v3.26.1
Share-based Compensation - Share option activities (Details) - $ / shares
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Number of Options        
Number of Options, Outstanding, Beginning Balance 21,426,000 24,097,223 41,475,503  
Number of Options, Forfeited and expired (2,715,000) (2,671,223) (17,378,280)  
Number of Options, Outstanding, Ending Balance 18,711,000 21,426,000 24,097,223 41,475,503
Number of Options, Exercisable 18,711,000      
Number of Options, Vested and expected to vest 18,711,000      
Weighted Average Exercise Price        
Weighted Average Exercise Price, Outstanding, Beginning Balance $ 0.37 $ 0.38 $ 0.4  
Weighted Average Exercise Price, Granted   0    
Weighted Average Exercise Price, Forfeited and expired 0.26 0.45 0.42  
Weighted Average Exercise Price, Outstanding, Ending Balance 0.38 $ 0.37 $ 0.38 $ 0.4
Weighted Average Exercise Price, Exercisable 0.38      
Weighted Average Exercise Price, Vested and expected to vest $ 0.38      
Weighted Average Remaining Contractual Life        
Weighted Average Remaining Contractual Life, Outstanding 3 years 7 months 6 days 4 years 7 months 6 days 5 years 1 month 6 days 4 years 9 months 18 days
Weighted Average Remaining Contractual Life, Exercisable 3 years 7 months 6 days      
Weighted Average Remaining Contractual Life, Vested and expected to vest 3 years 7 months 6 days