Research and Collaboration Arrangements - Summary of Deferred Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total deferred revenue	$ 5,090	$ 19,812
uniQure
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total deferred revenue	3,661	4,396
Roche
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total deferred revenue		14,318
CFF
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total deferred revenue	$ 1,429	$ 1,098