Common Stock - Schedule of Common Stock Shares Reserved for Future Issuance (Details) - 2020 Plan and 2014 Plan - shares	Sep. 30, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Common stock reserved for future issuances	11,748,083	9,839,680
Options Issued and Outstanding
Class Of Stock [Line Items]
Common stock reserved for future issuances	5,427,007	5,188,531
Shares Available for Future Stock Option Grants
Class Of Stock [Line Items]
Common stock reserved for future issuances	6,321,076	4,651,149