v3.26.1
Collaboration and License Agreements - Additional Information (Details) - Collaborative Arrangement
$ / shares in Units, $ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2026
USD ($)
non-clinicalStageCompound
geneTherapyProgram
undisclosedProgram
preclinicalCandidate
Mar. 31, 2025
USD ($)
Dec. 31, 2023
$ / shares
shares
Dec. 31, 2022
$ / shares
shares
Dec. 31, 2021
$ / shares
shares
Dec. 31, 2019
$ / shares
shares
Common Stock | Voyager            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Beneficial ownership (as a percent)     19.90%      
Nxera            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Research and development $ 22.5          
Potential milestone payments $ 2,480.0          
Agreement termination, contractual time threshold (in days) 90 days          
Agreement termination by counterparty, contractual time threshold (in days) 365 days          
Agreement termination by counterparty, minimal contractual time (in days) 120 days          
Takeda            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Research and development   $ 37.5        
Potential milestone payments $ 742.5          
Agreement termination, contractual time threshold (in days) 12 months          
Number of non-clinical stage compounds | non-clinicalStageCompound 3          
Agreement termination, minimal contractual time (in days) 6 months          
Xenon            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Research and development   $ 7.5        
Potential milestone payments $ 1,660.0          
Agreement termination, contractual time threshold (in days) 90 days          
Number of preclinical candidates | preclinicalCandidate 3          
Share price (in USD per share) | $ / shares       $ 31.855 $ 19.9755 $ 14.196
Xenon | Common Stock            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Sale of stock (in shares) | shares       300,000 300,000 1,400,000
2019 Voyager Agreement            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Potential milestone payments $ 465.0          
Agreement termination, contractual time threshold (in days) 1 year          
Agreement termination, minimal contractual time (in days) 180 days          
Share price (in USD per share) | $ / shares           $ 11.9625
Number of undisclosed programs | undisclosedProgram 2          
2019 Voyager Agreement | Common Stock            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Sale of stock (in shares) | shares           4,200,000
2023 Voyager Agreement            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Potential milestone payments $ 6,130.0          
Agreement termination, contractual time threshold (in days) 1 year          
Agreement termination, minimal contractual time (in days) 180 days          
Share price (in USD per share) | $ / shares     $ 8.88      
Number of gene therapy programs | geneTherapyProgram 3          
Board of directors maximum duration term (in years)     10 years      
2023 Voyager Agreement | Common Stock            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Sale of stock (in shares) | shares     4,400,000      
Sanofi S.A            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Potential milestone payments $ 10.0          
Sanofi S.A | Minimum            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Royalties at tiered percentage (as a percent) 3.00%          
Sanofi S.A | Minimum | Patents            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Patent term (in years) 16 years          
Sanofi S.A | Maximum            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Royalties at tiered percentage (as a percent) 5.00%