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Disposal group, including discontinued operation, cash consideration.

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Percentage of voting equity interest acquired in business combination.

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The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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Indicates name of component or group of components disposed of or classified as held-for-sale representing strategic shift that has or will have major effect on operation and financial result.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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Significant Accounting Policies - Additional Information (Detail) $ in Millions		6 Months Ended
	Feb. 20, 2025	Jun. 30, 2026 Segment shares	Dec. 31, 2025 shares	Aug. 29, 2025 USD ($)
Accounting Policy [Line Items]
Common Stock, Shares, Outstanding \| shares		4,049,000	4,047,000
Common stock, shares authorized \| shares		225,000,000	225,000,000
Number of reportable segment \| Segment		1
Discontinued Operation, Name [Extensible Enumeration]	FibroGen International [Member]	FibroGen International [Member]
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%
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
Share Purchase Agreement [Member] \| FibroGen International [Member] \| CHINA
Accounting Policy [Line Items]
Discontinued operation consideration				220.4
Discontinued operation consideration 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
Share Purchase Agreement [Member] \| Net Cash Held in China [Member] \| CHINA
Accounting Policy [Line Items]
Discontinued operation consideration in cash				$ 135.4