Net Loss Per Share - Schedule of Dilutive Shares Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive shares	10,474,613	7,161,541	10,474,613	7,161,541
Restricted Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive shares	415,521	1,191,750	415,521	1,191,750
Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive shares	10,033,270	5,918,124	10,033,270	5,918,124
Shares Committed Under ESPP
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive shares	25,822	51,667	25,822	51,667