Equity Incentive Plans - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Shares
Shares Subject to Options Outstanding, Outstanding as of December 31, 2020 (in shares)	9,401,082
Shares Subject to Options Outstanding, Options granted (in shares)	2,215,526
Shares Subject to Options Outstanding, Option exercised (in shares)	(5,721)
Shares Subject to Options Outstanding, Options forfeited/cancelled (in shares)	(220,656)
Shares Subject to Options Outstanding, Outstanding as of March 31, 2021 (in shares)	11,390,231	9,401,082
Shares Subject to Options Outstanding, Options vested and exercisable as of March 31, 2021 (in shares)	4,431,654
Weighted- Average Exercise Price
Weighted-Average Exercise Price, Outstanding as of December 31, 2020 (in USD per share)	$ 13.42
Weighted-Average Exercise Price, Options granted (in USD per share)	9.82
Weighted-Average Exercise Price, Option exercised (in USD per share)	2.61
Weighted-Average Exercise Price, Options forfeited/cancelled (in USD per share)	16.06
Weighted-Average Exercise Price, Outstanding as of March 31, 2021 (in USD per share)	13.83	$ 13.42
Weighted-Average Exercise Price, Options vested and exercisable as of March 31, 2021 (in USD per share)	$ 12.76
Weighted-Average Remaining Contractual Life (in years)	8 years 1 month 6 days	8 years 1 month 6 days
Weighted-Average Remaining Contractual Life (in years), Options vested and exercisable as of March 31, 2021	7 years 3 months 18 days
Aggregate Intrinsic Value	$ 9,464	$ 10,182
Aggregate Intrinsic Value, Options vested and exercisable as of March 31, 2021	$ 6,558