v3.25.2
Commitments and contingencies - Additional Information (Details)
$ in Thousands, ¥ in Millions
6 Months Ended
Jun. 30, 2025
USD ($)
Jun. 30, 2025
CNY (¥)
Jun. 30, 2024
USD ($)
Jun. 30, 2024
CNY (¥)
Jun. 30, 2025
CNY (¥)
Oct. 31, 2024
Jul. 31, 2024
USD ($)
Jul. 31, 2024
CNY (¥)
Jun. 30, 2023
USD ($)
Jun. 30, 2023
CNY (¥)
Commitments and contingencies                    
Consideration paid $ 1,112                  
Jingzhou Jinyu                    
Commitments and contingencies                    
Consideration paid 1,100 ¥ 8.0 $ 1,000 ¥ 7.0            
Equity method investment, ownership percentage (as a percent)           14.50%        
Shanghai IAT                    
Commitments and contingencies                    
Investment payable             $ 2,800 ¥ 20.0    
Consideration paid $ 1,400 10.0                
Equity method investment, ownership percentage (as a percent) 25.00%       25.00%          
Consideration payable $ 1,400       ¥ 10.0          
Suzhou Mingzhi                    
Commitments and contingencies                    
Investment payable                 $ 4,200 ¥ 30.0
Consideration paid $ 2,900 ¥ 21.0                
Equity method investment, ownership percentage (as a percent) 19.74%       19.74%          
Consideration payable $ 1,300       ¥ 9.0