Equity Incentive Plans - Stock Option Activity (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 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	962,140
Exercised, Shares underlying stock options and restricted stock awards (in shares) | shares	(29,677)
Cancelled/Forfeited, Shares underlying stock options and restricted stock awards (in shares) | shares	(957,925)
Outstanding ending balance, Shares underlying stock options and restricted stock awards (in shares) | shares	4,096,204
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Shares | shares	1,738,026
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	4.60
Exercised, Weighted - average exercise price (usd per share) | $ / shares	5.21
Cancelled/forfeited, Weighted - average exercise price (usd per share) | $ / shares	10.18
Outstanding ending balance, Weighted - average exercise price (usd per share) | $ / shares	7.22
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price | $ / shares	$ 10.74
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	8 years 2 months 12 days	[1]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	7 years 1 month 6 days	[1]
Outstanding, Aggregate Intrinsic Value | $	$ 1.0	[2]
Exercisable, Aggregate Intrinsic Value | $	$ 0.3	[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 $4.65 as of December 31, 2021, and the exercise price.