<DefinitionAndReference>
  <Element Id="us-gaap_AdditionalPaidInCapitalCommonStock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ChangeFromNetLossAttributableToParentCompanyAndTransfersToFromNoncontrollingInterests">
    <definition>Change from net loss attributable to parent company and transfers (to) from noncontrolling interests.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NetCashProvidedByUsedInInvestingActivities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SharesAcceleratedDuringPeriodUnderSecondTrancheOfLocalSubPlan">
    <definition>Shares accelerated during period under Second Tranche of Local Sub Plan.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_QuarterLagReportingUponEquityInvestmentDivestiture">
    <definition>Equity Divestiture.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TaxesAndOtherGovernmentReceivables">
    <definition>Taxes and other government receivables.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalEquityInstrumentsOtherThanOptionsVestedInPeriodUnderSecondTranche">
    <definition>Share based compensation arrangement by share based payment award additional equity instruments other than options vested in period under second tranche.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LiabilitiesCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DefinedBenefitPlanPlanAssetsTransferOut">
    <definition>Defined Benefit Plan Plan Assets Transfer Out.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_NoncontrollingInterestBusinessAcquisition">
    <definition>Noncontrolling interest Business Acquisition.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_FairValueMeasurementWithUnobservableInputsReconciliationNonRecurringBasisInvestmentsInEquitySecuritiesCarriedAtCost">
    <definition>Fair Value Measurement With Unobservable Inputs Reconciliation Non Recurring Basis Investments in equity securities carried at cost.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_RestrictedCashPolicyTextBlock">
    <definition>Restricted cash.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfEntityWideDisclosureOnGeographicAreasLongLivedAssetsInIndividualForeignCountriesByCountryTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_StockholdersEquity">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RevenueRecognitionPolicyTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_BusinessCombinationAcquiredEquityInvestment">
    <definition>Business Combination Acquired Equity Investment.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DetailsOfSecuritiesThatCurrentlyAreInUnrealizedLossPositionTextBlock">
    <definition>Details of securities that currently are in an unrealized loss position text block.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_IncreaseDecreaseInStockholdersEquityTextBlock">
    <definition>Increase decrease in stockholders' equity.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxLiabilitiesOther">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DebtCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_PercentageDetermindForWeightedAverageCostOfCapital">
    <definition>Percentage Determind For Weighted Average Cost of Capital.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_MarketableSecurities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_EarningsPerShareTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_TreasuryStockNumberOfSharesHeld">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_AdvancesReceivable">
    <definition>Advances receivable.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanAmortizationOfNetPriorServiceCostCredit">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_BusinessCombinationDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_CapitalInvestmentFunding">
    <definition>Capital investment funding.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DebtInstrumentRedemptionFeature">
    <definition>Debt Instrument Redemption Feature.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_GainContingencyUnrecordedAmount">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_GoodwillImpairmentLoss">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfGoodwillTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_EntityVoluntaryFilers">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CommonStockSharesOutstanding">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NetIncomeLoss">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ProceedsReceivedInBusinessCombinations">
    <definition>Proceeds Received In Business Combinations.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_IntangibleAssetsPolicyTextBlock">
    <definition>Intangible assets.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CommonStockSharesIssued">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_Assets">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ImpairmentOfCertainSpecificEquipment">
    <definition>Impairment on certain specific equipment.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_MaximumPercentageOfOutstandingAmountPerInstrumentWithBank">
    <definition>Maximum Percentage Of Outstanding Amount Per Instrument With Bank.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfOtherOperatingCostAndExpenseByComponentTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_StockOptionPlansOptionsForfeitedLowerRangePricePerShare">
    <definition>Stock option plans, options forfeited, lower  range, price per share.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DerivativesPolicyTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ValuationAllowancesAndReservesDeductions">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LongTermDebtNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanServiceCost">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_EarlyRepaymentOfSeniorDebtAndRepaymentOfConvertibleDebt">
    <definition>The cash outflow for the extinguishment of borrowing, with the highest claim on the assets of the entity in case of bankruptcy or liquidation, before its maturity. Additionally this item includes the aggregate net gain and losses (whether realized or unrealized) on all derivative instruments held for trading purposes whether or not settled physically.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherReceivablesAndAssetsTextBlock">
    <definition>Other Receivables And Assets.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_FirstTrancheOfOriginalPlanVestedShare">
    <definition>First tranche of the original plan vested share.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DueToAffiliateCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DebtDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_AntidilutiveSharesIncludedInOutstandingStockOptionsAmount">
    <definition>Antidilutive shares included in outstanding stock options amount.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LineOfCreditFacilityAmountOutstanding">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_FaceValueOfAuctionRateSecuritiesSold">
