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Commitments and Contingencies - Additional Information (Details) $ in Millions				1 Months Ended	9 Months Ended
	Jun. 05, 2020	Apr. 11, 2020 USD ($)	Sep. 27, 2017 USD ($)	Sep. 30, 2018 Patent	Sep. 30, 2020
Commitments And Contingencies [Line Items]
Minimum percentage of loan proceeds used to cover payroll costs eligible for loan forgiven	60.00%	75.00%
Pending Litigation \| Piper Sandler & Co.
Commitments And Contingencies [Line Items]
Loss contingency payable fees			$ 1.1
Loss contingency closing date			Sep. 19, 2017
Financing aggregate consideration			$ 15.7
Reimbursement expenses			$ 0.1
PPP Loan
Commitments And Contingencies [Line Items]
Debt instrument, description					On June 5, 2020, the Payroll Protection Flexibility Act of 2020 was signed into law, adjusting certain terms of the loans issued under the PPP, including extending the initial deferral period from six to up to ten months, reducing from 75% to 60% the portion of loan proceeds required to be used to cover payroll costs, and allowing borrowers to elect a 24-week rather than an eight-week period related to employment and compensation provisions.
PPP Loan \| JPMorgan Chase Bank, N.A
Commitments And Contingencies [Line Items]
CARES act of 2020 aid loan amount		$ 0.6
Promissory Note \| JPMorgan Chase Bank, N.A
Commitments And Contingencies [Line Items]
Debt Instrument, Term		2 years
Debt Instrument, fixed interest rate		1.00%
Assistance Publique – Hôpitaux de Paris (“AP-HP”) \| License Agreement
Commitments And Contingencies [Line Items]
Agreement entered date				2018-09
Number of patent applications \| Patent				3
Assistance Publique – Hôpitaux de Paris (“AP-HP”) \| Private Acer \| License Agreement
Commitments And Contingencies [Line Items]
Agreement entered date					2016-08