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Stock-based Compensation - Narrative (Details) $ / shares in Units, $ in Millions |  |  | 1 Months Ended | 3 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | ---
Jan. 01, 2024 shares | Nov. 16, 2023 USD ($) grantee $ / shares shares | Jun. 30, 2021 shares | Mar. 31, 2024 USD ($) $ / shares shares | Mar. 31, 2023 $ / shares shares | Dec. 31, 2018 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Total stock-based compensation cost related to unvested awards not yet recognized | $ |  |  |  | $ 66.0 |  |
Expected weighted-average period compensation cost to be recognized |  |  |  | 2 years 8 months 12 days |  |
Weighted average grant date fair value (in dollars per share) | $ / shares |  |  |  | $ 1.26 | $ 1.66 |
Performance Shares |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Award performance period |  |  |  | 3 years |  |
Service period from the milestone achievement date |  |  |  | 1 year |  |
Performance Shares | Achievement of applicable milestone |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Award vesting rights, percentage |  |  |  | 50.00% |  |
Performance Shares | Earlier of one year of service from achievement date and three-year performance period |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Award vesting rights, percentage |  |  |  | 50.00% |  |
2023 | Stock option |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Minimum exercise price of plan modifications (in dollars per share) | $ / shares |  | $ 2.37 |  |  |  |
Original exercise price lower range (in dollars per share) | $ / shares |  | 2.61 |  |  |  |
Original exercise price upper range (in dollars per share) | $ / shares |  | $ 17.95 |  |  |  |
Share-based payment arrangement, plan modification, number of grantees affected | grantee |  | 200 |  |  |  |
Shares repriced (in shares) |  | 23,416,860 |  |  |  |
Plan modification, exercise price (in dollars per share) | $ / shares |  | $ 1.87 |  |  |  |
Incremental stock-based compensation expense of modifications | $ |  | $ 8.9 |  |  |  |
Maximum | Performance Shares |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Performance period relative to total shareholder return |  |  |  | 3 years |  |
Awards granted, percentage of target |  |  |  | 200.00% |  |
Minimum | Performance Shares |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Performance period relative to total shareholder return |  |  |  | 2 years |  |
Awards granted, percentage of target |  |  |  | 0.00% |  |
2021 Plan |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Common shares reserved for future issuance (in shares) |  |  | 26,662,087 |  |  |
Award expiration period |  |  | 10 years |  |  |
Proportion of stock outstanding (as a percent) |  |  | 5.00% |  |  |
Number of additional shares authorized for issuance (in shares) | 12,697,885 |  |  |  |  |
Increase in proportion of common shares reserved for future issuance (as a percent) | 5.00% |  |  |  |  |
Future issuance of common shares (in shares) |  |  |  | 33,623,495 |  |
2021 Plan | Stock option |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Vesting period |  |  | 4 years |  |  |
2021 Plan | RSUs |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Vesting period |  |  | 4 years |  |  |
2021 Plan | Performance Shares |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Vesting period |  |  | 3 years |  |  |
2021 Plan | Maximum |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Award expiration period |  |  | 10 years |  |  |
2021 ESPP |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Common shares reserved for future issuance (in shares) |  |  | 2,470,000 |  |  |
Award expiration period |  |  | 10 years |  |  |
Proportion of stock outstanding (as a percent) |  |  | 1.00% |  |  |
Number of additional shares authorized for issuance (in shares) | 2,539,577 |  |  |  |  |
Future issuance of common shares (in shares) |  |  |  | 6,001,206 |  |
Purchase of common stock at discount (as a percent) |  |  | 15.00% |  |  |
Employee purchase of shares, proportion of fair value (as a percent) |  |  | 85.00% |  |  |
Maximum number of shares to be purchased under ESPP (in shares) |  |  | 4,940,000 |  |  |
Maximum offering period |  |  | 27 months |  |  |
Stock-based compensation (in shares) |  |  |  | 0 | 0 |
2018 Equity Incentive Plan |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Award expiration period |  |  |  |  |  | 10 years
Vesting period |  |  |  |  |  | 4 years
Future issuance of common shares (in shares) |  |  |  |  |  | 0

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