    <definition>Face value of Auction rate securities sold.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_InvestmentPositionsInFloatingRateNotes">
    <definition>Investment positions in floating rate notes.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeTaxReconciliationTaxHolidays">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FutureAmortizationExpenseYearOne">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_EquityMethodInvestmentsDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ClosingSharePrice">
    <definition>Closing share price.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_EntityCommonStockSharesOutstanding">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_DocumentType">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_PercentageOfTradeAccountReceivableRepresentedByOneCustomer">
    <definition>Percentage of Trade account Receivable represented by One customer.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DeferredTaxAssetsOnTaxLossCarryforwardsAndInvestmentCreditsExpirationYearThree">
    <definition>Deferred tax assets on tax loss carryforwards and investment credits expiration Year Three.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_StartUpAndPhaseOutCostsPolicyTextBlock">
    <definition>Start Up and Phase Out Costs Policy.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DueFromRelatedParties">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanAmortizationOfNetGainsLosses">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanActuarialNetGainsLosses">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherComprehensiveIncomeOfDefinedBenefitPlanForeignCurrencyTranslationForActuarialGainsLossesBeforeTax">
    <definition>Other Comprehensive Income Of Defined Benefit Plan Foreign Currency Translation For Actuarial Gains Losses Before Tax.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PaymentsToAcquireShortTermInvestments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ExpectedLicenseAndServicesRevenueYearOne">
    <definition>Expected License and Services Revenue, Year One.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxAssetsOther">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DecreaseInGoodwillDueToReleaseOfContingentConsiderationLiabilityBookedInitiallyUnderFasOneHundredFortyOne">
    <definition>Decrease in goodwill due to a release of contingent consideration liability booked initially under FAS141.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ValueOfRightToUseAssetCurrentLiability">
    <definition>value of right to use assetCurrent Liability.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DerivativeAssetsCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TotalObligationDueInThreeYears">
    <definition>Total Obligation Due In Three Years.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeTaxesPaid">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ProceedsFromIssuanceOfLongTermDebt">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_MaximumPercentageOfVotingRightsEvidencingSignificantInfluence">
    <definition>Maximum percentage of voting rights evidencing significant influence.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InventoryRawMaterialsNetOfReserves">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ReducedMaximumOutstandingAmountPerInstrumentWithBank">
    <definition>Reduced maximum outstanding amount per instrument with Bank.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NotionalAmountOfForeignCurrencyCashFlowHedgeDerivatives">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsInYearOne">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsInFiveFiscalYearsThereafter">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ScheduleOfOtherPayablesAndAccruedLiabilitiesTextBlock">
    <definition>Schedule of other payables and accrued liabilities.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherRestructuringCosts">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RestructuringReserveTranslationAdjustment">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherComprehensiveIncomeReclassificationOfDefinedBenefitPlansNetGainLossRecognizedInNetPeriodicBenefitCostBeforeTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfDerivativeInstrumentsGainLossInStatementOfFinancialPerformanceTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_NumberOfDebtInstrumentsRepurchased">
    <definition>Number Of Debt Instruments Repurchased</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_IncomeTaxReconciliationCurrentTaxCredits">
    <definition>Income Tax Reconciliation Current Tax Credits.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DeferredTaxAssetsOnTaxLossCarryforwardsAndInvestmentCreditsExpirationYearFive">
    <definition>Deferred Tax Assets On Tax Loss Carryforwards And Investment Credits Expiration Year Five</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ProceedsFromSaleOfMachineryAndEquipment">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TradeAccountsReceivableNetTextBlock">
    <definition>Trade Accounts Receivable Net.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_SummaryOfIncomeTaxContingenciesTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_NotionalAmountOfForeignCurrencyCashFlowHedgeDerivativesShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit">
    <definition>Notional Amount Of Foreign Currency Cash Flow Hedge Derivatives Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Lower Range Limit.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock">
    <definition>Schedule of Deferred Tax Assets and Liabilities.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CashFlowHedgeGainLossReclassifiedToOtherExpenseNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonvestedSharesVestedAwardRequiredRequisiteServicePeriod">
    <definition>Share Based Compensation Arrangement By Share Based Payment Award Nonvested Shares Vested Award Required Requisite Service Period.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_SignificantAccountingPoliciesTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherComprehensiveIncomeLossTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RetainedEarningsAccumulatedDeficit">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanSettlementsPlanAssets">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DerivativeLiabilityDesignatedAsHedgingInstrumentFairValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_RestructuringAndRelatedCostReportableSegmentIncurredCostPreTax">
    <definition>Restructuring And Related Cost Reportable Segment Incurred Cost Pre Tax.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_EntityWideDisclosureOnGeographicAreasRevenueFromExternalCustomersAttributedToIndividualForeignCountriesAmount">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanPlanAmendments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DerivativeAssetDesignatedAsHedgingInstrumentFairValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TotalObligation">
