Leases - Additional Information (Details) $ in Thousands	12 Months Ended		96 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2027 USD ($)	Feb. 28, 2021 ft²	Jun. 29, 2020 USD ($)	Apr. 30, 2020 ft²	Jan. 01, 2020 USD ($)	Oct. 31, 2019 USD ($) ft²
Lessee, Lease, Description
Restricted cash	$ 1,733	$ 1,733
Operating lease right-of-use assets	38,516	42,804
Operating lease liability	58,332	62,342
Future sublease income outstanding	1,900
Sublease income recorded as other income	2,500	1,000
Office and Laboratory Space In Cambridge, Massachusetts
Lessee, Lease, Description
Area of leased property | ft²								81,441
Lessee, operating lease, term of contract								8 years
Operating lease term extension								5 years
Reimbursements from lessor	2,500	$ 15,400
Restricted cash	$ 1,700
Operating lease right-of-use assets							$ 38,600
Operating lease liability							$ 38,300
Office and Laboratory Space In Cambridge, Massachusetts | Forecast
Lessee, Lease, Description
Operating lease rent payments			$ 60,300
Office and Laboratory Space In Cambridge, Massachusetts | Scenario, Adjustment
Lessee, Lease, Description
Operating lease right-of-use assets					$ 7,400
Operating lease liability					$ 7,400
Office Space In Cambridge, Massachusetts
Lessee, Lease, Description
Area of leased property | ft²						16,843
Lessor, operating lease, term of contract						2 years
Additional Office Space In Cambridge, Massachusetts
Lessee, Lease, Description
Area of leased property | ft²				2,980
Maximum | Office and Laboratory Space In Cambridge, Massachusetts
Lessee, Lease, Description
Leasehold improvements landlord allowance								$ 3,000
Leasehold improvements landlord allowance to be repaid								$ 16,300