v3.26.1
SHARE-BASED COMPENSATION - Share Options (Details) - $ / shares
 1 Months Ended 12 Months Ended
Dec. 30, 2019
Dec. 31, 2018
Oct. 31, 2014
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Summary of the stock option activity, Options granted share Number:            
Outstanding at end of year (in shares)       1,148,002    
Summary of the stock option activity, Weighted average exercise price per option:            
Outstanding at end of year (in dollars per share)       $ 0.6483    
Employee Stock Option            
Summary of the stock option activity, Options granted share Number:            
Exercised (in shares)       (1,510,880) (3,944,400) (2,560,304)
Employee Stock Option | Minimum            
SHARE-BASED COMPENSATION            
Vesting period (in years)     4 years 4 years    
Employee Stock Option | Maximum            
SHARE-BASED COMPENSATION            
Vesting period (in years)     5 years 5 years    
2014 Share Incentive Plan | Employee Stock Option            
SHARE-BASED COMPENSATION            
Maximum number of shares under the plan     135,032,132      
Expire period     10 years      
Modification of exercise price of number of stock options granted 8,113,145          
Modified of exercise price of stock options granted $ 0.6          
2019 Share Incentive Plan | Employee Stock Option | Maximum            
SHARE-BASED COMPENSATION            
Maximum percentage of shares available for issuance, based on total number of shares issued and outstanding on September 29, 2019   2.00%        
Maximum percentage of number of shares increased in each year   2.00%        
Maximum percentage of aggregate number of shares initially reserved and subsequently increased during the term of the total number of shares issued and outstanding on September 29   8.00%        
2014 Share Incentive Plan and 2019 share Incentive Plan | Employee Stock Option            
Summary of the stock option activity, Options granted share Number:            
Outstanding at beginning of year (in shares)       2,658,882 7,259,362 9,986,146
Exercised (in shares)       (1,510,880) (3,944,400) (2,560,304)
Granted (in shares)       0 0 128,000
Cancelled/Forfeited (in shares)         (656,080) (294,480)
Outstanding at end of year (in shares)       1,148,002 2,658,882 7,259,362
Summary of the stock option activity, Weighted average exercise price per option:            
Outstanding at beginning of year (in dollars per share)       $ 0.648 $ 0.5533 $ 0.5556
Exercised (in dollars per share)       0.6477 0.5205 0.5574
Granted (in dollars per share)           0.65
Cancelled/forfeited (in dollars per shares)         0.3667 0.6368
Outstanding at end of year (in dollars per share)       $ 0.6483 $ 0.648 $ 0.5533