    <definition>Total Obligation.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxAssetsLiabilitiesNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CompensationRelatedCostsPolicyTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ValueOfRightToUseAssetGranted">
    <definition>Value of right to use asset Granted.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DebtInstrumentConvertibleNumberOfEquityInstruments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherLiabilitiesNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedTechnology">
    <definition>Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Technology.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_RestructuringChargesAndOtherRelatedClosureCost">
    <definition>Restructuring charges and other related closure cost.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DefinedContributionPlanAccruedBenefits">
    <definition>Defined Contribution Plan Accrued Benefits.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ScheduleOfAllocationOfPensionPlanAssetsIncludingFairValueMeasurementsTableTextBlock">
    <definition>Schedule of Allocation of Pension Plan Assets, Including Fair Value Measurements Table.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeTaxPolicyTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeTaxReconciliationTaxSettlements">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxAssetsGross">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_CurrentFiscalYearEndDate">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfRevenueFromExternalCustomersAttributedToForeignCountriesByGeographicAreaTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RelatedPartyTransactionsDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NetCashProvidedByUsedInOperatingActivities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PaymentsOfDividendsMinorityInterest">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisChangeInFairValueSubordinatedNotes">
    <definition>Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Change in fair value subordinated notes.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InterestOnConvertibleDebtNetOfTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedContributionPlanCostRecognized">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_EntityCentralIndexKey">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_IncomeTaxReconciliationNondeductibleNonTaxableOtherPermanentDifferenceExpense">
    <definition>Income Tax Reconciliation Nondeductible Non Taxable Other Permanent Difference Expense.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ReceivablesFromGovernmentAgencies">
    <definition>Receivables from government agencies.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_EarningsPerShareDiluted">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CostMethodInvestmentsRealizedGainLoss">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsSecondTrancheOfSubplanVestedAndExpectedToVestOutstandingNumber">
    <definition>Share based compensation arrangement by share based payment award options second tranche of subplan vested and expected to vest outstanding number.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FutureAmortizationExpenseYearTwo">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShortTermInvestments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DueToRelatedPartiesCurrentAndNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NotionalAmountOfCashFlowHedgeInstruments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_AcquiredInProcessRAndDAndOtherNonRecurringPurchaseAccountingCharges">
    <definition>Acquired In-Process R&amp;D and other non-recurring purchase accounting charges.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_AmendmentFlag">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SharesSoldAfterEndOfLockUpPeriod">
    <definition>Shares sold after the end of the lock-up period.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_IncomeTaxReconciliationImpactOfDeconsolidation">
    <definition>Income Tax Reconciliation Impact Of Fmg Deconsolidation.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DividendPaid">
    <definition>Dividend Paid.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NotionalAmountOfFairValueHedgeInstruments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CashAndCashEquivalentsPolicyTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_EntityRegistrantName">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ProceedsFromRepaymentsOfShortTermDebt">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SharesAcceleratedDuringPeriodUnderFirstTrancheOfEmployeePlan">
    <definition>Shares accelerated during the period under First Tranche of Employee Plan.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TotalRevenueFromMultipleDeliverableAgreements">
    <definition>Total Revenue from Multiple Deliverable Agreements.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsInYearFive">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_FairValueHedgeTransferredToTradingSecuritiesUnrealizedGainLoss">
    <definition>Fair Value Hedge Transferred to Trading Securities, Unrealized Gain (Loss).</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CostOfGoodsAndServicesSold">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPeriodIncreaseDecrease">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_SalesRevenueNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfNewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxAssetsTaxDeferredExpenseOther">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TotalObligationDueInFiveYears">
    <definition>Total Obligation Due In Five Years.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_PurchaseConsiderationReceivedInCash">
    <definition>Purchase Consideration Received In cash.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_LongTermDebtDenominatedByCurrenciesTextBlock">
    <definition>Long Term Debt Denominated by Currencies.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_MarketableSecuritiesPolicyTextBlock">
    <definition>Marketable Securities Policy.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_TreasuryStockValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AssetsHeldForSaleLongLivedFairValueDisclosure">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_StockOptionPlansOptionsExpiredUpperRangePricePerShare">
    <definition>Stock option plans, options expired, upper range, price per share.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_UnrealizedGainLossOnPriceRiskCashFlowDerivativesBeforeTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_PeriodOfAccumulatedOtherComprehensiveIncomeLossExpectedToBeReclassifiedAsEarnings">
    <definition>Period of accumulated other comprehensive income loss expected to be reclassified as earnings.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncrementalCommonSharesAttributableToConversionOfDebtSecurities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SharesAccelerated">
    <definition>Shares Accelerated.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LoansPayableToBank">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock">
