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Fair Value Measurements - Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Recurring - USD ($) $ in Thousands | Dec. 31, 2021 | Dec. 31, 2020
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Assets: |  |  |  |  |
Total fair value of assets |  | $ 450,383 |  | $ 111,463 |
Liabilities: |  |  |  |  |
Total fair value of liabilities |  |  |  | 1,615 |
Preferred Stock Purchase Right Liability |  |  |  |  |
Liabilities: |  |  |  |  |
Total fair value of liabilities |  |  |  | 1,615 |
Money Market Funds | Cash and Cash Equivalents |  |  |  |  |
Assets: |  |  |  |  |
Total fair value of assets |  | 351,625 | [1] | 57,238 | [2]
US Treasury Securities | Short-Term Investments |  |  |  |  |
Assets: |  |  |  |  |
Total fair value of assets |  | 18,097 | [3] | 38,492 | [4]
US Treasury Securities | Long-Term Investments |  |  |  |  |
Assets: |  |  |  |  |
Total fair value of assets | [5] | 44,770 |  |  |
Corporate Debt Securities | Short-Term Investments |  |  |  |  |
Assets: |  |  |  |  |
Total fair value of assets |  | 2,822 | [3] | 3,793 | [4]
Commercial Paper | Cash and Cash Equivalents |  |  |  |  |
Assets: |  |  |  |  |
Total fair value of assets | [2] |  |  | 900 |
Commercial Paper | Short-Term Investments |  |  |  |  |
Assets: |  |  |  |  |
Total fair value of assets |  | 31,566 | [3] | 11,040 | [4]
Supranational Debt Securities | Short-Term Investments |  |  |  |  |
Assets: |  |  |  |  |
Total fair value of assets | [3] | 1,503 |  |  |
Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |  |  |
Assets: |  |  |  |  |
Total fair value of assets |  | 414,492 |  | 95,730 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Money Market Funds | Cash and Cash Equivalents |  |  |  |  |
Assets: |  |  |  |  |
Total fair value of assets |  | 351,625 | [1] | 57,238 | [2]
Quoted Prices in Active Markets for Identical Assets (Level 1) | US Treasury Securities | Short-Term Investments |  |  |  |  |
Assets: |  |  |  |  |
Total fair value of assets |  | 18,097 | [3] | 38,492 | [4]
Quoted Prices in Active Markets for Identical Assets (Level 1) | US Treasury Securities | Long-Term Investments |  |  |  |  |
Assets: |  |  |  |  |
Total fair value of assets | [5] | 44,770 |  |  |
Significant Other Observable Inputs (Level 2) |  |  |  |  |
Assets: |  |  |  |  |
Total fair value of assets |  | 35,891 |  | 15,733 |
Significant Other Observable Inputs (Level 2) | Corporate Debt Securities | Short-Term Investments |  |  |  |  |
Assets: |  |  |  |  |
Total fair value of assets |  | 2,822 | [3] | 3,793 | [4]
Significant Other Observable Inputs (Level 2) | Commercial Paper | Cash and Cash Equivalents |  |  |  |  |
Assets: |  |  |  |  |
Total fair value of assets | [2] |  |  | 900 |
Significant Other Observable Inputs (Level 2) | Commercial Paper | Short-Term Investments |  |  |  |  |
Assets: |  |  |  |  |
Total fair value of assets |  | 31,566 | [3] | 11,040 | [4]
Significant Other Observable Inputs (Level 2) | Supranational Debt Securities | Short-Term Investments |  |  |  |  |
Assets: |  |  |  |  |
Total fair value of assets | [3] | $ 1,503 |  |  |
Significant Unobservable Inputs (Level 3) |  |  |  |  |
Liabilities: |  |  |  |  |
Total fair value of liabilities |  |  |  | 1,615 |
Significant Unobservable Inputs (Level 3) | Preferred Stock Purchase Right Liability |  |  |  |  |
Liabilities: |  |  |  |  |
Total fair value of liabilities |  |  |  | $ 1,615 |
[1] | Included as cash and cash equivalents on the consolidated balance sheets.
[2] | Included as cash and cash equivalents on the consolidated balance sheets.
[3] | Included as short-term investments on the consolidated balance sheets.
[4] | Included as short-term investments on the consolidated balance sheets.
[5] | Included as long-term investments on the consolidated balance sheets.

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