability in the Company's statement of comprehensive loss for the year ended December 31, 2016 of $530,000.

The following table summarizes the Company’s warrant activity for the years ended December 31, 2016 and 2015:



	Common shares purchasable upon exercise of warrants		Weighted average exercise price (C$)		Weighted average exercise price (US$)		Range of exercise prices (C$)				Range of exercise prices (US$)					Weighted average remaining contractual life (years)	Aggregate intrinsic value (C$)		Aggregate intrinsic value (US$)
Balance, December 31, 2014	398,250		$	2.95	$	2.67	$2.60	—	$	3.35	$2.35		—	$	3.03	1.8	$	5,902	$	5,343
Exercised	(18,750	)	2.88		2.25		2.60	—	3.35		2.03		—	2.62
Balance, December 31, 2015	379,500		$	2.95	$	2.13	$2.60	—	$	3.35	$2.03		—	$	2.62	0.8	1,217		$	879
Exercised	(170,500	)	3.35		2.53		3.35	—	3.35		2.53		—	2.53
Expired	(8,000	)	3.35		2.53		3.35	—	3.35		2.53		—	2.53
Balance, December 31, 2016	201,000		$	2.60	$	1.94	$2.60	—	$	2.60	$	1.94	—	$	1.94	0.2	$	139	$	104

The aggregate intrinsic value in the table above is calculated based on the difference between the exercise price of the warrants and the quoted price of the Company’s common stock as of the reporting date.

All of the Company’s warrants were exercisable as of December 31, 2016.

The weighted average Black-Scholes option-pricing assumptions and the resultant fair values are as follows for warrants outstanding at December 31, 2016 and 2015 are as follows:



	As at December 31
	2016			2015
Dividend yield	—		%	—		%
Expected volatility	41.95		%	49.07		%
Risk-free interest rate	0.76		%	0.48		%
Expected average term (years)	0.2 years			0.6 years
Fair value of warrants outstanding	$	0.53		$	2.33
Aggregate fair value of warrants outstanding	$	107		$	883
Number of warrants outstanding	201,000			379,500

The value of the Company’s warrants is particularly sensitive to changes in the Company’s share price and the estimated share price volatility.

(d) Stock-based compensation

The Company has seven share-based compensation plans; the “2007 Plan”, the “2011 Plan”, the "2016 Plan", two “Designated Plans” (together, the “Arbutus Plans”), the “Protiva Option Plan”, and the "OnCore Option Plan".

On June 22, 2011, the shareholders of the Company approved an omnibus stock-based compensation plan (the “2011 Plan”). The Company’s pre-existing 2007 Plan was limited to the granting of stock options as equity incentive awards whereas the 2011 Plan also allows for the issuance of tandem stock appreciation rights, restricted stock units and deferred stock units (collectively, and including options, referred to as “Awards”). The 2011 Plan replaces the 2007 Plan. The 2007 Plan will continue to govern the options granted thereunder. No further options will be granted under the Company’s 2007 Plan.

Under the Company’s 2007 Plan the Board of Directors granted options to employees, directors and consultants of the Company. The exercise price of the options was determined by the Company’s Board of Directors but was always at least equal to the closing market price of the common shares on the day preceding the date of grant and the term of options granted did not exceed 10 years. The options granted generally vested over three years for employees and immediately for directors.

Under the Company’s 2011 Plan the Board of Directors may grant options, and other types of Awards, to employees, directors and consultants of the Company. The exercise price of the options is determined by the Company’s Board of Directors but will be at least equal to the closing market price of the common shares on the day preceding the date of grant and the term may not exceed 10 years. Options granted generally vest over three years for employees and immediately for directors.

At the Company’s annual general and special meeting of shareholders on May 8, 2014 and July 9, 2015, the shareholders of the Company approved respectively, a 800,000 and a 3,500,000 increase in the number of stock-based compensation awards that the Company is permitted to issue under the 2011 Plan.

At the Company’s annual general and special meeting of shareholders on May 19, 2016, the shareholders of the Company approved the adoption of the Company's 2016 Omnibus Share and Incentive Plan (the "2016 Plan") and the reserve of 5,000,000 shares of the Company issuable pursuant to awards under the 2016 Plan. These include both equity-classified and liability-classified stock options. The Company's 2011 Omnibus Share Compensation Plan, as amended, also remains in effect.

Additionally, the Company granted a total of 200,000 options in 2013 to two executive officers in conjunction with their new appointments as executive officers. These options were granted in accordance with the policies of the Toronto Stock Exchange and pursuant to newly designated share compensation plans (the “Designated Plans”). The Designated Plans are governed by substantially the same terms as the 2011 Plan. Hereafter, information on options governed by the 2007 Plan, the 2011 Plan, the 2016 Plan and the Designated Plans is presented on a consolidated basis as the terms of the five plans are similar. Information on the Protiva Option Plan and the OnCore Option Plan are presented separately.

Stock option activity for the Arbutus Plans

Equity-classified stock option activity:



	Number of optioned common shares		Weighted average exercise price (C$)		Weighted average exercise price (US$)		Aggregate intrinsic value (C$)		Aggregate intrinsic value (US$)
Balance, December 31, 2013	1,730,765		$	4.45	$	4.32	$	7,030	$	6,826
Options granted	431,125		13.63		12.34
Options exercised	(622,752	)	4.62		4.18		7,650		6,926
Options forfeited, canceled or expired	(9,000	)	8.20		7.42
Balance, December 31, 2014	1,530,138		6.95		6.29		16,573		15,004
Options granted	1,309,625		N/A		16.57
Options exercised	(398,293	)	5.03		3.93		6,887		5,386
Options forfeited, canceled or expired	(151,207	)	19.29		15.09
Balance, December 31, 2015	2,290,263		15.53		11.22		1,376		994
Options reclassified to liability¹	(718,333	)	7.24		5.23		836		604
Options granted	1,789,599		N/A		3.89
Options exercised	(56,125	)	2.88		2.18		160		121
Options forfeited, canceled or expired	(394,200	)	13.49		10.18
Balance, December 31, 2016	2,911,204		$	11.45	$	8.53	$	75	$	56


1.	Due to the change in the Company's functional currency as of January 1, 2016, certain stock option awards with exercise prices denominated in Canadian dollars changed from equity classification to liability classification - see note 2.

Options under the Arbutus Plans expire at various dates from March 21, 2017 to November 28, 2026.

The following table summarizes information pertaining to stock options outstanding at December 31, 2016 under the Arbutus Plans:



			Options outstanding December 31, 2016				Options exercisable December 31, 2016
Range of Exercise prices (US$)			Number of options outstanding	Weighted average remaining contractual life (years)	Weighted average exercise price (US$)		Number of options exercisable	Weighted average exercise price (US$)
$1.12	to	$3.05	121,725	6.4	2.23		75,225	1.78
$3.28	to	$3.84	209,033	8.4	3.64		62,033	3.69
$3.94	to	$3.94	1,369,849	9.2	3.94		—	N/A
$3.98	to	$8.64	81,713	8.1	4.49		71,380	4.38
$9.11	to	$9.73	118,843	7.8	9.44		91,375	9.44
$9.88	to	$13.89	201,000	8.1	13.42		74,271	13.26
$17.57	to	$17.57	809,041	8.2	17.57		324,957	17.57
$1.12	to	$17.57	2,911,204	8.6	$	8.53	699,241	$	11.77

At December 31, 2016, there were 699,241 options exercisable (December 31, 2015 - 938,730; December 31, 2014 – 1,088,908). The weighted average remaining contractual life of exercisable options as at December 31, 2016 was 7.5 years.

The aggregate intrinsic value of in-the-money options exercisable at December 31, 2016 was $56,000.

A summary of the Company’s non-vested stock option activity and related information for the year ended December 31, 2016 is as follows:



	Number of optioned common shares		Weighted average fair value (C$)		Weighted average fair value (US$)
Non-vested at December 31, 2015	1,351,541		$	15.69	$	11.34
Options reclassified to liability-options¹	(134,000	)	10.80		7.80
Options granted	1,789,599		5.15		3.89
Options vested	(472,479	)	14.20		10.72
Non-vested options forfeited	(322,698	)	9.70		7.33
Non-vested at December 31, 2016	2,211,963		$	7.17	$	5.34

1. Non-vested liability-classified stock options as at January 1, 2016

The weighted average remaining contractual life for options expected to vest at December 31, 2016 was 9.0 years and the weighted average exercise price for these options was $7.50 (C$10.07) per share.

The aggregate intrinsic value of options expected to vest as at December 31, 2016 was $0 (December 31, 2015 - $10,000; December 31, 2014 -$2,626,000).

The total fair value of options that vested during the year ended December 31, 2016 was $5,058,000 (December 31, 2015 - $1,718,000; December 31, 2014 -$2,505,000).

Valuation assumptions for the Arbutus Plans

On March 3, 2015, the Company voluntarily de-listed from the Toronto Stock Exchange. All stock options granted after March 3, 2015 were denominated in US dollars based on the Company's stock price on the NASDAQ. The methodology and assumptions used to estimate the fair value of stock options at date of grant under the Black-Scholes option-pricing model remain unchanged. Assumptions on the dividend yield are based on the fact that the Company has never paid cash dividends and has no present intention to pay cash dividends. Assumptions about the Company’s expected stock-price volatility are based on the historical volatility of the Company’s publicly traded stock. The risk-free interest rate used for each grant is equal to the zero coupon rate for instruments with a similar expected life. Expected life assumptions are based on the Company’s historical data. The Company recognizes forfeitures as they occur, and the effects of forfeitures are reflected in stock-based compensation expense recorded in the statement of operations and comprehensive loss for the year ended December 31, 2016. The weighted average option pricing assumptions for options granted during the year are as follows:



	Year ended December 31
	2016		2015		2014
Dividend yield	—	%	—	%	—	%
Expected volatility	77.99	%	76.88	%	101.08	%
Risk-free interest rate	0.90	%	1.10	%	2.25	%
Expected average option term	7.3 years		7.5 years		8.8 years

Liability-classified stock option activity:

Valuation assumptions

Liability options are re-measured to their fair values at each reporting date, using the Black-Scholes valuation model. The methodology and assumptions prevailing at the re-measurement date used to estimate the fair values of liability options remain unchanged from the date of grant of equity classified stock option awards. Assumptions about the Company’s expected stock-price volatility are based on the historical volatility of the Company’s publicly traded stock. The risk-free interest rate used for each grant is equal to the zero coupon rate for instruments with a similar expected life. Expected life assumptions are based on the Company’s historical data. The weighted average Black-Scholes option-pricing assumptions and the resultant fair values as at the reclassification date of January 1, 2016, and as at December 31, 2016, are presented in the following table:



	December 31,			January 1,
	2016			2016
Dividend yield	—		%	—		%
Expected volatility	66.18		%	97.78		%
Risk-free interest rate	0.88		%	0.86		%
Expected average term (years)	3.6			5.3
Fair value of options outstanding	$	0.87		$	3.33
Fair value of vested liability-classified options (in thousands)	$	553		$	1,909

Stock option activity for liability options



	Number of optioned common shares		Weighted average exercise price (C$)		Weighted average exercise price (US$)		Aggregate intrinsic value (US$)
Balance, January 1, 2016	718,333		$	7.24	$	5.23	$	604
Options exercised	(30,000	)	3.00		2.30		54
Options forfeited, canceled or expired	(49,833	)	8.29		6.17		—
Balance, December 31, 2016	638,500		$	7.35	$	5.48	$	116

Liability options expire at various dates from August 6, 2017 to May 7, 2024.

The following table summarizes information pertaining to liability options outstanding at December 31, 2016:



			Options outstanding December 31, 2016				Options exercisable December 31, 2016
Range of Exercise prices (US$)			Number of options outstanding	Weighted average remaining contractual life (years)	Weighted average exercise price (US$)		Number of options exercisable	Weighted average exercise price (US$)
$1.27	to	$1.79	120,000	3.7	$	1.48	120,000	$	1.48
$2.87	to	$3.84	120,000	3.6	3.42		120,000	3.42
$3.97	to	$4.28	74,000	1.6	4.22		74,000	4.22
$4.84	to	$6.18	76,250	0.7	5.83		76,250	5.83
$6.79	to	$6.79	150,000	6.8	6.79		150,000	6.79
$9.32	to	$12.21	98,250	6.0	11.53		83,500	11.44
$1.27	to	$12.21	638,500	4.2	$	5.48	623,750	$	5.32

At December 31, 2016, there were 623,750 liability options exercisable with a weighted average exercise price of $5.32 (C$7.14). The weighted average remaining contractual life of exercisable liability options as at December 31, 2016 was 4.1 years.

A summary of the Company's non-vested liability stock option activity and related information at December 31, 2016 is as follows:



	Number of optioned common shares		Weighted average fair value (US$)
Non-vested at January 1, 2016	134,000		$	3.61
Options vested	(93,250	)	0.67
Non-vested options forfeited	(26,000	)	0.04
Non-vested at December 31, 2016	14,750		$	0.92

The weighted average remaining contractual life for liability options expected to vest at December 31, 2016 was 7.1 years and the weighted average exercise price for these options was $12.06 (C$16.19) per share.

The total fair value of liability options that vested during the year ended December 31, 2016 was $62,200.

Protiva Option Plan

On May 30, 2008, as a condition of the acquisition of Protiva Biotherapeutics Inc., a total of 350,457 common shares of the Company were reserved for the exercise of 519,073 Protiva share options (“Protiva Options”). The Protiva Options have an exercise price of C$0.30, were fully vested and exercisable as of May 30, 2008. As at December 31, 2016, the outstanding options expire at various dates from April 3, 2017 to March 1, 2018 and upon exercise each option will be converted into approximately 0.6752 shares of the Company (the same ratio at which Protiva common shares were exchanged for Company common shares at completion of the acquisition of Protiva). The Protiva Options are not part of the Arbutus Plans and the Company is not permitted to grant any further Protiva Options.

The following table sets forth outstanding options under the Protiva Option Plan:



	Number of Protiva Options		Equivalent number of Company common shares		Weighted average exercise price (C$)		Weighted average exercise price (US$)
Balance, December 31, 2013	472,885		319,274		$	0.30	0.29
Options exercised	(38,145	)	(25,754	)	0.30		0.27
Options forfeited, canceled or expired	(1,000	)	(675	)	0.30		0.27
Balance, December 31, 2014	433,740		292,845		0.30		0.27
Options exercised	(358,675	)	(242,164	)	0.30		0.23
Options forfeited, canceled or expired	(8,065	)	(5,445	)	0.30		0.23
Balance, December 31, 2015	67,000		45,236		0.30		0.22
Options exercised	(21,000	)	(14,178	)	0.30		0.23
Options forfeited, canceled or expired	—		—		—		N/A
Balance, December 31, 2016	46,000		31,058		$	0.30	$	0.22

The weighted average remaining contractual life of exercisable Protiva Options as at December 31, 2016 was 1.0 years.

The aggregate intrinsic value of Protiva Options outstanding at December 31, 2016 was $56,000. The intrinsic value of Protiva Options exercised in the year ended December 31, 2016 was $49,000 (2015 - $1,249,000; 2014 -$378,000).