    <definition>Tabular disclosure of an entity's basic and diluted earnings per share calculations.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RestructuringReserveSettledWithCash">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RecordedUnconditionalPurchaseObligation">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InventoryNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DeferredTaxAssetsOnTaxLossCarryforwardsAndInvestmentCreditsExpirationThereafter">
    <definition>Deferred tax assets on tax loss carryforwards and investment credits expiration Thereafter.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InvestmentIncomeInterest">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_AmountOfTotalLossesForPeriodIncludedInEarningsAttributableToAssetsStillHeldAtReportingDate">
    <definition>Amount of total losses for the period included in earnings attributable to assets still held at the reporting date.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherReceivablesAndAssets">
    <definition>Other receivables and assets.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_RevenueRecognitionMultipleDeliverableArrangementsTableTextBlock">
    <definition>Tabular disclosure of the recognition of revenue arrangements under which the entity does or will perform multiple revenue-generating activities, categorized by type of arrangement. This item includes certain revenue arrangements that include software elements. This item does not include multiple-deliverable arrangements for industries that prepare disclosures under specific requirements (for instance, construction-type and production-type contracts) otherwise provided for in the taxonomy.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_GoodwillPeriodIncreaseDecrease">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_PercentageOfParentInGroupTwo">
    <definition>Percentage of parent in group two.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DepreciationAndAmortizationSegmentedInformationGeographicAreasTextBlock">
    <definition>Depreciation and amortization segmented information geographic areas.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FutureAmortizationExpenseYearThree">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ExtinguishmentOfDebtAmount">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CashFlowHedgeGainLossReclassifiedToEarningsNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_StockholdersEquityNoteDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_BusinessCombinationsAndGoodwillPolicyTextBlock">
    <definition>Business combinations and goodwill.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TotalObligationDueInTwoYears">
    <definition>Total Obligation Due In Two Years.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_SeveranceCosts">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InventoryDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_SegmentReportingReconcilingItemsRevenue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TreasuryStockRepurchaseAuthorization">
    <definition>Treasury Stock Repurchase Authorization.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OperatingIncomeLoss">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NotionalAmountOfForeignCurrencyDerivativePurchaseContracts">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NotionalAmountOfOtherDerivativesNotDesignatedAsHedgingInstruments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_InventoryStepUpCharge">
    <definition>Inventory step-up charge.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ProceedsFromShortTermDebt">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InventoryFinishedGoodsNetOfReserves">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DefinedBenefitPlanPlanAssetsTransferIn">
    <definition>Defined Benefit Plan Plan Assets Transfer In.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_LoansAndDeposits">
    <definition>Loans and deposits.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_MaximumPercentageForResearchAndDevelopmentAndCorporateCostsOfTotalForecastedTransactions">
    <definition>Maximum percentage for Research and development and Corporate costs of the total forecasted transactions.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherInvestmentsAndOtherNonCurrentAssets">
    <definition>Other investments and other non-current assets.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ScheduleOfCommitmentsTextBlock">
    <definition>Schedule of Commitments.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SeniorFloatingRateNoteWhoseImpairmentWasRecordedAsOtherThanTemporary">
    <definition>Senior floating rate note whose impairment was recorded as other than temporary.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPeriodIncreaseDecrease">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AvailableForSaleSecuritiesTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsInYearThree">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisPaidInKindInterestOnSubordinatedNotes">
    <definition>Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Paid in kind interest on subordinated notes.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ProceedsFromSaleOfNonCurrentMarketableSecurities">
    <definition>Proceeds from sale of non current marketable securities.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_LegalMattersAndContingenciesTextBlock">
    <definition>The entire disclosure for legal proceedings, legal contingencies, litigation, regulatory and environmental matters and other contingencies.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ConsolidationPolicyTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_EntityWellKnownSeasonedIssuer">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_IncomeTaxReconciliationEarningsOfSubsidiariesTaxedAtDifferentRates">
    <definition>Income Tax Reconciliation Earnings Of Subsidiaries Taxed At Different Rates.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NotesAndLoansReceivableNetNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DefinedBenefitPlanPlanAssetsBenefitsPaid">
    <definition>Defined Benefit Plan Plan Assets Benefits Paid.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherAccruedLiabilitiesCurrentAndNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DerivativeInstrumentsAndHedgesNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_MarketableSecuritiesRealizedGainLossOtherThanTemporaryImpairmentsAmount">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_EquityMethodInvestments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_SubsidiaryOrEquityMethodInvesteeCumulativeNumberOfSharesIssuedForAllTransactions">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredForeignIncomeTaxExpenseBenefit">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_RestructuringAndRelatedCostReportableSegmentExpectedCostPreTaxMaximum">
