Research and Collaboration Arrangements - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Jan. 31, 2014	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	Aug. 31, 2019
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized				$ 1,400,000	$ 14,000,000.0
Deferred revenue		$ 3,708,000		3,708,000		$ 5,090,000
Accounts receivable		0		0		47,000
uniQure
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue		2,309,000		2,309,000		3,661,000
Accounts receivable		$ 0		0		0
uniQure | uniQure Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Increase in revenue recognized related to performance obligations partially satisfied in the beginning of the current year				$ 1,300,000
Collaborative arrangement, initial research term	3 years
Upfront payments received	$ 200,000
Options to purchase ordinary shares	609,744
Ordinary shares vesting period	3 years
Fair value of options	$ 10,600,000
uniQure | uniQure Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contingent payments entitled to receive for achievement of research and development milestones	$ 5,000,000.0
Deferred revenue, estimated performance period		2 years		2 years
uniQure | uniQure Agreement | Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue, estimated performance period		1 year		1 year
uniQure | Amended uniQure Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized		$ 200,000	$ 300,000	$ 1,400,000	$ 700,000
Fair value of non monetary consideration of intellectual property right							$ 5,100,000
Remaining performance obligations		$ 2,500,000		$ 2,500,000		$ 3,700,000
uniQure | Amended uniQure Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contingent payments eliminated							$ 5,000,000.0