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("Beijing Sunlands") Beijing Yanchilaxiang Education Technology Company Limited [Member] Beijing yanchilaxiang education technology company limited. Proceeds from Sale of Property, Plant, and Equipment Proceeds from disposal of property and equipment Proceeds from Sale of Property, Plant, and Equipment, Total Other revenue. Other Revenue [Member] Others Segments [Domain] Segments Wuhan Jiayan Online Education Technology Company Limited. Wuhan Jiayan Online Education Technology Company Limited [Member] Wuhan Jiayan Online Education Technology Co., Ltd. ("Wuhan Jiayan") Concentration Risk Type [Axis] Concentration Risk Type Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Place of establishment Time for full refund of transaction price. Time For Full Refund Of Transaction Price Time for full refund of transaction price Fair Value Measurements, Recurring and Nonrecurring [Table Text Block] Schedule of Asset Measured at Fair Value on Recurring Basis Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Supplemental schedule of non-cash investing activities: Long-Term Debt, Excluding Current Maturities Long-term debt, non-current portion Long-Term Debt, Excluding Current Maturities, Total Plan Name [Axis] Plan Name Deferred Rent Receivables, Net, Noncurrent Rental deposits Equity [Abstract] Entity Current Reporting Status Entity Current Reporting Status Operating Expenses [Abstract] Operating expenses Fair Value, Inputs, Level 2 [Member] Significant Other Observable Inputs (Level 2) Significant risks and uncertainties. Significant Risks And Uncertainties Policy [Text Block] Significant Risks and Uncertainties Deferred Tax Assets, Net of Valuation Allowance Deferred tax assets, net Commitments and Contingencies Disclosure [Text Block] Commitments and Contingencies Contract with Customer, Refund Liability, Current Advanced deposits Common Stock, Shares Authorized Ordinary shares, shares authorized Other Nonoperating Income (Expense) [Member] Other Income Product and Service [Axis] Product and Service Document Fiscal Period Focus Document Fiscal Period Focus Debt Instrument, Interest Rate, Stated Percentage Debt instrument, interest rate Accounting Standards Update 2023-09 [Member] ASU 2023-09 Entity Shell Company Entity Shell Company Effective Income Tax Rate Reconciliation, Withholding Taxes Amount Effective income tax rate reconciliation, withholding taxes amount. PRC withholding taxes Contractual Obligation Investment commitment amount Contractual Obligation, Total Investment commitment Dividend paid Dividends, Common Stock, Cash Declared cash dividends Term of repayment of principal installments on which interest expense and service fees payable. Term Of Repayment Of Principal Installments On Which Interest Expense And Service Fees Payable Term of repayment of principal installments on which interest expense and service fees payable Inland Revenue, Hong Kong [Member] Hong Kong Subsidiaries and variable interest entities. Subsidiaries And Variable Interest Entities [Member] subsidiaries and the Variable Interest Entities Short-term Investments Short-Term Investments [Member] Deferred Sale Inducement Cost Deferred Sale Inducement Cost, Ending Balance Beginning balances (current and non-current) Cash and cash equivalents Cash, cash equivalents and restricted cash Cash and Cash Equivalent Cash and Cash Equivalents, at Carrying Value, Total Condensed Financial Information Disclosure [Abstract] Cybersecurity Risk Management, Strategy, and Governance [Abstract] Common Stock, Shares, Issued Ordinary shares, shares issued Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag] Cybersecurity Risk Board of Directors Oversight [Text Block] Statement [Table] Statement [Table] Qingyuan Qisi Information Technology Consulting Co., Ltd [Member] Qingyuan Qisi Information Technology Consulting Co., Ltd. Qingyuan Qisi Information Technology Consulting Co., Ltd ("Qingyuan Qisi") Beijing Shangde Online Education Technology Company Limited. Beijing Shangde Online Education Technology Company Limited [Member] Beijing Shangde Online Education Technology Company Limited Beijing Sunlands Impairment loss on deferred costs Impairment loss on deferred costs. Impairment Loss on Deferred Costs Increase (decrease) in right-of-use asset. Increase Decrease In Right Of Use Asset Right-of-use asset The entire disclosure for Deferred​ costs​ at the end of the reporting period. Deferred Costs Disclosure [Text Block] Deferred Costs Statement [Line Items] Statement [Line Items] Payment of dividends withholding tax percentage. Payment of dividends withholding tax, percentage Payment Of Dividends Withholding Tax Percentage Business Combination [Domain] Revenue from Contract with Customer [Policy Text Block] Revenue recognition, Deferred Revenue and Cost of revenue Entity Filer Category Entity Filer Category Selling, General and Administrative Expenses, Policy [Policy Text Block] Sales and marketing expenses Weighted-average remaining contractual term, Outstanding and exercisable Share based Compensation Arrangement By Share based Payment Award Options Outstanding and Exercisable Weighted Average Remaining Contractual Term2 Share based compensation arrangement by share based payment award options outstanding and exercisable weighted average remaining contractual term2. Proceeds from Maturities, Prepayments and Calls of Short-Term Investments Proceeds from maturity of short-term investments Liabilities and Equity TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY Gain (Loss) on Disposition of Stock in Subsidiary (Gain)/loss from disposal of subsidiaries Gain/(loss) on disposal of subsidiaries Debt Instrument [Line Items] Debt Instrument [Line Items] Payables and Accruals [Abstract] Long-Term Debt, Current Maturities Long-term debt, current portion Long-Term Debt, Current Maturities, Total Changes in unrecognized tax benefits Effective Income Tax Rate Reconciliation, Tax Contingency, Percent Effective Income Tax Rate Reconciliation, Tax Contingency, Percent, Total Long-Lived Tangible Asset [Axis] Long-Lived Tangible Asset Debt Instrument, Frequency of Periodic Payment Debt instrument periodic payment description Number of employees. Number Of Employees Number of employees Guangzhou Shangzhiside Education Technology Company Limited [Member] Guangzhou shangzhiside education technology company limited. Guangzhou Shangzhi Side Technology Co., Ltd. ("Shangzhi Side") Cybersecurity Risk Third Party Oversight and Identification Processes [Flag] Land use right. Land Use Right [Line Items] Land Use Right [Line Items] Chinese Mainland [Member] Chinese mainland. Chinese Mainland Deferred Tax Assets, Valuation Allowance Less: valuation allowance Schedule of Long-Term Investments Schedule Of Long Term Investments [Table Text Block] Schedule Of Long Term Investments. Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Statutory income tax rate Income tax expenses computed at applicable tax rates of 25% Schedule of subsidiaries, Variable interest entities ("VIEs") and VIEs subsidiaries. Schedule Of Subsidiaries Variable Interest Entities V I Es And V I Es Subsidiaries [Line Items] Schedule of Subsidiaries, Variable Interest Entities (VIEs) and VIEs Subsidiaries [Line Items] Subsequent Event [Line Items] Land use right. Land Use Right [Abstract] Pledged Status [Axis] Pledged Status Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amount Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amount, Total Non-deductible expense Cybersecurity Risk Management Third Party Engaged [Flag] Short-term investments. Short Term Investments Policy [Text Block] Short-term investments Effective Income Tax Rate Reconciliation, Percent Income tax expenses Income Taxes Paid Income tax paid Operating loss carryforwards expiration start date. Operating Loss Carryforwards Expiration Start Date Expiration start date Beijing Lingding Management Consulting Co., Ltd. ("Beijing Lingding") Beijing Lingding Management Consulting Company Limited [Member] Beijing lingding management consulting company limited. Investment Income, Interest Interest income Treasury Stock, Common, Value Treasury stock Income Tax Jurisdiction [Axis] Singapore Inland Revenue, Singapore (IRAS) [Member] Due to Affiliates Current Due to affiliates current. Amounts due to subsidiaries Geographical Geographical [Domain] Payments to Acquire Intangible Assets Acquisition of intangible assets Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Restricted cash Shufan Education Technology (Wuhan) Co., Ltd. Shufan Education Technology (Wuhan) Company Limited [Member] Shufan Education Technology (Wuhan) Company Limited. Assets, Noncurrent [Abstract] Non-current assets Variable Interest Entity [Table] Schedule Of Variable Interest Entities [Table] Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit Uncertain tax positions Wuhan Studyvip Online Education Company Limited. Wuhan Studyvip Online Education Company Limited [Member] Wuhan Studyvip Online Education Co., Limited ("Wuhan Zhibo") Additional Paid in Capital, Common Stock Additional paid-in capital Equity securities with readily determinable fair values Equity Securities, FV-NI, Noncurrent Significant Accounting Policies [Text Block] Significant Accounting Policies Property, Plant and Equipment [Line Items] Property Plant And Equipment [Line Items] Variable rate financial instruments Variable Rate Financial Instruments Variable-rate financial instruments Degree- or diploma-oriented post-secondary courses. Degree