Summary of Common Stock Reserved for Future Issuance (Detail)	Sep. 30, 2020 shares
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Common stock reserved for future issuance	11,026,866
Exercise of Outstanding Stock Options, Vesting of Restricted Stock Units ("RSU"), and Issuance of RSUs Vested but not Released
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Common stock reserved for future issuance	1,710,044
Employee Stock Purchase Plan
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Common stock reserved for future issuance	293,888
Shares of Common Stock Available for Grant Under the 2011 Plan
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Common stock reserved for future issuance	1,166,485
Warrants to Purchase Common Stock
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Common stock reserved for future issuance	315,000
Shares of Common Stock Issuable Upon Conversion of Series B Convertible Preferred Stock
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Common stock reserved for future issuance	7,541,449