v3.26.1
INCOME TAX - Summary (Details) - HKD ($)
$ in Millions
12 Months Ended
Dec. 31, 2027
Dec. 31, 2026
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2018
INCOME TAX          
Statutory income tax (as a percent)     25.00%    
Hong Kong S.A.R.          
INCOME TAX          
Statutory income tax (as a percent)     16.50%    
Withholding taxes on remittance of dividends     $ 0    
Threshold profit taxed at half of the current tax rate under two-tiered profits tax rates regime         $ 2
Tax rate at half of the current tax rate under two-tiered profits tax rates regime         8.25%
Mainland China          
INCOME TAX          
Statutory income tax (as a percent)     25.00%    
Mainland China | Beijing Niudian          
INCOME TAX          
Preferential tax rate     15.00%    
Mainland China | Forecast | Beijing Niudian          
INCOME TAX          
Preferential tax rate 15.00% 15.00%      
Mainland China | Jiangsu Xiaoniu          
INCOME TAX          
Preferential tax rate     15.00% 15.00%  
Mainland China | Jiangsu Xiaoniu | Forecast          
INCOME TAX          
Preferential tax rate   15.00%