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Leases - Additional Information (Details) $ in Thousands |  | 1 Months Ended | 3 Months Ended | 9 Months Ended |
--- | --- | --- | --- | --- | ---
Dec. 20, 2021 USD ($) ft² | Oct. 31, 2019 ft² | Mar. 31, 2024 USD ($) | Sep. 30, 2025 USD ($) | Dec. 31, 2024 USD ($)
Lessee Lease Description [Line Items] |  |  |  |  |
Operating lease liabilities, net of current portion |  |  |  | $ 68,450 | $ 72,423
impairment charge |  |  | $ 4,900 | 3,900 |
Land, Buildings and Improvements [Member] |  |  |  |  |
Lessee Lease Description [Line Items] |  |  |  |  |
Operating lease liabilities, net of current portion |  |  |  | 48,900 |
Operating lease right-of-use asset |  |  |  | 48,900 |
landlord [Member] |  |  |  |  |
Lessee Lease Description [Line Items] |  |  |  |  |
Leasehold improvements in excess of the tenant improvement allowance |  |  |  | 17,900 |
Leasehold improvements in property and equipment |  |  |  | 20,100 |
Watertown, Massachusetts |  |  |  |  |
Lessee Lease Description [Line Items] |  |  |  |  |
Lease term | 134 months |  |  |  |
Watertown, Massachusetts | Noncancelable Facility Lease Agreement |  |  |  |  |
Lessee Lease Description [Line Items] |  |  |  |  |
Area of office space | ft² | 100,624 | 34,522 |  |  |
Lease term |  | 120 months |  |  |
Lease expiration date |  | Mar. 31, 2030 |  |  |
Lease additional term | 5 years | 5 years |  |  |
Tenant incentive allowance receivable | $ 20,100 |  |  |  |
Base Rent | $ 800 |  |  |  |
Annual increase percentage of rent | 3.00% |  |  |  |
Watertown, Massachusetts | Noncancelable Facility Lease Agreement | Restricted Cash | Letter of Credit | 2019 Lease |  |  |  |  |
Lessee Lease Description [Line Items] |  |  |  |  |
Security deposit |  |  |  | 1,300 | 1,300
Watertown, Massachusetts | Noncancelable Facility Lease Agreement | Restricted Cash | Letter of Credit | 2021 Lease |  |  |  |  |
Lessee Lease Description [Line Items] |  |  |  |  |
Security deposit |  |  |  | $ 4,500 | $ 4,500
Watertown, Massachusetts | Facility Sublease Agreement |  |  |  |  |
Lessee Lease Description [Line Items] |  |  |  |  |
Lease commencement date | Dec. 31, 2023 |  |  |  |

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