Equity Incentive Plans and Stock-Based Compensation - Restricted Common Stock Awards - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, not purchased	4,195
Weighted-average grant date fair value, not purchased	$ 0.08
Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate fair value of restricted stock awards vested	$ 161,000	$ 336,000
Total intrinsic value of outstanding unvested restricted stock awards	$ 3,600,000		$ 3,300,000