Related Party Transactions (Details) $ in Thousands	12 Months Ended
Dec. 31, 2019 USD ($) ft²	Dec. 31, 2018 USD ($)
Roivant Sciences Ltd \| Co-venturer \| Research and development services
Related Party Transaction [Line Items]
Expenses from transactions with related party		$ 644
Genevant \| Equity Method Investee \| Research and development services
Related Party Transaction [Line Items]
Expenses from transactions with related party		398
Genevant \| Equity Method Investee \| Administrative and transitional services
Related Party Transaction [Line Items]
Income from related party	$ 106	226
Genevant \| Equity Method Investee \| Sublease Burnaby facility
Related Party Transaction [Line Items]
Income from related party	$ 180	$ 180
Area of sublease facility \| ft²	17,900

Net Rentable Area, Sublease

No definition available.

Name:	abus_NetRentableAreaSublease
Namespace Prefix:	abus_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

Name:	us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_RelatedPartyTransactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07.1(c))
-URI http://asc.fasb.org/extlink&oid=114873854&loc=SL114874292-224272

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(e))
-URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227

+ Details

Name:	us-gaap_RevenueFromRelatedParties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	srt_CounterpartyNameAxis=abus_RoivantSciencesLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_CoVenturerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=abus_ResearchAndDevelopmentServicesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=abus_GenevantSciencesCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_EquityMethodInvesteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=abus_AdministrativeAndTransitionalServicesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=abus_SubleaseBurnabyFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: