3.26.1 html 1687 844 1 true 492 0 false 9 false false R1.htm 1001 - Document - Cover Page Sheet http://www.sktelecom.com/role/CoverPage Cover Page Cover 1 false false R2.htm 1002 - Statement - Consolidated Statements of Financial Position Sheet http://www.sktelecom.com/role/ConsolidatedStatementsOfFinancialPosition Consolidated Statements of Financial Position Statements 2 false false R3.htm 1003 - Statement - Consolidated Statements of Income Sheet http://www.sktelecom.com/role/ConsolidatedStatementsOfIncome Consolidated Statements of Income Statements 3 false false R4.htm 1004 - Statement - Consolidated Statements of Comprehensive Income Sheet http://www.sktelecom.com/role/ConsolidatedStatementsOfComprehensiveIncome Consolidated Statements of Comprehensive Income Statements 4 false false R5.htm 1005 - Statement - Consolidated Statements of Changes in Equity Sheet http://www.sktelecom.com/role/ConsolidatedStatementsOfChangesInEquity Consolidated Statements of Changes in Equity Statements 5 false false R6.htm 1006 - Statement - Consolidated Statements of Cash Flows Sheet http://www.sktelecom.com/role/ConsolidatedStatementsOfCashFlows Consolidated Statements of Cash Flows Statements 6 false false R7.htm 995447 - Disclosure - Insider Trading Policies and Procedures Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingPoliciesProc Insider Trading Policies and Procedures Notes 7 false false R8.htm 995550 - Disclosure - Cybersecurity Risk Management and Strategy Disclosure Sheet http://xbrl.sec.gov/cyd/role/CybersecurityRiskManagementAndStrategyDisclosure Cybersecurity Risk Management and Strategy Disclosure Notes 8 false false R9.htm 999001 - Disclosure - Reporting Entity Sheet http://www.sktelecom.com/role/ReportingEntity Reporting Entity Notes 9 false false R10.htm 999002 - Disclosure - Basis of Preparation Sheet http://www.sktelecom.com/role/BasisOfPreparation Basis of Preparation Notes 10 false false R11.htm 999003 - Disclosure - Material Accounting Policies Sheet http://www.sktelecom.com/role/MaterialAccountingPolicies Material Accounting Policies Notes 11 false false R12.htm 999004 - Disclosure - Operating Segments Sheet http://www.sktelecom.com/role/OperatingSegments Operating Segments Notes 12 false false R13.htm 999005 - Disclosure - Deposits with Restrictions on Use Sheet http://www.sktelecom.com/role/DepositsWithRestrictionsOnUse Deposits with Restrictions on Use Notes 13 false false R14.htm 999006 - Disclosure - Trade and Other Receivables Sheet http://www.sktelecom.com/role/TradeAndOtherReceivables Trade and Other Receivables Notes 14 false false R15.htm 999007 - Disclosure - Prepaid expenses Sheet http://www.sktelecom.com/role/PrepaidExpenses Prepaid expenses Notes 15 false false R16.htm 999008 - Disclosure - Contract Assets and Liabilities Sheet http://www.sktelecom.com/role/ContractAssetsAndLiabilities Contract Assets and Liabilities Notes 16 false false R17.htm 999009 - Disclosure - Inventories Sheet http://www.sktelecom.com/role/Inventories Inventories Notes 17 false false R18.htm 999010 - Disclosure - Investment Securities Sheet http://www.sktelecom.com/role/InvestmentSecurities Investment Securities Notes 18 false false R19.htm 999011 - Disclosure - Investments in Associates and Joint Ventures Sheet http://www.sktelecom.com/role/InvestmentsInAssociatesAndJointVentures Investments in Associates and Joint Ventures Notes 19 false false R20.htm 999012 - Disclosure - Property and Equipment Sheet http://www.sktelecom.com/role/PropertyAndEquipment Property and Equipment Notes 20 false false R21.htm 999013 - Disclosure - Investment Property Sheet http://www.sktelecom.com/role/InvestmentProperty Investment Property Notes 21 false false R22.htm 999014 - Disclosure - Leases Sheet http://www.sktelecom.com/role/Leases Leases Notes 22 false false R23.htm 999015 - Disclosure - Goodwill Sheet http://www.sktelecom.com/role/Goodwill Goodwill Notes 23 false false R24.htm 999016 - Disclosure - Intangible Assets Sheet http://www.sktelecom.com/role/IntangibleAssets Intangible Assets Notes 24 false false R25.htm 999017 - Disclosure - Borrowings and Debentures Sheet http://www.sktelecom.com/role/BorrowingsAndDebentures Borrowings and Debentures Notes 25 false false R26.htm 999018 - Disclosure - Long-term Payables - other Sheet http://www.sktelecom.com/role/LongTermPayablesOther Long-term Payables - other Notes 26 false false R27.htm 999019 - Disclosure - Provisions Sheet http://www.sktelecom.com/role/Provisions Provisions Notes 27 false false R28.htm 999020 - Disclosure - Defined Benefit Liabilities (Assets) Sheet http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssets Defined Benefit Liabilities (Assets) Notes 28 false false R29.htm 999021 - Disclosure - Derivative Instruments Sheet http://www.sktelecom.com/role/DerivativeInstruments Derivative Instruments Notes 29 false false R30.htm 999022 - Disclosure - Share Capital and Capital Surplus and Others Sheet http://www.sktelecom.com/role/ShareCapitalAndCapitalSurplusAndOthers Share Capital and Capital Surplus and Others Notes 30 false false R31.htm 999023 - Disclosure - Treasury Shares Sheet http://www.sktelecom.com/role/TreasuryShares Treasury Shares Notes 31 false false R32.htm 999024 - Disclosure - Hybrid Bonds Sheet http://www.sktelecom.com/role/HybridBonds Hybrid Bonds Notes 32 false false R33.htm 999025 - Disclosure - Share-based payment Arrangement Sheet http://www.sktelecom.com/role/ShareBasedPaymentArrangement Share-based payment Arrangement Notes 33 false false R34.htm 999026 - Disclosure - Retained Earnings Sheet http://www.sktelecom.com/role/RetainedEarnings Retained Earnings Notes 34 false false R35.htm 999027 - Disclosure - Reserves Sheet http://www.sktelecom.com/role/Reserves Reserves Notes 35 false false R36.htm 999028 - Disclosure - Other Operating Income and Expenses Sheet http://www.sktelecom.com/role/OtherOperatingIncomeAndExpenses Other Operating Income and Expenses Notes 36 false false R37.htm 999029 - Disclosure - Finance Income and Costs Sheet http://www.sktelecom.com/role/FinanceIncomeAndCosts Finance Income and Costs Notes 37 false false R38.htm 999030 - Disclosure - Income Tax Expense Sheet http://www.sktelecom.com/role/IncomeTaxExpense Income Tax Expense Notes 38 false false R39.htm 999031 - Disclosure - Earnings per Share Sheet http://www.sktelecom.com/role/EarningsPerShare Earnings per Share Notes 39 false false R40.htm 999032 - Disclosure - Dividends Sheet http://www.sktelecom.com/role/Dividends Dividends Notes 40 false false R41.htm 999033 - Disclosure - Categories of Financial Instruments Sheet http://www.sktelecom.com/role/CategoriesOfFinancialInstruments Categories of Financial Instruments Notes 41 false false R42.htm 999034 - Disclosure - Financial Risk Management Sheet http://www.sktelecom.com/role/FinancialRiskManagement Financial Risk Management Notes 42 false false R43.htm 999035 - Disclosure - Transactions with Related Parties Sheet http://www.sktelecom.com/role/TransactionsWithRelatedParties Transactions with Related Parties Notes 43 false false R44.htm 999036 - Disclosure - Commitments and Contingencies Sheet http://www.sktelecom.com/role/CommitmentsAndContingencies Commitments and Contingencies Notes 44 false false R45.htm 999037 - Disclosure - Statements of Cash Flows Sheet http://www.sktelecom.com/role/StatementsOfCashFlows Statements of Cash Flows Notes 45 false false R46.htm 999038 - Disclosure - Emissions Liabilities Sheet http://www.sktelecom.com/role/EmissionsLiabilities Emissions Liabilities Notes 46 false false R47.htm 999039 - Disclosure - Assets and Liabilities Held for Sale Sheet http://www.sktelecom.com/role/AssetsAndLiabilitiesHeldForSale Assets and Liabilities Held for Sale Notes 47 false false R48.htm 999040 - Disclosure - Business Combinations Sheet http://www.sktelecom.com/role/BusinessCombinations Business Combinations Notes 48 false false R49.htm 999041 - Disclosure - Cash Dividends paid to the Parent Company Sheet http://www.sktelecom.com/role/CashDividendsPaidToTheParentCompany Cash Dividends paid to the Parent Company Notes 49 false false R50.htm 999042 - Disclosure - Material Accounting Policies (Policies) Sheet http://www.sktelecom.com/role/MaterialAccountingPoliciesPolicies Material Accounting Policies (Policies) Policies http://www.sktelecom.com/role/MaterialAccountingPolicies 50 false false R51.htm 999043 - Disclosure - Reporting Entity (Tables) Sheet http://www.sktelecom.com/role/ReportingEntityTables Reporting Entity (Tables) Tables http://www.sktelecom.com/role/ReportingEntity 51 false false R52.htm 999044 - Disclosure - Material Accounting Policies (Tables) Sheet http://www.sktelecom.com/role/MaterialAccountingPoliciesTables Material Accounting Policies (Tables) Tables http://www.sktelecom.com/role/MaterialAccountingPolicies 52 false false R53.htm 999045 - Disclosure - Operating Segments (Tables) Sheet http://www.sktelecom.com/role/OperatingSegmentsTables Operating Segments (Tables) Tables http://www.sktelecom.com/role/OperatingSegments 