Leases - Additional Information (Details) $ in Millions		1 Months Ended			12 Months Ended
	Dec. 20, 2021 USD ($) ft²	Mar. 31, 2020 USD ($)	Oct. 31, 2019 USD ($) ft²	Apr. 30, 2019 ft²	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Feb. 28, 2018 ft²
Cambridge, Massachusetts | Noncancelable Facility Lease Agreement
Lessee Lease Description [Line Items]
Area of office space | ft²							9,836
Reduction of right-of-use asset and liability due to lease modification		$ 2.2
Lease termination date		Jul. 31, 2020
Cambridge, Massachusetts | Facility Sublease Agreement
Lessee Lease Description [Line Items]
Area of office space | ft²				1,471
Lease commencement date				Jun. 24, 2019
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	$ 20.1		$ 5.5
Base Rent	$ 0.8
Rent paid					$ 0.8
Annual increase percentage of rent	3.00%
Watertown, Massachusetts | Noncancelable Facility Lease Agreement | Restricted Cash | Letter of Credit
Lessee Lease Description [Line Items]
Security deposit					$ 4.5	$ 1.6
Watertown, Massachusetts | Facility Sublease Agreement
Lessee Lease Description [Line Items]
Lease commencement date	Nov. 30, 2023