    <definition>Restructuring And Related Cost Reportable Segment Expected Cost Pre Tax Maximum.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest">
    <definition>Income Loss from Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DerivativeFairValueOfDerivativeLiability">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_GainLossOnFairValueHedgeIneffectivenessNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TransactionsWithSignificantShareholdersTheirAffiliatesAndOtherRelatedPartiesTextBlock">
    <definition>Transactions with significant shareholders, their affiliates and other related parties.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherComprehensiveIncomeOfDefinedBenefitPlanEffectOfCurtailmentSettlementTotalBeforeTax">
    <definition>Other Comprehensive Income Of Defined Benefit Plan Effect Of Curtailment Settlement Total Before Tax.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfRestructuringReserveByTypeOfCostTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfDerivativeInstrumentsTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RepaymentsOfLinesOfCredit">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_TradingSecuritiesRealizedLoss">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PaymentsOfDividendsCommonStock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_BusinessAcquisitionPurchasePriceAllocationPropertyPlantAndEquipment">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ImpairmentOfLongLivedAssetsHeldForUse">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredIncomeTaxExpenseBenefit">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_GainLossOnFinancialInstrumentsNet">
    <definition>This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain or loss of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain or loss which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains or losses realized during the period from the sale of investments accounted for under the cost method of accounting and losses recognized for other than temporary impairments of the subject investments. Finally, this item would also include aggregate net gain and losses (whether realized or unrealized) on all derivative instruments held for trading purposes whether or not settled physically.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherInvestmentsAndOtherNonCurrentAssetsTextBlock">
    <definition>Other Investments And Other Non-Current Assets.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_StockOptionPlansOptionsForfeitedUpperRangePricePerShare">
    <definition>Stock option plans, options forfeited, upper range, price per share.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DeferredIncomeTaxExpenseRelatingToUnvestedShareBasedCompensationExpense">
    <definition>Deferred Income Tax Expense relating To Unvested Share Based Compensation Expense.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_EntityFilerCategory">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InvestmentIncomeInvestmentExpense">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FiniteLivedIntangibleAssetsNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_MinorityInterestOwnershipPercentageByParent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxAssetsNetCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TotalObligationDueThereafter">
    <definition>Total Obligation Due Thereafter.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_NetRevenuesByProductLinesTextBlock">
    <definition>Net revenues by product lines text block.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanSettlementsBenefitObligation">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxAssetsInventory">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ComprehensiveIncomeNetOfTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherSalesRevenueNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LiabilitiesNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostCreditArisingDuringPeriodBeforeTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CommitmentsAndContingencies2009">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LoansPayable">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LicenseAndServicesRevenue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OperatingLeasesFutureMinimumPaymentsDue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ExpectedTotalRevenueFromMultipleDeliverableAgreementsYearOne">
    <definition>Expected Total Revenue from Multiple Deliverable Agreements, Year One</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ScheduleOfInterestIncomeNetTextBlock">
    <definition>Schedule of Interest Income, Net.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_Liabilities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncreaseDecreaseInOperatingCapital">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DefinedBenefitPlanContributionsByPlanParticipantsForPlanAssets">
    <definition>Defined Benefit Plan Contributions By Plan Participants for plan assets.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RestructuringReserve">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_BusinessAcquisitionCostOfAcquiredEntityCashPaid">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RecordedUnconditionalPurchaseObligationDueWithinOneYear">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_FinancialAssetsLiabilitiesMeasuredAtFairValueOnRecurringBasisTotal">
    <definition>Financial assets liabilities measured at fair value on recurring basis total.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ForeignCurrencyTransactionGainLossBeforeTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CashAndCashEquivalentsAtCarryingValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxLiabilitiesNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RelatedPartyTransactionRevenuesFromTransactionsWithRelatedParty">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecrease">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxAssetsNetNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SharesAcceleratedDuringPeriodUnderSecondTranche">
    <definition>Shares Accelerated during the period under Second Tranche.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeTaxReconciliationChangeInEnactedTaxRate">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PreferredStockSharesAuthorized">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_EntityCurrentReportingStatus">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherAssetsCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_MinimumPercentageOfVotingRightsEvidencingSignificantInfluence">
    <definition>Minimum percentage of voting rights evidencing significant influence.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ReconciliationOfRevenueFromSegmentsToConsolidatedTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RestrictedCashAndCashEquivalentsNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PropertyPlantAndEquipmentGross">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CommonStockDividendsPerShareDeclared">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedTextBlock">
