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Stock-Based Compensation Plans - Additional Information (Details) - USD ($) |  |  |  | 1 Months Ended | 3 Months Ended | 9 Months Ended | 45 Months Ended |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Jun. 28, 2023 | Aug. 01, 2021 | Apr. 25, 2021 | Sep. 30, 2023 | Jul. 31, 2019 | Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2021 | Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2021 | Sep. 30, 2023 | Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Expected dividend yield (as percent) |  |  |  |  |  |  |  |  | 0.00% |  |  |  |
Total unrecognized compensation expense |  |  |  | $ 12,700,000 |  | $ 12,700,000 |  |  | $ 12,700,000 |  |  | $ 12,700,000 |
Period over which compensation cost will be recognized, in years |  |  |  |  |  |  |  |  | 2 years 10 months 24 days |  |  |  |
2021 Employee stock Purchase Plan |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Purchase price of the stock, at discount from market price at purchase date (as a percent) |  |  | 85.00% |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant |  |  | 200,000 |  |  |  |  |  |  |  |  |  |
RSUs granted (in shares) |  | 167,642 |  |  |  |  |  |  |  |  |  |  |
Share-based compensation expense |  |  |  |  |  | $ 19,000 | $ 21,000 |  | $ 102,000 | $ 74,000 |  |  |
Maximum annual contributions per employee (as a percent) |  |  | 15.00% |  |  |  |  |  |  |  |  |  |
2021 Employee stock Purchase Plan | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Additional shares authorized (in shares) |  |  |  | 1,000,000 |  |  |  |  |  |  |  |  |
2019 Omnibus Equity Incentive Plan |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant |  |  |  |  | 1,500,000 |  |  |  |  |  |  |  |
Expected term of options (years) |  |  |  |  |  |  |  |  | 6 years 3 days | 6 years |  |  |
Expected dividend yield (as percent) |  |  |  |  |  |  |  |  | 0.00% | 0.00% |  |  |
Options granted in period, weighted-average grant date fair value (in USD per share) |  |  |  |  |  |  |  |  | $ 1.32 | $ 6.94 |  |  |
2019 Omnibus Equity Incentive Plan | Incentive stock options |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Vesting period (in years) |  |  |  |  |  |  |  |  | 4 years |  |  |  |
2019 Omnibus Equity Incentive Plan | Minimum | Non-statutory options |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Vesting period (in years) |  |  |  |  |  |  |  |  | 3 years |  |  |  |
2019 Omnibus Equity Incentive Plan | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Expected term of options (years) |  |  |  |  |  |  |  |  | 10 years |  |  |  |
2019 Omnibus Equity Incentive Plan | Maximum | Non-statutory options |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Vesting period (in years) |  |  |  |  |  |  |  |  | 4 years |  |  |  |
2019 Omnibus Equity Incentive Plan, Evergreen Provision |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Additional shares authorized (as a percent) |  |  |  |  | 4.00% |  |  |  |  |  |  |  |
Additional shares authorized (in shares) |  |  |  |  | 4,900,000 |  |  |  |  |  |  | 4,408,871 |
Increase in other share (in shares) | 4,440,000 |  |  |  |  |  |  |  |  |  |  |  |
2014 Equity Incentive Plan |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant |  |  |  | 43,311 |  | 43,311 |  |  | 43,311 |  |  | 43,311 |
2017 Inducement Equity Incentive Plan |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant |  |  |  |  |  |  |  |  |  |  |  |  | 46,250
Share-based compensation expense |  |  |  |  |  |  | $ 0 | $ 0 |  | $ 0 | $ 0 |  |

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