Equity Incentive Plans - Stock Option Activity (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($) $ / shares shares
Shares Underlying Stock Options
Outstanding beginning balance, Shares underlying stock options and restricted stock awards (in shares) | shares	4,121,666
Granted, Shares underlying stock options and restricted stock awards (in shares) | shares	335,548
Exercised, Shares underlying stock options and restricted stock awards (in shares) | shares	(29,000)
Cancelled/Forfeited, Shares underlying stock options and restricted stock awards (in shares) | shares	(316,695)
Outstanding ending balance, Shares underlying stock options and restricted stock awards (in shares) | shares	4,111,519
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Shares | shares	1,146,185
Weighted- Average Exercise Price per Share
Outstanding beginning balance, Weighted - average exercise price (usd per share) | $ / shares	$ 8.67
Granted, Weighted - average exercise price (usd per share) | $ / shares	5.48
Exercised, Weighted - average exercise price (usd per share) | $ / shares	5.25
Cancelled/forfeited, Weighted - average exercise price (usd per share) | $ / shares	8.00
Outstanding ending balance, Weighted - average exercise price (usd per share) | $ / shares	8.48
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price | $ / shares	$ 17.18
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	8 years 4 months 20 days	[1]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	5 years 8 months 4 days	[1]
Outstanding, Aggregate Intrinsic Value | $	$ 175,807	[2]
Exercisable, Aggregate Intrinsic Value | $	$ 21,693	[2]

[1] Represents the weighted-average remaining contractual term of stock options.

[2] Aggregate intrinsic value represents the product of the number of equity awards outstanding or equity awards exercisable multiplied by the difference between the Company’s closing stock price per share on the last trading day of the period, which was $4.24 as of March 31, 2021, and the exercise price.