53 false false R54.htm 999046 - Disclosure - Deposits with Restrictions on Use (Tables) Sheet http://www.sktelecom.com/role/DepositsWithRestrictionsOnUseTables Deposits with Restrictions on Use (Tables) Tables http://www.sktelecom.com/role/DepositsWithRestrictionsOnUse 54 false false R55.htm 999047 - Disclosure - Trade and Other Receivables (Tables) Sheet http://www.sktelecom.com/role/TradeAndOtherReceivablesTables Trade and Other Receivables (Tables) Tables http://www.sktelecom.com/role/TradeAndOtherReceivables 55 false false R56.htm 999048 - Disclosure - Prepaid expenses (Tables) Sheet http://www.sktelecom.com/role/PrepaidExpensesTables Prepaid expenses (Tables) Tables http://www.sktelecom.com/role/PrepaidExpenses 56 false false R57.htm 999049 - Disclosure - Contract Assets and Liabilities (Tables) Sheet http://www.sktelecom.com/role/ContractAssetsAndLiabilitiesTables Contract Assets and Liabilities (Tables) Tables http://www.sktelecom.com/role/ContractAssetsAndLiabilities 57 false false R58.htm 999050 - Disclosure - Inventories (Tables) Sheet http://www.sktelecom.com/role/InventoriesTables Inventories (Tables) Tables http://www.sktelecom.com/role/Inventories 58 false false R59.htm 999051 - Disclosure - Investment Securities (Tables) Sheet http://www.sktelecom.com/role/InvestmentSecuritiesTables Investment Securities (Tables) Tables http://www.sktelecom.com/role/InvestmentSecurities 59 false false R60.htm 999052 - Disclosure - Investments in Associates and Joint Ventures (Tables) Sheet http://www.sktelecom.com/role/InvestmentsInAssociatesAndJointVenturesTables Investments in Associates and Joint Ventures (Tables) Tables http://www.sktelecom.com/role/InvestmentsInAssociatesAndJointVentures 60 false false R61.htm 999053 - Disclosure - Property and Equipment (Tables) Sheet http://www.sktelecom.com/role/PropertyAndEquipmentTables Property and Equipment (Tables) Tables http://www.sktelecom.com/role/PropertyAndEquipment 61 false false R62.htm 999054 - Disclosure - Investment Property (Table) Sheet http://www.sktelecom.com/role/InvestmentPropertyTable Investment Property (Table) Tables http://www.sktelecom.com/role/InvestmentProperty 62 false false R63.htm 999055 - Disclosure - Leases (Tables) Sheet http://www.sktelecom.com/role/LeasesTables Leases (Tables) Tables http://www.sktelecom.com/role/Leases 63 false false R64.htm 999056 - Disclosure - Goodwill (Tables) Sheet http://www.sktelecom.com/role/GoodwillTables Goodwill (Tables) Tables http://www.sktelecom.com/role/Goodwill 64 false false R65.htm 999057 - Disclosure - Intangible Assets (Tables) Sheet http://www.sktelecom.com/role/IntangibleAssetsTables Intangible Assets (Tables) Tables http://www.sktelecom.com/role/IntangibleAssets 65 false false R66.htm 999058 - Disclosure - Borrowings and Debentures (Tables) Sheet http://www.sktelecom.com/role/BorrowingsAndDebenturesTables Borrowings and Debentures (Tables) Tables http://www.sktelecom.com/role/BorrowingsAndDebentures 66 false false R67.htm 999059 - Disclosure - Long-term Payables – other (Tables) Sheet http://www.sktelecom.com/role/LongTermPayablesOtherTables Long-term Payables – other (Tables) Tables 67 false false R68.htm 999060 - Disclosure - Provisions (Tables) Sheet http://www.sktelecom.com/role/ProvisionsTables Provisions (Tables) Tables http://www.sktelecom.com/role/Provisions 68 false false R69.htm 999061 - Disclosure - Defined Benefit Liabilities (Assets) (Tables) Sheet http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssetsTables Defined Benefit Liabilities (Assets) (Tables) Tables http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssets 69 false false R70.htm 999062 - Disclosure - Derivative Instruments (Tables) Sheet http://www.sktelecom.com/role/DerivativeInstrumentsTables Derivative Instruments (Tables) Tables http://www.sktelecom.com/role/DerivativeInstruments 70 false false R71.htm 999063 - Disclosure - Share Capital and Capital Surplus and Others (Tables) Sheet http://www.sktelecom.com/role/ShareCapitalAndCapitalSurplusAndOthersTables Share Capital and Capital Surplus and Others (Tables) Tables http://www.sktelecom.com/role/ShareCapitalAndCapitalSurplusAndOthers 71 false false R72.htm 999064 - Disclosure - Treasury Shares (Tables) Sheet http://www.sktelecom.com/role/TreasurySharesTables Treasury Shares (Tables) Tables http://www.sktelecom.com/role/TreasuryShares 72 false false R73.htm 999065 - Disclosure - Hybrid Bonds (Tables) Sheet http://www.sktelecom.com/role/HybridBondsTables Hybrid Bonds (Tables) Tables http://www.sktelecom.com/role/HybridBonds 73 false false R74.htm 999066 - Disclosure - Share-based payment Arrangement (Tables) Sheet http://www.sktelecom.com/role/ShareBasedPaymentArrangementTables Share-based payment Arrangement (Tables) Tables http://www.sktelecom.com/role/ShareBasedPaymentArrangement 74 false false R75.htm 999067 - Disclosure - Retained Earnings (Tables) Sheet http://www.sktelecom.com/role/RetainedEarningsTables Retained Earnings (Tables) Tables http://www.sktelecom.com/role/RetainedEarnings 75 false false R76.htm 999068 - Disclosure - Reserves (Tables) Sheet http://www.sktelecom.com/role/ReservesTables Reserves (Tables) Tables http://www.sktelecom.com/role/Reserves 76 false false R77.htm 999069 - Disclosure - Other Operating Income and Expenses (Tables) Sheet http://www.sktelecom.com/role/OtherOperatingIncomeAndExpensesTables Other Operating Income and Expenses (Tables) Tables http://www.sktelecom.com/role/OtherOperatingIncomeAndExpenses 77 false false R78.htm 999070 - Disclosure - Finance Income and Costs (Tables) Sheet http://www.sktelecom.com/role/FinanceIncomeAndCostsTables Finance Income and Costs (Tables) Tables http://www.sktelecom.com/role/FinanceIncomeAndCosts 78 false false R79.htm 999071 - Disclosure - Income Tax Expense (Tables) Sheet http://www.sktelecom.com/role/IncomeTaxExpenseTables Income Tax Expense (Tables) Tables http://www.sktelecom.com/role/IncomeTaxExpense 79 false false R80.htm 999072 - Disclosure - Earnings per Share (Tables) Sheet http://www.sktelecom.com/role/EarningsPerShareTables Earnings per Share (Tables) Tables http://www.sktelecom.com/role/EarningsPerShare 80 false false R81.htm 999073 - Disclosure - Dividends (Tables) Sheet http://www.sktelecom.com/role/DividendsTables Dividends (Tables) Tables http://www.sktelecom.com/role/Dividends 81 false false R82.htm 999074 - Disclosure - Categories of Financial Instruments (Tables) Sheet http://www.sktelecom.com/role/CategoriesOfFinancialInstrumentsTables Categories of Financial Instruments (Tables) Tables http://www.sktelecom.com/role/CategoriesOfFinancialInstruments 82 false false R83.htm 999075 - Disclosure - Financial Risk Management (Tables) Sheet http://www.sktelecom.com/role/FinancialRiskManagementTables Financial Risk Management (Tables) Tables http://www.sktelecom.com/role/FinancialRiskManagement 83 false false R84.htm 999076 - Disclosure - Transactions with Related Parties (Tables) Sheet http://www.sktelecom.com/role/TransactionsWithRelatedPartiesTables Transactions with Related Parties (Tables) Tables http://www.sktelecom.com/role/TransactionsWithRelatedParties 84 false false R85.htm 999077 - Disclosure - Statements of Cash Flows (Tables) Sheet http://www.sktelecom.com/role/StatementsOfCashFlowsTables Statements of Cash Flows (Tables) Tables http://www.sktelecom.com/role/StatementsOfCashFlows 85 false false R86.htm 999078 - Disclosure - Emissions Liabilities (Tables) Sheet http://www.sktelecom.com/role/EmissionsLiabilitiesTables Emissions Liabilities (Tables) Tables http://www.sktelecom.com/role/EmissionsLiabilities 86 false false R87.htm 999079 - Disclosure - Assets and Liabilities Held for Sale (Table) Sheet http://www.sktelecom.com/role/AssetsAndLiabilitiesHeldForSaleTable Assets and Liabilities Held for Sale (Table) Tables http://www.sktelecom.com/role/AssetsAndLiabilitiesHeldForSale 87 false false R88.htm 999080 - Disclosure - Business Combinations (Tables) Sheet http://www.sktelecom.com/role/BusinessCombinationsTables Business Combinations (Tables) Tables http://www.sktelecom.com/role/BusinessCombinations 88 false false R89.htm 999081 - Disclosure - Cash Dividends paid to the Parent Company (Tables) Sheet http://www.sktelecom.com/role/CashDividendsPaidToTheParentCompanyTables Cash Dividends paid to the Parent Company (Tables) Tables http://www.sktelecom.com/role/CashDividendsPaidToTheParentCompany 89 false false R90.htm 999082 - Disclosure - Reporting Entity - Total Issued Shares Held by Shareholders (Detail) Sheet http://www.sktelecom.com/role/ReportingEntityTotalIssuedSharesHeldByShareholdersDetail Reporting Entity - Total Issued Shares Held by Shareholders (Detail) Details 90 false false R91.htm 999083 - Disclosure - Reporting Entity - List of Subsidiaries (Detail) Sheet http://www.sktelecom.com/role/ReportingEntityListOfSubsidiariesDetail Reporting Entity - List of Subsidiaries (Detail) Details 91 false false R92.htm 999084 - Disclosure - Reporting Entity - Condensed Financial Information of the Significant Subsidiaries (Detail) Sheet http://www.sktelecom.com/role/ReportingEntityCondensedFinancialInformationOfTheSignificantSubsidiariesDetail Reporting Entity - Condensed Financial Information of the Significant Subsidiaries (Detail) Details 92 false false R93.htm 999085 - Disclosure - Reporting Entity - Information of Significant Non-controlling Interests of the Group (Detail) Sheet http://www.sktelecom.com/role/ReportingEntityInformationOfSignificantNonControllingInterestsOfTheGroupDetail Reporting Entity - Information of Significant Non-controlling Interests of the Group (Detail) Details 93 false false R94.htm 999086 - Disclosure - Material Accounting Policies - Estimated Useful Lives of the Group's Property and Equipment (Detail) Sheet http://www.sktelecom.com/role/MaterialAccountingPoliciesEstimatedUsefulLivesOfTheGroupsPropertyAndEquipmentDetail Material Accounting Policies - Estimated Useful Lives of the Group's Property and Equipment (Detail) Details 94 false false R95.htm 999087 - Disclosure - Material Accounting Policies - Estimated Useful Lives of the Group's Intangible Assets (Detail) Sheet http://www.sktelecom.com/role/MaterialAccountingPoliciesEstimatedUsefulLivesOfTheGroupsIntangibleAssetsDetail Material Accounting Policies - Estimated Useful Lives of the Group's Intangible Assets (Detail) Details 95 false false R96.htm 999088 - Disclosure - Material Accounting Policies - Additional Information (Detail) Sheet http://www.sktelecom.com/role/MaterialAccountingPoliciesAdditionalInformationDetail Material Accounting Policies - Additional Information (Detail) Details 96 false false R97.htm 999089 - Disclosure - Operating Segments - Segment Information (Detail) Sheet http://www.sktelecom.com/role/OperatingSegmentsSegmentInformationDetail Operating Segments - Segment Information (Detail) Details 97 false false R98.htm 999090 - Disclosure - Operating Segments - Reconciliation of Total Segment Operating Income to Consolidated Operating Profit from Continuing Operations (Detail) Sheet http://www.sktelecom.com/role/OperatingSegmentsReconciliationOfTotalSegmentOperatingIncomeToConsolidatedOperatingProfitFromContinuingOperationsDetail Operating Segments - Reconciliation of Total Segment Operating Income to Consolidated Operating Profit from Continuing Operations (Detail) Details 98 false false R99.htm 999091 - Disclosure - Operating Segments - Reconciliation of Total Segment Operating Income to Consolidated Operating Profit from Continuing Operations (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/OperatingSegmentsReconciliationOfTotalSegmentOperatingIncomeToConsolidatedOperatingProfitFromContinuingOperationsParentheticalDetail Operating Segments - Reconciliation of Total Segment Operating Income to Consolidated Operating Profit from Continuing Operations (Parenthetical) (Detail) Details 99 false false R100.htm 999092 - Disclosure - Operating Segments - Additional Information (Detail) Sheet http://www.sktelecom.com/role/OperatingSegmentsAdditionalInformationDetail Operating Segments - Additional Information (Detail) Details 100 false false R101.htm 999093 - Disclosure - Operating Segments - Summary of Disaggregation of Operating Revenue (Detail) Sheet http://www.sktelecom.com/role/OperatingSegmentsSummaryOfDisaggregationOfOperatingRevenueDetail Operating Segments - Summary of Disaggregation of Operating Revenue (Detail) Details 101 false false R102.htm 999094 - Disclosure - Deposits with Restrictions on Use - Deposits Which are Restricted in Use (Detail) Sheet http://www.sktelecom.com/role/DepositsWithRestrictionsOnUseDepositsWhichAreRestrictedInUseDetail Deposits with Restrictions on Use - Deposits Which are Restricted in Use (Detail) Details 102 false false R103.htm 999095 - Disclosure - Trade and Other Receivables - Details of Trade and Other Receivables (Detail) Sheet http://www.sktelecom.com/role/TradeAndOtherReceivablesDetailsOfTradeAndOtherReceivablesDetail Trade and Other Receivables - Details of Trade and Other Receivables (Detail) Details 103 false false R104.htm 999096 - Disclosure - Trade and Other Receivables - Details of Trade and Other Receivables (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/TradeAndOtherReceivablesDetailsOfTradeAndOtherReceivablesParentheticalDetail Trade and Other Receivables - Details of Trade and Other Receivables (Parenthetical) (Detail) Details 104 false false R105.htm 999097 - Disclosure - Trade and Other Receivables - Changes in Loss Allowance on Accounts Receivable - Trade Measured at Amortized Costs (Detail) Sheet http://www.sktelecom.com/role/TradeAndOtherReceivablesChangesInLossAllowanceOnAccountsReceivableTradeMeasuredAtAmortizedCostsDetail Trade and Other Receivables - Changes in Loss Allowance on Accounts Receivable - Trade Measured at Amortized Costs (Detail) Details 105 false false R106.htm 999098 - Disclosure - Trade and Other Receivables - Summary of Loss Allowance on Accounts Receivable - Trade (Detail) Sheet http://www.sktelecom.com/role/TradeAndOtherReceivablesSummaryOfLossAllowanceOnAccountsReceivableTradeDetail Trade and Other Receivables - Summary of Loss Allowance on Accounts Receivable - Trade (Detail) Details 106 false false R107.htm 999099 - Disclosure - Prepaid Expenses - Summary of Prepaid Expenses (Detail) Sheet http://www.sktelecom.com/role/PrepaidExpensesSummaryOfPrepaidExpensesDetail Prepaid Expenses - Summary of Prepaid Expenses (Detail) Details 107 false false R108.htm 999100 - Disclosure - Prepaid Expenses - Summary of Incremental Costs of Obtaining Contracts That Capitalized as Assets and Related Amortization Recognized as impairment losses (Detail) Sheet http://www.sktelecom.com/role/PrepaidExpensesSummaryOfIncrementalCostsOfObtainingContractsThatCapitalizedAsAssetsAndRelatedAmortizationRecognizedAsImpairmentLossesDetail Prepaid Expenses - Summary of Incremental Costs of Obtaining Contracts That Capitalized as Assets and Related Amortization Recognized as impairment losses (Detail) Details 108 false false R109.htm 999101 - Disclosure - Contract Assets and Liabilities - Summary of Contract Assets and Liabilities (Detail) Sheet http://www.sktelecom.com/role/ContractAssetsAndLiabilitiesSummaryOfContractAssetsAndLiabilitiesDetail Contract Assets and Liabilities - Summary of Contract Assets and Liabilities (Detail) Details 109 false false R110.htm 999102 - Disclosure - Contract Assets and Liabilities - Schedule of Performance Obligations (Detail) Sheet http://www.sktelecom.com/role/ContractAssetsAndLiabilitiesScheduleOfPerformanceObligationsDetail Contract Assets and Liabilities - Schedule of Performance Obligations (Detail) Details 110 false false R111.htm 999103 - Disclosure - Contract Assets and Liabilities - Additional Information (Detail) Sheet http://www.sktelecom.com/role/ContractAssetsAndLiabilitiesAdditionalInformationDetail Contract Assets and Liabilities - Additional Information (Detail) Details 111 false false R112.htm 999104 - Disclosure - Inventories - Details of Inventories (Detail) Sheet http://www.sktelecom.com/role/InventoriesDetailsOfInventoriesDetail Inventories - Details of Inventories (Detail) Details 112 false false R113.htm 999105 - Disclosure - Inventories - Amount of the Inventory Write-downs Charged to the Consolidated Statement of Income and Write-off of Inventories (Detail) Sheet http://www.sktelecom.com/role/InventoriesAmountOfTheInventoryWriteDownsChargedToTheConsolidatedStatementOfIncomeAndWriteOffOfInventoriesDetail Inventories - Amount of the Inventory Write-downs Charged to the Consolidated Statement of Income and Write-off of Inventories (Detail) Details 113 false false R114.htm 999106 - Disclosure - Inventories - Additional Information (Detail) Sheet http://www.sktelecom.com/role/InventoriesAdditionalInformationDetail Inventories - Additional Information (Detail) Details 114 false false R115.htm 999107 - Disclosure - Investment Securities - Details of Short-term Investment Securities (Detail) Sheet http://www.sktelecom.com/role/InvestmentSecuritiesDetailsOfShortTermInvestmentSecuritiesDetail Investment Securities - Details of Short-term Investment Securities (Detail) Details 115 false false R116.htm 999108 - Disclosure - Long-term Investment Securities - Details of Long-term Investment Securities (Detail) Sheet http://www.sktelecom.com/role/LongTermInvestmentSecuritiesDetailsOfLongTermInvestmentSecuritiesDetail Long-term Investment Securities - Details of Long-term Investment Securities (Detail) Details 116 false false R117.htm 999109 - Disclosure - Investments in Associates and Joint Ventures - Investments in Associates and Joint Ventures Accounted for using the Equity Method (Detail) Sheet http://www.sktelecom.com/role/InvestmentsInAssociatesAndJointVenturesInvestmentsInAssociatesAndJointVenturesAccountedForUsingTheEquityMethodDetail Investments in Associates and Joint Ventures - Investments in Associates and Joint Ventures Accounted for using the Equity Method (Detail) Details 117 false false R118.htm 999110 - Disclosure - Investments in Associates and Joint Ventures - Investments in Associates and Joint Ventures Accounted for using the Equity Method (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/InvestmentsInAssociatesAndJointVenturesInvestmentsInAssociatesAndJointVenturesAccountedForUsingTheEquityMethodParentheticalDetail Investments in Associates and Joint Ventures - Investments in Associates and Joint Ventures Accounted for using the Equity Method (Parenthetical) (Detail) Details 118 false false R119.htm 999111 - Disclosure - Investments in Associates and Joint Ventures - Market Price of Investments in Listed Associates (Detail) Sheet http://www.sktelecom.com/role/InvestmentsInAssociatesAndJointVenturesMarketPriceOfInvestmentsInListedAssociatesDetail Investments in Associates and Joint Ventures - Market Price of Investments in Listed Associates (Detail) Details 119 false false R120.htm 999112 - Disclosure - Investments in Associates and Joint Ventures - Condensed Financial Information of Material Associates (Detail) Sheet http://www.sktelecom.com/role/InvestmentsInAssociatesAndJointVenturesCondensedFinancialInformationOfMaterialAssociatesDetail Investments in Associates and Joint Ventures - Condensed Financial Information of Material Associates (Detail) Details 120 false false R121.htm 999113 - Disclosure - Investments in Associates and Joint Ventures - Reconciliations of Financial Information of Material Associates to Carrying Amounts of Investments in Associates in the Consolidated Financial Statements (Detail) Sheet http://www.sktelecom.com/role/InvestmentsInAssociatesAndJointVenturesReconciliationsOfFinancialInformationOfMaterialAssociatesToCarryingAmountsOfInvestmentsInAssociatesInTheConsolidatedFinancialStatementsDetail Investments in Associates and Joint Ventures - Reconciliations of Financial Information of Material Associates to Carrying Amounts of Investments in Associates in the Consolidated Financial Statements (Detail) Details 121 false false R122.htm 999114 - Disclosure - Investments in Associates and Joint Ventures - Details of the Changes in Investments in Associates and Joint Ventures Accounted for using the Equity Method (Detail) Sheet http://www.sktelecom.com/role/InvestmentsInAssociatesAndJointVenturesDetailsOfTheChangesInInvestmentsInAssociatesAndJointVenturesAccountedForUsingTheEquityMethodDetail Investments in Associates and Joint Ventures - Details of the Changes in Investments in Associates and Joint Ventures Accounted for using the Equity Method (Detail) Details 122 false false R123.htm 999115 - Disclosure - Investments in Associates and Joint Ventures - Details of Cumulative Unrecognized Equity Method Losses (Detail) Sheet http://www.sktelecom.com/role/InvestmentsInAssociatesAndJointVenturesDetailsOfCumulativeUnrecognizedEquityMethodLossesDetail Investments in Associates and Joint Ventures - Details of Cumulative Unrecognized Equity Method Losses (Detail) Details 123 false false R124.htm 999116 - Disclosure - Property and Equipment - Summary of Property and Equipment (Detail) Sheet http://www.sktelecom.com/role/PropertyAndEquipmentSummaryOfPropertyAndEquipmentDetail Property and Equipment - Summary of Property and Equipment (Detail) Details 124 false false R125.htm 999117 - Disclosure - Property and Equipment - Changes in Property and Equipment (Detail) Sheet http://www.sktelecom.com/role/PropertyAndEquipmentChangesInPropertyAndEquipmentDetail Property and Equipment - Changes in Property and Equipment (Detail) Details 125 false false R126.htm 999118 - Disclosure - Property and Equipment - Changes in Property and Equipment (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/PropertyAndEquipmentChangesInPropertyAndEquipmentParentheticalDetail Property and Equipment - Changes in Property and Equipment (Parenthetical) (Detail) Details 126 false false R127.htm 999119 - Disclosure - Investment Property - Disclosure of Detailed Information About Investment Property Explanatory (Detail) Sheet http://www.sktelecom.com/role/InvestmentPropertyDisclosureOfDetailedInformationAboutInvestmentPropertyExplanatoryDetail Investment Property - Disclosure of Detailed Information About Investment Property Explanatory (Detail) Details 127 false false R128.htm 999120 - Disclosure - Leases - Summary of Right of Use Assets (Detail) Sheet http://www.sktelecom.com/role/LeasesSummaryOfRightOfUseAssetsDetail Leases - Summary of Right of Use Assets (Detail) Details 128 false false R129.htm 999121 - Disclosure - Leases - Summary of Amounts Recognized in the Condensed Consolidated Interim Statements of Income of Leases (Detail) Sheet http://www.sktelecom.com/role/LeasesSummaryOfAmountsRecognizedInTheCondensedConsolidatedInterimStatementsOfIncomeOfLeasesDetail Leases - Summary of Amounts Recognized in the Condensed Consolidated Interim Statements of Income of Leases (Detail) Details 129 false false R130.htm 999122 - Disclosure - Leases - Summary of Maturity Analysis for Finance Lease Receivables (Detail) Sheet http://www.sktelecom.com/role/LeasesSummaryOfMaturityAnalysisForFinanceLeaseReceivablesDetail Leases - Summary of Maturity Analysis for Finance Lease Receivables (Detail) Details 130 false false R131.htm 999123 - Disclosure - Leases - Summary of Maturity Analysis for Operating Lease Receivables (Detail) Sheet http://www.sktelecom.com/role/LeasesSummaryOfMaturityAnalysisForOperatingLeaseReceivablesDetail Leases - Summary of Maturity Analysis for Operating Lease Receivables (Detail) Details 131 false false R132.htm 999124 - Disclosure - Leases - Additional Information (Detail) Sheet http://www.sktelecom.com/role/LeasesAdditionalInformationDetail Leases - Additional Information (Detail) Details 132 false false R133.htm 999125 - Disclosure - Goodwill - Summary of Goodwill (Detail) Sheet http://www.sktelecom.com/role/GoodwillSummaryOfGoodwillDetail Goodwill - Summary of Goodwill (Detail) Details 133 false false R134.htm 999126 - Disclosure - Goodwill - Summary of Discount Rates and Perpetual Growth Rates (Detail) Sheet http://www.sktelecom.com/role/GoodwillSummaryOfDiscountRatesAndPerpetualGrowthRatesDetail Goodwill - Summary of Discount Rates and Perpetual Growth Rates (Detail) Details 134 false false R135.htm 999127 - Disclosure - Goodwill - Details of the Changes in Goodwill (Detail) Sheet http://www.sktelecom.com/role/GoodwillDetailsOfTheChangesInGoodwillDetail Goodwill - Details of the Changes in Goodwill (Detail) Details 135 false false R136.htm 999128 - Disclosure - Goodwill - Details of the Changes in Goodwill (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/GoodwillDetailsOfTheChangesInGoodwillParentheticalDetail Goodwill - Details of the Changes in Goodwill (Parenthetical) (Detail) Details 136 false false R137.htm 999129 - Disclosure - Intangible Assets - Summary of Intangible Assets (Detail) Sheet http://www.sktelecom.com/role/IntangibleAssetsSummaryOfIntangibleAssetsDetail Intangible Assets - Summary of Intangible Assets (Detail) Details 137 false false R138.htm 999130 - Disclosure - Intangible Assets - Summary of Intangible Assets (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/IntangibleAssetsSummaryOfIntangibleAssetsParentheticalDetail Intangible Assets - Summary of Intangible Assets (Parenthetical) (Detail) Details 138 false false R139.htm 999131 - Disclosure - Intangible Assets - Details of the Changes in Intangible Assets (Detail) Sheet http://www.sktelecom.com/role/IntangibleAssetsDetailsOfTheChangesInIntangibleAssetsDetail Intangible Assets - Details of the Changes in Intangible Assets (Detail) Details 139 false false R140.htm 999132 - Disclosure - Intangible Assets - Details of the Changes in Intangible Assets (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/IntangibleAssetsDetailsOfTheChangesInIntangibleAssetsParentheticalDetail Intangible Assets - Details of the Changes in Intangible Assets (Parenthetical) (Detail) Details 140 false false R141.htm 999133 - Disclosure - Intangible Assets - Research and Development Expenditures Recognized as Expense (Detail) Sheet http://www.sktelecom.com/role/IntangibleAssetsResearchAndDevelopmentExpendituresRecognizedAsExpenseDetail Intangible Assets - Research and Development Expenditures Recognized as Expense (Detail) Details 141 false false R142.htm 999134 - Disclosure - Intangible Assets - Carrying Amount and Residual Useful Lives of Frequency Usage Rights (Detail) Sheet http://www.sktelecom.com/role/IntangibleAssetsCarryingAmountAndResidualUsefulLivesOfFrequencyUsageRightsDetail Intangible Assets - Carrying Amount and Residual Useful Lives of Frequency Usage Rights (Detail) Details 142 false false R143.htm 999135 - Disclosure - Borrowings and Debentures - Short-term Borrowings (Detail) Sheet http://www.sktelecom.com/role/BorrowingsAndDebenturesShortTermBorrowingsDetail Borrowings and Debentures - Short-term Borrowings (Detail) Details 143 false false R144.htm 999136 - Disclosure - Borrowings and Debentures - Long-term Borrowings (Detail) Sheet