Or Diploma Oriented Post Secondary Courses [Member] Degree- or Diploma-oriented Post-secondary Courses Finite-Lived Intangible Asset, Useful Life Estimated useful life Term of land certificate Number of shares, Granted Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross Number of shares granted Disaggregation of Revenue [Table] Disaggregation Of Revenue [Table] Impairment loss on long-term investments Impairment loss on long-term investments Impairment Loss on Long Term Investments Impairment loss on long-term investments. Impairment loss for its equity method investments Impairment loss for its equity method investments. Impairment Loss For Its Equity Method Investments Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of Calculation of Net (Loss) / Income Per Share Equity Securities Equity Securities [Member] Convenience translation. Convenience Translation Policy [Text Block] Convenience Translation Sale or purchase of assets or rights minimum amount. Sale Or Purchase Of Assets Or Rights Minimum Amount Sale or purchase of assets or rights minimum amount Earnings Per Share, Basic, Total Earnings Per Share, Basic Basic Disaggregation of Revenue [Table Text Block] Schedule of Disaggregation of Revenue Lessee, operating lease, liability, payments, due year five and after year five. Lessee Operating Lease Liability Payments Due Year Five And After Year Five 2031 and thereafter Payments for Repurchase of Equity Share repurchase Payments for Repurchase of Equity, Total Document Shell Company Report Document Shell Company Report First two million profits. First Two Million Profits [Member] For the First 2 Million Profits Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Change in cumulative foreign currency translation adjustments Foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Total Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number Number of shares, Outstanding beginning balance Number of shares, Outstanding ending balance Effective Income Tax Rate Reconciliation, Non-Taxable Income, Amount Effective income tax rate reconciliation, non-taxable income, amount. Non-taxable income Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Repayments of Secured Debt Repayment of secured loans Value added taxes. Value Added Taxes Policy [Text Block] Value added taxes ("VAT") Liabilities, Current Total current liabilities Loss From Fair Value Change Of Long-term Investments Loss from fair value change of long-term investments. Gain from fair value change of long-term investments Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Adjustments to reconcile net income to net cash generated from operating activities: Lessee, Operating Lease, Liability, to be Paid, Year Five 2030 Exercise price Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Exercise Price Land use right useful life. Land Use Right Useful Life Land Use Right Useful Life Variable Interest Entity, Qualitative or Quantitative Information, Activities of VIE Principal activities Parent Company [Member] Parent Company Effective Income Tax Rate Reconciliation [Table] Accounting Standards Update [Axis] Accounting Standards Update Land use right accumulated amortization. Land Use Right Accumulated Amortization Less: Accumulated amortization Variable interest entity, measure of activity net cash generated from (used in) operating activities. Variable Interest Entity Measure Of Activity Net Cash Generated From Used In Operating Activities Net cash generated from operating activities Non-Chinese Mainland Operations [Member] Non-Chinese mainland operations. Non-Chinese Mainland Operations Condensed Statement of Comprehensive Income [Table] Retained Earnings (Accumulated Deficit) Accumulated deficit Retained Earnings (Accumulated Deficit), Total Value added tax rate. Value Added Tax Rate Rate of VAT Effective Income Tax Rate Reconciliation, Cross-Border Tax Effect, Amount Effective Income Tax Rate Reconciliation, Cross-Border Tax Effect, Amount, Total Effect of cross-border tax laws Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period Number of shares, Forfeited Aggregated intrinsic value, Exercised Aggregated intrinsic value, Exercised Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value Represents the preferential tax rate applicable to the entity under the preferential tax treatment. Income Tax Preferential Tax Rate Preferential tax rate description Wuhan Fangtang Technology Co., Ltd. Wuhan fangtang technology company limited [Member] Wuhan fangtang technology company limited. Share-Based Payment Arrangement [Text Block] Share Incentive Plan Payments to Acquire Short-Term Investments Purchase of short-term investments Organization, Consolidation and Presentation of Financial Statements [Abstract] Payment for cash dividend Payments of Dividends Payments of Dividends, Total Leases [Abstract] Common Class A [Member] Class A Ordinary Shares Beginning balance (current and non-current) Ending balance (current and non-current) Contract with Customer, Liability Deferred revenue Contract with Customer, Liability, Total Amendment Flag Amendment Flag Product and Service [Domain] Product and Service Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount Income tax expenses computed at applicable tax rates of 25% Taxable income Net income (loss) available to common stockholders basic and diluted. Net Income Loss Available To Common Stockholders Basic And Diluted [Abstract] Numerator: Earnings Per Share, Policy [Policy Text Block] Net income per share Liabilities and Equity [Abstract] LIABILITIES AND SHAREHOLDERS' EQUITY Entity Address, Postal Zip Code Entity Address, Postal Zip Code Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Net cash generated from operating activities Rate of VAT, simple VAT collection method Value Added Tax Rate Simple VAT Collection Method Value added tax rate simple VAT collection method. Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss, Current Held-to-maturity investments Segment Reporting, CODM, Profit (Loss) Measure, How Used, Description Segment Reporting, CODM, Profit (Loss) Measure, How Used, Description Common Stock [Member] Additional Ordinary Share Ordinary Shares Cybersecurity Risk Role of Management [Text Block] Private company. Private Company [Member] Private Company Weighted-average exercise price, Granted Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Interest Receivable, Current Interest receivables Lessee, Operating Lease, Liability, to be Paid, Year Three 2028 Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Less: Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Total Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Beginning Balance Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Ending Balance Entity Address, Address Line One Entity Address, Address Line One Statutory Reserves Statutory reserves. Statutory reserves Deferred Tax Liabilities, Gross Total deferred tax liabilities Deferred Tax Liabilities, Gross, Total Total deferred tax liabilities Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false] Change in accounting principle, accounting standards update, immaterial effect Schedule of Estimated Fair Value of Options Granted Using Black-Scholes Model Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV Threshold percentage of general reserve of the registered capital The percentage of paid in capital that the general reserve would not surpass. Required General Reserve Registered Capital Ratio To De Force Compulsory Net Profit Allocation To General Reserve Earnings Per Share [Abstract] Net income per share attributable to ordinary shareholders of Sunlands Technology Group: Income Tax, Policy [Policy Text Block] Income taxes Other non-current assets disclosure. Other Non Current Assets Disclosure [Text Block] Other Non-Current Assets Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag] Supplemental Cash Flow Information [Abstract] Supplemental disclosure of cash flow information: Foreign Currency Transactions and Translations Policy [Policy Text Block] Foreign currency translation and transactions Two thousand and seventeen share incentive plan. Two Thousand And Seventeen Share Incentive Plan [Member] 2017 Share Incentive Plan Electronic and office equipment. Electronic And Office Equipment [Member] Electronic And Office Equipment Equity Securities without Readily Determinable Fair Value, Amount Equity securities without readily determinable fair values Restricted net assets. Restricted Net Assets [Abstract] Investment Type [Axis] Investment Type Beijing Jiayan Online Education Technology Company Limited. Beijing Jiayan Online Education Technology Company Limited [Member] Beijing Jiayan Online Education Technology Co., Ltd. Due from affiliates current. Due From Affiliates Current Amounts due from subsidiaries Operating Lease, Right-of-Use Asset Right-of-use assets Deferred Tax Assets, Gross Total deferred tax assets Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block] Net Income (Loss) Attributable to Noncontrolling Interest Net Income (Loss) Attributable to Noncontrolling Interest, Total Less: Net income attributable to non-controlling interest OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax, Total Unrealized (loss)/gain on available-for-sale investments, net of tax effect of nil Unrealized gain (loss) on available-for-sale investments, net of tax effect of nil Document Type Document Type Gross profit Gross Profit Gross profit Deferred Sale Inducement Cost, Capitalization Additions Beijing Shangren Chongye Education Technology Company