OnCore Option Plan

As at the acquisition date in March 2015, the Company reserved 184,332 shares for the future exercise of OnCore (Arbutus Inc.) stock options. The total fair value of OnCore stock options at the date of acquisition has been determined to be $3,287,000, using the Black-Scholes pricing model with an assumed risk-free interest rate of 0.97%, volatility of 78%, a zero dividend yield and an expected life of 8 years, which are consistent with the assumption inputs used by the Company to determine the fair value of its options. Of the total fair value, $1,127,000 has been attributed as pre-combination service and included as part of the total acquisition consideration. The post-combination attribution of $2,160,000 will be recognized as compensation expense over the vesting period of the stock options through to December 2018.

Following the merger, the Company is not permitted to grant any further options under the OnCore Option Plan. The Company has included $577,000 of compensation expense related to the vesting of Arbutus Inc. stock options for the year ended December 31, 2016.

The following table sets forth outstanding options under the OnCore Option Plan:



	Number of OnCore Options	Equivalent number of Company common shares	Weighted average exercise price (US$)
Balance, December 31, 2015	183,040	184,332	$	0.57
Options exercised	—	—	N/A
Options forfeited, canceled or expired	—	—	N/A
Balance, December 31, 2016	183,040	184,332	$	0.57

At December 31, 2016, there were 119,988 OnCore options (120,835 Arbutus equivalent) exercisable with a weighted average exercise price of $0.57. The weighted average remaining contractual life of exercisable options as at December 31, 2016 was 7.9 years. The aggregate intrinsic value of in-the-money options exercisable at December 31, 2016 was $226,000.

A summary of the OnCore Option Plan's non-vested stock option activity and related information for the year ended December 31, 2016 is as follows:



	Number of OnCore Options		Equivalent number of Company common shares		Weighted average fair value (US$)
Non-vested at December 31, 2015	96,382		97,063		$	16.42
Options vested	(33,331	)	(33,566	)	16.80
Non-vested options forfeited	—		—		N/A
Non-vested at December 31, 2016	63,051		63,497		$	16.80

The weighted average remaining contractual life for options expected to vest at December 31, 2016 was 7.9 years and the weighted average exercise price for these options was $0.57 per share.

The aggregate intrinsic value of options expected to vest as at December 31, 2016 was $119,000.

The total fair value of options that vested during the year ended December 31, 2016 was $560,000.

Stock-based compensation expense

Total stock-based compensation expense is comprised of: (1) the vesting options awarded to employees under the Arbutus and OnCore option plans calculated in accordance with the fair value method as described above; and (2) the expiration of repurchase rights related to the post-combination service portion of the total fair value of shares issued to Arbutus Inc.'s employees.

The total stock-based compensation has been recorded in the consolidated statement of operations and comprehensive income (loss) as follows:



	Year ended December 31
	2016		2015		2014
Research, development, collaborations and contracts expenses	$	11,155	$	7,868	$	2,343
General and administrative expenses	28,004		14,225		940
Total	$	39,159	$	22,093	$	3,283

At December 31, 2016, there remains $8,835,000 of unearned compensation expense related to unvested equity employee stock options to be recognized as expense over a weighted-average period of approximately 12 months, as well as a remaining $7,912,000 unearned compensation expense related to unexpired repurchase rights on shares issued to Arbutus Inc. employees to be recognized as expense over a weighted average period of approximately 5 months.

Awards outstanding and available for issuance

Combining all of the Company’s share-based compensation plans, at December 31, 2016, the Company has 3,765,094 options outstanding and a further 6,790,414 Awards available for issuance.

(e) Replacement awards

Included in the total consideration transferred for the acquisition of Arbutus Inc. in March 2015 are common shares issued as replacement awards, which are subject to repurchase provisions. The total fair value of these common shares attributed to the post acquisition period was approximately $56,934,000 and is being recognized as compensation expense over the expiry period of repurchase provision rights subsequent to the acquisition date.

In July 2015, in conjunction with amendments to the employment contracts of Arbutus Inc.’s founding executives, the Company amended the repurchase provision rights period of expiry from August 2018 to August 2017. This amendment results in an acceleration of compensation expense recognized in each subsequent period by approximately $1,900,000 per quarter, effective in Q3 2015.

In April and May 2016, two of the four shareholders of these common shares subject to repurchase provision departed from the Company, resulting in accelerated expiry of the repurchase provision. These departures triggered the recognition of an incremental compensation expense of $14,008,000 during the year, for a total of $31,986,000 (2015 - $16,687,000) in stock-based compensation expense related to the expiration of repurchase provision rights for the year-ended December 31, 2016. The total unrecognized compensation expense related to the expiry of repurchase provisions was $7,972,000 as at December 31, 2016.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB Topic 4.E)
-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74567-122707

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21484-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21488-112644

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(e))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(31))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB Topic 4.C)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(30))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(d))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6405834&loc=d3e23285-112656

Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Preferred Stock
-URI http://asc.fasb.org/extlink&oid=6521494

Reference 15: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 16: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21564-112644

+ Details

Government Grants and Refundable Investment Tax Credits	12 Months Ended
Government Grants and Refundable Investment Tax Credits	Dec. 31, 2016
Government Grants And Refundable Investment Tax Credits [Abstract]
Government grants and refundable investment tax credits	Government grants and refundable investment tax credits Government grants and refundable investment tax credits have been recorded as a reduction in research and development expenses. (a) Government grants On December 22, 2014, the Company entered into a Manufacturing and Clinical Trial Agreement with the University of Oxford to provide the new TKM-Ebola-Guinea therapeutic product for clinical studies in West Africa. The University of Oxford is the representative of the International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC), who conducted clinical studies of TKM-Ebola-Guinea in Ebola virus infected patients, with funding provided by the Wellcome Trust. In January 2015, the Company received $1,098,000 from ISARIC for materials manufactured and used in the March 2015 TKM-Ebola-Guinea Phase II single arm trial conducted in Sierra Leone. In June 2015, the Company announced closing of the enrollment for the trial as it reached a futility boundary, which was a predefined statistical endpoint. No further funding is expected under this grant. Government grants for the year ended December 31, 2016 include $129,000 in funding from the U.S. National Institutes of Health (2015 - $1,245,000). (b) Refundable investment tax credits The Company’s estimated claim for refundable Scientific Research and Experimental Development investment tax credits for the year ended December 31, 2016 is $145,000 (2015 - $196,000).

Income Taxes

12 Months Ended

Dec. 31, 2016

Income Tax Disclosure [Abstract]

Income taxes

Income tax (recovery) expense varies from the amounts that would be computed by applying the combined Canadian federal and provincial income tax rate of 26% (2015 - 26%; 2014 – 26%) to the loss before income taxes as shown in the following tables:



	Year ended December 31,
	2016			2015			2014
Computed taxes (recoveries) at Canadian federal and provincial tax rates	$	(127,183	)	$	(20,100	)	$	(10,097	)
Permanent and other differences	(3,598		)	769			2,594
Change in valuation allowance - other	17,043			3,675			6,599
Difference due to income taxed at foreign rates	(47,962		)	(7,874		)	—
Stock-based compensation	9,727			7,345			904
Impairment of goodwill	46,971			—			—
Deferred income tax recovery	$	(105,002	)	$	(16,185	)	$	—

As at December 31, 2016, the Company has investment tax credits available to reduce Canadian federal income taxes of $10,245,000 (December 31, 2015 - $7,969,000) and provincial income taxes of $5,337,000 (December 31, 2015 - $3,869,000), expiring between 2027 and 2036. In addition, the Company has research and development credits of $1,454,000 available for indefinite carry-forward, which can be used to reduce future taxable income in the U.S.

At December 31, 2016, the Company has scientific research and experimental development expenditures of $65,332,000 (December 31, 2015 - $51,823,000) available for indefinite carry-forward and $71,460,000 (December 31, 2015 - $24,745,000) of net operating losses due to expire between 2027 and 2035 and which can be used to offset future taxable income in Canada.

As at December 31, 2016, the Company has $14,621,000 of net operating losses due to expire between 2030 and 2036, which can be used to offset future taxable income in the U.S. Future use of a portion of the U.S. loss carry-forwards is subject to limitations under the Internal Revenue Code Section 382. As a result of ownership changes occurring on October 1, 2014 and March 4, 2015, the Company's ability to use these losses may be limited. Losses incurred to date may be further limited if a subsequent change in control occurs.

On November 23, 2011, the Company was registered as a corporation under the Business Activity Act in the province of British Columbia. Under this program, provincial corporation tax charged on foreign income earned from the Company’s patents will be eligible for a 75% tax refund up to a maximum of C$8,000,000.

Significant components of the Company’s deferred tax assets and liabilities are shown below:



	As at December 31,
	2016			2015
Deferred tax assets (liabilities):
Non-capital loss carryforwards	$	24,275		$	13,932
Research and development deductions	16,986			13,474
Book amortization in excess of tax	451			2,142
Share issue costs	486			777
Revenue recognized for tax purposes in excess of revenue recognized for accounting purposes	410			281
Tax value in excess of accounting value in lease inducements	58			77
Federal investment tax credits	8,630			6,303
Provincial investment tax credits	5,270			3,879
In-process research and development	(41,263		)	(146,324		)
Upfront license fees	536			629
Other	1,435			—
Total deferred tax assets (liabilities)	17,274			(104,830		)
Valuation allowance	(58,537		)	(41,494		)
Net deferred tax assets (liabilities)	$	(41,263	)	$	(146,324	)

Loan Payable	12 Months Ended
Loan Payable	Dec. 31, 2016
Debt Disclosure [Abstract]
Loan Payable	Loan payable On December 27, 2016, the Company obtained a loan of $12,001,000 from Wells Fargo in the form of a promissory note for the purpose of financing its operations, including the expansion of laboratory facilities for its U.S. operations. The loan accrues interest daily based on an interest rate with a variable and fixed component. The variable component is the one-month London Interbank Offered Rate (LIBOR), and the fixed component is a margin of 1.25% per annum. The carrying value of the loan is recorded at the principal plus any accrued interest not yet paid. The loan is due on December 27, 2019. The loan is secured by the Company's cash of $12,601,000, and is restricted from use until the loan has been settled in full. The Company invested the restricted cash in a two-year fixed certificate of deposit with Wells Fargo (see note 2) and is presented as restricted investment in the Company's balance sheet for the period ended December 31, 2016.

Contingencies and Commitments

12 Months Ended

Dec. 31, 2016

Commitments and Contingencies Disclosure [Abstract]

Contingencies and commitments

Property lease

On August 9, 2016, the Company signed a lease agreement for 701 Veterans Circle, Warminster, Pennsylvania. The facility has approximately 35,000 square feet of laboratory and office space. Renovations commenced in October 2016 and, once completed, this facility will replace the current Doylestown, Pennsylvania facility. The term of the lease is 10.6 years and expires on April 30, 2027, with the option to extend for up to two 5 -year terms. The estimated total facility commitment, including operating costs, is approximately $6,900,000.

The total minimum rent and estimated operating cost commitment, net of lease inducements, for both our head office in Burnaby and new Warminster facility is as follows:



Year ended December 31, 2017	$	1,475,444
Year ended December 31, 2018	1,539,323
Year ended December 31, 2019	1,203,863
Year ended December 31, 2020	656,469
Year ended December 31, 2021 and after	4,486,194
	$	9,361,293

The Company’s lease expense, for the year ended December 31, 2016 of $1,341,000 has been recorded in the consolidated statements of operations and comprehensive loss (2015 of $1,158,000; 2014 of $1,133,000).

Product development partnership with the Canadian Government

The Company entered into a Technology Partnerships Canada (TPC) agreement with the Canadian Federal Government on November 12, 1999. Under this agreement, TPC agreed to fund 27% of the costs incurred by the Company, prior to March 31, 2004, in the development of certain oligonucleotide product candidates up to a maximum contribution from TPC of $7,179,000 (C$9,330,000). As at December 31, 2016, a cumulative contribution of $2,756,000 (C$3,702,000) had been received and the Company does not expect any further funding under this agreement. In return for the funding provided by TPC, the Company agreed to pay royalties on the share of future licensing and product revenue, if any, that is received by the Company on certain non-siRNA oligonucleotide product candidates covered by the funding under the agreement. These royalties are payable until a certain cumulative payment amount is achieved or until a pre-specified date. In addition, until a cumulative amount equal to the funding actually received under the agreement has been paid to TPC, the Company agreed to pay 2.5% royalties on any royalties the Company receives for Marqibo. For the year ended December 31, 2016, the Company earned royalties on Marqibo sales in the amount of $212,000 (see note 4(e)), resulting in $5,000 recorded by the Company as royalty payable to TPC (2015 - $6,000; 2014 -$5,000). The cumulative amount paid or accrued up to December 31, 2016 was $17,000, resulting in the contingent amount due to TPC being $2,741,000 (C$3,680,000).

Arbitration with the University of British Columbia (“UBC”)

Certain early work on lipid nanoparticle delivery systems and related inventions was undertaken at UBC. These inventions are licensed to the Company by UBC under a license agreement, initially entered in 1998 as amended in 2001, 2006 and 2007. The Company has granted sublicenses under the UBC license to Alnylam as well as to Talon. Alnylam has in turn sublicensed back to the Company under the licensed UBC patents. In 2009, the Company entered into a supplemental agreement with UBC, Alnylam and Acuitas, in relation to a separate research collaboration to be conducted among UBC, Alnylam and Acuitas to which the Company has license rights. The settlement agreement signed in late 2012 to resolve the litigation among the Company, Alnylam, and Acuitas, provided for the effective termination of all obligations under such supplemental agreement as between and among all litigants.

On November 10, 2014, UBC filed a notice of arbitration against the Company and on January 16, 2015, filed a Statement of Claim, which alleges entitlement to $3,500,000 in allegedly unpaid royalties based on publicly available information, and an unspecified amount based on non-public information. UBC also seeks interest and costs, including legal fees. The Company continues to dispute UBC’s allegations. The proceeding has been bifurcated into phases, beginning with a liability phase, addressing UBC’s Claims and Arbutus’ Counterclaim, that is presently set for hearing from June 19-30, 2017. However, the Company notes that arbitration is subject to inherent uncertainty and an arbitrator could rule against the Company. The Company has not recorded an estimate of the possible loss associated with this arbitration, due to the uncertainties related to both the likelihood and amount of any possible loss or range of loss. However, the defense of arbitration and related matters are costly and may divert the attention of the Company’s management and other resources that would otherwise be engaged in other activities. Costs related to the arbitration have been recorded in the statement of operations and comprehensive loss by the Company as incurred.

Contingent consideration from Arbutus Inc. acquisition of Enantigen and License Agreements between Enantigen and Baruch S. Blumberg Institute (Blumberg) and Drexel

In October 2014, Arbutus Inc. acquired all of the outstanding shares of Enantigen pursuant to a stock purchase agreement. Through this transaction, Arbutus Inc. acquired a HBV surface antigen secretion inhibitor program and a capsid assembly inhibitor program, each of which are now assets of Arbutus, following the Company’s merger with Arbutus Inc. in March 2015.

Under the stock purchase agreement, Arbutus Inc. agreed to pay up to a total of $21,000,000 to Enantigen’s selling stockholders upon the achievement of certain triggering events related to HBV therapies. The first triggering event is enrollment of the first patient in a Phase 1b clinical trial in HBV patients.

