FAIR VALUE MEASUREMENTS - Assets and Liabilities Measured Using Unobservable Inputs (Details) - CNY (¥) ¥ in Thousands |
12 Months Ended | |||
|---|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
|
| Balance at January 1, | ¥ 150,922 | ¥ 104,134 | ||
| Balance at December 31, | ¥ 238,464 | 150,922 | ¥ 104,134 | |
| Convertible Senior Notes | ||||
| Balance at January 1, | 782,969 | 1,070,699 | ||
| Foreign exchange loss/(gain) | 6,093 | ¥ (54,377) | ||
| Change in fair value of convertible senior notes loss/(gain) | (323,474) | 84,669 | ||
| Change in the instrument-specific credit risk | (421) | (70,732) | ||
| Conversion of convertible senior notes | ¥ (465,167) | (247,290) | ||
| Balance at December 31, | ¥ 782,969 | ¥ 1,070,699 | ||