Equity Incentive Plans and Stock-Based Compensation - 2020 Employee Stock Purchase Plan - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total shares reserved for future issuance		7,416,476		7,416,476		20,346,844
Stock-based compensation expense		$ 1,169,000	$ 480,000	$ 2,380,000	$ 1,298,000
Shares of Common Stock Available for Future Issuance under the 2020 ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total shares reserved for future issuance	700,000
Employee stock purchase plan, description				The 2020 ESPP provides that the number of shares reserved and available for issuance will automatically increase on January 1 of each calendar year, beginning January 1, 2021, by the least of (1) 1.0% of the total number of shares of common stock outstanding on December 31 of the preceding calendar year, (2) 700,000 shares or (3) such lesser amount as determined by the administrator of the 2020 ESPP, which is the compensation committee of the board of directors.
Common stock shares outstanding percentage	1.00%
Percentage of payroll deductions		15.00%		15.00%
Employee stock purchase plan offering period				6 months
Stock-based compensation expense		$ 200,000	$ 0	$ 200,000	$ 0
Common stock fair market value percentage				85.00%
Number of common stock issued				0