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Significant Accounting Policies - Estimated Fair Value of Assets and Liability (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands | Mar. 31, 2023 | Dec. 31, 2022
--- | --- | ---
Asset: |  |
Asset, fair value | $ 196,417 | $ 192,307
Agency Securities |  |
Asset: |  |
Asset, fair value | 3,999 | 1,554
Money Market Fund |  |
Asset: |  |
Asset, fair value | 80,105 | 81,870
U.S. Treasury Securities |  |
Asset: |  |
Asset, fair value | 3,153 | 3,117
Corporate Bonds |  |
Asset: |  |
Asset, fair value | 16,035 | 28,416
Commercial Paper |  |
Asset: |  |
Asset, fair value | 79,440 | 62,347
Repo Securities |  |
Asset: |  |
Asset, fair value | 3,250 | 3,250
Asset Backed Securities |  |
Asset: |  |
Asset, fair value | 546 | 1,260
Certificates of Deposit |  |
Asset: |  |
Asset, fair value | 8,490 | 9,100
Non-US Government |  |
Asset: |  |
Asset, fair value | 1,399 | 1,393
Level 1 |  |
Asset: |  |
Asset, fair value | 87,257 | 86,541
Level 1 | Agency Securities |  |
Asset: |  |
Asset, fair value | 3,999 | 1,554
Level 1 | Money Market Fund |  |
Asset: |  |
Asset, fair value | 80,105 | 81,870
Level 1 | U.S. Treasury Securities |  |
Asset: |  |
Asset, fair value | 3,153 | 3,117
Level 2 |  |
Asset: |  |
Asset, fair value | 109,160 | 105,766
Level 2 | Corporate Bonds |  |
Asset: |  |
Asset, fair value | 16,035 | 28,416
Level 2 | Commercial Paper |  |
Asset: |  |
Asset, fair value | 79,440 | 62,347
Level 2 | Repo Securities |  |
Asset: |  |
Asset, fair value | 3,250 | 3,250
Level 2 | Asset Backed Securities |  |
Asset: |  |
Asset, fair value | 546 | 1,260
Level 2 | Certificates of Deposit |  |
Asset: |  |
Asset, fair value | 8,490 | 9,100
Level 2 | Non-US Government |  |
Asset: |  |
Asset, fair value | $ 1,399 | $ 1,393

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