SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Property, equipment, and intangible assets, net (Details) |
Dec. 31, 2025 |
|---|---|
| Electronic Equipment | |
| Property Plant And Equipment [Line Items] | |
| Useful life (in years) | 3 years |
| Office Equipment | Minimum | |
| Property Plant And Equipment [Line Items] | |
| Useful life (in years) | 5 years |
| Office Equipment | Maximum | |
| Property Plant And Equipment [Line Items] | |
| Useful life (in years) | 14 years 3 months |
| Software | Minimum | |
| Property Plant And Equipment [Line Items] | |
| Useful life (in years) | 3 years |
| Software | Maximum | |
| Property Plant And Equipment [Line Items] | |
| Useful life (in years) | 5 years |
| Leasehold improvement | |
| Property Plant And Equipment [Line Items] | |
| Property, Plant, and Equipment, Useful Life, Term, Description [Extensible Enumeration] | us-gaap:UsefulLifeShorterOfTermOfLeaseOrAssetUtilityMember |