v3.26.3
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Concentration and risk (Details)
$ in Thousands
 6 Months Ended 12 Months Ended
Jun. 30, 2026
USD ($)
customer
Jun. 30, 2025
USD ($)
customer
Dec. 31, 2025
Dec. 31, 2024
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES        
Related party transactions | $ $ 11,297 $ 17,854    
Number of customer | customer 0 0    
Revenue Benchmark | Customer Concentration Risk | Geely Group        
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES        
Concentration risk (as a percent) 99.66%   96.20% 78.67%
Accounts receivable | Credit concentration | Geely Group        
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES        
Concentration risk (as a percent) 65.90%   72.70%  
Purchases | Supplier concentration | Geely Group        
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES        
Concentration risk (as a percent) 82.80% 48.80%    
Accounts Payable | Supplier concentration | Geely Group        
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES        
Concentration risk (as a percent) 76.70%   67.50%