http://www.sktelecom.com/role/BorrowingsAndDebenturesLongTermBorrowingsDetail Borrowings and Debentures - Long-term Borrowings (Detail) Details 144 false false R145.htm 999137 - Disclosure - Borrowings and Debentures - Long-term Borrowings (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/BorrowingsAndDebenturesLongTermBorrowingsParentheticalDetail Borrowings and Debentures - Long-term Borrowings (Parenthetical) (Detail) Details 145 false false R146.htm 999138 - Disclosure - Borrowings and Debentures - Debentures (Detail) Sheet http://www.sktelecom.com/role/BorrowingsAndDebenturesDebenturesDetail Borrowings and Debentures - Debentures (Detail) Details 146 false false R147.htm 999139 - Disclosure - Borrowings and Debentures - Debentures (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/BorrowingsAndDebenturesDebenturesParentheticalDetail Borrowings and Debentures - Debentures (Parenthetical) (Detail) Details 147 false false R148.htm 999140 - Disclosure - Long-term Payables – other - Details of Long-term Payables - Other, Which Consist of Payables Related to the Acquisition of Frequency Usage Rights (Detail) Sheet http://www.sktelecom.com/role/LongTermPayablesOtherDetailsOfLongTermPayablesOtherWhichConsistOfPayablesRelatedToTheAcquisitionOfFrequencyUsageRightsDetail Long-term Payables – other - Details of Long-term Payables - Other, Which Consist of Payables Related to the Acquisition of Frequency Usage Rights (Detail) Details 148 false false R149.htm 999141 - Disclosure - Long-term Payables – other - Repayment Schedule of the Principal Amount of Long-term Payables - Other Related to Acquisition of Frequency Usage Rights (Detail) Sheet http://www.sktelecom.com/role/LongTermPayablesOtherRepaymentScheduleOfThePrincipalAmountOfLongTermPayablesOtherRelatedToAcquisitionOfFrequencyUsageRightsDetail Long-term Payables – other - Repayment Schedule of the Principal Amount of Long-term Payables - Other Related to Acquisition of Frequency Usage Rights (Detail) Details 149 false false R150.htm 999142 - Disclosure - Provisions - Changes in Provisions (Detail) Sheet http://www.sktelecom.com/role/ProvisionsChangesInProvisionsDetail Provisions - Changes in Provisions (Detail) Details 150 false false R151.htm 999143 - Disclosure - Defined Benefit Liabilities (Assets) - Details of Defined Benefit Liabilities (Assets) (Detail) Sheet http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssetsDetailsOfDefinedBenefitLiabilitiesAssetsDetail Defined Benefit Liabilities (Assets) - Details of Defined Benefit Liabilities (Assets) (Detail) Details http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssetsTables 151 false false R152.htm 999144 - Disclosure - Defined Benefit Liabilities (Assets) - Principal Actuarial Assumptions (Detail) Sheet http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssetsPrincipalActuarialAssumptionsDetail Defined Benefit Liabilities (Assets) - Principal Actuarial Assumptions (Detail) Details http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssetsTables 152 false false R153.htm 999145 - Disclosure - Defined Benefit Liabilities (Assets) - Changes in Defined Benefit Obligations (Detail) Sheet http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssetsChangesInDefinedBenefitObligationsDetail Defined Benefit Liabilities (Assets) - Changes in Defined Benefit Obligations (Detail) Details http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssetsTables 153 false false R154.htm 999146 - Disclosure - Defined Benefit Liabilities (Assets) - Changes in Plan Assets (Detail) Sheet http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssetsChangesInPlanAssetsDetail Defined Benefit Liabilities (Assets) - Changes in Plan Assets (Detail) Details http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssetsTables 154 false false R155.htm 999147 - Disclosure - Defined Benefit Liabilities (Assets) - Additional Information (Detail) Sheet http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssetsAdditionalInformationDetail Defined Benefit Liabilities (Assets) - Additional Information (Detail) Details http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssetsTables 155 false false R156.htm 999148 - Disclosure - Defined Benefit Liabilities (Assets) - Cost of Benefit Plan Recognized in Profit And Loss (Detail) Sheet http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssetsCostOfBenefitPlanRecognizedInProfitAndLossDetail Defined Benefit Liabilities (Assets) - Cost of Benefit Plan Recognized in Profit And Loss (Detail) Details http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssetsTables 156 false false R157.htm 999149 - Disclosure - Defined Benefit Liabilities (Assets) - Details of Plan Assets (Detail) Sheet http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssetsDetailsOfPlanAssetsDetail Defined Benefit Liabilities (Assets) - Details of Plan Assets (Detail) Details http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssetsTables 157 false false R158.htm 999150 - Disclosure - Defined Benefit Liabilities (Assets) - Effects on Defined Benefit Obligations if Each of Significant Actuarial Assumptions Changes Within Expectable and Reasonable Range (Detail) Sheet http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssetsEffectsOnDefinedBenefitObligationsIfEachOfSignificantActuarialAssumptionsChangesWithinExpectableAndReasonableRangeDetail Defined Benefit Liabilities (Assets) - Effects on Defined Benefit Obligations if Each of Significant Actuarial Assumptions Changes Within Expectable and Reasonable Range (Detail) Details http://www.sktelecom.com/role/DefinedBenefitLiabilitiesAssetsTables 158 false false R159.htm 999151 - Disclosure - Derivative Instruments - Currency and Interest Rate Swap Contracts under Cash Flow Hedge Accounting (Detail) Sheet http://www.sktelecom.com/role/DerivativeInstrumentsCurrencyAndInterestRateSwapContractsUnderCashFlowHedgeAccountingDetail Derivative Instruments - Currency and Interest Rate Swap Contracts under Cash Flow Hedge Accounting (Detail) Details 159 false false R160.htm 999152 - Disclosure - Derivative Instruments - Currency and Interest Rate Swap Contracts under Cash Flow Hedge Accounting (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/DerivativeInstrumentsCurrencyAndInterestRateSwapContractsUnderCashFlowHedgeAccountingParentheticalDetail Derivative Instruments - Currency and Interest Rate Swap Contracts under Cash Flow Hedge Accounting (Parenthetical) (Detail) Details 160 false false R161.htm 999153 - Disclosure - Derivative Instruments - Details of Fair Values of the Above Derivatives Recorded in Assets or Liabilities (Detail) Sheet http://www.sktelecom.com/role/DerivativeInstrumentsDetailsOfFairValuesOfTheAboveDerivativesRecordedInAssetsOrLiabilitiesDetail Derivative Instruments - Details of Fair Values of the Above Derivatives Recorded in Assets or Liabilities (Detail) Details 161 false false R162.htm 999154 - Disclosure - Derivative Instruments - Details of Fair Values of the Above Derivatives Recorded in Assets or Liabilities (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/DerivativeInstrumentsDetailsOfFairValuesOfTheAboveDerivativesRecordedInAssetsOrLiabilitiesParentheticalDetail Derivative Instruments - Details of Fair Values of the Above Derivatives Recorded in Assets or Liabilities (Parenthetical) (Detail) Details 162 false false R163.htm 999155 - Disclosure - Derivative Instruments - Detailed Information about Financial Instruments under Cash Flow Hedge (Detail) Sheet http://www.sktelecom.com/role/DerivativeInstrumentsDetailedInformationAboutFinancialInstrumentsUnderCashFlowHedgeDetail Derivative Instruments - Detailed Information about Financial Instruments under Cash Flow Hedge (Detail) Details 163 false false R164.htm 999156 - Disclosure - Share Capital and Capital Surplus and Others - Number of Authorized, Issued and Outstanding Common Shares and the Details of Capital Surplus and Others (Detail) Sheet http://www.sktelecom.com/role/ShareCapitalAndCapitalSurplusAndOthersNumberOfAuthorizedIssuedAndOutstandingCommonSharesAndTheDetailsOfCapitalSurplusAndOthersDetail Share Capital and Capital Surplus and Others - Number of Authorized, Issued and Outstanding Common Shares and the Details of Capital Surplus and Others (Detail) Details 164 false false R165.htm 999157 - Disclosure - Share Capital and Capital Surplus and Others - Number of Authorized, Issued and Outstanding Common Shares and the Details of Capital Surplus and Others (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/ShareCapitalAndCapitalSurplusAndOthersNumberOfAuthorizedIssuedAndOutstandingCommonSharesAndTheDetailsOfCapitalSurplusAndOthersParentheticalDetail Share Capital and Capital Surplus and Others - Number of Authorized, Issued and Outstanding Common Shares and the Details of Capital Surplus and Others (Parenthetical) (Detail) Details 165 false false R166.htm 999158 - Disclosure - Share Capital and Capital Surplus and Others - Details of Shares Outstanding (Detail) Sheet http://www.sktelecom.com/role/ShareCapitalAndCapitalSurplusAndOthersDetailsOfSharesOutstandingDetail Share Capital and Capital Surplus and Others - Details of Shares Outstanding (Detail) Details 166 false false R167.htm 999159 - Disclosure - Share Capital and Capital Surplus and Others - Summary of changes in issued shares (Detail) Sheet http://www.sktelecom.com/role/ShareCapitalAndCapitalSurplusAndOthersSummaryOfChangesInIssuedSharesDetail Share Capital and Capital Surplus and Others - Summary of changes in issued shares (Detail) Details 167 false false R168.htm 999160 - Disclosure - Share Capital and Capital Surplus and Others - Summary of changes in issued shares (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/ShareCapitalAndCapitalSurplusAndOthersSummaryOfChangesInIssuedSharesParentheticalDetail Share Capital and Capital Surplus and Others - Summary of changes in issued shares (Parenthetical) (Detail) Details 168 false false R169.htm 999161 - Disclosure - Treasury Shares - Summary of Treasury Shares (Detail) Sheet http://www.sktelecom.com/role/TreasurySharesSummaryOfTreasurySharesDetail Treasury Shares - Summary of Treasury Shares (Detail) Details 169 false false R170.htm 999162 - Disclosure - Treasury Shares - Summary of Changes in Treasury Shares (Detail) Sheet http://www.sktelecom.com/role/TreasurySharesSummaryOfChangesInTreasurySharesDetail Treasury Shares - Summary of Changes in Treasury Shares (Detail) Details 170 false false R171.htm 999163 - Disclosure - Treasury Shares - Summary of Changes in Treasury Shares (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/TreasurySharesSummaryOfChangesInTreasurySharesParentheticalDetail Treasury Shares - Summary of Changes in Treasury Shares (Parenthetical) (Detail) Details 171 false false R172.htm 999164 - Disclosure - Hybrid Bonds - Summary of Hybrid Bonds (Detail) Sheet http://www.sktelecom.com/role/HybridBondsSummaryOfHybridBondsDetail Hybrid Bonds - Summary of Hybrid Bonds (Detail) Details 172 false false R173.htm 999165 - Disclosure - Hybrid Bonds - Summary of Hybrid Bonds (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/HybridBondsSummaryOfHybridBondsParentheticalDetail Hybrid Bonds - Summary of Hybrid Bonds (Parenthetical) (Detail) Details 173 false false R174.htm 999166 - Disclosure - Share-based payment Arrangement - Summary of Terms and Conditions Related to Grants of Share Based Payment Arrangement (Detail) Sheet http://www.sktelecom.com/role/ShareBasedPaymentArrangementSummaryOfTermsAndConditionsRelatedToGrantsOfShareBasedPaymentArrangementDetail Share-based payment Arrangement - Summary of Terms and Conditions Related to Grants of Share Based Payment Arrangement (Detail) Details 174 false false R175.htm 999167 - Disclosure - Share-based payment Arrangement - Summary of Terms and Conditions Related to Grants of Share Based Payment Arrangement (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/ShareBasedPaymentArrangementSummaryOfTermsAndConditionsRelatedToGrantsOfShareBasedPaymentArrangementParentheticalDetail Share-based payment Arrangement - Summary of Terms and Conditions Related to Grants of Share Based Payment Arrangement (Parenthetical) (Detail) Details 175 false false R176.htm 999168 - Disclosure - Share-based payment Arrangement - Summary of Share Compensation Expense Recognized (Detail) Sheet http://www.sktelecom.com/role/ShareBasedPaymentArrangementSummaryOfShareCompensationExpenseRecognizedDetail Share-based payment Arrangement - Summary of Share Compensation Expense Recognized (Detail) Details 176 false false R177.htm 999169 - Disclosure - Share-based payment Arrangement - Summary of Inputs Used in Binomial Option Pricing Model (Detail) Sheet http://www.sktelecom.com/role/ShareBasedPaymentArrangementSummaryOfInputsUsedInBinomialOptionPricingModelDetail Share-based payment Arrangement - Summary of Inputs Used in Binomial Option Pricing Model (Detail) Details 177 false false R178.htm 999170 - Disclosure - Share-based payment Arrangement - Additional Information (Detail) Sheet http://www.sktelecom.com/role/ShareBasedPaymentArrangementAdditionalInformationDetail Share-based payment Arrangement - Additional Information (Detail) Details 178 false false R179.htm 999171 - Disclosure - Retained Earnings - Summary of Retained Earnings (Detail) Sheet http://www.sktelecom.com/role/RetainedEarningsSummaryOfRetainedEarningsDetail Retained Earnings - Summary of Retained Earnings (Detail) Details 179 false false R180.htm 999172 - Disclosure - Retained Earnings - Additional Information (Detail) Sheet http://www.sktelecom.com/role/RetainedEarningsAdditionalInformationDetail Retained Earnings - Additional Information (Detail) Details 180 false false R181.htm 999173 - Disclosure - Reserves - Details of Reserves, Net of Taxes (Detail) Sheet http://www.sktelecom.com/role/ReservesDetailsOfReservesNetOfTaxesDetail Reserves - Details of Reserves, Net of Taxes (Detail) Details 181 false false R182.htm 999174 - Disclosure - Reserves - Changes in Reserves (Detail) Sheet http://www.sktelecom.com/role/ReservesChangesInReservesDetail Reserves - Changes in Reserves (Detail) Details 182 false false R183.htm 999175 - Disclosure - Reserves - Changes In Valuation Gain (Loss) On Financial Assets At FVOCI (Detail) Sheet http://www.sktelecom.com/role/ReservesChangesInValuationGainLossOnFinancialAssetsAtFvociDetail Reserves - Changes In Valuation Gain (Loss) On Financial Assets At FVOCI (Detail) Details 183 false false R184.htm 999176 - Disclosure - Reserves - Changes in Valuation Gain (Loss) on Derivatives (Detail) Sheet http://www.sktelecom.com/role/ReservesChangesInValuationGainLossOnDerivativesDetail Reserves - Changes in Valuation Gain (Loss) on Derivatives (Detail) Details 184 false false R185.htm 999177 - Disclosure - Other Operating Income and Expenses - Details of Other Operating Income and Expenses (Detail) Sheet http://www.sktelecom.com/role/OtherOperatingIncomeAndExpensesDetailsOfOtherOperatingIncomeAndExpensesDetail Other Operating Income and Expenses - Details of Other Operating Income and Expenses (Detail) Details 185 false false R186.htm 999178 - Disclosure - Other Operating Income and Expenses - Additional Information (Detail) Sheet http://www.sktelecom.com/role/OtherOperatingIncomeAndExpensesAdditionalInformationDetail Other Operating Income and Expenses - Additional Information (Detail) Details 186 false false R187.htm 999179 - Disclosure - Finance Income and Costs - Details of Finance Income and Costs (Detail) Sheet http://www.sktelecom.com/role/FinanceIncomeAndCostsDetailsOfFinanceIncomeAndCostsDetail Finance Income and Costs - Details of Finance Income and Costs (Detail) Details 187 false false R188.htm 999180 - Disclosure - Finance Income and Costs - Details of Interest Income Included in Finance Income (Detail) Sheet http://www.sktelecom.com/role/FinanceIncomeAndCostsDetailsOfInterestIncomeIncludedInFinanceIncomeDetail Finance Income and Costs - Details of Interest Income Included in Finance Income (Detail) Details 188 false false R189.htm 999181 - Disclosure - Finance Income and Costs - Details of Interest Expenses Included in Finance Costs (Detail) Sheet http://www.sktelecom.com/role/FinanceIncomeAndCostsDetailsOfInterestExpensesIncludedInFinanceCostsDetail Finance Income and Costs - Details of Interest Expenses Included in Finance Costs (Detail) Details 189 false false R190.htm 999182 - Disclosure - Finance Income and Costs - Finance Income and Costs by Category of Financial Instruments (Detail) Sheet http://www.sktelecom.com/role/FinanceIncomeAndCostsFinanceIncomeAndCostsByCategoryOfFinancialInstrumentsDetail Finance Income and Costs - Finance Income and Costs by Category of Financial Instruments (Detail) Details 190 false false R191.htm 999183 - Disclosure - Finance Income and Costs - Details of Impairment Losses for Financial Assets (Detail) Sheet http://www.sktelecom.com/role/FinanceIncomeAndCostsDetailsOfImpairmentLossesForFinancialAssetsDetail Finance Income and Costs - Details of Impairment Losses for Financial Assets (Detail) Details 191 false false R192.htm 999184 - Disclosure - Income Tax Expense - Summary of Income Tax Expenses (Detail) Sheet http://www.sktelecom.com/role/IncomeTaxExpenseSummaryOfIncomeTaxExpensesDetail Income Tax Expense - Summary of Income Tax Expenses (Detail) Details 192 false false R193.htm 999185 - Disclosure - Income Tax Expense - Difference Between Income Taxes Computed using the Statutory Corporate Income Tax Rates and the Recorded Income Taxes (Detail) Sheet http://www.sktelecom.com/role/IncomeTaxExpenseDifferenceBetweenIncomeTaxesComputedUsingTheStatutoryCorporateIncomeTaxRatesAndTheRecordedIncomeTaxesDetail Income Tax Expense - Difference Between Income Taxes Computed using the Statutory Corporate Income Tax Rates and the Recorded Income Taxes (Detail) Details 193 false false R194.htm 999186 - Disclosure - Income Tax Expense - Deferred Taxes Directly Charged to (Credited from) Equity (Detail) Sheet