Limited. Beijing Shangren Chongye Education Technology Company Limited [Member] Beijing Shangren Chongye Education Technology Co., Ltd. Subsidiary, Ownership Percentage, Parent Ownership percentage by parent Percentage of direct or indirect economic ownership Entity Central Index Key Entity Central Index Key Investments, Debt and Equity Securities [Abstract] Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block] Wuhan Zhidao Online Education Technology Co., Ltd. ("Wuhan Shangde") Wuhan Zhidao Online Education Technology Company Limited [Member] Wuhan zhidao online education technology company limited. Consideration from disposition of subsidiary group Proceeds from Sales of Business, Affiliate and Productive Assets Recourse Status [Domain] Recourse Status Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Net increase/(decrease) in cash, cash equivalents and restricted cash Subsequent Event Type [Domain] Schedule of variable interest entities and variable Interest entities' subsidiaries. Schedule Of Variable Interest Entities And Variable Interest Entities Subsidiaries Table [Text Block] Summary Financial Information of VIEs and their Subsidiaries Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive securities excluded from computation of earnings per share Impairment loss on long-lived assets Impairment of Long-Lived Assets to be Disposed of Impairment loss on long-lived assets Recognized impairment loss Required percentage of after tax profit allocated to statutory common reserve. Required Percentage Of After Tax Profit Allocated To Statutory Common Reserve Required minimum percentage of after-tax-profit allocated to statutory common reserve Common Stock, Par or Stated Value Per Share Ordinary shares, par value Accounting Standards Update [Domain] Accounting Standards Update Payables to educational institutions. Payables To Educational Institutions Payables to educational institutions Customer Refund Liability, Current Refund liability Government subsidies. Government Subsidies Policy [Text Block] Government subsidies Liabilities [Abstract] LIABILITIES Operating Lease, Right-of-Use Asset, Periodic Reduction Carrying amount of right-of-use assets Noncontrolling Interest, Increase from Subsidiary Equity Issuance Disposal of a subsidiary Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Weighted-average remaining contractual term, Outstanding Sales and marketing expenses (expenses reversal) allocated share based compensation expense Sales and Marketing Expenses (Expenses Reversal) Allocated Share Based Compensation Expense Sales and marketing expenses Debt Securities, Available-for-Sale, Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Total Available-for-sale debt securities at cost Foreign Tax Jurisdiction, Other [Member] Other Foreign Jurisdictions Available-for-sale investments Debt Securities, Available-for-Sale Debt Securities, Available-for-Sale, Total Gain (Loss) on Termination of Lease Gain from early termination of operating leases (Note 17) Gain from early termination of operating lease Parent [Member] Total Sunlands Technology Group Shareholders' Deficit Document Financial Statement Error Correction [Flag] Number of shares, Exercised Exercise of stock options, shares Number of shares, Exercised Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Other Prepaid Expense, Current Others Debt Disclosure [Abstract] Condensed Cash Flow Statements, Captions [Line Items] Prepaid Advertising Prepaid marketing expenses Excise and Sales Taxes Less: sales tax and surcharges Less: VAT related surcharges Effective Income Tax Rate Reconciliation, Tax Holiday, Percent Effect of tax holidays in PRC Effect of tax holidays in PRC Accrued Liabilities, Current Total Accrued expenses and other current liabilities Accrued expenses and other current liabilities (including accrued expenses and other current liabilities of the consolidated VIEs without recourse to Sunlands Technology Group of RMB228,825 and RMB102,424 as of December 31, 2024 and 2025, respectively) Cost of Sales [Member] Cost of Revenues Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Ownership [Domain] Ownership Current Fiscal Year End Date Current Fiscal Year End Date Schedule of Long-Term Debt Instruments [Table] Debt Instrument [Table] First Ten Thousand Taxable Income [Member] First ten thousand taxable income. For First SGD$10,000 Taxable Income Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures, Total Investments in subsidiaries,VIEs and VIEs' subsidiaries Advertising Cost [Policy Text Block] Advertising expenditure Entity Address, State or Province Entity Address, State or Province Leasehold and buildings improvements. Leasehold And Buildings Improvements [Member] Leasehold And Buildings Improvements Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive income attributable to Sunlands Technology Group Online Education Service and Insurance Service. Online Education Service And Insurance Service [Member] Online Education Service and Insurance Service Research and Development Expense, Policy [Policy Text Block] Product development expenses Common Stock, Capital Shares Reserved for Future Issuance Common Stock, Capital Shares Reserved for Future Issuance Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Disposal of Subsidiaries Geographical [Axis] Geographical Line of Credit Facility, Lender [Domain] Line of Credit Facility, Lender Conversion Class C Ordinary shares to Class A Ordinary shares (Note 13), shares Conversion of Stock, Shares Converted Conversion of shares Non-controlling interest Equity, Attributable to Noncontrolling Interest Stockholders' Equity Attributable to Noncontrolling Interest, Total Stockholders' Equity Attributable to Noncontrolling Interest, Beginning Balance Stockholders' Equity Attributable to Noncontrolling Interest, Ending Balance Ordinary shares disclosure. Ordinary Shares Disclosure [Text Block] Ordinary Shares License [Member] License Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Schedule of Share-based Compensation Expense Recognized Exercise of share option Stock Issued During Period, Value, Stock Options Exercised Comprehensive Income, Policy [Policy Text Block] Comprehensive income Proceeds from disposal of subsidiaries, net of cash Payments for (Proceeds from) Businesses and Interest in Affiliates Disposal of subsidiaries, net of cash received Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Schedule of Components of Deferred Income Tax Other Comprehensive Income (Loss), Net of Tax [Abstract] Other comprehensive income/(loss), net of tax effect of nil: Other comprehensive income/(loss) Dividend payout ratio Dividend Payout Ratio Dividend payout ratio. Deferred Income Tax Assets, Net Deferred tax assets Weighted-average remaining contractual term, Granted Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Granted, Weighted Average Remaining Contractual Term Share-based compensation arrangement by share-based payment award, options, granted, weighted average remaining contractual term. Threshold percentage of statutory common reserve need to be made over entities registered capital. Threshold Percentage Of Statutory Common Reserve Need To Be Made Over Entities Registered Capital Threshold percentage of statutory common reserve of the registered capital, used as criteria of allocation requirement Subsequent Event [Member] Subsequent Event Property, Plant and Equipment [Abstract] Other Assets, Noncurrent Other non-current assets Total Antidilutive Securities Antidilutive Securities [Axis] Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding and Exercisable Weighted Average Exercise Price Share based compensation arrangement by share based payment award options outstanding and exercisable weighted average exercise price. Weighted-average exercise price, Outstanding and exercisable beginning balance Weighted-average exercise price, Outstanding and exercisable ending balance Outside Chinese Mainland Outside Chinese Mainland [Member] Outside chinese mainland. AOCI Attributable to Parent [Member] Accumulated Other Comprehensive income/(loss) Customer [Domain] Customer Staff advances Staff advances current. Staff Advances Current Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name Balances, Treasury stock (in shares) Balances, Treasury stock (in shares) Treasury Stock, Common, Shares Lease liabilities Increase (decrease) in lease liability. Increase Decrease In Lease Liability Customer with contract liability additions. Customer With Contract Liability Additions Additions Percentage of variable interest entity assets on consolidated assets. Percentage Of Variable Interest Entity Assets On Consolidated Assets Aggregate percentage of variable interest entity assets on Group's consolidated total assets Minimum [Member] Minimum Weighted average grant date fair value, Granted Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Percentage of cash and cash equivalents at carrying value available for conversion to foreign currency. Percentage Of Cash And Cash Equivalents At Carrying Value Available For Conversion To Foreign Currency Percentage of cash and cash equivalents available for conversion to foreign currency Financial Instrument [Axis] Financial Instrument Assets, Current [Abstract] Current assets Class of Warrant or Right, Number of Securities Called by Each Warrant or Right Class of each ordinary shares convertible into class A ordinary shares Tianjin Shangde. Tianjin Shangde [Member] Tianjin Shangde Online Education Technology Co., Ltd. ("Tianjin Shangde") Amortization