Leases - Narrative (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023	Nov. 30, 2021
Lessee, Lease, Description [Line Items]
Restricted cash	$ 13,496	$ 13,496
Operating lease right-of-use assets	51,594	13,941
Total operating lease liability	41,583
Prepaid expenses	(4,199)	(19,057)
60 First Street, Cambridge, Massachusetts Lease
Lessee, Lease, Description [Line Items]
Term of contract, lease not yet commenced (in years)			10 years
Operating lease, extension (in years)			10 years
Restricted cash	13,100	$ 13,100
Operating lease right-of-use assets	44,900
Total operating lease liability	33,600
60 First Street, Cambridge, Massachusetts Lease | Revision of Prior Period, Reclassification, Adjustment
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets	11,300
Prepaid expenses	$ 11,300