Collaborations, Licensing Agreements and Other Agreements - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended					6 Months Ended
	May 31, 2020	Jun. 30, 2026	Mar. 31, 2026	Jun. 30, 2025	Mar. 31, 2024	Mar. 31, 2023	Jun. 30, 2026	Jun. 30, 2025	Jan. 31, 2024	Dec. 31, 2023	Aug. 31, 2023	May 31, 2023	Oct. 07, 2022
Collaborations, Licensing Agreements And Other Agreements [Line Items]
Research and development expense		$ 44,430		$ 37,638			$ 81,783	$ 66,656
Upfront payment										$ 1,100
License Agreement
Collaborations, Licensing Agreements And Other Agreements [Line Items]
Obligation to be paid		2,000					$ 2,000
Payment term							3 years
License maintenance fee	$ 33						$ 10
Total milestone payments							21,000
Amounts due to agreement		0					0
License Agreement \| Maximum
Collaborations, Licensing Agreements And Other Agreements [Line Items]
Total milestone payments							12,000
Sponsored Research Agreements
Collaborations, Licensing Agreements And Other Agreements [Line Items]
Obligation to be paid		12,560					12,560
Master Translational Research Services Agreement
Collaborations, Licensing Agreements And Other Agreements [Line Items]
Research and development expense		167		$ 2,232			929	$ 3,274
Remaining research and development expense to be incurred			$ 0
Oxford Biomedica
Collaborations, Licensing Agreements And Other Agreements [Line Items]
Obligation to be paid											$ 5,000
Total milestone payments							500
Research and development expense							23,000
Upfront payment												$ 500
Expenses							14,233
Nanjing IASO Biotherapeutics Co., Ltd.
Collaborations, Licensing Agreements And Other Agreements [Line Items]
Total milestone payments					$ 1,500	$ 1,000	2,500
Upfront payment		$ 162,000					162,000						$ 2,500
Autolus Holdings
Collaborations, Licensing Agreements And Other Agreements [Line Items]
Upfront payment						$ 1,200			$ 100
Autolus Holdings \| Maximum
Collaborations, Licensing Agreements And Other Agreements [Line Items]
Total milestone payments							$ 15,000