of Intangible Assets Amortization expenses Common Class B [Member] Class B Ordinary Shares Fair Value, Inputs, Level 3 [Member] Significant Unobservable Inputs (Level 3) Segment Reporting [Abstract] Tax Period [Domain] Tax Period Liabilities, Current [Abstract] Current liabilities Shangzhi Side [Member] Shangzhi Side [Member]. Shangzhi Side Non-cash lease expense. Non-cash Lease Expense Non-cash lease expenses Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities Accrued expenses Operating Loss Carryforwards Operating loss carryforwards Prepayment to acquire a building Prepaid Expense, Noncurrent Prepaid Expense, Noncurrent, Total OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment, Tax OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment, Tax, Total Unrealized income (loss) on available-for-sale investments, tax effect Unrealized (loss)/gain on available-for-sale investments, tax effect Restricted Cash and Cash Equivalents, Total Restricted Cash and Cash Equivalent Restricted cash Commitments and Contingencies COMMITMENTS AND CONTINGENCIES (Note 20) Lessee, Leases [Policy Text Block] Leases Tax Bureau in Guangdong Tax Bureau in Guangdong [Member] Tax bureau in guangdong. Operating loss carryforwards expiration end date. Operating Loss Carryforwards Expiration End Date Expiration end date Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Weighted average grant date fair value, Outstanding ending balance Weighted average grant date fair value, Outstanding beginning balance Condensed Income Statements, Captions [Line Items] Percentage of Sale of Goods on Revenue Percentage of sale of goods on revenue. Percentage of sale of goods on revenue Hubei Fangtang Technology Co., Ltd.. Hubei Fangtang Technology Company Limited [Member] Hubei fangtang technology company limited. Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Share-based compensation, shares Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture, Total General and Administrative Expense [Member] General and Administrative Expense Reversal of rental expenses. Reversal of Rental Expenses Reversal of rental expenses Operating Lease, Liability Total lease liability balance Operating Lease, Liability, Total Operating lease liabilities Deferred tax assets advertising expenses carryforwards. Deferred Tax Assets Advertising Expenses Carryforwards Advertising expenses carry-forwards Auditor Firm ID Auditor Firm ID Accrued Marketing Costs, Current Accrued marketing expenses Restricted cash Restricted Cash, Current Concentration Risk Benchmark [Axis] Concentration Risk Benchmark Variable Interest Entity, Primary Beneficiary [Member] VIEs Deferred sales inducements net of impairment. Deferred Sales Inducements Net Of Impairment Ending balances (current and non-current) Change in valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent Liabilities, Noncurrent [Abstract] Non-current liabilities Effect of Exchange Rate on Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Including Discontinued Operation Effect of exchange rate changes Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations, Total Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net income Net income Net income for the year Xiangyang Shufan Education Technology Company Limited [Member] Xiangyang shufan education technology company limited. Xiangyang Shufan Education Technology Co., Ltd. Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss, Total Held-to-maturity investments Long-Term Debt, Type [Domain] Long-term Debt, Type Cybersecurity Risk Management Positions or Committees Responsible [Text Block] Weighted Average Number of Shares Outstanding, Basic, Total Weighted Average Number of Shares Outstanding, Basic Weighted average ordinary shares outstanding used in computing basic net (loss)/income per share Weighted average shares used in calculating net income per ordinary share, Basic Scenario [Axis] Scenario Number of shares, Outstanding and exercisable beginning balance Number of shares, Outstanding and exercisable ending balance Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding and Exercisable Number Share based compensation arrangement by share based payment award options outstanding and exercisable number. Lessee, schedule of operating lease. Lessee Schedule Of Operating Lease Table [Text Block] Summary of Operating Leases Earning Per Share Basic And Diluted [Abstract] Earning Per Share Basic And Diluted [Abstract] Net income per share Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of Reconciliation of Effective Tax Rate and Statutory Income Tax Rate Applicable to PRC Operations Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Segments [Axis] Segments Long-Lived Tangible Asset [Domain] Long-Lived Tangible Asset Significant accounting policies. Significant Accounting Policies [Line Items] Significant Accounting Policies [Line Items] Beijing Baobian Consumer Technology Company Limited. Beijing Baobian Consumer Technology Company Limited [Member] Beijing Baobian Consumer Technology Co., Ltd. Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block] Asset Pledged as Collateral [Member] Assets Pledged as Collateral Deferred Tax Assets, Net [Abstract] Deferred tax assets Subsequent Events Subsequent Events [Text Block] APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Share-based compensation APIC, Share-Based Payment Arrangement, Increase for Cost Recognition, Total Online educational courses. Online Educational Courses [Member] Subtotal Online Educational Courses Exempted income tax rate Effective Income Tax Rate Reconciliation, Tax Exempt Income, Percent Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount Change in valuation allowance Equity, Attributable to Parent Stockholders' Equity Attributable to Parent, Beginning Balance Stockholders' Equity Attributable to Parent, Ending Balance Total Sunlands Technology Group shareholders' equity Document Registration Statement Document Registration Statement Amortization of land use right. Amortization Of Land Use Right Amortization expenses of land use right Statement of Stockholders' Equity [Abstract] Equity method investments Equity Method Investments Deferred Sales Inducement Cost, Impairment Loss Impairment loss on deferred costs Impairments Equity Method Investment [Table] Schedule Of Equity Method Investments [Table] Business Contact [Member] Business Contact Treasury Stock Treasury Stock, Common [Member] Commissions Expense, Policy [Policy Text Block] Sales commission Sales and Marketing Expenses Selling and Marketing Expense [Member] Selling and Marketing Expense Entity Address, Address Line Two Entity Address, Address Line Two Fair Value Measurement Fair Value Disclosures [Text Block] Income tax benefit/expenses if the tax holidays granted to Wuhan Shangde were not available Income tax expense (benefit) if the tax holidays granted were not available. Income Tax Expense Benefit If Tax Holidays Granted Were Not Available Income tax benefit/expenses if the tax holidays granted to Wuhan Shangde were not available Number of performance obligation. Number Of Performance Obligation Number of performance obligation Income taxes. Income Taxes [Line Items] Income Taxes [Line Items] Noncontrolling Interest [Member] Noncontrolling Interest Entity Incorporation, Date of Incorporation Date of establishment/ acquisition Schedule of Accrued Liabilities [Table Text Block] Schedule of Accrued Expenses and Other Liabilities Debt Instrument, Collateral Amount Debt instrument, security deposit Income (Loss) from Equity Method Investments (Loss) gain from equity method investments Loss from equity method investments Loss from equity method investments Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration] Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration] Deferred Costs, Noncurrent Deferred costs, non-current Deferred Costs, Noncurrent, Total Condensed Financial Information of Parent Company Only Disclosure [Text Block] Condensed Financial Information of Parent Company Plan Name [Domain] Plan Name Tax Year 2016 [Member] 2016 Chinese Mainland Operations Chinese Mainland Operations [Member] Chinese Mainland Operations. Interest Expense, Operating and Nonoperating Interest expense Interest Expense, Total Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date Building Building [Member] Buildings Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Text Block] Impairment loss on long-lived assets Impairment, Long-Lived Asset, Held-for-Use Impairment, Long-Lived Asset, Held-for-Use, Total Cybersecurity Risk Management Expertise of Management Responsible [Text Block] Tax Period [Axis] Tax Period Allocated share based compensation expense (reversal) Allocated share based compensation expense (reversal). Allocated Share Based Compensation Expense (Reversal) Treasury Stock, Value Treasury stock Treasury Stock, Value, Total Stock repurchased during period, value Cost of Revenue Allocated Share Based Compensation Expense Cost of revenues Cost of Revenue Allocated Share Based Compensation Expense Increase (decrease) in deferred tax liabilities. Increase Decrease In Deferred Tax Liabilities Deferred tax liabilities Property, Plant and Equipment, Policy [Policy Text Block] Property and equipment, net Entity Address, City or Town Entity Address, City or Town Contract with customer liability deductions. Contract With Customer Liability Deductions Deductions Stock Repurchased During Period, Shares Number of shares repurchased Share repurchase, shares Number of Reportable Segments Number of