Equity Incentive Plans - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares
Shares
Shares Subject to Options Outstanding, Outstanding as of beginning of period (in shares) | shares	9,401,082
Shares Subject to Options Outstanding, Options granted (in shares) | shares	2,591,751
Shares Subject to Options Outstanding, Option exercised (in shares) | shares	(109,643)
Shares Subject to Options Outstanding, Options forfeited/cancelled (in shares) | shares	(1,447,260)
Shares Subject to Options Outstanding, Outstanding as of end of period (in shares) | shares	10,435,930	9,401,082
Shares Subject to Options Outstanding, Options vested and exercisable as of end of period (in shares) | shares	4,431,654
Weighted- Average Exercise Price
Weighted-Average Exercise Price, Outstanding as of beginning of period (in USD per share) | $ / shares	$ 13.42
Weighted-Average Exercise Price, Options granted (in USD per share) | $ / shares	9.70
Weighted-Average Exercise Price, Option exercised (in USD per share) | $ / shares	2.61
Weighted-Average Exercise Price, Options forfeited/cancelled (in USD per share) | $ / shares	13.71
Weighted-Average Exercise Price, Outstanding as of end of period (in USD per share) | $ / shares	12.56	$ 13.42
Weighted-Average Exercise Price, Options vested and exercisable as of end of period (in USD per share) | $ / shares	$ 12.89
Weighted-Average Remaining Contractual Life (in years)	7 years 7 months 6 days	8 years 1 month 6 days
Weighted-Average Remaining Contractual Life (in years), Options vested and exercisable as of end of period	6 years 3 months 18 days
Aggregate Intrinsic Value | $	$ 6,887	$ 10,182
Aggregate Intrinsic Value, Options vested and exercisable as of end of period | $	$ 5,333