v3.25.1
Share-based compensation - Share-based compensation-Share options-2011 Share Incentive Scheme (Details) - 2011 Incentive Scheme - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Balance ,options 8,574,220 9,414,400 9,414,400  
Forfeited ,Options (499,720) (840,180)  
Balance ,options 8,074,500 8,574,220 9,414,400 9,414,400
Expected to vest at December 31 ,options 8,074,500      
Exercisable at December 31, options 8,074,500      
Balance, weighted average exercise price $ 3.8256 $ 3.7997 $ 3.7997  
Forfeited ,weighted average exercise price 3.535 3.535  
Balance, weighted average exercise price 3.8436 $ 3.8256 $ 3.7997 $ 3.7997
Expected to vest at December 31, weighted average exercise price 3.8436      
Exercisable at December 31, weighted average exercise price $ 3.8436      
Balance ,contractual life 9 months 3 days 1 year 7 months 9 days 1 year 9 months 18 days 2 years 9 months 18 days
Expected to vest at December 31, contractual life 9 months 3 days      
Exercisable at December 31, contractual life 9 months 3 days      
Balance, December 31, aggregate intrinsic value $ 0      
Balance, December 31, aggregate intrinsic value 0 $ 0    
Expected to vest at December 31, aggregate intrinsic value 0      
Total intrinsic value $ 0 $ 0 $ 0