reportable segments Security Exchange Name Security Exchange Name Contact Personnel Name Contact Personnel Name Property, Plant and Equipment, Gross Total cost Cost of property and equipment Property, Plant and Equipment, Gross, Total Property, Plant and Equipment, Gross, Beginning Balance Property, Plant and Equipment, Gross, Ending Balance Intangible Assets Disclosure [Text Block] Intangible Assets, Net Prepaid Rent Deposits (Loss)/income before income tax benefit/(expenses) and gain/(loss) from equity method investments Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income before income tax expenses Loss/(income) before income tax expenses Payment Of Capital Contribution To Subsidiary Payment of capital contribution to subsidiary. Capital contribution to a subsidiary Concentration Risk Type [Domain] Concentration Risk Type Operating lease liabilities at carrying amount. Operating Lease Liabilities At Carrying Amount Carrying amount of operating lease liabilities Lessee, Operating Lease, Lease Not yet Commenced, Description Operating lease, lease not yet commenced, description Guangzhou Shangzhi Side Technology Co., Ltd. Guangzhou Shangzhi Side Technology Co., Ltd Sales of products [Member] Sales of products [Member] Sales of Products Antidilutive Securities, Name [Domain] Antidilutive Securities, Name Income tax rate outside the PRC PRC income tax rate Foreign tax effect Long-term investments. Long Term Investments [Member] Long-term Investments Long-term Investments Inventory Inventory, Net Inventory, Net, Total Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Beginning Balance Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Ending Balance Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Total cash, cash equivalents and restricted cash Total cash, cash equivalents and restricted cash Interest Paid, Excluding Capitalized Interest, Operating Activity Interest paid Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table] Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Table] Statistical Measurement Statistical Measurement [Domain] Assets, Current Total current assets Compensation expense Share-Based Payment Arrangement, Expense Allocated Share-based Compensation Expense Allocated Share-based Compensation Expense Document Period End Date Document Period End Date Equity Method Investments and Joint Ventures [Abstract] Title and Position [Axis] Title of Individual Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV Defined Contribution Plan, Cost Amounts expensed as incurred for employee defined contribution plan ICFR Auditor Attestation Flag ICFR Auditor Attestation Flag Other Assets, Miscellaneous, Noncurrent Others Gain (Loss) on Disposition of Property Plant Equipment Gain (Loss) on Disposition of Property Plant Equipment, Total Gain on disposal of property and equipment Equity Securities without Readily Determinable Fair Values [Policy Text Block] Equity securities without readily determinable fair values. Equity securities without readily determinable fair values Long-Term Debt [Text Block] Long-Term Debt Schedule of prepaid expenses and other current assets. Schedule Of Prepaid Expenses And Other Current Assets Table [Text Block] Summary of Prepaid Expenses and Other Current Assets Hubei Zhidao Online Education Technology Co., Ltd. Hubei zhidao online education technology company limited. Hubei Zhidao Online Education Technology Company Limited [Member] Statement of Financial Position [Abstract] Antidilutive Security, Excluded EPS Calculation [Table] Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation [Abstract] Reconciliation of cash, cash equivalents and restricted cash: Class of Stock [Axis] Class of Stock Preferential tax exemption approved start period. Preferential Tax Exemption Approved Start Period Preferential tax exemption approved start year Aggregated intrinsic value, Granted Share Based Compensation Arrangement By Share Based Payment Award Options Granted In Period Total Intrinsic Value Share based compensation arrangement by share based payment award options granted in period total intrinsic value. Weighted average service period. Weighted Average Service Period Weighted average service period Interest, professional skills and professional certification preparation courses. Interest, Professional Skills and Professional Certification Preparation Courses [Member] Interest, Pofessional Skills and Professional Certification Preparation Courses Current tax expenses Current Income Tax Expense (Benefit) Current Income Tax Expense (Benefit), Total Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent Income tax rate Effect of changes in tax laws or rates enacted in the current year Liabilities Consolidated VIE creditor TOTAL LIABILITIES Financial Instruments [Domain] Financial Instruments Deferred Sales Inducement Cost, Amortization Expense Amortizations Deferred Sales Inducement Cost, Amortization Expense, Total Statutory Reserves and Restricted Net Assets Statutory reserves and restricted net assets. Restricted Net Assets Customer. Customer [Member] Customer Equity Method Investments [Policy Text Block] Long-term investments Foreign tax effect Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount Lessee, Operating Lease, Liability, to be Paid, Year Two 2027 Advertising Expense Advertising expenses Finite-Lived Intangible Assets, Gross Intangible assets, gross Finite-Lived Intangible Assets, Gross, Total Weighted Average Number of Shares Outstanding, Diluted, Total Weighted Average Number of Shares Outstanding, Diluted Weighted average ordinary shares outstanding used in computing diluted net (loss)/income per share Weighted average shares used in calculating net income per ordinary share, Diluted Entity File Number Entity File Number OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Unrealized loss on available-for-sale investments, net of tax effect of nil Payment to related parties. Payment To Related Parties Share repurchase Cover [Abstract] Value Added Tax Receivable Prepaid and input VAT Prepaid Expense and Other Assets, Current Prepaid expenses and other current assets Total Payment of dividends withholding tax Payment of Dividends Withholding Tax Payment of dividends withholding tax. Tax Year 2021 [Member] 2021 Investments [Domain] Investments Proceeds from Sale of Long-Term Investments Proceeds received from disposal of long-term investments Percentage of variable interest entity liabilities on consolidated liabilities Percentage Of Variable Interest Entity Liabilities On Consolidated Liabilities Aggregate percentage of variable interest entity liabilities on Group's consolidated total liabilities Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Income before income tax expenses and loss from equity method investments Revenue Benchmark [Member] Total Net Revenues Scenario [Domain] Scenario Mortgages [Member] Mortgage Loan Mortgage Bank Loan Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized Number of shares approved for grant Number of Operating Segments Number of operating segments Segment Reporting Disclosure [Text Block] Segment Reporting General and Administrative Expense General and administrative expenses General and Administrative Expense, Total General and administrative expenses Revenue from Contract with Customer, Including Assessed Tax Total revenues Shares vested upon grant Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested, Number of Shares Subsequent Event [Table] Weighted-average remaining contractual term, Exercised Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Exercised, Weighted Average Remaining Contractual Term Share-based compensation arrangement by share-based payment award, options, exercised, weighted average remaining contractual term. Deferred Costs Deferred costs Deferred costs Impairment loss on short-term investments. Impairment Loss On Short Term Investments Impairment on short-term investments Finite-Lived Intangible Assets, Net Intangible assets, net Intangible assets, net Finite-Lived Intangible Assets, Net, Beginning Balance Finite-Lived Intangible Assets, Net, Ending Balance Effect of changes in tax laws or rates enacted in the current year Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount Preferential tax rate. Preferential Tax Rate Preferential tax rate Pledged Status [Domain] Pledged Status Debt instrument number of loan agreement. Debt Instrument Number Of Loan Agreement Debt instrument number of loan agreement Property, Plant and Equipment, Useful Life Buildings Recent accounting pronouncements adopted New Accounting Pronouncements, Policy [Policy Text Block] Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] Summary of Maturity Analysis of Annual Undiscounted Cash Flows for Lease Liabilities Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Contract with Customer, Liability, Current Deferred revenue, current Deferred revenue, current (including deferred revenue, current of the consolidated VIEs without recourse to Sunlands Technology Group of RMB281,776 and RMB92,472 as of December 31, 2024 and 2025, respectively) Ownership [Axis] Ownership Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract] Amount Depreciation Depreciation expenses Depreciation, Total Other Receivables, Net, Current Other receivables Other Receivables, Net, Current, Total Long-term investments Long-Term Investments Long-term investments Long-term investments (including available-for-sale investments of RMB189,422 and RMB193,148 as of December 31, 2024 and 2025, respectively) Common