SHARE BASED COMPENSATION EXPENSES - Fair value of options (Details) - CNY (¥) ¥ / shares in Units, ¥ in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
SHARE BASED COMPENSATION EXPENSES
Risk-free interest rate			2.80%
Risk-free interest rate, Minimum	4.32%	2.21%
Risk-free interest rate, Maximum	4.57%	4.57%
Expected volatility			36.82%
Expected volatility, Minimum	38.00%	38.00%
Expected volatility, Maximum	39.90%	39.91%
Expected dividend yield	0.00%	0.00%	0.00%
Expected post-vesting forfeiture rate	0.00%	0.00%	0.97%
Fair value of the underlying shares on the date of option grants			¥ 9.78
Fair value of the underlying shares on the date of option grants, Minimum	¥ 102.21	¥ 57.05
Fair value of the underlying shares on the date of option grants, Maximum	¥ 203.08	¥ 102.21
Share-based compensation expenses			¥ 7.0
Class A Ordinary shares
SHARE BASED COMPENSATION EXPENSES
Exchange of ordinary shares for preferred shares (in shares)			1,046,761
Class B Ordinary shares
SHARE BASED COMPENSATION EXPENSES
Exchange of ordinary shares for preferred shares (in shares)			1,610,888

The expected post-vesting percentage that is used in valuing an option on its own shares.

No definition available.

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- Definition

The fair value assumption that is used in valuing an option on its own shares.

+ References

No definition available.

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- Definition

The maximum fair value assumption that is used in valuing an option on its own shares.

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- Definition

The minimum fair value assumption that is used in valuing an option on its own shares.

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No definition available.

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Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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- Definition

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The estimated measure of the maximum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The estimated measure of the minimum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

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The maximum risk-free interest rate assumption that is used in valuing an option on its own shares.

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The minimum risk-free interest rate assumption that is used in valuing an option on its own shares.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Number of shares that have been repurchased and retired during the period.

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