The regulatory, development and sales milestone payments had an estimated fair value of approximately $6,727,000 as at the date of acquisition of Arbutus Inc., and were treated as contingent consideration payable in the purchase price allocation. The contingent consideration was calculated based on information available at the date of acquisition, using a probability weighted assessment of the likelihood the milestones would be met and the estimated timing of such payments, and then the potential contingent payments were discounted to their present value using a probability adjusted discount rate that reflects the early stage nature of the development program, time to complete the program development, and overall biotech indices.

Contingent consideration is a financial liability and measured at its fair value at each reporting period, with any changes in fair value from the previous reporting period recorded in the statement of operations and comprehensive loss. For the period ended December 31, 2016, the Company performed an evaluation of the fair value of the contingent consideration using the probability weighted assessment of likelihood of milestone payments as described above. The Company determined the fair value of the contingent consideration has increased by $1,568,000 to $9,065,000 and the increase in fair value has been recorded in other losses in the statement of operations and comprehensive loss for the year ended December 31, 2016.

Drexel and Blumberg

In February 2014, Arbutus Inc. entered into a license agreement with Blumberg and Drexel that granted an exclusive, worldwide, sub-licensable license to three different compound series: cccDNA inhibitors, capsid assembly inhibitors and HCC inhibitors.

In partial consideration for this license, Arbutus Inc. paid a license initiation fee of $150,000 and issued warrants to Blumberg and Drexel. The warrants were exercised in 2014. Under this license agreement, Arbutus Inc. also agreed to pay up to $3,500,000 in development and regulatory milestones per licensed compound series, up to $92,500,000 in sales performance milestones per licensed product, and royalties in the mid-single digits based upon the proportionate net sales of licensed products in any commercialized combination. The Company is obligated to pay Blumberg and Drexel a double digit percentage of all amounts received from the sub-licensees, subject to customary exclusions.

In November 2014, Arbutus Inc. entered into an additional license agreement with Blumberg and Drexel pursuant to which it received an exclusive, worldwide, sub-licensable license under specified patents and know-how controlled by Blumberg and Drexel covering epigenetic modifiers of cccDNA and STING agonists. In consideration for these exclusive licenses, Arbutus Inc. made an upfront payment of $50,000. Under this agreement, the Company will be required to pay up to $1,000,000 for each licensed product upon the achievement of a specified regulatory milestone and a low single digit royalty, based upon the proportionate net sales of compounds covered by this intellectual property in any commercialized combination. The Company is also obligated to pay Blumberg and Drexel a double digit percentage of all amounts received from its sub-licensees, subject to exclusions.

Research Collaboration and Funding Agreement with Blumberg

In October 2014, Arbutus Inc. entered into a research collaboration and funding agreement with Blumberg under which the Company will provide $1,000,000 per year of research funding for three years, renewable at the Company’s option for an additional three years, for Blumberg to conduct research projects in HBV and liver cancer pursuant to a research plan to be agreed upon by the parties. Blumberg has exclusivity obligations to Arbutus with respect to HBV research funded under the agreement. In addition, the Company has the right to match any third party offer to fund HBV research that falls outside the scope of the research being funded under the agreement. Blumberg has granted the Company the right to obtain an exclusive, royalty bearing, worldwide license to any intellectual property generated by any funded research project. If the Company elects to exercise its right to obtain such a license, the Company will have a specified period of time to negotiate and enter into a mutually agreeable license agreement with Blumberg. This license agreement will include the following pre negotiated upfront, milestone and royalty payments: an upfront payment in the amount of $100,000; up to $8,100,000 upon the achievement of specified development and regulatory milestones; up to $92,500,000 upon the achievement of specified commercialization milestones; and royalties at a low single to mid-single digit rates based upon the proportionate net sales of licensed products from any commercialized combination.

On June 5, 2016, the Company and Blumberg entered into an amended and restated research collaboration and funding agreement, primarily to: (i) increase the annual funding amount to Blumberg from $1,000,000 to $1,100,000; (ii) extend the initial term through to October 29, 2018; (iii) provide an option for the Company to extend the term past October 29, 2018 for two additional one year terms; and (iv) expand the Company's exclusive license under the Agreement to include the sole and exclusive right to obtain an exclusive, royalty-bearing, worldwide and all-fields license under Blumberg's rights in certain other inventions described in the agreement.

NeuroVive Pharmaceutical AB (“NeuroVive”)

In September 2014, Arbutus Inc. entered into a license agreement with NeuroVive that granted them an exclusive, worldwide, sub-licensable license to develop, manufacture and commercialize, for the treatment of HBV, oral dosage form sanglifehrin based cyclophilin inhibitors (including OCB-030).

In 2015, the Company discontinued the OCB-30 development program based on significant research and analysis. In July 2016, the Company provided NeuroVive with a notice of termination of the license agreement. The parties agreed to terminate the agreement in October 2016.

Cytos Biotechnology Ltd (“Cytos”)

On December 30, 2014, Arbutus Inc. entered into an exclusive, worldwide, sub-licensable (subject to certain restrictions with respect to licensed viral infections other than hepatitis) license to six different series of compounds. The licensed compounds are Qbeta-derived virus-like particles that encapsulate TLR9, TLR7 or RIG-I agonists and may or may not be conjugated with antigens from the hepatitis virus or other licensed viruses. The Company has an option to expand this license to include additional viral infections other than influenza and Cytos will retain all rights for influenza, all non-viral infections, and all viral infections (other than hepatitis) for which it has not exercised its option.

In partial consideration for this license, the Company is obligated to pay Cytos up to a total of $67,000,000 for each of the six licensed compound series upon the achievement of specified development and regulatory milestones; for hepatitis and each additional licensed viral infection, up to a total of $110,000,000 upon the achievement of specified sales performance milestones; and tiered royalty payments in the high-single to low-double digits, based upon the proportionate net sales of licensed products in any commercialized combination. In June 2016, the Company discontinued the TLR9 development program based on significant levels of research and analysis (refer to note 3 above).

Concentrations of Business Risk

12 Months Ended

Dec. 31, 2016

Risks and Uncertainties [Abstract]

Concentrations of business risk

Credit risk

Credit risk is defined by the Company as an unexpected loss in cash and earnings if a collaborative partner is unable to pay its obligations in due time. The Company’s main source of credit risk is related to its accounts receivable balance which principally represents temporary financing provided to collaborative partners in the normal course of operations.

The Company does not currently maintain a provision for bad debts as the majority of accounts receivable are from collaborative partners or government agencies and are considered low risk.

The carrying amount of financial assets represents the maximum credit exposure. The maximum exposure to credit risk at December 31, 2016 was the accounts receivable balance of $273,000 (2015 - $1,008,000).

All accounts receivable balances were current as at December 31, 2016 and December 31, 2015.

Significant collaborators and customers risk

We depend on a small number of collaborators and customers for a significant portion of our revenues (see note 4).

Liquidity Risk

Liquidity risk results from the Company’s potential inability to meet its financial liabilities, for example payments to suppliers. The Company ensures sufficient liquidity through the management of net working capital and cash balances.

The Company’s liquidity risk is primarily attributable to its cash and cash equivalents, and short-term investments. The Company limits exposure to liquidity risk on its liquid assets through maintaining its cash and cash equivalent, and short-term investments with high-credit quality financial institutions. Due to the nature of these investments, the funds are available on demand to provide optimal financial flexibility.

The Company believes that its current sources of liquidity are sufficient to cover its likely applicable short term cash obligations. The Company’s financial obligations include accounts payable and accrued liabilities which generally fall due within 45 days. The net liquidity of the Company is considered to be the cash and cash equivalents and short-term investments less accounts payable and accrued liabilities.



	December 31, 2016			December 31, 2015
Cash, cash equivalents and short-term investments	$	130,559		$	181,304
Less: Accounts payable and accrued liabilities	$	(9,910	)	$	(8,827	)
	$	120,649		$	172,477

Foreign currency risk

The results of the Company’s operations are subject to foreign currency transaction and translation risk as the Company’s revenues and expenses are denominated in both Canadian and US dollars. The fluctuation of the Canadian dollar in relation to the US dollar will consequently have an impact upon the Company’s reported income or loss and may also affect the value of the Company’s assets, liabilities, and the amount of shareholders’ equity both as recorded in the Company’s financial statements, in the US functional currency, and as reported, for presentation purposes, in the US dollar.

The Company manages its foreign currency risk by using cash received in a currency to pay for expenses in that same currency, whenever possible. The Company’s policy to maintain US and Canadian dollar cash and investment and short-term investment balances based on long term forecasts of currency needs thereby creating a natural currency hedge.

The Company has not entered into any agreements or purchased any instruments to hedge possible currency risks. The Company’s exposure to Canadian dollar currency expressed in US dollars was as follows:



(in US$)	December 31, 2016
Cash and cash equivalents and short-term investments	$	43,094
Accounts receivable	289
Accrued revenue	128
Accounts payable and accrued liabilities	(3,238		)
	$	40,273

An analysis of the Company’s sensitivity to foreign currency exchange rate movements is not provided in these financial statements as the Company’s Canadian dollar cash holdings and expected Canadian dollar revenues are sufficient to cover Canadian dollar expenses for the foreseeable future.

Interim Financial Data (Unaudited)

12 Months Ended

Dec. 31, 2016

Quarterly Financial Information Disclosure [Abstract]

Interim financial data (unaudited)



	2016
	Q1			Q2			Q3			Q4			Total
Revenue	$	603		$	309		$	774		$	(195	)	$	1,491
Loss from operations	(19,977		)	(195,248		)	(18,975		)	(257,439		)	(491,639		)
Net loss	$	(15,874	)	$	(130,000	)	$	(19,595	)	$	(218,695	)	$	(384,164	)
Basic and diluted net loss per share	$	(0.31	)	$	(2.47	)	$	(0.37	)	$	(4.05	)	$	(7.24	)



	2015
	Q1			Q2			Q3			Q4			Total
Revenue	$	4,682		$	3,440		$	4,065		$	12,686		$	24,873
Loss from operations	(18,006		)	(14,420		)	(58,138		)	(11,758		)	(102,322		)
Net loss	$	(11,989	)	$	(14,886	)	$	(28,982	)	$	(5,264	)	$	(61,121	)
Basic and diluted net loss per share	$	(0.40	)	$	(0.27	)	$	(0.57	)	$	(0.10	)	$	(1.34	)

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2016
Subsequent Events [Abstract]
Subsequent events	Subsequent events (a) Termination of License Agreement with Acuitas In December 2013, the Company entered into a cross-license agreement with Acuitas Therapeutics Inc., or Acuitas. The terms of the cross-license agreement provided Acuitas with access to certain of the Company's earlier intellectual property generated prior to April 2010 for a specific field. On August 29, 2016, the Company provided Acuitas with notice that it considered Acuitas to be in material breach of the cross-license agreement. The cross-license agreement provides that it may be terminated upon any material breach by the other party 60 days after receipt of written notice of termination describing the material breach in reasonable detail. On October 25, 2016, Acuitas filed a Notice of Civil Claim in the Supreme Court of British Columbia seeking an order that the Company perform its obligations under the Cross License Agreement, for damages ancillary to specific performance, injunctive relief, interest and costs. The Company disputes Acuitas’ position and have not recorded an estimate of the possible loss associated with this claim, due to the uncertainties related to both the likelihood and amount of any possible loss or range of loss. The Company has filed its response within the time frame prescribed by the Court. On February 8, 2017, the Company announced that the Supreme Court of British Columbia granted Arbutus' request for a pre-trial injunction against Acuitas, preventing Acuitas from further sublicensing of Arbutus' lipid nanoparticle (LNP) technology until the end of October 2017, or further order of the Court. Under the terms of the pre-clinical injunction, Acuitas is prevented from entering into any new agreements which include sublicensing of Arbutus' LNP. (b) LNP License with Alexion On March 16, 2017, the Company announced that it had entered into an agreement to license its LNP delivery technology to Alexion. Under the terms of the agreement, the Company will receive $7,500,000 up front and subsequent payments up to $75,000,000 for the achievement of development, regulatory and commercial milestones as well as future royalties.

Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2016

Accounting Policies [Abstract]

Basis of presentation

Foreign currency translation and functional currency conversion

Use of estimates

Cash and cash equivalents

Short-term and long-term investments

Loan payable and restricted cash (investment)

Fair value of financial instruments

We measure certain financial instruments and other items at fair value.


•	Level 1 inputs are quoted market prices for identical instruments available in active markets.


•	Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability either directly or indirectly. If the asset or liability has a contractual term, the input must be observable for substantially the full term. An example includes quoted market prices for similar assets or liabilities in active markets.


•	Level 3 inputs are unobservable inputs for the asset or liability and will reflect management’s assumptions about market assumptions that would be used to price the asset or liability.

Property and equipment



	Useful life (years)
Laboratory equipment		5
Computer and office equipment	2	—	5
Furniture and fixtures		5

Leasehold improvements are depreciated over their estimated useful lives but in no case longer than the lease term, except where lease renewal is reasonably assured.

Impairment of property and equipment

Goodwill and intangible assets

The costs incurred in establishing and maintaining patents for intellectual property developed internally are expensed in the period incurred.

Revenue recognition

Leases and lease inducements

All other leases are accounted for as operating leases wherein rental payments are expensed as incurred.

Research and development costs

Income or loss per share

Government grants and refundable investment tax credits

Deferred income taxes

Equity and liability classified stock option awards

Equity classified stock option awards

The fair value of equity classified stock options is measured at the grant date and amortized on a straight-line basis over the vesting period.

Liability-classified stock option awards

Replacement awards

Warrants

Segment information

Recent accounting pronouncements

Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Accounting Policies [Abstract]

Schedule of assets and liabilities measured at fair value on a recurring basis



	Level 1		Level 2	Level 3		December 31, 2016
Assets
Cash and cash equivalents	$	23,413	—	—		$	23,413
Short-term investments	107,146		—	—		107,146
Restricted investment	12,601		—	—		12,601
Total	$	143,160	—	—		$	143,160
Liabilities
Warrants	—		—	$	107	$	107
Liability-classified stock option awards	—		—	553		553
Contingent consideration	—		—	9,065		9,065
Total	—		—	9,725		$	9,725



	Level 1		Level 2	Level 3		December 31, 2015
Assets
Cash and cash equivalents	$	166,779	—	—		$	166,779
Guaranteed investment certificates	14,525		—	—		14,525
Term deposit	10,070		—	—		10,070
Total	$	191,374	—	—		$	191,374
Liabilities
Warrants	—		—	$	883	$	883
Contingent consideration	—		—	7,497		7,497
Total	—		—	$	8,380	$	8,380

Changes in fair value of warrants

The following table presents the changes in fair value of the Company’s warrants:



	Liability at beginning of the period		Fair value of warrants exercised in the period			Increase (decrease) in fair value of warrants			Foreign exchange loss			Liability at end of the period
Year ended December 31, 2014	$	5,379	$	(10,208	)	$	10,383		$	(455	)	$	5,099
Year ended December 31, 2015	$	5,099	$	(334	)	$	(3,341	)	$	(541	)	$	883
Year ended December 31, 2016	$	883	$	(247	)	$	(529	)	$	—		$	107

Changes in fair value of liability-classified stock options

The following table presents the changes in fair value of the Company’s liability-classified stock option awards:



	Reclassification of equity to liability ⁽¹⁾		Fair value of liability-classified stock option awards exercised in the period			Increase (decrease) in fair value of liability			Liability at end of the period
Year ended December 31, 2016	$	1,909	$	(54	)	$	(1,302	)	$	553

(1) Upon functional currency conversion on January 1, 2016 - see functional currency conversion above.

