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Significant Accounting Policies - Estimated Fair Value of Assets and Liability (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands | Mar. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Asset: |  |
Asset, fair value | $ 238,419 | $ 235,380
Money Market Fund |  |
Asset: |  |
Asset, fair value | 122,759 | 99,226
Agency Securities |  |
Asset: |  |
Asset, fair value |  | 8,912
Repo Securities |  |
Asset: |  |
Asset, fair value | 3,250 | 3,250
U.S. Treasury Securities |  |
Asset: |  |
Asset, fair value | 112,410 | 123,992
Level 1 |  |
Asset: |  |
Asset, fair value | 235,169 | 223,218
Level 1 | Money Market Fund |  |
Asset: |  |
Asset, fair value | 122,759 | 99,226
Level 1 | Agency Securities |  |
Asset: |  |
Asset, fair value |  | 0
Level 1 | U.S. Treasury Securities |  |
Asset: |  |
Asset, fair value | 112,410 | 123,992
Level 2 |  |
Asset: |  |
Asset, fair value | 3,250 | 12,162
Level 2 | Agency Securities |  |
Asset: |  |
Asset, fair value |  | 8,912
Level 2 | Repo Securities |  |
Asset: |  |
Asset, fair value | $ 3,250 | $ 3,250

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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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