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v3.25.3

Significant Accounting Policies - Additional Information (Detail) $ in Millions |  | 9 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Aug. 29, 2025 USD ($) | Sep. 30, 2025 Segment shares | Jun. 16, 2025 shares | Feb. 20, 2025 | Dec. 31, 2024 shares
Accounting Policy [Line Items] |  |  |  |  |
Common Stock, Shares, Outstanding | shares |  | 4,045,000 |  |  | 4,037,000
Common stock, shares authorized | shares |  | 225,000,000 | 4,000,000 |  | 225,000,000
Number of reportable segment | Segment |  | 1 |  |  |
Reverse Stock Split [Member] |  |  |  |  |
Accounting Policy [Line Items] |  |  |  |  |
Reverse stock split |  | 1-for-25 |  |  |
Common Stock, Shares, Outstanding | shares |  |  | 101,100,000 |  |
FibroGen International [Member] |  |  |  |  |
Accounting Policy [Line Items] |  |  |  |  |
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% |
Share Purchase Agreement [Member] |  |  |  |  |
Accounting Policy [Line Items] |  |  |  |  |
Discontinued operation consideration | $ 220.4 |  |  |  |
Share Purchase Agreement [Member] | FibroGen International [Member] |  |  |  |  |
Accounting Policy [Line Items] |  |  |  |  |
Discontinued operation consideration | 220.4 |  |  |  |
Discontinued operation consideration in cash | 85.0 |  |  |  |
Cash received for sale of discontinued operation | 210.4 |  |  |  |
Outstanding interest and related premium and fees | 80.9 |  |  |  |
Purchase price in cash | 85.0 |  |  |  |
Share Purchase Agreement [Member] | FibroGen International [Member] | CHINA |  |  |  |  |
Accounting Policy [Line Items] |  |  |  |  |
Discontinued operation consideration | 220.4 |  |  |  |
Discontinued operation consideration in cash | 85.0 |  |  |  |
Purchase price in cash | 85.0 |  |  |  |
Share Purchase Agreement [Member] | Net Cash Held in China [Member] |  |  |  |  |
Accounting Policy [Line Items] |  |  |  |  |
Discontinued operation consideration in cash | 135.4 |  |  |  |
Purchase price in cash | 135.4 |  |  |  |
Share Purchase Agreement [Member] | Net Cash Held in China [Member] | CHINA |  |  |  |  |
Accounting Policy [Line Items] |  |  |  |  |
Discontinued operation consideration in cash | 135.4 |  |  |  |
Purchase price in cash | $ 135.4 |  |  |  |

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