    <definition>Share based compensation arrangement by share based payment award equity instruments other than options nonvested.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_PensionPlanAssetAllocationTextBlock">
    <definition>Pension plan asset allocation.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsFirstTrancheOfSubplanVestedAndExpectedToVestOutstandingNumber">
    <definition>Share Based Compensation Arrangement By Share Based Payment Award Options First Tranche Of Subplan Vested And Expected To Vest Outstanding Number.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_EstimatedFutureBenefitPaymentsTextBlock">
    <definition>Estimated future benefit payments.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DebtInstrumentConvertibleConversionRatio">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanOtherPlanAssets">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ValuationAllowancesAndReservesBalance">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SharesAcceleratedDuringPeriodUnderFirstTranche">
    <definition>Shares Accelerated during the period under First Tranche.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfOtherAssetsNoncurrentTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PropertyPlantAndEquipmentUsefulLifeAverage">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FiniteLivedIntangibleAssetsUsefulLifeMinimum">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ExtinguishmentOfNotesReceivable">
    <definition>Extinguishment of notes receivable.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PropertyPlantAndEquipmentUsefulLifeMinimum">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_EquityAndCostMethodInvestmentsPolicyTextBlock">
    <definition>Equity and Cost Method Investments Policy</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_BusinessAcquisitionPurchasePriceAllocationAmortizableIntangibleAssets">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherComprehensiveIncomeOfDefinedBenefitPlanForeignCurrencyTranslationTotalBeforeTax">
    <definition>Other Comprehensive Income Of Defined Benefit Plan Foreign Currency Translation Total Before Tax.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LongTermDebtCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_GainLossOnSaleOfDerivatives">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_MaximumPercentageForManufacturingCostsOfTotalForecastedTransactions">
    <definition>Maximum percentage for manufacturing costs of the total forecasted transactions.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ContributedCashAmountsToRelatedParty">
    <definition>Contributed cash amounts to related Party.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SecondTrancheOfOriginalPlanVestedShare">
    <definition>Second tranche of original plan vested share.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherObligationDueThereafter">
    <definition>Other Obligation Due Thereafter.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccountsReceivableGrossCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ChangesInValueOfMarketableSecuritiesReportedInCurrentAndNoncurrentAssetsOnConsolidatedBalanceSheetsTextBlock">
    <definition>Changes in value of marketable securities reported in current and non-current assets on consolidated balance sheets.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsInYearTwo">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanEquitySecurities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_NotionalAmountOfCollarDerivatives">
    <definition>Notional Amount Of Collar Derivatives.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherIncrease">
    <definition>Other increase.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LongTermDebt">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DerivativeInstrumentsPayable">
    <definition>Derivative instruments Payable.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherComprehensiveIncomeAmortizationOfDefinedBenefitPlanNetPriorServiceCostCreditRecognizedInNetPeriodicBenefitCostBeforeTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensation">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedGoodwill">
    <definition>Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Goodwill.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_FairValueMeasurementWithUnobservableInputsReconciliationNonRecurringBasisOtherThanTemporaryImpairmentOnEquitySecurities">
    <definition>Fair Value Measurement With Unobservable Inputs Reconciliation Non Recurring Basis Other than temporary impairment on equity securities.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PaymentsForRepurchaseOfCommonStock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DefinedBenefitPlanActuarialNetGainsLossesPlanAssets">
    <definition>Defined Benefit Plan Actuarial Net Gains Losses in plan assets.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlements">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PropertyPlantAndEquipmentTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonvestedSharesVestedAwardRequisiteServicePeriod">
    <definition>Share Based Compensation Arrangement By Share Based Payment Award Nonvested Shares Vested Award Requisite Service Period.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_IssuePriceAsPercentageOfPrincipalAmount">
    <definition>Issue price as percentage of principal amount.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ApproximateAmountAwardedInConnectionWithUnauthorizedAuctionRateSecurities">
    <definition>Approximate amount Awarded in connection with unauthorized auction rate securities.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RestructuringCostsAndAssetImpairmentCharges">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_RestructuringAndRelatedCostReportableSegmentExpectedCostPreTaxMinimum">
    <definition>Restructuring And Related Cost Reportable Segment Expected Cost Pre Tax Minimum.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_CompensationCostExcludingPayrollTaxAndSocialContributionCapitalizedAsPartOfInventory">
    <definition>Compensation cost, excluding payroll tax and social contribution, capitalized as part of inventory.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_RedemptionOfSubordinatedNotes">
    <definition>Redemption of subordinated notes.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_MinorityInterestIncreaseFromStockIssuance">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CostMethodInvestmentsAggregateCarryingAmount">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_GuaranteeObligationsCurrentCarryingValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccruedRoyaltiesCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPeriodIncreaseDecrease">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_UnamortizedDebtIssuanceExpense">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ScheduleOfChangesInBenefitObligationsAndFairValueOfPlanAssetsTableTextBlock">
    <definition>Changes In Benefit Obligations And Fair Value of Plan Assets Table.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ExpectedTrainingAndSupportServicesYearTwo">
    <definition>Expected Training and Support Services, Year Two.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_PeriodOfAccumulatedOtherComprehensiveIncomeLoss">
    <definition>Period of accumulated other comprehensive income loss.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DebtInstrumentMaturityDateDescription">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InventoryPolicyTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DebtSecuritiesCancelledUponTransferOfFacility">
    <definition>Debt securities cancelled upon transfer of facility.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_GrossProfit">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AssetsHeldForSaleCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTaxPeriodIncreaseDecrease">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AdjustmentsToAdditionalPaidInCapitalReallocationOfMinorityInterest">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_PreferenceSharesOutstandingMaximumPeriod">
    <definition>Preference shares outstanding maximum period.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeTaxesReceivableNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncome">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_SellingGeneralAndAdministrativeExpense">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ObligationToReturnCashCollateralRelatedToCashFlowHedgeTransactionOnShares">
    <definition>Obligation to return cash collateral related to the cash-flow hedge transaction on Micron shares.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SeniorBonds">
    <definition>Senior Bonds.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_RelatedPartyTransactionResearchAndDevelopmentExpensesFromTransactionsWithRelatedParty">
    <definition>Research and development expenses from transactions with related party realized during the period.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LiabilitiesAndStockholdersEquity">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AssetImpairmentCharges">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AdvertisingCostsPolicyTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ProportionalShareOfLossBenefitRelatedToAmortization">
    <definition>Proportional share of the (loss) benefit related to amortization.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_AmountOfInterestAwardAlreadyReceived">
    <definition>Amount of Interest Award already received.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_NotionalAmountToHedgeForcastedSalesShares">
    <definition>Notional amount to hedge forcasted sales, shares.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherDecrease">
    <definition>Other decrease.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_MarketableSecuritiesReceivedInExchangeOfDivestiture">
    <definition>Marketable securities received in exchange of divestiture.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DebtPolicyTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_FairValueMeasurementWithUnobservableInputsReconciliationNonRecurringBasisEquityShareInLoss">
    <definition>Fair Value Measurement With Unobservable Inputs Reconciliation Non Recurring Basis Equity Share in Loss.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DeferredTaxAssetsOnTaxLossCarryforwardsAndInvestmentCreditsExpirationYearOne">
    <definition>Deferred tax assets on tax loss carryforwards and investment credits expiration.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_NotionalShareAmountOfPriceRiskDerivatives">
    <definition>Notional share amount of price risk derivatives.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DerivativeFairValueOfDerivativeAsset">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_FutureAmortizationExpenseAfterYearFive">
    <definition>The amount of amortization expense expected to be recognized for the remainder of the finite-lived intangible asset useful life after the fifth succeeding fiscal year.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccruedPayrollTaxesCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TotalObligationDueInFourYears">
    <definition>Total Obligation Due In Four Years.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxAssetsValuationAllowance">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NetCashProvidedByUsedInFinancingActivities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ShareOfCustomerInConsolidatedNetRevenues">
    <definition>Share of customer in consolidated net revenues.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeTaxReconciliationEquityInEarningsLossesOfUnconsolidatedSubsidiary">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SharesAccelarated">
    <definition>Shares accelarated.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsForeign">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_MarketableSecuritiesSharesSold">
    <definition>Marketable Securities Shares Sold.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanTransfersBetweenMeasurementLevels">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AmortizationOfDebtDiscountPremium">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccountsReceivableNetCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DeferredTaxAssetsOnTaxLossCarryforwardsAndInvestmentCreditsExpirationYearTwo">
    <definition>Deferred tax assets on tax loss carryforwards and investment credits expiration Year Two.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_RelatedPartyTransactionOtherPurchasesFromTransactionsWithRelatedParty">
    <definition>Other purchases from transactions with related party realized during the period.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_GainLossOnDerivativeInstrumentsHeldForTradingPurposesNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CapitalizedComputerSoftwareAmortization">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NatureOfOperations">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxLiabilitiesCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalEquityInstrumentsOtherThanOptionsVestedInPeriodUnderThirdTranche">
    <definition>Share based compensation arrangement by share based payment award additional equity instruments other than options vested in period under third tranche.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardExpirationDating">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RecordedUnconditionalPurchaseObligationDueInFifthYear">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ResearchAndDevelopmentInProcess">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeTaxExpenseBenefit">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CommitmentsDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CashFlowHedgeGainLossReclassifiedToCostOfSalesNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherMarketableSecuritiesNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_UnrecognizedTaxBenefitsIncreasesDecreaseResultingFromForeignCurrencyTranslation">
