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Significant Accounting Policies - Estimated Fair Value of Assets and Liability (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands | Sep. 30, 2023 | Dec. 31, 2022
--- | --- | ---
Asset: |  |
Asset, fair value | $ 232,240 | $ 192,307
Money Market Fund |  |
Asset: |  |
Asset, fair value | 179,173 | 81,870
Commercial Paper |  |
Asset: |  |
Asset, fair value | 4,769 | 62,347
Agency Securities |  |
Asset: |  |
Asset, fair value | 18,762 | 1,554
Certificates of Deposit |  |
Asset: |  |
Asset, fair value | 1,600 | 9,100
Corporate Bonds |  |
Asset: |  |
Asset, fair value |  | 28,416
Repo Securities |  |
Asset: |  |
Asset, fair value | 3,250 | 3,250
U.S. Treasury Securities |  |
Asset: |  |
Asset, fair value | 24,686 | 3,117
Asset Backed Securities |  |
Asset: |  |
Asset, fair value |  | 1,260
Non-US Government |  |
Asset: |  |
Asset, fair value |  | 1,393
Level 1 |  |
Asset: |  |
Asset, fair value | 203,859 | 86,541
Level 1 | Money Market Fund |  |
Asset: |  |
Asset, fair value | 179,173 | 81,870
Level 1 | Agency Securities |  |
Asset: |  |
Asset, fair value |  | 1,554
Level 1 | U.S. Treasury Securities |  |
Asset: |  |
Asset, fair value | 24,686 | 3,117
Level 2 |  |
Asset: |  |
Asset, fair value | 28,381 | 105,766
Level 2 | Commercial Paper |  |
Asset: |  |
Asset, fair value | 4,769 | 62,347
Level 2 | Agency Securities |  |
Asset: |  |
Asset, fair value | 18,762 |
Level 2 | Certificates of Deposit |  |
Asset: |  |
Asset, fair value | 1,600 | 9,100
Level 2 | Corporate Bonds |  |
Asset: |  |
Asset, fair value |  | 28,416
Level 2 | Repo Securities |  |
Asset: |  |
Asset, fair value | $ 3,250 | 3,250
Level 2 | Asset Backed Securities |  |
Asset: |  |
Asset, fair value |  | 1,260
Level 2 | Non-US Government |  |
Asset: |  |
Asset, fair value |  | $ 1,393

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- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-2 + Details
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