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Significant Accounting Policies - Additional Information (Detail) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2025 USD ($) Segment | Feb. 20, 2025 USD ($)
Accounting Policy [Line Items] |  |
Number of reportable segment | Segment | 1 |
FibroGen International [Member] |  |
Accounting Policy [Line Items] |  |
Purchase price in cash |  | $ 85
Discontinued operations name | FibroGen International |
Beijing Falikang Pharmaceutical Co Ltd | Beijing Kangda Yongfu Pharmaceutical Co., LTD [Member] | AstraZenecaAB [Member] |  |
Accounting Policy [Line Items] |  |
Percentage of outstanding shares acquired | 51.10% | 51.10%
Minimum [Member] |  |
Accounting Policy [Line Items] |  |
Unrestricted cash and cash equivalent balance required to maintain in accounts | $ 27 |
Debt Financing Agreement [Member] | Minimum [Member] |  |
Accounting Policy [Line Items] |  |
Unrestricted cash and cash equivalent balance required to maintain in accounts | $ 30 |

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