Shareholders’ equity - Stock-based Compensation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average exercise price (in USD per share)	$ 3.34	$ 3.27	$ 3.32	$ 2.49
Restricted stock units granted during period (in shares)	0	0	901,900	1,316,200
Grant date fair value (in USD per share)	$ 0	$ 0	$ 3.29	$ 2.40
Allocated share-based compensation expense	$ 764	$ 3,180	$ 2,057	$ 5,194
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense	374	1,119	929	2,160
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense	$ 390	$ 2,061	$ 1,128	$ 3,034
Arbutus Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted during period (in shares)	762,400	424,200	4,706,122	4,163,000

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.

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+ Details

Arbutus Biopharma Corp 10-Q