http://www.sktelecom.com/role/IncomeTaxExpenseDeferredTaxesDirectlyChargedToCreditedFromEquityDetail Income Tax Expense - Deferred Taxes Directly Charged to (Credited from) Equity (Detail) Details 194 false false R195.htm 999187 - Disclosure - Income Tax Expense - Details of the Changes in Deferred Tax Assets (Liabilities) (Detail) Sheet http://www.sktelecom.com/role/IncomeTaxExpenseDetailsOfTheChangesInDeferredTaxAssetsLiabilitiesDetail Income Tax Expense - Details of the Changes in Deferred Tax Assets (Liabilities) (Detail) Details 195 false false R196.htm 999188 - Disclosure - Income Tax Expense - Details of Temporary Differences, Unused Tax Loss Carryforwards and Unused Tax Credits Carryforwards Which are Not Recognized as Deferred Tax Assets (Detail) Sheet http://www.sktelecom.com/role/IncomeTaxExpenseDetailsOfTemporaryDifferencesUnusedTaxLossCarryforwardsAndUnusedTaxCreditsCarryforwardsWhichAreNotRecognizedAsDeferredTaxAssetsDetail Income Tax Expense - Details of Temporary Differences, Unused Tax Loss Carryforwards and Unused Tax Credits Carryforwards Which are Not Recognized as Deferred Tax Assets (Detail) Details 196 false false R197.htm 999189 - Disclosure - Income Tax Expense - Unused Tax Loss Carryforwards Which are Not Recognized as Deferred Tax Assets (Detail) Sheet http://www.sktelecom.com/role/IncomeTaxExpenseUnusedTaxLossCarryforwardsWhichAreNotRecognizedAsDeferredTaxAssetsDetail Income Tax Expense - Unused Tax Loss Carryforwards Which are Not Recognized as Deferred Tax Assets (Detail) Details 197 false false R198.htm 999190 - Disclosure - Income Tax Expense - Additional Information (Detail) Sheet http://www.sktelecom.com/role/IncomeTaxExpenseAdditionalInformationDetail Income Tax Expense - Additional Information (Detail) Details 198 false false R199.htm 999191 - Disclosure - Income Tax Expense - Details of the aggregate temporary differences related to investments in subsidiaries and associates (Details) Sheet http://www.sktelecom.com/role/IncomeTaxExpenseDetailsOfTheAggregateTemporaryDifferencesRelatedToInvestmentsInSubsidiariesAndAssociatesDetails Income Tax Expense - Details of the aggregate temporary differences related to investments in subsidiaries and associates (Details) Details 199 false false R200.htm 999192 - Disclosure - Earnings per Share - Summary of Basic Earnings Per Share (Detail) Sheet http://www.sktelecom.com/role/EarningsPerShareSummaryOfBasicEarningsPerShareDetail Earnings per Share - Summary of Basic Earnings Per Share (Detail) Details 200 false false R201.htm 999193 - Disclosure - Earnings per Share - Weighted Average Number of Common Shares Outstanding (Detail) Sheet http://www.sktelecom.com/role/EarningsPerShareWeightedAverageNumberOfCommonSharesOutstandingDetail Earnings per Share - Weighted Average Number of Common Shares Outstanding (Detail) Details 201 false false R202.htm 999194 - Disclosure - Earnings per Share - Summary Of Detailed Information Of Diluted Earnings Per Share (Detail) Sheet http://www.sktelecom.com/role/EarningsPerShareSummaryOfDetailedInformationOfDilutedEarningsPerShareDetail Earnings per Share - Summary Of Detailed Information Of Diluted Earnings Per Share (Detail) Details 202 false false R203.htm 999195 - Disclosure - Earnings Per Share - Summary Of Weighted Average Number Of Diluted Common Shares Outstanding (Detail) Sheet http://www.sktelecom.com/role/EarningsPerShareSummaryOfWeightedAverageNumberOfDilutedCommonSharesOutstandingDetail Earnings Per Share - Summary Of Weighted Average Number Of Diluted Common Shares Outstanding (Detail) Details 203 false false R204.htm 999196 - Disclosure - Dividends - Details of Dividend Declared (Detail) Sheet http://www.sktelecom.com/role/DividendsDetailsOfDividendDeclaredDetail Dividends - Details of Dividend Declared (Detail) Details 204 false false R205.htm 999197 - Disclosure - Dividends - Dividends Yield Ratios (Detail) Sheet http://www.sktelecom.com/role/DividendsDividendsYieldRatiosDetail Dividends - Dividends Yield Ratios (Detail) Details 205 false false R206.htm 999198 - Disclosure - Categories of Financial Instruments - Financial Assets by Category (Detail) Sheet http://www.sktelecom.com/role/CategoriesOfFinancialInstrumentsFinancialAssetsByCategoryDetail Categories of Financial Instruments - Financial Assets by Category (Detail) Details 206 false false R207.htm 999199 - Disclosure - Categories of Financial Instruments - Financial Assets by Category (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/CategoriesOfFinancialInstrumentsFinancialAssetsByCategoryParentheticalDetail Categories of Financial Instruments - Financial Assets by Category (Parenthetical) (Detail) Details 207 false false R208.htm 999200 - Disclosure - Categories of Financial Instruments - Financial Liabilities by Category (Detail) Sheet http://www.sktelecom.com/role/CategoriesOfFinancialInstrumentsFinancialLiabilitiesByCategoryDetail Categories of Financial Instruments - Financial Liabilities by Category (Detail) Details 208 false false R209.htm 999201 - Disclosure - Financial Risk Management - Monetary Assets and Liabilities Denominated in Foreign Currencies (Detail) Sheet http://www.sktelecom.com/role/FinancialRiskManagementMonetaryAssetsAndLiabilitiesDenominatedInForeignCurrenciesDetail Financial Risk Management - Monetary Assets and Liabilities Denominated in Foreign Currencies (Detail) Details 209 false false R210.htm 999202 - Disclosure - Financial Risk Management - Hypothetical Change in Exchange Rates by 10% would have Increased (Decreased) the Group's Profit Before Income Tax and Equity (Detail) Sheet http://www.sktelecom.com/role/FinancialRiskManagementHypotheticalChangeInExchangeRatesBy10WouldHaveIncreasedDecreasedTheGroupSProfitBeforeIncomeTaxAndEquityDetail Financial Risk Management - Hypothetical Change in Exchange Rates by 10% would have Increased (Decreased) the Group's Profit Before Income Tax and Equity (Detail) Details 210 false false R211.htm 999203 - Disclosure - Financial Risk Management - Hypothetical Change in Exchange Rates by 10% would have Increased (Decreased) the Group's Profit Before Income Tax and Equity (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/FinancialRiskManagementHypotheticalChangeInExchangeRatesBy10WouldHaveIncreasedDecreasedTheGroupSProfitBeforeIncomeTaxAndEquityParentheticalDetail Financial Risk Management - Hypothetical Change in Exchange Rates by 10% would have Increased (Decreased) the Group's Profit Before Income Tax and Equity (Parenthetical) (Detail) Details 211 false false R212.htm 999204 - Disclosure - Financial Risk Management - Additional Information (Detail) Sheet http://www.sktelecom.com/role/FinancialRiskManagementAdditionalInformationDetail Financial Risk Management - Additional Information (Detail) Details 212 false false R213.htm 999205 - Disclosure - Financial Risk Management - Disclosure Of Rate Of Per Values Of Floating Rate Long Term Payables Explanatory (Details) Sheet http://www.sktelecom.com/role/FinancialRiskManagementDisclosureOfRateOfPerValuesOfFloatingRateLongTermPayablesExplanatoryDetails Financial Risk Management - Disclosure Of Rate Of Per Values Of Floating Rate Long Term Payables Explanatory (Details) Details 213 false false R214.htm 999206 - Disclosure - Financial Risk Management - Disclosure of Rate Of Fluctuation In The Per Stock Price Of The Equity Securities (Detail) Sheet http://www.sktelecom.com/role/FinancialRiskManagementDisclosureOfRateOfFluctuationInThePerStockPriceOfTheEquitySecuritiesDetail Financial Risk Management - Disclosure of Rate Of Fluctuation In The Per Stock Price Of The Equity Securities (Detail) Details 214 false false R215.htm 999207 - Disclosure - Financial Risk Management - Maximum Credit Exposure (Detail) Sheet http://www.sktelecom.com/role/FinancialRiskManagementMaximumCreditExposureDetail Financial Risk Management - Maximum Credit Exposure (Detail) Details 215 false false R216.htm 999208 - Disclosure - Financial Risk Management - Summary of Gross Carrying Amounts of Each Financial Asset Except for Accounts Receivable Trade and Derivative Financial Asset (Detail) Sheet http://www.sktelecom.com/role/FinancialRiskManagementSummaryOfGrossCarryingAmountsOfEachFinancialAssetExceptForAccountsReceivableTradeAndDerivativeFinancialAssetDetail Financial Risk Management - Summary of Gross Carrying Amounts of Each Financial Asset Except for Accounts Receivable Trade and Derivative Financial Asset (Detail) Details 216 false false R217.htm 999209 - Disclosure - Financial Risk Management - Summary of Changes in Loss Allowance for Debt Investments (Detail) Sheet http://www.sktelecom.com/role/FinancialRiskManagementSummaryOfChangesInLossAllowanceForDebtInvestmentsDetail Financial Risk Management - Summary of Changes in Loss Allowance for Debt Investments (Detail) Details 217 false false R218.htm 999210 - Disclosure - Financial Risk Management - Contractual Maturities of Financial Liabilities (Detail) Sheet http://www.sktelecom.com/role/FinancialRiskManagementContractualMaturitiesOfFinancialLiabilitiesDetail