Commitments and Contingencies - Additional Information (Details) - USD ($)	1 Months Ended	9 Months Ended
	Jun. 30, 2020	Sep. 30, 2020
Commitments and Contingencies [Line Items]
Operating lease, description		Currently, the Company is only party to non-cancellable office and laboratory space operating leases and a short-term office lease. Under the relevant guidance, the Company recognizes operating lease right-of-use (ROU) assets and liabilities based on the present value of the future minimum lease payments over the lease term at the commencement date, using the Company’s assumed incremental borrowing rate of 5.5%, and amortizes the ROU assets and liabilities over the lease term. Lease expense for operating leases is recognized on a straight-line basis over the lease term. The Company’s short-term lease is not subject to recognition of an ROU asset or liability or straight-line lease expense requirements.
Incremental borrowing rate		5.50%
Loss contingencies accrued		$ 0
Lease Term through November 2017 | Office and Laboratory Space
Commitments and Contingencies [Line Items]
Operating lease, term of contract, description		In March 2014, the Company entered into a non-cancellable operating lease for office and laboratory space with a lease term through November 2017
Lease Term through December 2021 | Office and Laboratory Space
Commitments and Contingencies [Line Items]
Operating lease, term of contract, description		In July 2017, the Company entered into an amendment to this lease to extend the lease term through December 2021.
New Lease | Office and Laboratory Space
Commitments and Contingencies [Line Items]
Operating lease, lease not yet commenced, description		On June 1, 2020, the Company entered into a second amendment to its existing operating lease (as amended, the 2014 Lease) and entered into a new non-cancellable temporary operating lease (the Temporary Lease) in connection with a newly executed non-cancellable operating lease for its headquarters location, commencing on July 1, 2021 (the New Lease).
Operating lease, lease not yet commenced, lease payment under new lease		$ 7,300,000
Operating lease, lease not yet commenced, term of contract	5 years
Operating lease, lease not yet commenced, initial monthly base rent	$ 124,000
Operating lease, lease not yet commenced, monthly base rent for last year lease	139,000
Letter of credit	$ 124,000
Temporary Lease | Office and Laboratory Space
Commitments and Contingencies [Line Items]
Operating lease expiration period, description		The lease term under both the 2014 Lease and the Temporary Lease ends 15 days after the commencement date of the New Lease in July 2021.
Operating lease lease expiration period	15 days