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Stock-based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions |  | 12 Months Ended
--- | --- | ---
Feb. 06, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
2019 Equity Incentive Plan |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | 4 years |  |  |
Expected weighted average period |  | 2 years 7 months 6 days |  |
Common stock reserved for issuance |  | 15,628,217 |  |
Percentage of stock owned by Individual | 10.00% |  |  |
Percentage of exercise price per share from fair market value | 110.00% |  |  |
Stock options, term | 5 years |  |  |
Cliff vesting percentage | 25.00% |  |  |
Cliff vesting period | 1 year |  |  |
Common stock, shares available for issuance | 2,973,219 |  |  |
Aggregate intrinsic value of option exercised |  | $ 11.1 | $ 1.8 | $ 0.0
Unrecognized stock-based compensation |  | $ 82.9 |  |
Weighted-average grant-date fair value per share of options granted |  | $ 10.14 | $ 12.06 | $ 6.27
2019 Employee Stock Purchase Plan |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Purchase price of common stock, percentage | 85.00% |  |  |
Subsequent offering period | 6 months |  |  |
Un-recognized compensation expense |  | $ 0.4 |  |
Minimum | 2019 Equity Incentive Plan |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Stock options, term | 10 years |  |  |
Restricted Common Stock |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period |  | 4 years |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage |  | 25.00% |  |
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount |  | $ 0.9 |  |
Expected weighted average period |  | 9 months 18 days |  |

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- Definition The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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