Changes in fair value of contingent consideration

The following table presents the changes in fair value of the Company’s contingent consideration:



	Contingent consideration at beginning of the period		Increase in fair value of contingent consideration		Contingent consideration at end of the period
Year ended December 31, 2015⁽¹⁾	$	6,727	$	770	$	7,497
Year ended December 31, 2016	$	7,497	$	1,568	$	9,065

(1) As at acquisition date of March 4, 2015.

Property and equipment estimated useful lives

The Company records depreciation using the straight-line method over the estimated useful lives of the capital assets as follows:



	Useful life (years)
Laboratory equipment		5
Computer and office equipment	2	—	5
Furniture and fixtures		5

Schedule of basic and diluted net income (loss) per common share

The following table sets out the computation of basic and diluted net income (loss) per common share:



	For the year ended December 31
	2016			2015			2014
Numerator:
Net loss	$	(384,164	)	$	(61,121	)	$	(38,837	)
Denominator:
Weighted average number of common shares	53,074,401			45,462,324			21,603,136
Basic income (loss) per common share	$	(7.24	)	$	(1.34	)	$	(1.80	)
Diluted income (loss) per common share	$	(7.24	)	$	(1.34	)	$	(1.80	)

Impairment Evaluations For Intangible Assets and Goodwill (Tables)

12 Months Ended

Dec. 31, 2016

Goodwill and Intangible Assets Disclosure [Abstract]

Summary of carrying values, net of impairment of the intangible assets

The following table summarizes the carrying values, net of impairment of the intangible assets as at December 31, 2016:



Year ended December 31	2016		2015
IPR&D – Immune Modulators	40,798		183,103
IPR&D – Antigen Inhibitors	14,811		36,437
IPR&D – cccDNA Sterilizers	43,836		133,102
Total IPR&D	$	99,445	$	352,642

Collaborations, Contracts and Licensing Agreements (Tables)

12 Months Ended

Dec. 31, 2016

Deferred Revenue Disclosure [Abstract]

Schedule of revenue recognized under collaborations, contracts and licensing agreements

The following tables set forth revenue recognized under collaborations, contracts and licensing agreements:



	Year ended December 31
	2016		2015		2014
Collaborations and contracts
DoD (a)	$	—	$	6,764	$	8,407
Monsanto (b)	—		4,725		1,080
BMS (c)	—		—		1,741
Dicerna (d)	229		1,820		510
Total research and development collaborations and contracts	229		13,309		11,738
Licensing fees, milestone and royalty payments
Monsanto licensing fees and milestone payments (b)	—		10,256		2,744
Dicerna licensing fee (d)	1,066		1,053		131
Other milestone and royalty payments (e)	196		255		340
Total licensing fees, milestone and royalty payments	1,262		11,564		3,215
Total revenue	$	1,491	$	24,873	$	14,953

(a) Contract with United States Government’s Department of Defense (“DoD”) to develop TKM-Ebola

On July 14, 2010, the Company signed a contract with the DoD to advance TKM-Ebola, an RNAi therapeutic utilizing the Company’s lipid nanoparticle technology to treat Ebola virus infection.

(b) Option and Services Agreements with Monsanto Company (“Monsanto”)

Revenue from the May 10, 2010 agreement with BMS is being recognized as the Company produces the related LNP batches.

(d) License and Development and Supply Agreement with Dicerna Pharmaceuticals, Inc. (“Dicerna”)

(e) Agreements with Spectrum Pharmaceuticals, Inc. (“Spectrum”)

Schedule of deferred collaborations and contracts revenue

(a) Contract with United States Government’s Department of Defense (“DoD”) to develop TKM-Ebola

On July 14, 2010, the Company signed a contract with the DoD to advance TKM-Ebola, an RNAi therapeutic utilizing the Company’s lipid nanoparticle technology to treat Ebola virus infection.

(b) Option and Services Agreements with Monsanto Company (“Monsanto”)

(d) License and Development and Supply Agreement with Dicerna Pharmaceuticals, Inc. (“Dicerna”)

The following table sets forth deferred collaborations and contracts revenue:



	December 31, 2016		December 31, 2015
DoD (a)	$	15	$	15
Monsanto current portion (b)	—		—
Dicerna current portion (d)	—		853
Deferred revenue, current portion	15		868
Monsanto long-term portion (b)	—		—
Dicerna long-term portion (d)	—		213
Total deferred revenue	$	15	$	1,081

Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2016

Property, Plant and Equipment [Abstract]

Schedule of property and equipment



December 31, 2016	Cost		Accumulated depreciation			Net book value
Lab equipment	$	7,894	$	(4,305	)	$	3,589
Leasehold improvements	4,928		(4,454		)	474
Computer hardware and software	2,103		(1,665		)	438
Furniture and fixtures	374		(314		)	60
Assets under construction	$	2,384	$	—		$	2,384
	$	17,683	$	(10,738	)	$	6,945



December 31, 2015	Cost		Accumulated depreciation			Net book value
Lab equipment	$	5,910	$	(3,748	)	$	2,162
Leasehold improvements	4,681		(4,189		)	492
Computer hardware and software	2,014		(1,487		)	527
Furniture and fixtures	307		(305		)	2
	$	12,912	$	(9,729	)	$	3,183

Share Capital (Tables)

12 Months Ended

Dec. 31, 2016

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of warrant activity

The following table summarizes the Company’s warrant activity for the years ended December 31, 2016 and 2015:



	Common shares purchasable upon exercise of warrants		Weighted average exercise price (C$)		Weighted average exercise price (US$)		Range of exercise prices (C$)				Range of exercise prices (US$)					Weighted average remaining contractual life (years)	Aggregate intrinsic value (C$)		Aggregate intrinsic value (US$)
Balance, December 31, 2014	398,250		$	2.95	$	2.67	$2.60	—	$	3.35	$2.35		—	$	3.03	1.8	$	5,902	$	5,343
Exercised	(18,750	)	2.88		2.25		2.60	—	3.35		2.03		—	2.62
Balance, December 31, 2015	379,500		$	2.95	$	2.13	$2.60	—	$	3.35	$2.03		—	$	2.62	0.8	1,217		$	879
Exercised	(170,500	)	3.35		2.53		3.35	—	3.35		2.53		—	2.53
Expired	(8,000	)	3.35		2.53		3.35	—	3.35		2.53		—	2.53
Balance, December 31, 2016	201,000		$	2.60	$	1.94	$2.60	—	$	2.60	$	1.94	—	$	1.94	0.2	$	139	$	104

Schedule of weighted average Black-Scholes option-pricing assumptions and resultant fair values

The weighted average Black-Scholes option-pricing assumptions and the resultant fair values are as follows for warrants outstanding at December 31, 2016 and 2015 are as follows:



	As at December 31
	2016			2015
Dividend yield	—		%	—		%
Expected volatility	41.95		%	49.07		%
Risk-free interest rate	0.76		%	0.48		%
Expected average term (years)	0.2 years			0.6 years
Fair value of warrants outstanding	$	0.53		$	2.33
Aggregate fair value of warrants outstanding	$	107		$	883
Number of warrants outstanding	201,000			379,500

Schedule of stock option activity for the Arbutus Plans

Equity-classified stock option activity:



	Number of optioned common shares		Weighted average exercise price (C$)		Weighted average exercise price (US$)		Aggregate intrinsic value (C$)		Aggregate intrinsic value (US$)
Balance, December 31, 2013	1,730,765		$	4.45	$	4.32	$	7,030	$	6,826
Options granted	431,125		13.63		12.34
Options exercised	(622,752	)	4.62		4.18		7,650		6,926
Options forfeited, canceled or expired	(9,000	)	8.20		7.42
Balance, December 31, 2014	1,530,138		6.95		6.29		16,573		15,004
Options granted	1,309,625		N/A		16.57
Options exercised	(398,293	)	5.03		3.93		6,887		5,386
Options forfeited, canceled or expired	(151,207	)	19.29		15.09
Balance, December 31, 2015	2,290,263		15.53		11.22		1,376		994
Options reclassified to liability¹	(718,333	)	7.24		5.23		836		604
Options granted	1,789,599		N/A		3.89
Options exercised	(56,125	)	2.88		2.18		160		121
Options forfeited, canceled or expired	(394,200	)	13.49		10.18
Balance, December 31, 2016	2,911,204		$	11.45	$	8.53	$	75	$	56


1.	Due to the change in the Company's functional currency as of January 1, 2016, certain stock option awards with exercise prices denominated in Canadian dollars changed from equity classification to liability classification - see note 2.

Summary of stock options outstanding by exercise price range

The following table summarizes information pertaining to stock options outstanding at December 31, 2016 under the Arbutus Plans:



			Options outstanding December 31, 2016				Options exercisable December 31, 2016
Range of Exercise prices (US$)			Number of options outstanding	Weighted average remaining contractual life (years)	Weighted average exercise price (US$)		Number of options exercisable	Weighted average exercise price (US$)
$1.12	to	$3.05	121,725	6.4	2.23		75,225	1.78
$3.28	to	$3.84	209,033	8.4	3.64		62,033	3.69
$3.94	to	$3.94	1,369,849	9.2	3.94		—	N/A
$3.98	to	$8.64	81,713	8.1	4.49		71,380	4.38
$9.11	to	$9.73	118,843	7.8	9.44		91,375	9.44
$9.88	to	$13.89	201,000	8.1	13.42		74,271	13.26
$17.57	to	$17.57	809,041	8.2	17.57		324,957	17.57
$1.12	to	$17.57	2,911,204	8.6	$	8.53	699,241	$	11.77

Schedule of non-vested stock option activity

A summary of the Company’s non-vested stock option activity and related information for the year ended December 31, 2016 is as follows:



	Number of optioned common shares		Weighted average fair value (C$)		Weighted average fair value (US$)
Non-vested at December 31, 2015	1,351,541		$	15.69	$	11.34
Options reclassified to liability-options¹	(134,000	)	10.80		7.80
Options granted	1,789,599		5.15		3.89
Options vested	(472,479	)	14.20		10.72
Non-vested options forfeited	(322,698	)	9.70		7.33
Non-vested at December 31, 2016	2,211,963		$	7.17	$	5.34

1. Non-vested liability-classified stock options as at January 1, 2016

Schedule of weighted average option pricing assumptions and the resultant fair values

The weighted average option pricing assumptions for options granted during the year are as follows:



	Year ended December 31
	2016		2015		2014
Dividend yield	—	%	—	%	—	%
Expected volatility	77.99	%	76.88	%	101.08	%
Risk-free interest rate	0.90	%	1.10	%	2.25	%
Expected average option term	7.3 years		7.5 years		8.8 years

Schedule of allocation of stock-based compensation

The total stock-based compensation has been recorded in the consolidated statement of operations and comprehensive income (loss) as follows:



	Year ended December 31
	2016		2015		2014
Research, development, collaborations and contracts expenses	$	11,155	$	7,868	$	2,343
General and administrative expenses	28,004		14,225		940
Total	$	39,159	$	22,093	$	3,283

Protiva Option Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of option activity

The following table sets forth outstanding options under the Protiva Option Plan:



	Number of Protiva Options		Equivalent number of Company common shares		Weighted average exercise price (C$)		Weighted average exercise price (US$)
Balance, December 31, 2013	472,885		319,274		$	0.30	0.29
Options exercised	(38,145	)	(25,754	)	0.30		0.27
Options forfeited, canceled or expired	(1,000	)	(675	)	0.30		0.27
Balance, December 31, 2014	433,740		292,845		0.30		0.27
Options exercised	(358,675	)	(242,164	)	0.30		0.23
Options forfeited, canceled or expired	(8,065	)	(5,445	)	0.30		0.23
Balance, December 31, 2015	67,000		45,236		0.30		0.22
Options exercised	(21,000	)	(14,178	)	0.30		0.23
Options forfeited, canceled or expired	—		—		—		N/A
Balance, December 31, 2016	46,000		31,058		$	0.30	$	0.22

OnCore Option Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of non-vested stock option activity

A summary of the OnCore Option Plan's non-vested stock option activity and related information for the year ended December 31, 2016 is as follows:



	Number of OnCore Options		Equivalent number of Company common shares		Weighted average fair value (US$)
Non-vested at December 31, 2015	96,382		97,063		$	16.42
Options vested	(33,331	)	(33,566	)	16.80
Non-vested options forfeited	—		—		N/A
Non-vested at December 31, 2016	63,051		63,497		$	16.80

Schedule of option activity

The following table sets forth outstanding options under the OnCore Option Plan:



	Number of OnCore Options	Equivalent number of Company common shares	Weighted average exercise price (US$)
Balance, December 31, 2015	183,040	184,332	$	0.57
Options exercised	—	—	N/A
Options forfeited, canceled or expired	—	—	N/A
Balance, December 31, 2016	183,040	184,332	$	0.57

Liability classified stock options

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of weighted average Black-Scholes option-pricing assumptions and resultant fair values

The weighted average Black-Scholes option-pricing assumptions and the resultant fair values as at the reclassification date of January 1, 2016, and as at December 31, 2016, are presented in the following table:



	December 31,			January 1,
	2016			2016
Dividend yield	—		%	—		%
Expected volatility	66.18		%	97.78		%
Risk-free interest rate	0.88		%	0.86		%
Expected average term (years)	3.6			5.3
Fair value of options outstanding	$	0.87		$	3.33
Fair value of vested liability-classified options (in thousands)	$	553		$	1,909

Schedule of stock option activity for the Arbutus Plans

Stock option activity for liability options



	Number of optioned common shares		Weighted average exercise price (C$)		Weighted average exercise price (US$)		Aggregate intrinsic value (US$)
Balance, January 1, 2016	718,333		$	7.24	$	5.23	$	604
Options exercised	(30,000	)	3.00		2.30		54
Options forfeited, canceled or expired	(49,833	)	8.29		6.17		—
Balance, December 31, 2016	638,500		$	7.35	$	5.48	$	116

Summary of stock options outstanding by exercise price range

The following table summarizes information pertaining to liability options outstanding at December 31, 2016:



			Options outstanding December 31, 2016				Options exercisable December 31, 2016
Range of Exercise prices (US$)			Number of options outstanding	Weighted average remaining contractual life (years)	Weighted average exercise price (US$)		Number of options exercisable	Weighted average exercise price (US$)
$1.27	to	$1.79	120,000	3.7	$	1.48	120,000	$	1.48
$2.87	to	$3.84	120,000	3.6	3.42		120,000	3.42
$3.97	to	$4.28	74,000	1.6	4.22		74,000	4.22
$4.84	to	$6.18	76,250	0.7	5.83		76,250	5.83
$6.79	to	$6.79	150,000	6.8	6.79		150,000	6.79
$9.32	to	$12.21	98,250	6.0	11.53		83,500	11.44
$1.27	to	$12.21	638,500	4.2	$	5.48	623,750	$	5.32

Schedule of non-vested stock option activity

A summary of the Company's non-vested liability stock option activity and related information at December 31, 2016 is as follows:



	Number of optioned common shares		Weighted average fair value (US$)
Non-vested at January 1, 2016	134,000		$	3.61
Options vested	(93,250	)	0.67
Non-vested options forfeited	(26,000	)	0.04
Non-vested at December 31, 2016	14,750		$	0.92

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2016

Income Tax Disclosure [Abstract]

Schedule of effective income tax rate reconciliation



	Year ended December 31,
	2016			2015			2014
Computed taxes (recoveries) at Canadian federal and provincial tax rates	$	(127,183	)	$	(20,100	)	$	(10,097	)
Permanent and other differences	(3,598		)	769			2,594
Change in valuation allowance - other	17,043			3,675			6,599
Difference due to income taxed at foreign rates	(47,962		)	(7,874		)	—
Stock-based compensation	9,727			7,345			904
Impairment of goodwill	46,971			—			—
Deferred income tax recovery	$	(105,002	)	$	(16,185	)	$	—

Schedule of components of deferred tax assets

Significant components of the Company’s deferred tax assets and liabilities are shown below:



	As at December 31,
	2016			2015
Deferred tax assets (liabilities):
Non-capital loss carryforwards	$	24,275		$	13,932
Research and development deductions	16,986			13,474
Book amortization in excess of tax	451			2,142
Share issue costs	486			777
Revenue recognized for tax purposes in excess of revenue recognized for accounting purposes	410			281
Tax value in excess of accounting value in lease inducements	58			77
Federal investment tax credits	8,630			6,303
Provincial investment tax credits	5,270			3,879
In-process research and development	(41,263		)	(146,324		)
Upfront license fees	536			629
Other	1,435			—
Total deferred tax assets (liabilities)	17,274			(104,830		)
Valuation allowance	(58,537		)	(41,494		)
Net deferred tax assets (liabilities)	$	(41,263	)	$	(146,324	)

Concentrations of Business Risk (Tables)

12 Months Ended

Dec. 31, 2016

Risks and Uncertainties [Abstract]

Net liquidity

The net liquidity of the Company is considered to be the cash and cash equivalents and short-term investments less accounts payable and accrued liabilities.



	December 31, 2016			December 31, 2015
Cash, cash equivalents and short-term investments	$	130,559		$	181,304
Less: Accounts payable and accrued liabilities	$	(9,910	)	$	(8,827	)
	$	120,649		$	172,477

Schedule of exposure to US dollar currency expressed in Canadian dollars

The Company’s exposure to Canadian dollar currency expressed in US dollars was as follows:



(in US$)	December 31, 2016
Cash and cash equivalents and short-term investments	$	43,094
Accounts receivable	289
Accrued revenue	128
Accounts payable and accrued liabilities	(3,238		)
	$	40,273

Interim Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2016

Quarterly Financial Information Disclosure [Abstract]

Schedule of interim financial data (unaudited)



	2016
	Q1			Q2			Q3			Q4			Total
Revenue	$	603		$	309		$	774		$	(195	)	$	1,491
Loss from operations	(19,977		)	(195,248		)	(18,975		)	(257,439		)	(491,639		)
Net loss	$	(15,874	)	$	(130,000	)	$	(19,595	)	$	(218,695	)	$	(384,164	)
Basic and diluted net loss per share	$	(0.31	)	$	(2.47	)	$	(0.37	)	$	(4.05	)	$	(7.24	)



	2015
	Q1			Q2			Q3			Q4			Total
Revenue	$	4,682		$	3,440		$	4,065		$	12,686		$	24,873
Loss from operations	(18,006		)	(14,420		)	(58,138		)	(11,758		)	(102,322		)
Net loss	$	(11,989	)	$	(14,886	)	$	(28,982	)	$	(5,264	)	$	(61,121	)
Basic and diluted net loss per share	$	(0.40	)	$	(0.27	)	$	(0.57	)	$	(0.10	)	$	(1.34	)

Significant Accounting Policies - Narrative (Details) $ in Thousands	10 Months Ended	12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2016 USD ($) subsidiary shares	Dec. 31, 2015 USD ($) shares	Dec. 31, 2014 USD ($) shares	Mar. 04, 2016	Mar. 04, 2015 USD ($)
Accounting Policies [Abstract]
Wholly-owned subsidiaries \| subsidiary		2
Business Acquisition [Line Items]
Restricted investment, term		2 years
Interest rate on restricted investment		1.25%
Fair value of contingent consideration	$ 7,497	$ 9,065	$ 7,497			$ 6,727
Increase in fair value of contingent consideration	$ 770	$ 1,568	$ 770	$ 0
Anti-dilutive common shares excluded from calculation of income per common share (in shares) \| shares		4,645,864	2,899,331	2,221,233
Monsanto \| PADCo.
Business Acquisition [Line Items]
Business acquisition, percentage of outstanding shares acquired					100.00%

Significant Accounting Policies - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Mar. 04, 2015	Dec. 31, 2014	Dec. 31, 2013
Assets
Cash and cash equivalents	$ 23,413	$ 166,779
Short-term investments and guaranteed investment certificates	107,146	14,525
Restricted investment	12,601
Term deposit	0	10,070
Total Assets	143,160	191,374
Liabilities
Warrants	107	883		$ 5,099	$ 5,379
Liability-classified stock option awards	553
Contingent consideration	9,065	7,497	$ 6,727
Total Liabilities	9,725	8,380
Fair value, inputs, Level 1
Assets
Cash and cash equivalents	23,413	166,779
Short-term investments and guaranteed investment certificates	107,146	14,525
Restricted investment	12,601
Term deposit		10,070
Total Assets	143,160	191,374
Fair value, inputs, Level 3
Liabilities
Warrants	107	883
Liability-classified stock option awards	553
Contingent consideration	9,065	7,497
Total Liabilities	$ 9,725	$ 8,380

Significant Accounting Policies - Changes in Fair Value of the Company's Warrants (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Liabilities Measured on Recurring Basis [Roll Forward]
Liability at beginning of the period	$ 883	$ 5,099	$ 5,379
Fair value of warrants exercised in the period	(247)	(334)	(10,208)
Increase (decrease) in fair value of warrants	(529)	(3,341)	10,383
Foreign exchange loss	0	(541)	(455)
Liability at end of the period	$ 107	$ 883	$ 5,099

Significant Accounting Policies - Changes in Fair Value of Liability-Classified Stock Options (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)
Fair Value, Liabilities Measured on Recurring Basis [Roll Forward]
Liability at end of the period	$ 553
Liability classified stock options
Fair Value, Liabilities Measured on Recurring Basis [Roll Forward]
Liability at beginning of the period	1,909
Fair value of liability-classified stock option awards exercised in the period	(54)
Increase (decrease) in fair value of liability	(1,302)
Liability at end of the period	$ 553

Significant Accounting Policies - Changes in Fair Value of Contingent Consideration (Details) - USD ($) $ in Thousands	10 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration Fair Value, Liability [Roll Forward]
Contingent consideration at beginning of the period	$ 6,727	$ 7,497
Increase in fair value of contingent consideration	770	1,568	$ 770	$ 0
Contingent consideration at end of the period	$ 7,497	$ 9,065	$ 7,497

Significant Accounting Policies - Estimated Useful Lives (Details)	12 Months Ended
	Dec. 31, 2016
Laboratory equipment
Property, Plant and Equipment [Line Items]
Useful lives	5 years
Computer and office equipment \| Minimum
Property, Plant and Equipment [Line Items]
Useful lives	2 years
Computer and office equipment \| Maximum
Property, Plant and Equipment [Line Items]
Useful lives	5 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Useful lives	5 years

Significant Accounting Policies - Computation of Basic and Diluted Net Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Net loss	$ (218,695)	$ (19,595)	$ (130,000)	$ (15,874)	$ (5,264)	$ (28,982)	$ (14,886)	$ (11,989)	$ (384,164)	$ (61,121)	$ (38,837)
Weighted average number of common shares									53,074,401	45,462,324	21,603,136
Basic income (loss) per common share (in USD per share)									$ (7.24)	$ (1.34)	$ (1.80)
Diluted income (loss) per common share (in USD per share)									$ (7.24)	$ (1.34)	$ (1.80)

Impairment Evaluations For Intangible Assets and Goodwill - Narrative (Details) $ in Thousands		3 Months Ended	12 Months Ended
	Dec. 31, 2016 USD ($)	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($) reporting_unit	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Indefinite-lived Intangible Assets [Line Items]
Cumulative impairment charge against intangible assets and goodwill			$ 391,347
Impairment charge			253,197	$ 39,007	$ 0
Income tax benefit on impairment charge			$ 105,002	16,185	0
Number of reporting units \| reporting_unit			1
Goodwill	$ 24,364		$ 24,364	162,514
Goodwill impairment charge			138,150	$ 0	$ 0
Immune Modulator and cccDNA Sterilizer drug classes
Indefinite-lived Intangible Assets [Line Items]
Impairment charge	$ 96,873	$ 156,324	253,197
Income tax benefit on impairment charge			$ 105,002

Impairment Evaluations For Intangible Assets and Goodwill - Summary of carrying value of intangible assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Indefinite-lived Intangible Assets [Line Items]
Intangible assets	$ 99,445	$ 352,642
IPR&D – Immune Modulators
Indefinite-lived Intangible Assets [Line Items]
Intangible assets	40,798	183,103
IPR&D – Antigen Inhibitors
Indefinite-lived Intangible Assets [Line Items]
Intangible assets	14,811	36,437
IPR&D – cccDNA Sterilizers
Indefinite-lived Intangible Assets [Line Items]
Intangible assets	$ 43,836	$ 133,102

Collaborations, Contracts and Licensing Agreements (Details)				1 Months Ended	3 Months Ended								9 Months Ended	12 Months Ended				24 Months Ended
	Nov. 16, 2014 USD ($)	Jan. 13, 2014 USD ($)	May 10, 2010 USD ($)	May 31, 2015 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2015 USD ($)	Mar. 04, 2016 USD ($)	Apr. 22, 2014 USD ($)	May 08, 2013 USD ($)	Jul. 14, 2010 USD ($)	May 06, 2006 chemotherapy_products
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue					$ (195,000)	$ 774,000	$ 309,000	$ 603,000	$ 12,686,000	$ 4,065,000	$ 3,440,000	$ 4,682,000		$ 1,491,000	$ 24,873,000	$ 14,953,000
Deferred revenue					15,000				$ 1,081,000					15,000	1,081,000			$ 1,081,000
Licensing fees, milestone and royalty payments														1,262,000	11,564,000	3,215,000
Number of chemotherapy products with worldwide licenses \| chemotherapy_products																							3
Contracts revenue														229,000	13,309,000	11,738,000
DoD
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Potential contract funding amount																						$ 34,700,000
Optional exercised contractual option, amount																7,000,000
Contracts revenue														0	6,764,000	8,407,000
Monsanto
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Approximate option period		4 years
Maximum potential transaction value		$ 86,200,000		$ 2,000,000
Option period extension				5 months
Payments from inception of contract																		$ 19,300,000
Revenue															14,981,000
Licensing fees, milestone and royalty payments														0	10,256,000	2,744,000
Contracts revenue														0	4,725,000	1,080,000
BMS
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Deferred revenue			$ 3,000,000
Length of agreement with Bristol-Myers Squibb			4 years
Contracts revenue														0	0	1,741,000
Dicerna
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Deferred revenue	$ 2,500,000
Milestone payment	$ 22,000,000
Licensing fees, milestone and royalty payments													$ 1,066,000	1,066,000	1,053,000	131,000
Contracts revenue														229,000	1,820,000	510,000
Talon Therapeutics
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Potential contract funding amount																	$ 18,000,000
Contract extension \| Maximum
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Potential contract funding amount																						$ 140,000,000
Marqibo Commercial Sales
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Contracts revenue																	$ 1,000,000
Marqibo
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Royalty revenue														212,000	$ 240,000	$ 190,000
Accrued royalties					$ 5,000									$ 5,000
Increase to support development plans \| DoD
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Potential contract funding amount																					$ 6,970,000
Increased funding for stage one \| DoD
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Potential contract funding amount																				$ 2,100,000
Stage one \| DoD
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Potential contract funding amount																				$ 43,819,000
PADCo. \| Monsanto
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Optional exercised contractual option, amount																			$ 1,000,000
Business acquisition, percentage of outstanding shares acquired																			100.00%

Collaborations, Contracts and Licensing Agreements - Revenue Recognized Under Collaborations, Contracts and Licensing Agreements (Details) - USD ($) $ in Thousands	3 Months Ended								9 Months Ended	12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Collaborations and contracts
Contracts revenue										$ 229	$ 13,309	$ 11,738
Licensing fees, milestone and royalty payments
Licensing fees, milestone and royalty payments										1,262	11,564	3,215
Total revenue	$ (195)	$ 774	$ 309	$ 603	$ 12,686	$ 4,065	$ 3,440	$ 4,682		1,491	24,873	14,953
DoD
Collaborations and contracts
Contracts revenue										0	6,764	8,407
Monsanto
Collaborations and contracts
Contracts revenue										0	4,725	1,080
Licensing fees, milestone and royalty payments
Licensing fees, milestone and royalty payments										0	10,256	2,744
Total revenue											14,981
BMS
Collaborations and contracts
Contracts revenue										0	0	1,741
Dicerna
Collaborations and contracts
Contracts revenue										229	1,820	510
Licensing fees, milestone and royalty payments
Licensing fees, milestone and royalty payments									$ 1,066	1,066	1,053	131
Other
Licensing fees, milestone and royalty payments
Licensing fees, milestone and royalty payments										$ 196	$ 255	$ 340

Collaborations, Contracts and Licensing Agreements - Deferred Collaborations and Contracts Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Nov. 16, 2014
Deferred Revenue Arrangement [Line Items]
Deferred revenue, current portion	$ 15	$ 868
Deferred revenue, long-term portion	0	213
Total deferred revenue	15	1,081
DoD
Deferred Revenue Arrangement [Line Items]
Deferred revenue, current portion	15	15
Monsanto
Deferred Revenue Arrangement [Line Items]
Deferred revenue, current portion	0	0
Deferred revenue, long-term portion	0	0
Dicerna
Deferred Revenue Arrangement [Line Items]
Deferred revenue, current portion	0	853
Deferred revenue, long-term portion	$ 0	$ 213
Total deferred revenue			$ 2,500

- Definition

The carrying amount of consideration received or receivable as of the balance sheet date on potential earnings that were not recognized as revenue in conformity with GAAP, and which are expected to be recognized as such within one year or the normal operating cycle, if longer, including sales, license fees, and royalties, but excluding interest income.