Financial Risk Management - Contractual Maturities of Financial Liabilities (Detail) Details 218 false false R219.htm 999211 - Disclosure - Financial Risk Management - Periods in Which Cash Flows from Cash Flow Hedge Derivatives are Expected to Occur (Detail) Sheet http://www.sktelecom.com/role/FinancialRiskManagementPeriodsInWhichCashFlowsFromCashFlowHedgeDerivativesAreExpectedToOccurDetail Financial Risk Management - Periods in Which Cash Flows from Cash Flow Hedge Derivatives are Expected to Occur (Detail) Details 219 false false R220.htm 999212 - Disclosure - Financial Risk Management - Debt-equity Ratio (Detail) Sheet http://www.sktelecom.com/role/FinancialRiskManagementDebtEquityRatioDetail Financial Risk Management - Debt-equity Ratio (Detail) Details 220 false false R221.htm 999213 - Disclosure - Financial Risk Management - Fair Value and Carrying Amount of Financial Assets and Liabilities Including Fair Value Hierarchy (Detail) Sheet http://www.sktelecom.com/role/FinancialRiskManagementFairValueAndCarryingAmountOfFinancialAssetsAndLiabilitiesIncludingFairValueHierarchyDetail Financial Risk Management - Fair Value and Carrying Amount of Financial Assets and Liabilities Including Fair Value Hierarchy (Detail) Details 221 false false R222.htm 999214 - Disclosure - Financial Risk Management - Interest Rates Used by the Group for the Fair Value Measurement (Detail) Sheet http://www.sktelecom.com/role/FinancialRiskManagementInterestRatesUsedByTheGroupForTheFairValueMeasurementDetail Financial Risk Management - Interest Rates Used by the Group for the Fair Value Measurement (Detail) Details 222 false false R223.htm 999215 - Disclosure - Financial Risk Management - Changes of Financial Assets Classified as Level 3 (Detail) Sheet http://www.sktelecom.com/role/FinancialRiskManagementChangesOfFinancialAssetsClassifiedAsLevel3Detail Financial Risk Management - Changes of Financial Assets Classified as Level 3 (Detail) Details 223 false false R224.htm 999216 - Disclosure - Financial Risk Management - Carrying Amount of Financial Instruments Recognized of Which Offset Agreements are Applicable (Detail) Sheet http://www.sktelecom.com/role/FinancialRiskManagementCarryingAmountOfFinancialInstrumentsRecognizedOfWhichOffsetAgreementsAreApplicableDetail Financial Risk Management - Carrying Amount of Financial Instruments Recognized of Which Offset Agreements are Applicable (Detail) Details 224 false false R225.htm 999217 - Disclosure - Transactions with Related Parties - Compensation for the Key Management (Detail) Sheet http://www.sktelecom.com/role/TransactionsWithRelatedPartiesCompensationForTheKeyManagementDetail Transactions with Related Parties - Compensation for the Key Management (Detail) Details 225 false false R226.htm 999218 - Disclosure - Transactions with Related Parties - Transactions with Related Parties (Detail) Sheet http://www.sktelecom.com/role/TransactionsWithRelatedPartiesTransactionsWithRelatedPartiesDetail Transactions with Related Parties - Transactions with Related Parties (Detail) Details 226 false false R227.htm 999219 - Disclosure - Transactions with Related Parties - Transactions with Related Parties (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/TransactionsWithRelatedPartiesTransactionsWithRelatedPartiesParentheticalDetail Transactions with Related Parties - Transactions with Related Parties (Parenthetical) (Detail) Details 227 false false R228.htm 999220 - Disclosure - Transactions with Related Parties - Account Balances with Related Parties (Detail) Sheet http://www.sktelecom.com/role/TransactionsWithRelatedPartiesAccountBalancesWithRelatedPartiesDetail Transactions with Related Parties - Account Balances with Related Parties (Detail) Details 228 false false R229.htm 999221 - Disclosure - Commitments and Contingencies - Additional Information (Detail) Sheet http://www.sktelecom.com/role/CommitmentsAndContingenciesAdditionalInformationDetail Commitments and Contingencies - Additional Information (Detail) Details 229 false false R230.htm 999222 - Disclosure - Statements of Cash Flows - Adjustments for Income and Expenses from Operating Activities (Detail) Sheet http://www.sktelecom.com/role/StatementsOfCashFlowsAdjustmentsForIncomeAndExpensesFromOperatingActivitiesDetail Statements of Cash Flows - Adjustments for Income and Expenses from Operating Activities (Detail) Details 230 false false R231.htm 999223 - Disclosure - Statements of Cash Flows - Changes in Assets and Liabilities from Operating Activities (Detail) Sheet http://www.sktelecom.com/role/StatementsOfCashFlowsChangesInAssetsAndLiabilitiesFromOperatingActivitiesDetail Statements of Cash Flows - Changes in Assets and Liabilities from Operating Activities (Detail) Details 231 false false R232.htm 999224 - Disclosure - Statements of Cash Flows - Significant Non-cash Transactions (Detail) Sheet http://www.sktelecom.com/role/StatementsOfCashFlowsSignificantNonCashTransactionsDetail Statements of Cash Flows - Significant Non-cash Transactions (Detail) Details 232 false false R233.htm 999225 - Disclosure - Statements of Cash Flows - Reconciliation of Liabilities Arising from Financing Activities (Detail) Sheet http://www.sktelecom.com/role/StatementsOfCashFlowsReconciliationOfLiabilitiesArisingFromFinancingActivitiesDetail Statements of Cash Flows - Reconciliation of Liabilities Arising from Financing Activities (Detail) Details 233 false false R234.htm 999226 - Disclosure - Statements of Cash Flows - Reconciliation of Liabilities Arising from Financing Activities (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/StatementsOfCashFlowsReconciliationOfLiabilitiesArisingFromFinancingActivitiesParentheticalDetail Statements of Cash Flows - Reconciliation of Liabilities Arising from Financing Activities (Parenthetical) (Detail) Details 234 false false R235.htm 999227 - Disclosure - Reconciliation of Liabilities Arising from Financing Activities (Detail) Sheet http://www.sktelecom.com/role/ReconciliationOfLiabilitiesArisingFromFinancingActivitiesDetail Reconciliation of Liabilities Arising from Financing Activities (Detail) Details 235 false false R236.htm 999228 - Disclosure - Emissions Liabilities - Disclosure of Quantity of Emissions Rights Allocated Free of Charge (Detail) Sheet http://www.sktelecom.com/role/EmissionsLiabilitiesDisclosureOfQuantityOfEmissionsRightsAllocatedFreeOfChargeDetail Emissions Liabilities - Disclosure of Quantity of Emissions Rights Allocated Free of Charge (Detail) Details 236 false false R237.htm 999229 - Disclosure - Emissions Liabilities - Summary of Changes in Emissions Rights Quantities (Detail) Sheet http://www.sktelecom.com/role/EmissionsLiabilitiesSummaryOfChangesInEmissionsRightsQuantitiesDetail Emissions Liabilities - Summary of Changes in Emissions Rights Quantities (Detail) Details 237 false false R238.htm 999230 - Disclosure - Emissions Liabilities - Additional Information (Detail) Sheet http://www.sktelecom.com/role/EmissionsLiabilitiesAdditionalInformationDetail Emissions Liabilities - Additional Information (Detail) Details 238 false false R239.htm 999231 - Disclosure - Assets and Liabilities Held for Sale - Summary of Assets and Liabilities Held for Sale (Detail) Sheet http://www.sktelecom.com/role/AssetsAndLiabilitiesHeldForSaleSummaryOfAssetsAndLiabilitiesHeldForSaleDetail Assets and Liabilities Held for Sale - Summary of Assets and Liabilities Held for Sale (Detail) Details 239 false false R240.htm 999232 - Disclosure - Assets and Liabilities Held for Sale - Assets and liabilities held for sale (Parenthetical) (Detail) Sheet http://www.sktelecom.com/role/AssetsAndLiabilitiesHeldForSaleAssetsAndLiabilitiesHeldForSaleParentheticalDetail Assets and Liabilities Held for Sale - Assets and liabilities held for sale (Parenthetical) (Detail) Details 240 false false R241.htm 999233 - Disclosure - Business Combinations - Considerations Transferred Identifiable Assets Acquired and Liabilities Assumed as of the Acquisition Date (Detail) Sheet http://www.sktelecom.com/role/BusinessCombinationsConsiderationsTransferredIdentifiableAssetsAcquiredAndLiabilitiesAssumedAsOfTheAcquisitionDateDetail Business Combinations - Considerations Transferred Identifiable Assets Acquired and Liabilities Assumed as of the Acquisition Date (Detail) Details 241 false false R242.htm 999234 - Disclosure - Cash Dividends paid to the Parent Company - Summary of Cash Dividends Received from Consolidated Subsidiaries and Associates (Detail) Sheet http://www.sktelecom.com/role/CashDividendsPaidToTheParentCompanySummaryOfCashDividendsReceivedFromConsolidatedSubsidiariesAndAssociatesDetail Cash Dividends paid to the Parent Company - Summary of Cash Dividends Received from Consolidated Subsidiaries and Associates (Detail) Details 242 false false All Reports Book All Reports d78252d20f.htm skm-20251231.xsd http://xbrl.sec.gov/cyd/2025 http://xbrl.sec.gov/dei/2025 http://xbrl.sec.gov/ecd/2025 https://xbrl.ifrs.org/taxonomy/2025-03-27/ifrs-full false false