Stock, Shares, Outstanding Balances (in shares) Balances (in shares) Ordinary shares, shares outstanding Operating Lease, Liability, Current Lease liabilities, current Lease liabilities, current (including lease liabilities, current of the consolidated VIEs without recourse to Sunlands Technology Group of RMB7,780 and RMB354 as of December 31, 2024 and 2025, respectively) Depreciation, Depletion and Amortization Depreciation and amortization Depreciation, Depletion and Amortization, Total Revenue, Remaining Performance Obligation, Amount Recognized revenue of remaining performance obligation Dividends [Domain] Cybersecurity Risk Management Processes Integrated [Flag] Document Transition Report Document Transition Report Short-Term Investments Short-term investments Total Operating Expenses Total operating expenses Operating Expenses, Total Research and Development Expense Product development expenses Research and Development Expense, Total Transferred to designated agent account for share repurchase. Transferred To Designated Agent Account For Share Repurchase Transferred to designated agent account for share repurchase Cost of Revenue Cost of revenues Cost of Revenue, Total Cost of revenues Lessee, Operating Leases [Text Block] Leases No Trading Symbol Flag No Trading Symbol Flag Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Total comprehensive income Statement of Cash Flows [Abstract] Share-based compensation arrangement by share-based payment award options forfeited in period intrinsic value. Share Based Compensation Arrangement By Share Based Payment Award Options Forfeited In Period Intrinsic Value Aggregated intrinsic value, Forfeited Schedule of estimated useful lives of property plant and equipment table text block. Schedule Of Estimated Useful Lives Of Property Plant And Equipment Table [Text Block] Summary of Estimated Useful Lives of Property and Equipment Share-Based Payment Arrangement, Option, Activity [Table Text Block] Summary of Option Activitiy and Changes Sunlands HK Sunlands HK [Member] Sunlands HK. Finite-Lived Intangible Assets [Line Items] Finite Lived Intangible Assets [Line Items] Earnings Per Share [Text Block] Net Income Per Share Effective Income Tax Rate Reconciliation, Non-Taxable Income, Percent Effective income tax rate reconciliation, non-taxable income, percent. Non-taxable income Discontinued Operations and Disposal Groups [Abstract] Cybersecurity Risk Management Processes Integrated [Text Block] Net income attributable to Sunlands Technology Group Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value Aggregated intrinsic value, Outstanding ending balance Aggregated intrinsic value, Outstanding beginning balance Depositary shares. Depositary Shares [Member] American Depositary Shares Partner Type of Partners' Capital Account, Name [Domain] Partner Type of Partners' Capital Account, Name Operating Lease, Cost Total operating lease expense Equity securities with readily determinable fair values Equity Securities with Readily Determinable Fair Values [Policy Text Block] Equity securities with readily determinable fair values. Expected dividend yield Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate Summary of subsidiaries and variable interest entities and variable interest entities subsidiaries. Summary Of Subsidiaries And Variable Interest Entities And Variable Interest Entities Subsidiaries Table [Text Block] Summary of Significant Subsidiaries VIEs and VIEs' Subsidiaries Accrual for Taxes Other than Income Taxes, Current Other tax liabilities Operating Lease, Payments Cash paid for amounts included in the measurement of lease liabilities, Operating cash flows from operating leases Assets [Abstract] ASSETS Partner Type [Axis] Partner Type Income Tax Authority, Name [Axis] Income Tax Authority, Name Effective Income Tax Rate Reconciliation, Withholding Taxes, Percent Effective income tax rate reconciliation, withholding taxes, percent. PRC withholding taxes Wuhan, Hubei. Wuhan Hubei [Member] Wuhan, Hubei Risk-free interest rate Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Increase (Decrease) in Prepaid Expense and Other Assets Prepaid expenses and other current assets Document Fiscal Year Focus Document Fiscal Year Focus Autonomous Regions [Member] Autonomous regions. Autonomous Regions Concentration Risk Benchmark [Domain] Concentration Risk Benchmark Condensed Cash Flow Statement [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Revenue, remaining performance obligation, expected timing of satisfaction, period Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] CASH FLOWS FROM INVESTING ACTIVITIES Retirement Benefits [Abstract] Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Short-Term Investments Increase (Decrease) in Other Noncurrent Assets Other non-current assets Sunlands Online Education HK Limited. Sunlands Online Education H K Limited [Member] Sunlands Online Education HK Limited ("Sunlands HK") Provision for statutory reserves Provision for Statutory Reserves Provision for statutory reserves. Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Schedule of Movements of the Deferred Revenue Gain (loss) on equity securities fair value Equity Securities, FV-NI, Gain (Loss) Equity Securities, FV-NI, Gain (Loss), Total Income on equity securities fair value Increase (decrease) in deferred tax assets. Increase Decrease In Deferred Tax Assets Deferred tax assets Finite-Lived Intangible Asset, Expected Amortization, Year One 2026 Finite-Lived Intangible Assets Amortization Expense [Table Text Block] Summary of Estimated Useful Lives of Intangible Assets Fair Value Measurement, Policy [Policy Text Block] Fair value Online Educational Services [Member] Online Educational Services. Subtotal Online educational services Proceeds from exercise of share options Proceeds from Stock Options Exercised Fair Value Disclosures [Abstract] Commitments and Contingencies Disclosure [Abstract] Lessee, Operating Lease, Liability, to be Paid, Year One 2026 Effective Income Tax Rate Reconciliation [Line Items] Income (Loss) from Subsidiaries, Net of Tax Income (Loss) from Subsidiaries, Net of Tax, Total Income from investment in subsidiaries Preferential tax exemption approved end period. Preferential Tax Exemption Approved End Period Preferential tax exemption approved end year Share-Based Payment Arrangement [Abstract] Significant accounting policies. Significant Accounting Policies [Table] Significant Accounting Policies [Table] Concentration Risk, Percentage Revenues from customers individually representing portion of total net revenues Equity Method Investments and Joint Ventures Disclosure [Text Block] Long-Term Investments Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Net cash generated from/(used in) investing activities Title of 12(b) Security Title of 12(b) Security Deferred Tax Liabilities, Net [Abstract] Deferred tax liabilities Entity Address, Address Line Three Entity Address, Address Line Three Effective Income Tax Rate Reconciliation, Tax Holiday, Amount Effect of tax holidays in PRC Effect of tax holidays in PRC Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Weighted-average exercise price, Forfeited Condensed Financial Statements, Captions [Line Items] Condensed Financial Statements Captions [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Weighted average grant date fair value, Forfeited Prepaid expenses and other current assets. Prepaid Expenses And Other Current Assets [Text Block] Prepaid Expenses and Other Current Assets Income Tax Disclosure [Text Block] Income Taxes Variable interest entity, measure of activity net cash generated from (used in) investing activities. Variable Interest Entity Measure Of Activity Net Cash Generated From Used In Investing Activities Net cash (used in)/generated from investing activities Tax Exemption Approved End Period Tax exemption approved end period. Tax exemption approved end period Other Liabilities, Noncurrent Other non-current liabilities Other non-current liabilities (including other non-current liabilities of the consolidated VIEs without recourse to Sunlands Technology Group of RMB1,415 and RMB100 as of December 31, 2024 and 2025, respectively) Consolidated Entities [Axis] Consolidated Entities Number of deconsolidated entities. Number Of Deconsolidated Entities Number of deconsolidated entities Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Changes in operating assets and liabilities: Property, Plant and Equipment [Table Text Block] Summary of Property and Equipment Consisted Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price Weighted-average exercise price, Outstanding beginning balance Weighted-average exercise price, Outstanding ending balance Income Tax Disclosure [Abstract] Fair Value, Recurring and Nonrecurring [Table] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Deferred costs. Deferred Costs Table [Text Block] Schedule of Movement of Deferred Costs Additional Paid-in Capital [Member] Additional Paid-in Capital Measurement Frequency [Domain] Measurement Frequency Share Repurchase Program, Authorized, Amount Authorized amount under share repurchase program Statement of Income Location, Balance [Axis] Income Statement Location Change in Accounting Principle, Accounting Standards Update, Adoption Date Change in accounting principle accounting standards update adoption date Trading Symbol Trading Symbol Basis of presentation and use of estimates. Basis Of Presentation And Use Of Estimates Policy [Text Block] Basis of presentation and use of estimates Intangible