+ References + Details

- Definition

The noncurrent portion of deferred revenue amount as of balance sheet date. Deferred revenue is a liability related to a revenue producing activity for which revenue has not yet been recognized, and is not expected to be recognized in the next twelve months. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

+ References + Details

Property and Equipment - Property and Equipment Summary (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Cost	$ 17,683	$ 12,912
Accumulated depreciation	(10,738)	(9,729)
Property and equipment, net of accumulated depreciation	6,945	3,183
Lab equipment
Property, Plant and Equipment [Line Items]
Cost	7,894	5,910
Accumulated depreciation	(4,305)	(3,748)
Property and equipment, net of accumulated depreciation	3,589	2,162
Leasehold improvements
Property, Plant and Equipment [Line Items]
Cost	4,928	4,681
Accumulated depreciation	(4,454)	(4,189)
Property and equipment, net of accumulated depreciation	474	492
Computer hardware and software
Property, Plant and Equipment [Line Items]
Cost	2,103	2,014
Accumulated depreciation	(1,665)	(1,487)
Property and equipment, net of accumulated depreciation	438	527
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Cost	374	307
Accumulated depreciation	(314)	(305)
Property and equipment, net of accumulated depreciation	60	$ 2
Assets under construction
Property, Plant and Equipment [Line Items]
Cost	2,384
Property and equipment, net of accumulated depreciation	$ 2,384

Share Capital - Narrative (Details) CAD / shares in Units, $ / shares in Units, CAD in Thousands								1 Months Ended	2 Months Ended	3 Months Ended	12 Months Ended
	May 19, 2016 shares	Jan. 01, 2016 shares	Mar. 25, 2015 USD ($) $ / shares shares	Mar. 04, 2015 USD ($) shares	Mar. 26, 2014 USD ($) $ / shares shares	Jun. 22, 2011	May 30, 2008 CAD / shares shares	Jun. 30, 2016 shares	May 31, 2016 USD ($) shareholder	Sep. 30, 2015 USD ($)	Dec. 31, 2016 USD ($) compensation_plan $ / shares shares	Dec. 31, 2016 USD ($) compensation_plan $ / shares shares	Dec. 31, 2016 CAD shares	Dec. 31, 2015 USD ($) shares	Dec. 31, 2015 CAD shares	Dec. 31, 2014 USD ($) shares	Dec. 31, 2014 CAD shares	Dec. 31, 2013 executive_officers shares	Dec. 31, 2016 CAD / shares	Jul. 09, 2015 shares	May 08, 2014 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued during underwritten public offering (in shares) \| shares			7,500,000		2,125,000
Stock price at public offering (in USD per share) \| $ / shares			$ 20.25		$ 28.50
Gross proceeds from issuance of stock			$ 151,875,000		$ 60,562,000							$ 0		$ 142,177,000		$ 56,477,000
Period for option to purchase additional shares			30 days		30 days
Number of additional shares authorized (in shares) \| shares					318,750
Potential proceeds of additional shares authorized			$ 22,781,000		$ 9,084,000
Payments of stock issuance costs, including commissions and professional fees			9,700,000		4,085,000
Proceeds from issuance of common stock, net			$ 142,177,000		$ 56,477,000
Warrants exercised (in shares) \| shares												170,500	170,500	18,750	18,750
Proceeds from warrant exercises												$ 445,000		$ 42,000		1,583,000
Common shares issued from warrants exercise (in shares) \| shares														0	0
Warrants expired (in shares) \| shares								8,000				8,000	8,000
Decrease in fair value of warrant liability												$ 530,000		$ 3,341,000		$ (10,383,000)
Number of share-based compensation plans \| compensation_plan											7	7
Number of stock-based compensation awards approved to be issued (in shares) \| shares											6,790,414	6,790,414								3,500,000	800,000
Number of additional shares authorized (in shares) \| shares	5,000,000
Options granted (in shares) \| shares			1,125,000									1,789,599	1,789,599
Number of executive officers granted options with new appointments \| executive_officers																		2
Options exercisable (in shares) \| shares											699,241	699,241		938,730		1,088,908
Weighted average remaining contractual life of exercisable options												7 years 5 months 27 days	7 years 5 months 27 days
Options exercisable, intrinsic value											$ 56,000	$ 56,000
Weighted average remaining contractual life for options expected to vest												9 years	9 years
Average exercise price for options expected to vest (in CAD and USD per share) \| (per share)											$ 7.50	$ 7.50							CAD 10.07
Aggregate intrinsic value of option expected to vest											$ 0	$ 0		$ 10,000		$ 2,626,000
Total fair value of options that vested during period												$ 5,058,000		$ 1,718,000		2,505,000
Risk-free interest rate												0.76%	0.76%	0.48%	0.48%
Expected volatility												41.95%	41.95%	49.07%	49.07%
Dividend yield												0.00%	0.00%	0.00%	0.00%
Expected average term (years)												2 months 12 days	2 months 12 days	7 months 6 days	7 months 6 days
Business acquisition, post-combination attribution recognized as compensation expense				$ 56,934,000
Stock-based compensation expense												$ 39,159,000		$ 22,093,000		$ 3,283,000
Unearned compensation expense											$ 8,835,000	$ 8,835,000
Unearned compensation expense, recognition period												12 months	12 months
Number of options outstanding (in shares) \| shares											3,765,094	3,765,094
Accelerated compensation expense recognized in each subsequent period										$ 1,900,000
Number of shareholders whose departure accelerated compensation expense \| shareholder									2
Number of shareholders subject to repurchase provision \| shareholder									4
Unrecognized compensation expense related to expiry of repurchase provisions											$ 7,972,000	$ 7,972,000
Liability classified stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected average term (years)		5 years 3 months 18 days										3 years 7 months 6 days	3 years 7 months 6 days
Weighted average remaining contractual life of exercisable options												4 years 1 month 6 days	4 years 1 month 6 days
Weighted average remaining contractual life for options expected to vest												7 years 1 month 6 days	7 years 1 month 6 days
Average exercise price for options expected to vest (in CAD and USD per share) \| (per share)											$ 12.06	$ 12.06							16.19
Total fair value of options that vested during period												$ 62,200
Number of exercisable liability options (in shares) \| shares											623,750	623,750
Weighted average exercise price (in CAD and USD per share) \| (per share)											$ 5.32	$ 5.32							CAD 7.14
Options exercised, aggregate intrinsic value											$ 54,000
Number of options outstanding (in shares) \| shares		718,333									638,500	638,500
Cashless Exercise Provision
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants exercised (in shares) \| shares												0	0	0	0
Unexpired repurchase rights on shares issued to Arbutus Inc.
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unearned compensation expense											$ 7,912,000	$ 7,912,000
Unearned compensation expense, recognition period												5 months	5 months
Expired repurchase rights on shares issued to Arbutus Inc.
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense									$ 14,008,000			$ 31,986,000		$ 16,687,000
2007 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period						3 years
2007 Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected average term (years)						10 years
2011 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period						3 years
2011 Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected average term (years)						10 years
Designated Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares) \| shares																		200,000
Arbutus Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected average term (years)												7 years 3 months 18 days	7 years 3 months 18 days	7 years 6 months	7 years 6 months	8 years 9 months 18 days	8 years 9 months 18 days
Options granted (in shares) \| shares												1,789,599	1,789,599	1,309,625	1,309,625	431,125	431,125
Risk-free interest rate												0.00%	0.00%
Options exercised, aggregate intrinsic value												$ 121,000	CAD 160	$ 5,386,000	CAD 6,887	$ 6,926,000	CAD 7,650
Number of options outstanding (in shares) \| shares											2,911,204	2,911,204		2,290,263		1,530,138		1,730,765
Protiva Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future exercise (in shares) \| shares							350,457
Option exercise price (in CAD per share) \| CAD / shares							CAD 0.30
Conversion of stock, shares converted (in shares) \| shares							0.6752
Protiva Option Plan \| Revised new common shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future exercise (in shares) \| shares							519,073
Protiva Option Plan \| Protiva Share Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining contractual life of exercisable options												1 year	1 year
Options exercisable, intrinsic value											$ 56,000	$ 56,000
Options exercised, aggregate intrinsic value												$ 49,000		$ 1,249,000		$ 378,000
OnCore Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock-based compensation awards approved to be issued (in shares) \| shares				184,332
Options exercisable (in shares) \| shares											119,988	119,988
Weighted average remaining contractual life of exercisable options												7 years 10 months 24 days	7 years 10 months 24 days
Options exercisable, intrinsic value											$ 226,000	$ 226,000
Weighted average remaining contractual life for options expected to vest												7 years 10 months 24 days	7 years 10 months 24 days
Average exercise price for options expected to vest (in CAD and USD per share) \| $ / shares											$ 0.57	$ 0.57
Aggregate intrinsic value of option expected to vest											$ 119,000	$ 119,000
Total fair value of options that vested during period												560,000
Risk-free interest rate				0.97%
Fair value of consideration issued				$ 3,287,000
Expected volatility				78.00%
Dividend yield				0.00%
Expected average term (years)				8 years
Business acquisition, fair value amount attributed as pre-combination service and included as part of acquisition consideration				$ 1,127,000
Business acquisition, post-combination attribution recognized as compensation expense				$ 2,160,000
Stock-based compensation expense												$ 577,000
Options exercisable weighted average exercise price (in USD per share) \| $ / shares											$ 0.57	$ 0.57
Number of options outstanding (in shares) \| shares											183,040	183,040		183,040
OnCore Option Plan \| Equivalent number of Company common shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options exercisable (in shares) \| shares											120,835	120,835
Number of options outstanding (in shares) \| shares											184,332	184,332		184,332

Share Capital - Summary of Warrant Activity (Details) CAD / shares in Units, $ / shares in Units, CAD in Thousands, $ in Thousands	1 Months Ended	12 Months Ended
	Jun. 30, 2016 shares	Dec. 31, 2016 USD ($) CAD / shares shares	Dec. 31, 2016 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) CAD / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) CAD / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2016 CAD	Dec. 31, 2015 CAD	Dec. 31, 2014 CAD
Class Of Warrant Or Right Number Of Securities Called By Warrants Or Rights [Roll Forward]
Balance, Common shares purchasable upon exercise of warrants (in shares)		379,500	379,500	398,250	398,250
Exercised, Common shares purchasable upon exercise of warrants (in shares)		(170,500)	(170,500)	(18,750)	(18,750)
Expired, Common shares purchasable upon exercise of warrants (in shares)	(8,000)	(8,000)	(8,000)
Balance, Common shares purchasable upon exercise of warrants (in shares)		201,000	201,000	379,500	379,500	398,250	398,250
Balance, Weighted average exercise price (in CAD and USD per share) \| (per share)		CAD 2.95	$ 2.13	CAD 2.95	$ 2.67
Exercised, Weighted average exercise price (in CAD and USD per share) \| (per share)		3.35	2.53	2.88	2.25
Expired, Weighted average exercise price (in CAD and USD per share) \| (per share)		3.35	2.53
Balance, Weighted average exercise price (in CAD and USD per share) \| (per share)		CAD 2.60	$ 1.94	CAD 2.95	$ 2.13	CAD 2.95	$ 2.67
Balance, Weighted average remaining contractual life		2 months 12 days	2 months 12 days	9 months 18 days	9 months 18 days	1 year 9 months 18 days	1 year 9 months 18 days
Balance, Aggregate intrinsic value		CAD 104	$ 104	CAD 879	$ 879	CAD 5,343	$ 5,343	CAD 139	CAD 1,217	CAD 5,902
Minimum
Class Of Warrant Or Right Number Of Securities Called By Warrants Or Rights [Roll Forward]
Balance, Range of exercise prices (in CAD and USD per share) \| (per share)		CAD 2.60	$ 2.03	CAD 2.60	$ 2.35
Exercised, Range of exercise prices (in CAD and USD per share) \| (per share)		3.35	2.53	2.60	2.03
Expired, Range of exercise prices (in CAD and USD per share) \| (per share)		3.35	2.53
Balance, Range of exercise prices (in CAD and USD per share) \| (per share)		2.60	1.94	2.60	2.03	CAD 2.60	$ 2.35
Maximum
Class Of Warrant Or Right Number Of Securities Called By Warrants Or Rights [Roll Forward]
Balance, Range of exercise prices (in CAD and USD per share) \| (per share)		3.35	2.62	3.35	3.03
Exercised, Range of exercise prices (in CAD and USD per share) \| (per share)		3.35	2.53	3.35	2.62
Expired, Range of exercise prices (in CAD and USD per share) \| (per share)		3.35	2.53
Balance, Range of exercise prices (in CAD and USD per share) \| (per share)		CAD 2.60	$ 1.94	CAD 3.35	$ 2.62	CAD 3.35	$ 3.03

Share Capital - Valuation Assumptions Assumptions - Warrants (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Stockholders' Equity Note [Abstract]
Dividend yield	0.00%	0.00%
Expected volatility	41.95%	49.07%
Risk-free interest rate	0.76%	0.48%
Expected average term (years)	2 months 12 days	7 months 6 days
Fair value of warrants outstanding (in USD per share)	$ 0.53	$ 2.33
Aggregate fair value of warrants outstanding	$ 107	$ 883
Number of warrants outstanding (in shares)	201,000	379,500

Share Capital - Summary of Information - Equity Options (Details) CAD / shares in Units, $ / shares in Units, CAD in Thousands, $ in Thousands		12 Months Ended
	Mar. 25, 2015 shares	Dec. 31, 2016 USD ($) $ / shares shares	Dec. 31, 2016 CAD CAD / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2015 CAD CAD / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2014 CAD CAD / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options granted (in shares)	1,125,000	1,789,599	1,789,599
Balance - Number of optioned common shares (in shares)		3,765,094	3,765,094
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Options reclassified liability - Weighted average exercise price (in CAD and USD per share) \| (per share)		$ 5.23	CAD 7.24
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Options reclassified - Aggregate intrinsic value		$ 604	CAD 836
Arbutus Plans
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance - Number of optioned common shares (in shares)		2,290,263	2,290,263	1,530,138	1,530,138	1,730,765	1,730,765
Options reclassified to liability (in shares)		(718,333)	(718,333)
Options granted (in shares)		1,789,599	1,789,599	1,309,625	1,309,625	431,125	431,125
Options exercised (in shares)		(56,125)	(56,125)	(398,293)	(398,293)	(622,752)	(622,752)
Options forfeited, canceled or expired (in shares)		(394,200)	(394,200)	(151,207)	(151,207)	(9,000)	(9,000)
Balance - Number of optioned common shares (in shares)		2,911,204	2,911,204	2,290,263	2,290,263	1,530,138	1,530,138
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Balance - Weighted average exercise price (in CAD and USD per share) \| (per share)		$ 11.22	CAD 15.53	$ 6.29	CAD 6.95	$ 4.32	CAD 4.45
Options granted - Weighted average exercise price (in CAD and USD per share) \| (per share)		3.89		16.57		12.34	13.63
Options exercised - Weighted average exercise price (in CAD and USD per share) \| (per share)		2.18	2.88	3.93	5.03	4.18	4.62
Options forfeited, canceled or expired - Weighted average exercise price (in CAD and USD per share) \| (per share)		10.18	13.49	15.09	19.29	7.42	8.20
Balance - Weighted average exercise price (in CAD and USD per share) \| (per share)		$ 8.53	CAD 11.45	$ 11.22	CAD 15.53	$ 6.29	CAD 6.95
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Balance - Aggregate intrinsic value		$ 994	CAD 1,376	$ 15,004	CAD 16,573	$ 6,826	CAD 7,030
Options exercised, aggregate intrinsic value		121	160	5,386	6,887	6,926	7,650
Balance - Aggregate intrinsic value		$ 56	CAD 75	$ 994	CAD 1,376	$ 15,004	CAD 16,573

