Operating Leases - Additional Information (Details)						3 Months Ended		9 Months Ended
	Dec. 16, 2021 OfficeSuite	Nov. 17, 2021 USD ($)	Nov. 10, 2021	May 10, 2021 USD ($)	Jan. 27, 2021 OfficeSuite	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Aug. 31, 2023 USD ($)	Aug. 01, 2023 USD ($)	Dec. 31, 2022 USD ($)
Lessee Lease Description [Line Items]
Operating lease right-of-use assets						$ 13,195,000		$ 13,195,000				$ 5,580,000
Operating lease liability						53,111,000		53,111,000
Contractual Obligation, to be Paid, Remainder of Fiscal Year						0		0
Current portions of operating lease liability						3,439,000		3,439,000				4,045,000
Non-current portions of operating lease liability						$ 49,672,000		$ 49,672,000				$ 1,749,000
Remaining lease term on operating leases						110 months		110 months
Weighted average incremental borrowing rate on operating lease						10.90%		10.90%
Lease expense						$ 2,400,000	$ 1,700,000	$ 6,400,000	$ 5,000,000
Variable lease payments						800,000	$ 300,000	1,800,000	$ 1,000,000
Explora BioLabs, Inc
Lessee Lease Description [Line Items]
Operating lease right-of-use assets						0		0
Operating lease liability						0		$ 0
Lease Agreement
Lessee Lease Description [Line Items]
Lessee, operating lease, option to extend								The term of the lease is 44 months for the first office suite and 43 months for the second office suite with an option to extend the term for an additional two years on the same terms and conditions
Number of office suites | OfficeSuite					2
Operating lease right-of-use assets						13,200,000		$ 13,200,000
Operating lease liability						53,100,000		$ 53,100,000
First Office Suite
Lessee Lease Description [Line Items]
Operating lease commencement date			Nov. 10, 2021		Jul. 31, 2021
Sublease expire date			Dec. 06, 2023
Second Office Suite
Lessee Lease Description [Line Items]
Operating lease commencement date					Aug. 31, 2021
Embedded Lease Agreement | Laboratory For Cell And Gene Medicine
Lessee Lease Description [Line Items]
Finance lease maturity date				Apr. 30, 2023
Fixed lease payments				$ 5,600,000
License Service Agreement and Master Services Agreement | Explora BioLabs, Inc
Lessee Lease Description [Line Items]
Finance lease maturity date		Nov. 30, 2023
Fixed lease payments		$ 700,000
Bayside Lease [Member]
Lessee Lease Description [Line Items]
Term of contract	120 months									20 months	20 months
Office And Laboratory Space | OfficeSuite	85,165
Lessee, operating lease, option to extend								The term of the lease is 120 months with the option to extend the term up to an additional ten years.
Operating lease liability						32,000,000		$ 32,000,000
Leasehold improvements						27,200,000		27,200,000
Leasehold tenant improvement allowance								14,900,000
Leasehold improvements liability utilized and recorded						14,900,000		14,900,000
Sublease payments										$ 500,000	$ 500,000
Sublease Income						$ 100,000		$ 100,000