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The number of shares sold by the collaboration partner per stock transaction.

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Amount of expense for research and development. Includes, but is not limited to, cost for computer software product to be sold, leased, or otherwise marketed and writeoff of research and development assets acquired in transaction other than business combination or joint venture formation or both. Excludes write-down of intangible asset acquired in business combination or from joint venture formation or both, used in research and development activity.

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Collaboration and License Agreements - Additional Information (Details) - Collaborative Arrangement $ / shares in Units, $ in Millions	3 Months Ended			6 Months Ended	12 Months Ended
	Mar. 31, 2026 USD ($)	Jun. 30, 2025 USD ($)	Mar. 31, 2025 USD ($)	Jun. 30, 2026 USD ($) geneTherapyProgram non-clinicalStageCompound preclinicalCandidate undisclosedProgram	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	$ 15.0
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%