Asset, Finite-Lived [Table] Schedule Of Finite Lived Intangible Assets [Table] Property, Plant and Equipment Disclosure [Text Block] Property and Equipment, Net State Administration of Taxation, China [Member] China Non-deductible expense Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent, Total Condensed Financial Statements [Table] Schedule Of Condensed Financial Statements [Table] Subsequent Event Type [Axis] Foreign Currency Exchange Rate, Translation Currency exchange rate, Renminbi ("RMB") to U.S. dollar Schedule of Finite-Lived Intangible Assets [Table Text Block] Summary of Intangible Assets Employee-related Liabilities, Current Salary and welfare payables Employee-related Liabilities, Current, Total Future cash outflow to pay for leasehold improvement and intangible assets. Payables For Leasehold Improvement And Intangible Assets Payables for leasehold improvement and intangible assets Accumulated Impairment Loss On Property And Equipment Accumulated impairment loss on property and equipment. Less: Accumulated impairment loss Less: Accumulated impairment loss Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] CASH FLOWS FROM FINANCING ACTIVITIES Expected life (years) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term Fair Value, Recurring [Member] Fair Value, Recurring Accounts Payable and Accrued Liabilities Disclosure [Text Block] Accrued Expenses and Other Current Liabilities Entity Ex Transition Period Entity Ex Transition Period Schedule of Equity Method Investments [Line Items] Schedule Of Equity Method Investments [Line Items] Lessee, Operating Lease, Liability, to be Paid Total future lease payments Lessee, Operating Lease, Liability, Undiscounted Excess Amount Less: Imputed interest Selling and Marketing Expense Sales and marketing expenses Selling and Marketing Expense, Total Sales and marketing expenses Equity Components [Axis] Treasury Stock Stock Issued During Period, Value, Stock Dividend Dividend declared Dividend declared Variable interest entity, measure of activity net cash generated from (used in) financing activities. Variable Interest Entity Measure Of Activity Net Cash Generated From Used In Financing Activities Net cash generated from financing activities Equity Component [Domain] Equity Component Wuhan Shangde Online Education Technology Company Limited. Wuhan Shangde Online Education Technology Company Limited [Member] Wuhan Shangde Online Education Technology Co., Ltd. ("Wuhan Shangde") Deferred revenue Deferred Tax Assets, Deferred Income Address Type [Domain] Address Type PRC Bank. P R C Bank [Member] PRC Bank Document Annual Report Document Annual Report Business Combination [Axis] Cash and cash equivalents at carrying value available for conversion to foreign currency. Cash And Cash Equivalents At Carrying Value Available For Conversion To Foreign Currency Cash and cash equivalents available for conversion to foreign currency Customer [Axis] Customer Proceeds from interest in subsidiaries, Proceeds From Interest In Subsidiaries Amounts due from subsidiaries Purchase of long-term investments Payment for long-term investments Payment for long-term investments Payments to Acquire Long-Term Investments Document Accounting Standard Document Accounting Standard Common Stock, Voting Rights Common stock, voting right Effective Income Tax Rate Reconciliation, Tax Contingency, Amount Effective Income Tax Rate Reconciliation, Tax Contingency, Amount, Total Changes in unrecognized tax benefits Statement of Comprehensive Income [Abstract] Intangible Assets, Net (Excluding Goodwill) [Abstract] Repayments of Bank Debt Repayment of bank loans Maximum [Member] Maximum Summary of land use right. Summary Of Land Use Right Table [Text Block] Summary of Land Use Right Entity Addresses, Address Type [Axis] Entity Addresses, Address Type Statistical Measurement [Axis] Statistical Measurement Weighted-average exercise price, Exercised Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Contract with Customer, Liability, Noncurrent Deferred revenue, non-current Deferred revenue, non-current (including deferred revenue, non-current of the consolidated VIEs without recourse to Sunlands Technology Group of RMB107,441 and RMB8,917 as of December 31, 2024 and 2025, respectively) Finite-Lived Intangible Assets, Accumulated Amortization Less: Accumulated amortization Prepaid Expense, Current Prepaid expenses Prepaid Expense, Current, Total Increase (Decrease) in Other Accounts Payable and Accrued Liabilities Accrued expenses and other current liabilities Common Stock, Value, Issued Ordinary shares Wuhan Zhibo [Member] Wuhan Zhibo. Wuhan Zhibo Nonrecourse [Member] Nonrecourse Dividends [Axis] Income taxes. Income Taxes [Table] Income Taxes [Table] Consolidation, Policy [Policy Text Block] Principles of consolidation Remaining Profits [Member] For the Remaining Profits Remaining profits. Equity, Including Portion Attributable to Noncontrolling Interest Balances Balances TOTAL SHAREHOLDERS' EQUITY Contact Personnel Email Address Contact Personnel Email Address Deferred Tax Assets, Operating Loss Carryforwards Net operating loss carry-forwards Deferred Tax Assets, Operating Loss Carryforwards, Total Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block] Option agreement maximum contract amount. Option Agreement Maximum Contract Amount Option agreement maximum contract amount Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Impairment of long-lived assets General and administrative expenses General and administrative expenses allocated share based compensation expenses General and Administrative Expenses Allocated Share Based Compensation Expenses Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Summary of Amortization Expenses of Intangible Assets Income tax reconciliation non-deductible and (super deduction) expense. Income Tax Reconciliation Non Deductible And Super Deduction Expense Non-deductible and super deduction expenses Deferred Costs, Current Deferred Costs, Current, Total Deferred costs, current portion Deferred costs, current Volatility Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate Variable Interest Entity, Measure of Activity, Operating Income or Loss Net income Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest, Total Less: comprehensive income attributable to non-controlling interest Lessee, Finance Lease, Description Finance lease, description Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class Lender Name [Axis] Lender Name Effective Income Tax Rate Reconciliation, Cross-Border Tax Effect, Percent Effective Income Tax Rate Reconciliation, Cross-Border Tax Effect, Percent, Total Effect of cross-border tax laws Revenue from Contract with Customer [Text Block] Revenues and Deferred Revenue Entity Registrant Name Entity Registrant Name Land use right. Land Use Right [Table] Land Use Right [Table] Income tax reconciliation effect of tax holidays and tax rate difference. Income Tax Reconciliation Effect Of Tax Holidays And Tax Rate Difference Effect of tax holidays and tax rate difference Entity Voluntary Filers Entity Voluntary Filers Customer Concentration Risk [Member] Customer Concentration Risk Cayman CAYMAN ISLANDS Finite-Lived Intangible Asset, Expected Amortization, Year Two 2027 Available-for-Sale Investments Available for Sale Investments [Member] Available for sale investments. Other Nonoperating Income (Expense) Other Nonoperating Income (Expense), Total Other income, net Other income, net Hubei Houduan Yuanli Technology Co., Ltd. Hubei Houduan Yuanli Technology Company Limited [Member] Hubei houduan yuanli technology company limited. Subsequent Events [Abstract] Payables for leasehold improvement and intangible assets. Payable For Leasehold Improvement And Intangible Assets Payables for leasehold improvement and intangible assets Operating lease noncash changes in right-of-use assets from new lease obligations. Operating Lease Noncash Changes In Right Of Use Assets From New Lease Obligations Non-cash changes in right-of-use assets from new lease obligations and lease modification: Operating leases Cybersecurity Risk Management Positions or Committees Responsible [Flag] Consolidated Entities [Domain] Consolidated Entities Finite-Lived Intangible Asset, Expected Amortization, Year Three 2027 Income tax (benefit)/expenses Income Tax Expense (Benefit) Income tax expenses Income tax expenses Income tax expenses Beijing Feibian Technology Company Limited [Member] Beijing feibian technology company limited. Beijing Feibian Education Technology Co., Ltd. ("Beijing Feibian") Measurement Frequency Measurement Frequency [Axis] Stock Repurchased During Period, Value Share repurchase Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Statutory Accounting Practices, Statutory Capital and Surplus, Balance Statutory reserves Compensation Related Costs, Policy [Policy Text Block] Share-based compensation Statutory Reserves [Member] Statutory reserves. Statutory Reserves Wholly foreign-owned enterprise. Wholly Foreign Owned Enterprise [Member] WFOE Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax, Total Payments to Acquire Property, Plant, and Equipment Acquisition of property and equipment Payments to Acquire Property, Plant, and Equipment, Total Limited Partner [Member] Limited Partnerships Next One lakh Ninety Thousand Taxable Income [Member] Next ONE lakh ninety thousand taxable income. For Next SGD$190,000 Taxable Income Assets Consolidated VIE assets TOTAL ASSETS Property, Plant and Equipment [Table] Schedule Of Property Plant