Share Capital - Stock Options Outstanding - Equity Options (Details)	12 Months Ended
	Dec. 31, 2016 $ / shares shares
Range 1
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise prices - Low (in USD per share)	$ 1.12
Range of Exercise prices - High (in USD per share)	$ 3.05
Number of options outstanding (in shares) \| shares	121,725
Weighted average remaining contractual life (years)	6 years 4 months 24 days
Options outstanding, Weighted average exercise price (in USD per share)	$ 2.23
Number of options exercisable (in shares) \| shares	75,225
Weighted average exercise price (in USD per share)	$ 1.78
Range 2
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise prices - Low (in USD per share)	3.28
Range of Exercise prices - High (in USD per share)	$ 3.84
Number of options outstanding (in shares) \| shares	209,033
Weighted average remaining contractual life (years)	8 years 4 months 24 days
Options outstanding, Weighted average exercise price (in USD per share)	$ 3.64
Number of options exercisable (in shares) \| shares	62,033
Weighted average exercise price (in USD per share)	$ 3.69
Range 3
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise prices - Low (in USD per share)	3.94
Range of Exercise prices - High (in USD per share)	$ 3.94
Number of options outstanding (in shares) \| shares	1,369,849
Weighted average remaining contractual life (years)	9 years 2 months 12 days
Options outstanding, Weighted average exercise price (in USD per share)	$ 3.94
Number of options exercisable (in shares) \| shares	0
Range 4
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise prices - Low (in USD per share)	$ 3.98
Range of Exercise prices - High (in USD per share)	$ 8.64
Number of options outstanding (in shares) \| shares	81,713
Weighted average remaining contractual life (years)	8 years 1 month 6 days
Options outstanding, Weighted average exercise price (in USD per share)	$ 4.49
Number of options exercisable (in shares) \| shares	71,380
Weighted average exercise price (in USD per share)	$ 4.38
Range 5
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise prices - Low (in USD per share)	9.11
Range of Exercise prices - High (in USD per share)	$ 9.73
Number of options outstanding (in shares) \| shares	118,843
Weighted average remaining contractual life (years)	7 years 9 months 18 days
Options outstanding, Weighted average exercise price (in USD per share)	$ 9.44
Number of options exercisable (in shares) \| shares	91,375
Weighted average exercise price (in USD per share)	$ 9.44
Range 6
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise prices - Low (in USD per share)	9.88
Range of Exercise prices - High (in USD per share)	$ 13.89
Number of options outstanding (in shares) \| shares	201,000
Weighted average remaining contractual life (years)	8 years 1 month 6 days
Options outstanding, Weighted average exercise price (in USD per share)	$ 13.42
Number of options exercisable (in shares) \| shares	74,271
Weighted average exercise price (in USD per share)	$ 13.26
Range 7
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise prices - Low (in USD per share)	17.57
Range of Exercise prices - High (in USD per share)	$ 17.57
Number of options outstanding (in shares) \| shares	809,041
Weighted average remaining contractual life (years)	8 years 2 months 12 days
Options outstanding, Weighted average exercise price (in USD per share)	$ 17.57
Number of options exercisable (in shares) \| shares	324,957
Weighted average exercise price (in USD per share)	$ 17.57
Total Range
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise prices - Low (in USD per share)	1.12
Range of Exercise prices - High (in USD per share)	$ 17.57
Number of options outstanding (in shares) \| shares	2,911,204
Weighted average remaining contractual life (years)	8 years 7 months 6 days
Options outstanding, Weighted average exercise price (in USD per share)	$ 8.53
Number of options exercisable (in shares) \| shares	699,241
Weighted average exercise price (in USD per share)	$ 11.77

Share Capital - Non-vested Stock Option Activity - Equity Options (Details)		12 Months Ended
	Mar. 25, 2015 shares	Dec. 31, 2016 CAD / shares shares	Dec. 31, 2016 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Non-vested, beginning balance (in shares)		1,351,541	1,351,541
Options reclassified to liability-options (in shares)		(134,000)	(134,000)
Options granted (in shares)	1,125,000	1,789,599	1,789,599
Options vested (in shares)		(472,479)	(472,479)
Non-vested options forfeited (in shares)		(322,698)	(322,698)
Non-vested, ending balance (in shares)		2,211,963	2,211,963
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Non-vested, beginning balance, weighted average fair value (in CAD and USD per share) \| (per share)		CAD 15.69	$ 11.34
Options reclassified to liability (in CAD and USD per share) \| (per share)		10.80	7.80
Options granted (in CAD and USD per share) \| (per share)		5.15	3.89
Options vested (in CAD and USD per share) \| (per share)		14.20	10.72
Non-vested options forfeited (in CAD and USD per share) \| (per share)		9.70	7.33
Non-vested, ending balance, weighted average fair value (in CAD and USD per share) \| (per share)		CAD 7.17	$ 5.34

Share Capital - Valuation Assumptions - Equity Options (Details) - Arbutus Plans	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%	0.00%	0.00%
Expected volatility	77.99%	76.88%	101.08%
Risk-free interest rate	0.90%	1.10%	2.25%
Expected average option term	7 years 3 months 18 days	7 years 6 months	8 years 9 months 18 days

Share Capital - Valuation Assumptions - Liability-Classified Options (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Jan. 01, 2016	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of vested liability-classified options (in thousands)		$ 553
Liability classified stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%	0.00%
Expected volatility	97.78%	66.18%
Risk-free interest rate	0.86%	0.88%
Expected average term (years)	5 years 3 months 18 days	3 years 7 months 6 days
Fair value of liability options outstanding (in USD per share)	$ 3.33	$ 0.87
Fair value of vested liability-classified options (in thousands)	$ 1,909	$ 553

Share Capital - Stock Option Activity for Liability-Classified Options (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares	Dec. 31, 2016 CAD / shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance - Number of optioned common shares (in shares)	3,765,094
Liability classified stock options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance - Number of optioned common shares (in shares)	718,333
Options exercised (in shares)	(30,000)
Options forfeited, canceled or expired (in shares)	(49,833)
Balance - Number of optioned common shares (in shares)	638,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Balance - Weighted average exercise price (in CAD and USD per share) \| (per share)	$ 5.23	CAD 7.24
Options exercised - Weighted average exercise price (in CAD and USD per share) \| (per share)	2.30	3.00
Options forfeited, canceled or expired - Weighted average exercise price (in CAD and USD per share) \| (per share)	6.17	8.29
Balance - Weighted average exercise price (in CAD and USD per share) \| (per share)	$ 5.48	CAD 7.35
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Balance - Aggregate intrinsic value \| $	$ 604
Options exercised, aggregate intrinsic value \| $	54
Balance - Aggregate intrinsic value \| $	$ 116

Share Capital - Summary of Information Liability-Classified Options (Details)	12 Months Ended
	Dec. 31, 2016 CAD / shares $ / shares shares	Dec. 31, 2016 $ / shares shares	Jan. 01, 2016 CAD / shares	Jan. 01, 2016 $ / shares
Liability classified stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding, Weighted average exercise price (in USD per share) \| (per share)	CAD 7.35	$ 5.48	CAD 7.24	$ 5.23
Number of options exercisable (in shares) \| shares	623,750	623,750
Weighted average exercise price (in USD per share) \| (per share)	CAD 7.14	$ 5.32
Range 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise prices - Low (in USD per share)	CAD 1.12
Range of Exercise prices - High (in USD per share)	CAD 3.05
Number of options outstanding (in shares) \| shares	121,725	121,725
Weighted average remaining contractual life (years)	6 years 4 months 24 days
Options outstanding, Weighted average exercise price (in USD per share)		$ 2.23
Number of options exercisable (in shares) \| shares	75,225	75,225
Weighted average exercise price (in USD per share)		$ 1.78
Range 1 \| Liability classified stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise prices - Low (in USD per share)	CAD 1.27
Range of Exercise prices - High (in USD per share)	CAD 1.79
Number of options outstanding (in shares) \| shares	120,000	120,000
Weighted average remaining contractual life (years)	3 years 8 months 12 days
Options outstanding, Weighted average exercise price (in USD per share)		$ 1.48
Number of options exercisable (in shares) \| shares	120,000	120,000
Weighted average exercise price (in USD per share)		$ 1.48
Range 2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise prices - Low (in USD per share)	CAD 3.28
Range of Exercise prices - High (in USD per share)	CAD 3.84
Number of options outstanding (in shares) \| shares	209,033	209,033
Weighted average remaining contractual life (years)	8 years 4 months 24 days
Options outstanding, Weighted average exercise price (in USD per share)		$ 3.64
Number of options exercisable (in shares) \| shares	62,033	62,033
Weighted average exercise price (in USD per share)		$ 3.69
Range 2 \| Liability classified stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise prices - Low (in USD per share)	CAD 2.87
Range of Exercise prices - High (in USD per share)	CAD 3.84
Number of options outstanding (in shares) \| shares	120,000	120,000
Weighted average remaining contractual life (years)	3 years 7 months 6 days
Options outstanding, Weighted average exercise price (in USD per share)		$ 3.42
Number of options exercisable (in shares) \| shares	120,000	120,000
Weighted average exercise price (in USD per share)		$ 3.42
Range 3
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise prices - Low (in USD per share)	CAD 3.94
Range of Exercise prices - High (in USD per share)	CAD 3.94
Number of options outstanding (in shares) \| shares	1,369,849	1,369,849
Weighted average remaining contractual life (years)	9 years 2 months 12 days
Options outstanding, Weighted average exercise price (in USD per share)		$ 3.94
Number of options exercisable (in shares) \| shares	0	0
Range 3 \| Liability classified stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise prices - Low (in USD per share)	CAD 3.97
Range of Exercise prices - High (in USD per share)	CAD 4.28
Number of options outstanding (in shares) \| shares	74,000	74,000
Weighted average remaining contractual life (years)	1 year 7 months 6 days
Options outstanding, Weighted average exercise price (in USD per share)		$ 4.22
Number of options exercisable (in shares) \| shares	74,000	74,000
Weighted average exercise price (in USD per share)		$ 4.22
Range 4
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise prices - Low (in USD per share)	CAD 3.98
Range of Exercise prices - High (in USD per share)	CAD 8.64
Number of options outstanding (in shares) \| shares	81,713	81,713
Weighted average remaining contractual life (years)	8 years 1 month 6 days
Options outstanding, Weighted average exercise price (in USD per share)		$ 4.49
Number of options exercisable (in shares) \| shares	71,380	71,380
Weighted average exercise price (in USD per share)		$ 4.38
Range 4 \| Liability classified stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise prices - Low (in USD per share)	CAD 4.84
Range of Exercise prices - High (in USD per share)	CAD 6.18
Number of options outstanding (in shares) \| shares	76,250	76,250
Weighted average remaining contractual life (years)	8 months 12 days
Options outstanding, Weighted average exercise price (in USD per share)		$ 5.83
Number of options exercisable (in shares) \| shares	76,250	76,250
Weighted average exercise price (in USD per share)		$ 5.83
Range 5
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise prices - Low (in USD per share)	CAD 9.11
Range of Exercise prices - High (in USD per share)	CAD 9.73
Number of options outstanding (in shares) \| shares	118,843	118,843
Weighted average remaining contractual life (years)	7 years 9 months 18 days
Options outstanding, Weighted average exercise price (in USD per share)		$ 9.44
Number of options exercisable (in shares) \| shares	91,375	91,375
Weighted average exercise price (in USD per share)		$ 9.44
Range 5 \| Liability classified stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise prices - Low (in USD per share)	CAD 6.79
Range of Exercise prices - High (in USD per share)	CAD 6.79
Number of options outstanding (in shares) \| shares	150,000	150,000
Weighted average remaining contractual life (years)	6 years 9 months 18 days
Options outstanding, Weighted average exercise price (in USD per share)		$ 6.79
Number of options exercisable (in shares) \| shares	150,000	150,000
Weighted average exercise price (in USD per share)		$ 6.79
Range 6
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise prices - Low (in USD per share)	CAD 9.88
Range of Exercise prices - High (in USD per share)	CAD 13.89
Number of options outstanding (in shares) \| shares	201,000	201,000
Weighted average remaining contractual life (years)	8 years 1 month 6 days
Options outstanding, Weighted average exercise price (in USD per share)		$ 13.42
Number of options exercisable (in shares) \| shares	74,271	74,271
Weighted average exercise price (in USD per share)		$ 13.26
Range 6 \| Liability classified stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise prices - Low (in USD per share)	CAD 9.32
Range of Exercise prices - High (in USD per share)	CAD 12.21
Number of options outstanding (in shares) \| shares	98,250	98,250
Weighted average remaining contractual life (years)	6 years
Options outstanding, Weighted average exercise price (in USD per share)		$ 11.53
Number of options exercisable (in shares) \| shares	83,500	83,500
Weighted average exercise price (in USD per share)		$ 11.44
Total Range
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise prices - Low (in USD per share)	CAD 1.12
Range of Exercise prices - High (in USD per share)	CAD 17.57
Number of options outstanding (in shares) \| shares	2,911,204	2,911,204
Weighted average remaining contractual life (years)	8 years 7 months 6 days
Options outstanding, Weighted average exercise price (in USD per share)		$ 8.53
Number of options exercisable (in shares) \| shares	699,241	699,241
Weighted average exercise price (in USD per share)		$ 11.77
Total Range \| Liability classified stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise prices - Low (in USD per share)	CAD 1.27
Range of Exercise prices - High (in USD per share)	CAD 12.21
Number of options outstanding (in shares) \| shares	638,500	638,500
Weighted average remaining contractual life (years)	4 years 2 months 12 days
Options outstanding, Weighted average exercise price (in USD per share)		$ 5.48

Share Capital - Non-vested Liability Stock Option Activity (Details)	12 Months Ended
	Dec. 31, 2016 CAD / shares shares	Dec. 31, 2016 $ / shares shares	Dec. 31, 2016 CAD / shares shares	Dec. 31, 2016 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Non-vested, beginning balance (in shares)	1,351,541	1,351,541
Options vested (in shares)	(472,479)	(472,479)
Non-vested options forfeited (in shares)	(322,698)	(322,698)
Non-vested, ending balance (in shares)	2,211,963	2,211,963	2,211,963	2,211,963
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Non-vested, beginning balance, weighted average fair value (in CAD and USD per share) \| (per share)	CAD 15.69	$ 11.34
Options vested (in CAD and USD per share) \| (per share)	14.20	10.72
Non-vested options forfeited (in CAD and USD per share) \| (per share)	9.70	7.33
Non-vested, ending balance, weighted average fair value (in CAD and USD per share) \| (per share)	CAD 7.17	$ 5.34	CAD 7.17	$ 5.34
Liability classified stock options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Non-vested, beginning balance (in shares)			134,000	134,000
Options vested (in shares)			(93,250)	(93,250)
Non-vested options forfeited (in shares)			(26,000)	(26,000)
Non-vested, ending balance (in shares)	14,750	14,750	14,750	14,750
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Non-vested, beginning balance, weighted average fair value (in CAD and USD per share) \| $ / shares				$ 3.61
Options vested (in CAD and USD per share) \| $ / shares				0.67
Non-vested options forfeited (in CAD and USD per share) \| $ / shares				0.04
Non-vested, ending balance, weighted average fair value (in CAD and USD per share) \| $ / shares		$ 0.92		$ 0.92

