SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Long-term investments (Details) - USD ($) $ in Thousands |
6 Months Ended | ||
|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Dec. 31, 2025 |
|
| SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES | |||
| Investment securities - related party | $ 1,358 | $ 1,811 | |
| Equity method investments | 20,234 | 10,625 | |
| Equity security without readily determinable fair values using the measurement alternative - related party | 36,706 | 35,568 | |
| Total | 58,298 | $ 48,004 | |
| Impairment charge of equity method investments | $ 0 | $ 0 | |