And Equipment [Table] Proceeds from repayment of loan to employees. Proceeds From Repayment Of Loan To Employees Repayment of employee loans Weighted-average remaining contractual term, Exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Income Statement [Abstract] Fair Value of Financial Instruments, Policy [Policy Text Block] Financial instruments Deferred Income Tax Expense (Benefit) Deferred Income Tax Expense (Benefit), Total Deferred tax expenses Other assets noncurrent employee loans. Other Assets Noncurrent Employee Loans Employee loans Number of vote ordinary shares entitled. Number Of Vote Ordinary Shares Entitled Number of vote each ordinary shares entitled Consolidation, Variable Interest Entity, Policy [Policy Text Block] The VIE arrangements Accounts Payable, Other, Current Other payables Schedule of subsidiaries, Variable interest entities ("VIEs") and VIEs subsidiaries. Schedule Of Subsidiaries Variable Interest Entities V I Es And V I Es Subsidiaries [Table] Schedule Of Subsidiaries Variable Interest Entities V I Es And V I Es Subsidiaries [Table] Earnings Per Share, Diluted, Total Earnings Per Share, Diluted Diluted Effective Income Tax Rate Reconciliation, Percent [Abstract] Percent Title and Position [Domain] Title of Individual Debt Securities Available for Sale Unrealized Gain (Loss) Position Debt securities Available-for-sale unrealized gain (loss) position. Available-for-Sale recognized unrealized gain (loss) Disaggregation of Revenue [Abstract] Two employees. Two Employees [Member] Two Employees Property, Plant, and Equipment, Useful Life, Term, Description [Extensible Enumeration] City Area Code City Area Code Auditor Name Auditor Name Land use right, net. Land Use Right Net Land use right, net Land use right, net Debt Instrument, Face Amount Debt instrument, face amount Amount of loan obtained to purchase buildings Intangible Assets, Finite-Lived, Policy [Policy Text Block] Intangible assets, net Commissions [Member] Commissions [Member] Commissions Compensation and Employee Benefit Plans, Other than Share-Based Compensation [Text Block] Employee Defined Contribution Plan Receivables from third party payment agencies. Receivables From Third Party Payment Agencies Receivables from third-party payment agencies The maximum percentage of the appropriation to the statutory surplus fund over the after-tax profits calculated in accordance with PRC GAAP. Portion Of After Tax Profit To Be Allocated To General Reserve Under Prc Law Required minimum percentage of after-tax-profit allocated to general reserve Recourse Status [Axis] Recourse Status Variable Interest Entity, Measure of Activity, Revenues Net revenues Variable Lease, Cost Variable lease cost Increase (Decrease) in Deferred Charges Deferred costs Operating Lease, Weighted Average Remaining Lease Term Operating leases, Weighted average remaining lease term Computer Software, Intangible Asset [Member] Computer Software Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract] Cash and Cash Equivalents, Policy [Policy Text Block] Cash and cash equivalents Business Combination, Consideration Transferred, Equity Interest Transfer of equity interest, cash consideration Professional Certification Preparation, Professional Skills and Interest Courses Professional Certification Preparation, Professional Skills and Interest Courses [Member] Professional certification preparation, professional skills and interest courses. Property, Plant and Equipment, Net Property and equipment, net Property and equipment, net O 2022 Q2 Dividends [Member] O 2024 Q4 Dividends. O 2022 Q2 Dividends Restricted Assets Disclosure [Text Block] Restricted Net Assets Proceeds from bank loans Proceeds from Bank Debt Cash, cash equivalents and restricted cash at end of the year Cash, cash equivalents and restricted cash at beginning of the year Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Including Discontinued Operation Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations, Total Operating Income (Loss) Loss from operations Income from operations Land use right. Land Use Right [Text Block] Land Use Right, Net Retained Earnings [Member] Accumulated Deficit Entity Address, Country Entity Address, Country Condensed Statement of Income Captions [Line Items] Assets, Noncurrent Total non-current assets Common Class C [Member] Class C Ordinary Shares Share-Based Payment Arrangement, Noncash Expense Share-based compensation Share-Based Payment Arrangement, Noncash Expense, Total Liabilities, Noncurrent Total non-current liabilities Operating Lease, Weighted Average Discount Rate, Percent Operating leases, Weighted average discount rate Operating Lease, Liability, Noncurrent Lease liabilities, non-current Lease liabilities, non-current (including lease liabilities, non-current of the consolidated VIEs without recourse to Sunlands Technology Group of RMB133,994 and RMB1,085 as of December 31, 2024 and 2025, respectively) Fair Value, Inputs, Level 1 [Member] Quoted Prices in Active Market for Identical Assets (Level 1) Class of Stock [Line Items] Ordinary Shares [Line Items] Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Net cash used in financing activities Change in Accounting Principle, Accounting Standards Update, Adopted [true false] Change In accounting principle accounting standards update adopted Auditor Location Auditor Location Deferred Income Tax Liabilities, Net Deferred tax liabilities Deferred tax liabilities ADS American depository shares. American Depository Shares [Member] American Depository Shares Investments Investments, Fair Value Disclosure Short-term investments Investments, Fair Value Disclosure, Total Marketable Securities [Table Text Block] Schedule of Short-Term Investment Tianjin Alaman Education Technology Company Limited. Tianjin Alaman Education Technology Company Limited [Member] Tianjin Alaman Education Technology Co., Ltd. ("Tianjin Alaman") Other Long-Term Investments [Member] Share based compensation arrangement by share based payment award equity instruments other than option exercised in period weighted average grant date fair value. Weighted average grant date fair value, Exercised Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Option Exercised In Period Weighted Average Grant Date Fair Value Income Tax Jurisdiction [Domain] Entity Interactive Data Current Entity Interactive Data Current Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent [Abstract] Net income attributable to Sunlands Technology Group used in basic and diluted net income per share: Increase (Decrease) in Contract with Customer, Liability Deferred revenue Statement of Income Location, Balance [Domain] Income Statement Location Tax Exemption Approved Start Period Tax exemption approved start period. Tax exemption approved start period Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] CASH FLOWS FROM OPERATING ACTIVITIES Variable-rate financial instruments. Variable Rate Financial Instruments [Member] Variable-Rate Financial Instruments Increase (Decrease) in Other Noncurrent Liabilities Other non-current liabilities Beijing Feibian Education Technology Company Limited [Member] Beijing Feibian Education Technology Company Limited [Member] Beijing Feibian Education Technology Co., Ltd. Dividend declared per share Common Stock, Dividends, Per Share, Declared Government Subsidies. Government Subsidies Government subsidies Amount of Restricted Net Assets for Consolidated and Unconsolidated Subsidiaries Amount of restricted paid-in-capital and statutory reserves Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] SHAREHOLDERS' EQUITY Fair value of underlying ordinary share Share Price Accrued withholding tax expenses Accrued withholding tax expenses Long-Term Debt, Type [Axis] Long-term Debt, Type Condensed Income Statement [Table] Debt Instrument, Term Debt instrument, term Land use right gross. Land Use Right Gross Land use right Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Organization and Basis of Presentation Income Tax Authority, Name [Domain] Income Tax Authority, Name Local Phone Number Local Phone Number Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount Unrecognized share-based compensation expenses Weighted Average Number of Shares Outstanding, Diluted [Abstract] Denominator: Weighted average shares used in calculating net income per ordinary share: Auditor Opinion [Text Block] Auditor Opinion Accounting Policies [Abstract] Proceeds from repayment of employee loans. Proceeds from Repayment of Employee Loans Repayment of employee loans Disaggregation of Revenue [Line Items] Disaggregation Of Revenue [Line Items] Deferred Tax Liabilities, Undistributed Foreign Earnings Withholding tax on undistributed earnings Income tax accrued withholding tax expenses Withholding tax on undistributed earnings Revenue from Contract with Customer, Excluding Assessed Tax Net revenues Total net revenues Schedule of Other Assets, Noncurrent [Table Text Block] Schedule of Other Non-Current Assets Lessee, Operating Lease, Liability, to be Paid, Year Four 2029 Class of Stock [Domain] Class of Stock Accrued Professional Fees, Current Accrued service fees Deferred Tax Liabilities, Deferred Expense Deferred costs Deferred Tax Liabilities, Deferred Expense, Total Stock, Class of Stock [Table] Schedule Of Stock By Class [Table] Entity Emerging Growth Company Entity Emerging Growth Company Weighted-average remaining contractual term, Vested And Expected to Vest Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term Area of Land Area of land