Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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The earnings that is allocated to common stock and participating securities to the extent that each security may share in earnings as if all of the earnings for the period had been distributed.

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Amount of expense for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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Minimum percentage of equity interests in PRC foreign-invested enterprise to be subject to special withholding tax rate.

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Percentage of qualified research and development expenses enterprises are entitled to claim as additional tax deduction.

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Withholding income tax rate.

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Withholding income tax rate on dividends for holding company which is not considered to be beneficial owner.

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INCOME TAX EXPENSES - Additional information (Details) - CNY (¥) ¥ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2018
INCOME TAX EXPENSES
Uncertain tax positions	¥ 0	¥ 0
Hong Kong \| Taxable Income Within HKD$2 million
INCOME TAX EXPENSES
Income tax rate	8.25%
Hong Kong \| Taxable Income Beyond HKD$2 million
INCOME TAX EXPENSES
Income tax rate	16.50%
PRC
INCOME TAX EXPENSES
Percentage of qualified research and development expenses enterprises are entitled to claim as additional tax deduction	100.00%			75.00%	50.00%	50.00%
Withholding tax rate	10.00%
Undistributed earnings available for distribution	¥ 0	¥ 102,347
Statute of limitations year	3 years
Statute of limitations extended period	5 years
PRC \| Arrangement Between PRC and Hong Kong Special Administrative Region on Avoidance of Double Taxation and Prevention of Fiscal Evasion with Respect to Taxes on Income and Capital
INCOME TAX EXPENSES
Withholding tax rate	5.00%
Minimum percentage of equity interests in PRC foreign-invested enterprise to be subject to special withholding tax rate	25.00%
Withholding income tax rate on dividends for Hong Kong holding company which is not considered to be beneficial owner	10.00%
PRC \| 2020
INCOME TAX EXPENSES
Percentage of qualified research and development expenses enterprises are entitled to claim as additional tax deduction	75.00%
PRC \| Enterprise Income Tax
INCOME TAX EXPENSES
Income tax rate	25.00%
PRC \| Subsidiaries and VIEs and Predecessor Operations
INCOME TAX EXPENSES
Income tax rate	25.00%	25.00%	25.00%
PRC \| High and New Technology Enterprises
INCOME TAX EXPENSES
Income tax rate	15.00%