v3.25.1
Principal accounting policies - Property and equipment estimated useful lives and residual rate (Details)
Dec. 31, 2024
Buildings  
Property and equipment, net  
Residual rate (as a percent) 0.00%
Buildings | Minimum  
Property and equipment, net  
Estimated useful lives 32 years
Buildings | Maximum  
Property and equipment, net  
Estimated useful lives 40 years
Servers, computers and equipment | Minimum  
Property and equipment, net  
Estimated useful lives 3 years
Residual rate (as a percent) 0.00%
Servers, computers and equipment | Maximum  
Property and equipment, net  
Estimated useful lives 5 years
Residual rate (as a percent) 5.00%
Leasehold improvements  
Property and equipment, net  
Property, Plant, and Equipment, Useful Life, Term, Description [Extensible Enumeration] us-gaap:UsefulLifeTermOfLeaseMember
Residual rate (as a percent) 0.00%
Renovation of buildings  
Property and equipment, net  
Estimated useful lives 10 years
Residual rate (as a percent) 0.00%
Motor vehicles | Minimum  
Property and equipment, net  
Estimated useful lives 3 years
Residual rate (as a percent) 0.00%
Motor vehicles | Maximum  
Property and equipment, net  
Estimated useful lives 10 years
Residual rate (as a percent) 5.00%
Furniture, fixture and office equipment | Minimum  
Property and equipment, net  
Estimated useful lives 3 years
Residual rate (as a percent) 0.00%
Furniture, fixture and office equipment | Maximum  
Property and equipment, net  
Estimated useful lives 5 years
Residual rate (as a percent) 5.00%