v3.25.2
INVESTMENTS AND PUT RIGHT LIABILITIES - Additional Information (Details) - USD ($)
6 Months Ended
Feb. 06, 2024
Sep. 15, 2020
Jun. 30, 2025
Jun. 30, 2024
Dec. 31, 2024
Apr. 02, 2024
Dec. 31, 2023
Dec. 31, 2022
Jul. 31, 2022
Dec. 31, 2020
Jun. 16, 2019
Schedule of Equity Method Investments                      
Common stock, shares outstanding     188,108,178   187,452,495            
Equity in (loss) income of affiliates       $ (1,038,000)              
Share-based compensation expense     $ 400,000 (2,300,000)              
Extinguishment of repurchase obligation $ 183,000,000                    
Unrealized gain on the available-for-sale investments     $ 3,644,000                
Fair value of put right liability       2,000,000              
I-Mab Hong Kong                      
Schedule of Equity Method Investments                      
Registered capital of subsidiary                     $ 30,000,000
Common stock, shares outstanding                   13,500,000  
Domestic Investors                      
Schedule of Equity Method Investments                      
Common stock, shares outstanding                   12,000,000  
TJBio Hangzhou                      
Schedule of Equity Method Investments                      
Assets recognized value   $ 105,000,000                  
Equity method investment, ownership percentage     0.00%   15.00%            
Proceeds from Contributions from Affiliates   30,000,000                  
Common stock, shares outstanding                   25,500,000  
Purchase price committed     $ 3,000,000                
Investments at fair value, available-for-sale debt securities     34,500,000                
Unrealized gain on the available-for-sale investments     $ 3,600,000                
TJBio Hangzhou | Series C Investment, Equity Transfer and Shares Repurchase Transactions                      
Schedule of Equity Method Investments                      
Equity method investment, ownership percentage 5.65%                    
Amount agreed to raise $ 19,000,000                    
TJBio Hangzhou | Series B Domestic Investors                      
Schedule of Equity Method Investments                      
Amount agreed to raise                 $ 46,000,000    
TJBio Hangzhou | Minimum                      
Schedule of Equity Method Investments                      
Potential repurchase obligation           $ 30,000,000          
TJBio Hangzhou | Maximum                      
Schedule of Equity Method Investments                      
Potential repurchase obligation           $ 35,000,000          
TJBio Hangzhou | Management Holdco                      
Schedule of Equity Method Investments                      
Registered capital of subsidiary   $ 3,000,000                  
Equity method investment, ownership percentage   10.00%               10.00%  
Shares issued         0   750,000 750,000      
Share-based compensation expense recognized in equity method       1,100,000              
Cash Commitment   $ 3,000,000                  
TJBio Hangzhou | Management Holdco | SPA                      
Schedule of Equity Method Investments                      
Equity method investment, ownership percentage     10.00%                
TJBio Hangzhou | Management Holdco and ESOP Holdco                      
Schedule of Equity Method Investments                      
Shares subscribed, not yet been purchased or issued                   4,500,000  
TJBio Hangzhou | Esop Holdco                      
Schedule of Equity Method Investments                      
Equity method investment, ownership percentage   5.00%               5.00%  
Registered capital of affiliates   $ 1,500,000                  
TJBio Hangzhou | Domestic Investors                      
Schedule of Equity Method Investments                      
Registered capital of subsidiary   $ 12,000,000                  
Equity method investment, ownership percentage   40.00%               40.00%  
Cash Payments   $ 120,000,000                  
TJBio Hangzhou | I-Mab Hong Kong                      
Schedule of Equity Method Investments                      
Equity method investment, ownership percentage                   45.00%  
TJBio Hangzhou | I-Mab Hangzhou                      
Schedule of Equity Method Investments                      
Equity method investment, ownership percentage                 40.36%    
TJBio Hangzhou | Group's Share Based Compensation                      
Schedule of Equity Method Investments                      
Equity in (loss) income of affiliates       700,000              
TJBio Hangzhou | TJBio Hangzhou Share Based Compensation                      
Schedule of Equity Method Investments                      
Equity in (loss) income of affiliates     $ 0 $ 600,000