v3.26.1
Discontinued Operations and Divestiture - Additional Information (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Nov. 06, 2025
Feb. 20, 2025
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Jun. 02, 2026
Dec. 31, 2025
Aug. 29, 2025
Disposal Group, Including Discontinued Operations [Line Items]                  
Discontinued Operation, Name [Extensible Enumeration]   FibroGen International [Member]     FibroGen International [Member]        
Loss on divestiture         $ (66) $ 0      
Accounts receivable from related parties     $ 347   $ 347     $ 216  
Share Purchase Agreement [Member]                  
Disposal Group, Including Discontinued Operations [Line Items]                  
Discontinued operation consideration                 $ 220,400
Discontinued operation cash paid at closing                 210,400
Falikang [Member]                  
Disposal Group, Including Discontinued Operations [Line Items]                  
Percentage of outstanding shares owned         51.10%        
Investment loss       $ 1,700   1,100      
Falikang [Member] | Collaborative Arrangement [Member]                  
Disposal Group, Including Discontinued Operations [Line Items]                  
Revenues       16,400   53,300      
Astra Zeneca [Member] | Collaborative Arrangement [Member]                  
Disposal Group, Including Discontinued Operations [Line Items]                  
Description of discontinued operations         In July 2013, the Company entered into a collaboration agreement with AstraZeneca for the development and commercialization of roxadustat for the treatment of anemia in the U.S. and all other countries in the world, other than China, not previously licensed under the Astellas Europe Agreement and Astellas Japan Agreement as discussed below in Note 4, Collaboration Agreements, License Agreement and Revenues, (“AstraZeneca U.S./RoW Agreement”). Later in 2024, the Company and AstraZeneca entered into an agreement to terminate the AstraZeneca U.S./RoW Agreement, effective as of February 25, 2024 (“AstraZeneca Termination and Transition Agreement”), as amended and restated on August 29, 2025. Neither party incurred any early termination penalties.        
Astra Zeneca [Member] | Share Purchase Agreement [Member]                  
Disposal Group, Including Discontinued Operations [Line Items]                  
Discontinued operation cash payable at closing subject to holdbacks                 10,000
Discontinued operation hold back amount to offset final net cash adjustments                 6,000
Disposal group including discontinued operation additional payment following final net cash adjustments after closing $ 400                
Discontinued operation hold back amount received as final net cash adjustments $ 6,400           $ 4,000    
Discontinued operation, hold back amount to satisfy any indemnity claims                 4,000
FibroGen International [Member]                  
Disposal Group, Including Discontinued Operations [Line Items]                  
Description of discontinued operations         On February 20, 2025, the Company entered into the Share Purchase Agreement with AstraZeneca Treasury Limited, pursuant to which the Company and its subsidiary FibroGen China Anemia Holdings, Ltd. agreed to sell all of the issued and outstanding equity interests of FibroGen International to AstraZeneca Treasury Limited. This sale included all of the Company’s roxadustat assets in China, including FibroGen International’s subsidiary FibroGen Beijing and its 51.1% interest in Falikang. The Company determined that FibroGen International met the “held for sale” criteria and the “discontinued operations” criteria in accordance with FASB ASC 205, Presentation of Financial Statements, as of December 31, 2024. Accordingly, the operating results related to the FibroGen International are classified as discontinued operations, and have been reflected as discontinued operations in the condensed consolidated statements of operations.        
Loss on divestiture     $ (0) $ 0 $ (66) $ 0      
FibroGen International [Member] | Share Purchase Agreement [Member]                  
Disposal Group, Including Discontinued Operations [Line Items]                  
Discontinued operation consideration                 220,400
Discontinued operation consideration in cash                 85,000
Net Cash Held in China [Member] | Share Purchase Agreement [Member]                  
Disposal Group, Including Discontinued Operations [Line Items]                  
Discontinued operation consideration in cash                 $ 135,400
Closing of Divestiture of FibroGen International [Member]                  
Disposal Group, Including Discontinued Operations [Line Items]                  
Loss Contingency, Receivable, Current               $ 4,000