Share Capital - Outstanding Options Under the Protiva Option Plan (Details)	12 Months Ended
	Dec. 31, 2016 CAD / shares shares	Dec. 31, 2016 $ / shares shares	Dec. 31, 2015 CAD / shares shares	Dec. 31, 2015 $ / shares shares	Dec. 31, 2014 CAD / shares shares	Dec. 31, 2014 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance - Number of optioned common shares (in shares)	3,765,094	3,765,094
Protiva Share Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance - Number of optioned common shares (in shares)	67,000	67,000	433,740	433,740	472,885	472,885
Options exercised (in shares)	(21,000)	(21,000)	(358,675)	(358,675)	(38,145)	(38,145)
Options forfeited, canceled or expired (in shares)	0	0	(8,065)	(8,065)	(1,000)	(1,000)
Balance - Number of optioned common shares (in shares)	46,000	46,000	67,000	67,000	433,740	433,740
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Balance - Weighted average exercise price (in CAD and USD per share) \| (per share)	CAD 0.30	$ 0.22	CAD 0.30	$ 0.27	CAD 0.30	$ 0.29
Options exercised - Weighted average exercise price (in CAD and USD per share) \| (per share)	0.30	0.23	0.30	0.23	0.30	0.27
Options forfeited, canceled or expired - Weighted average exercise price (in CAD and USD per share) \| (per share)	0.00		0.30	0.23	0.30	0.27
Balance - Weighted average exercise price (in CAD and USD per share) \| (per share)	CAD 0.30	$ 0.22	CAD 0.30	$ 0.22	CAD 0.30	$ 0.27
Equivalent number of Company common shares \| Protiva Share Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance - Number of optioned common shares (in shares)	45,236	45,236	292,845	292,845	319,274	319,274
Options exercised (in shares)	(14,178)	(14,178)	(242,164)	(242,164)	(25,754)	(25,754)
Options forfeited, canceled or expired (in shares)	0	0	(5,445)	(5,445)	(675)	(675)
Balance - Number of optioned common shares (in shares)	31,058	31,058	45,236	45,236	292,845	292,845

Share Capital - Outstanding Options Under the OnCore Option Plan (Details)	12 Months Ended
	Dec. 31, 2016 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance - Number of optioned common shares (in shares)	3,765,094
OnCore Option Plan
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance - Number of optioned common shares (in shares)	183,040
Options exercised (in shares)	0
Options forfeited, canceled or expired (in shares)	0
Balance - Number of optioned common shares (in shares)	183,040
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Balance - Weighted average exercise price (in CAD and USD per share) \| $ / shares	$ 0.57
Balance - Weighted average exercise price (in CAD and USD per share) \| $ / shares	$ 0.57
Equivalent number of Company common shares \| OnCore Option Plan
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance - Number of optioned common shares (in shares)	184,332
Options exercised (in shares)	0
Options forfeited, canceled or expired (in shares)	0
Balance - Number of optioned common shares (in shares)	184,332

Share Capital - Non-vested Stock Option Activity OnCore Option Plan (Details)	12 Months Ended
	Dec. 31, 2016 CAD / shares shares	Dec. 31, 2016 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Non-vested, beginning balance (in shares)	1,351,541	1,351,541
Options vested (in shares)	(472,479)	(472,479)
Non-vested options forfeited (in shares)	(322,698)	(322,698)
Non-vested, ending balance (in shares)	2,211,963	2,211,963
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Non-vested, beginning balance, weighted average fair value (in CAD and USD per share) \| (per share)	CAD 15.69	$ 11.34
Options vested (in CAD and USD per share) \| (per share)	14.20	10.72
Non-vested, ending balance, weighted average fair value (in CAD and USD per share) \| (per share)	CAD 7.17	$ 5.34
OnCore Option Plan
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Non-vested, beginning balance (in shares)	96,382	96,382
Options vested (in shares)	(33,331)	(33,331)
Non-vested options forfeited (in shares)	0	0
Non-vested, ending balance (in shares)	63,051	63,051
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Non-vested, beginning balance, weighted average fair value (in CAD and USD per share) \| $ / shares		$ 16.42
Options vested (in CAD and USD per share) \| $ / shares		16.80
Non-vested, ending balance, weighted average fair value (in CAD and USD per share) \| $ / shares		$ 16.80
Equivalent number of Company common shares \| OnCore Option Plan
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Non-vested, beginning balance (in shares)	97,063	97,063
Options vested (in shares)	(33,566)	(33,566)
Non-vested options forfeited (in shares)	0	0
Non-vested, ending balance (in shares)	63,497	63,497

Share Capital - Location Of Expenses for Stock-based Compensation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 39,159	$ 22,093	$ 3,283
Research, development, collaborations and contracts expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	11,155	7,868	2,343
General and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 28,004	$ 14,225	$ 940

Government Grants and Refundable Investment Tax Credits (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Government Grants and Refundable Investment Tax Credits [Line Items]
Contracts revenue		$ 229	$ 13,309	$ 11,738
Revenue from government grants		129	1,245
Investment tax credit		$ 145	$ 196
ISARIC
Government Grants and Refundable Investment Tax Credits [Line Items]
Contracts revenue	$ 1,098

Income Taxes (Details) $ in Thousands		12 Months Ended
Income Taxes (Details) $ in Thousands	Nov. 23, 2011 CAD	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Income Taxes [Line Items]
Canadian federal and provincial income tax rate		26.00%	26.00%	26.00%
Research and development credits		$ 1,454
Scientific research and experimental development expenditures available for indefinite carry-forward		24,275	$ 13,932
Deferred tax assets, operating loss carryforwards, subject to expiration		14,621
Patent tax refund percentage	75.00%
Income tax refund maximum from patents		0	24	$ 0
Maximum
Income Taxes [Line Items]
Income tax refund maximum from patents \| CAD	CAD 8,000,000
Investment tax credit carryforward
Income Taxes [Line Items]
Investment tax credits available to reduce Canadian federal income taxes		10,245	7,969
Investment tax credits available to reduce provincial income taxes		5,337	3,869
Research tax credit carryforward
Income Taxes [Line Items]
Scientific research and experimental development expenditures available for indefinite carry-forward		65,332	51,823
Deferred tax assets, operating loss carryforwards, subject to expiration		$ 71,460	$ 24,745

Income Taxes - Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Computed taxes (recoveries) at Canadian federal and provincial tax rates	$ (127,183)	$ (20,100)	$ (10,097)
Permanent and other differences	(3,598)	769	2,594
Change in valuation allowance - other	17,043	3,675	6,599
Difference due to income taxed at foreign rates	(47,962)	(7,874)	0
Stock-based compensation	9,727	7,345	904
Impairment of goodwill	46,971	0	0
Deferred income tax recovery	$ (105,002)	$ (16,185)	$ 0

Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Components of Deferred Tax Assets [Line Items]
Non-capital loss carryforwards	$ 24,275	$ 13,932
Research and development deductions	16,986	13,474
Book amortization in excess of tax	451	2,142
Share issue costs	486	777
Revenue recognized for tax purposes in excess of revenue recognized for accounting purposes	410	281
Tax value in excess of accounting value in lease inducements	58	77
In-process research and development	(41,263)	(146,324)
Upfront license fees	536	629
Other	1,435	0
Total deferred tax assets	17,274
Total deferred tax (liabilities)		(104,830)
Valuation allowance	(58,537)	(41,494)
Net deferred tax assets (liabilities)	(41,263)	(146,324)
Federal
Components of Deferred Tax Assets [Line Items]
Investment tax credits	8,630	6,303
Provincial
Components of Deferred Tax Assets [Line Items]
Investment tax credits	$ 5,270	$ 3,879

Loan Payable (Details) - USD ($)	12 Months Ended
Loan Payable (Details) - USD ($)	Dec. 31, 2016	Dec. 27, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Restricted investment	$ 12,601,000		$ 0
Restricted investment, term	2 years
LIBOR \| Loans payable \| Promissory note with Wells Fargo
Debt Instrument [Line Items]
Fixed component of interest rate	1.25%
Wells Fargo \| Loans payable \| Promissory note with Wells Fargo
Debt Instrument [Line Items]
Loan payable		$ 12,001,000

Contingencies and Commitments (Details) ft² in Thousands, CAD in Thousands				1 Months Ended			12 Months Ended				53 Months Ended
	Aug. 09, 2016 USD ($) ft² renewal_term	Jun. 05, 2016 USD ($) research_funding_period_extensions	Jan. 16, 2015 USD ($)	Nov. 30, 2014 USD ($)	Oct. 31, 2014 USD ($)	Feb. 28, 2014 USD ($) compound_series	Dec. 31, 2016 USD ($)	Dec. 31, 2016 CAD	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Mar. 31, 2004 USD ($)	Mar. 31, 2004 CAD	Dec. 31, 2016 CAD	Dec. 30, 2014 USD ($) compound_series
Contingencies and Commitments [Line Items]
Total facility commitment							$ 9,361,293
Lease expense							1,341,000		$ 1,158,000	$ 1,133,000
Percent of costs funded by TPC											27.00%	27.00%
Maximum contribution for product											$ 7,179,000	CAD 9,330
Cumulative contribution for product							$ 2,756,000	CAD 3,702
Royalty guarantees commitments percentage							2.50%	2.50%
Increase in fair value of contingent consideration							$ 1,568,000		770,000	0
Arbutus Inc. \| Enantigen
Contingencies and Commitments [Line Items]
Business combination, high end of payment upon achievement of certain triggering events					$ 21,000,000
Business combination, regulatory, development and sales milestone payments estimated fair value					6,727,000		9,065,000
Increase in fair value of contingent consideration							1,568,000
Arbitration with the University of British Columbia
Contingencies and Commitments [Line Items]
Loss contingency, damages sought for allegedly unpaid royalties			$ 3,500,000
Blumberg and Drexel \| Arbutus Inc.
Contingencies and Commitments [Line Items]
Number of series of compounds \| compound_series						3
License fee				$ 50,000		$ 150,000
Development and regulatory milestones payment per licensed compound series, maximum				$ 1,000,000		3,500,000
Sales performance milestones payment per licensed product, maximum						$ 92,500,000
Blumberg \| Arbutus Inc.
Contingencies and Commitments [Line Items]
Research funding per year under research collaboration and funding agreement		$ 1,100,000			$ 1,000,000
Research funding period					3 years
Research funding period, renewable option		1 year			3 years
Research funding agreement exclusive license upfront payment					$ 100,000
Research funding agreement exclusive license maximum development and regulatory milestone payments					8,100,000
Research funding agreement license maximum commercialization milestone payments					$ 92,500,000
Research funding period, number of renewable options \| research_funding_period_extensions		2
Cytos \| Arbutus Inc.
Contingencies and Commitments [Line Items]
Number of series of compounds \| compound_series														6
Development and regulatory milestones payment per licensed compound series, maximum														$ 67,000,000
Sales performance milestones payment per licensed product, maximum														$ 110,000,000
Marqibo
Contingencies and Commitments [Line Items]
Royalty revenue							212,000
Royalty payable							5,000		$ 6,000	$ 5,000
Royalties paid or accrued							17,000
Contractual obligation							$ 2,741,000						CAD 3,680
Laboratory facilities and office space
Contingencies and Commitments [Line Items]
Area of property (in sq ft) \| ft²	35
Lease term	10 years 7 months 6 days
Lease extension option \| renewal_term	2
Lease extension term	5 years
Total facility commitment	$ 6,900,000

Contingencies and Commitments - Minimum Rent and Estimated Operating Cost Commitment, Net Lease Inducements (Details)	Dec. 31, 2016 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Year ended December 31, 2017	$ 1,475,444
Year ended December 31, 2018	1,539,323
Year ended December 31, 2019	1,203,863
Year ended December 31, 2020	656,469
Year ended December 31, 2021 and after	4,486,194
Future minimum rent and estimated operating cost commitment, net of lease inducements	$ 9,361,293

Concentrations of Business Risk (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Risks and Uncertainties [Abstract]
Accounts receivable	$ 273	$ 1,008
Financial obligations, period to pay	45 days

Concentrations of Business Risk - Net Liquidity of the Company (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Risks and Uncertainties [Abstract]
Cash, cash equivalents and short-term investments	$ 130,559	$ 181,304
Less: Accounts payable and accrued liabilities	(9,910)	(8,827)
Net liquidity	$ 120,649	$ 172,477

- Definition

Cash includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the customer may deposit additional funds at any time and effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid Investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Short-term investments, exclusive of cash equivalents, generally consist of marketable securities intended to be sold within one year (or the normal operating cycle if longer) and may include trading securities, available-for-sale securities, or held-to-maturity securities (if maturing within one year), as applicable.

+ References + Details

Concentrations of Business Risk - Foreign Currency Exposure (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Intercompany Foreign Currency Balance [Line Items]
Cash and cash equivalents and short-term investments	$ 130,559	$ 181,304
Accounts receivable	273	1,008
Accrued revenue	128	128
Accounts payable and accrued liabilities	(9,910)	$ (8,827)
Foreign currency exposure
Intercompany Foreign Currency Balance [Line Items]
Cash and cash equivalents and short-term investments	43,094
Accounts receivable	289
Accrued revenue	128
Accounts payable and accrued liabilities	(3,238)
Exposure to Canadian dollar	$ 40,273

- Definition

+ References + Details

Supplementary Information (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Payables and Accruals [Abstract]
Trade accounts payable	$ 3,215	$ 2,610
Research and development accruals	3,131	2,358
Professional fee accruals	498	640
Deferred lease inducements	350	297
Payroll accruals	2,178	2,331
Other accrued liabilities	538	591
Accounts payable and accrued liabilities	$ 9,910	$ 8,827

Interim Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ (195)	$ 774	$ 309	$ 603	$ 12,686	$ 4,065	$ 3,440	$ 4,682	$ 1,491	$ 24,873	$ 14,953
Loss from operations	(257,439)	(18,975)	(195,248)	(19,977)	(11,758)	(58,138)	(14,420)	(18,006)	(491,639)	(102,322)	(33,434)
Net loss	$ (218,695)	$ (19,595)	$ (130,000)	$ (15,874)	$ (5,264)	$ (28,982)	$ (14,886)	$ (11,989)	$ (384,164)	$ (61,121)	$ (38,837)
Basic and diluted net loss per share (in USD per share)	$ (4.05)	$ (0.37)	$ (2.47)	$ (0.31)	$ (0.10)	$ (0.57)	$ (0.27)	$ (0.40)	$ (7.24)	$ (1.34)

Subsequent Events Subsequent Events (Details) - Alexion - Subsequent event	Mar. 16, 2017 USD ($)
Subsequent Event [Line Items]
Upfront payment	$ 7,500,000
Subsequent payments	$ 75,000,000

Consolidated Statement of Stockholders Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Statement of Stockholders' Equity [Abstract]
Issuance of common shares in conjunction with private offering, issuance costs	$ 4,085	$ 2,462

Property and Equipment (Details)	12 Months Ended
Property and Equipment (Details)	Dec. 31, 2016 USD ($)
Property, Plant and Equipment [Abstract]
Asset impairment charges	$ 0