    <definition>Unrecognized Tax Benefits Increases Decrease Resulting From Foreign currency translation.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SignificantLossesInCountriesSubjectToTaxHolidays">
    <definition>Significant losses in countries subject to tax holidays.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccruedIncomeTaxesCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock">
    <definition>Schedule of Components of Income Tax Expense Benefit.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_BusinessAcquisitionPurchasePriceAllocationOtherCurrentAssetsAndLiabilitiesNet">
    <definition>Business Acquisition Purchase Price Allocation Other current assets and liabilities, net.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_StockOptionPlansOptionsExpiredLowerRangePricePerShare">
    <definition>Stock option plans, options expired, lower range, price per share.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ProceedsFromSaleOfDerivatives">
    <definition>Proceeds from Sale of Derivatives</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeLossFromEquityMethodInvestments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InterestIncomeAndInterestExpenseDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DefinedBenefitPlanTransferOut">
    <definition>Defined Benefit Plan, Transfer Out.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_SegmentReportingReconcilingItemsForOperatingProfitLoss">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueMeasuredOnRecurringBasisInvestments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfNoncashOrPartNoncashDivestituresTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_MarketableSecuritiesCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CapitalLeaseObligations">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueByBalanceSheetGroupingTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueAssetsMeasuredOnNonrecurringBasisTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_MaturitiesOfLongTermDebtAndCapitalLeaseObligationsTextBlock">
    <definition>Maturities Of Long Term Debt And Capital Lease Obligations.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_GainLossOnFairValueHedgesRecognizedInEarnings">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PropertyPlantAndEquipmentUsefulLifeMaximum">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_InventoriesNetOfReserveTextBlock">
    <definition>Inventories, net of reserve.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_IncrementalCommonSharesAttributableToStockOptions">
    <definition>Incremental Common Shares Attributable To Stock Options.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_IncomeLossBeforeIncomeTaxesAndMinorityInterests">
    <definition>Income (loss) before income taxes and minority interests.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ReductionInDepreciationChargesDueToPublicFunding">
    <definition>Reduction in depreciation charges due to Public funding.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeTaxDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_Goodwill">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CommonStockParOrStatedValuePerShare">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_RangeOfExercisePricesWeightedAverageExercisePriceAndWeightedAverageRemainingContractualLifeOfOptionsExcercisableTextBlock">
    <definition>Range of exercise prices, the weighted average exercise price and the weighted average remaining contractual life of options excercisable.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DebtInstrumentFaceAmount">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueDisclosuresTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PaymentsToMinorityShareholders">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_BusinessAcquisitionPurchasePriceAllocationIdentifiableAssetsAcquiredNet">
    <definition>Business Acquisition Purchase Price Allocation Identifiable Assets Acquired Net.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_NumberOfCommonSharesOutstandingForConvertibleDebt">
    <definition>Number Of Common Shares Outstanding For Convertible Debt.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_UseOfEstimatesPolicyTextBlock">
    <definition>Use of estimates Policy Text Block.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_Depreciation">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ComponentsOfNetPeriodicBenefitCostTextBlock">
    <definition>Components of the net periodic benefit cost.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVenturesFairValueDisclosure">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccountsPayableTradeCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsRestructuringCharges">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncreaseDecreaseInAccountsPayableTrade">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_GrossDeferredTaxAssetsOnTaxLossCarryforwardsAndInvestmentCreditsExpirationTextBlock">
    <definition>Gross deferred tax assets on tax loss carryforwards and investment credits expiration.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ReconciliationForAssetsMeasuredAtFairValueOnRecurringBasisUsingSignificantUnobservableInputsLevel3TextBlock">
    <definition>Reconciliation for assets measured at fair value on a recurring basis using significant unobservable inputs Level 3.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RestructuringReserveAccrualAdjustment">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RecordedUnconditionalPurchaseObligationDueInFourthYear">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DebtInstrumentCallFeature">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_DocumentFiscalPeriodFocus">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_SegmentReportingDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_StockAwardsImmediatelyWaived">
    <definition>Stock Awards Immediately Waived.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FutureAmortizationExpenseYearFive">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpense">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_IncomeLossInRetainedEarningsFromEquityInvestmentSoldThatWasAccountedForOnLag">
    <definition>Income (loss) in retained earnings from equity investment sold that was accounted for on a lag.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAggregateLosses">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpense">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncreaseDecreaseInReceivables">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShortTermBorrowings">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LeaseAndRentalExpense">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_GrantsReceivableNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_RevenueRecognitionMultipleDeliverableArrangementsTextBlock">
    <definition>Revenue Recognition Multiple Deliverable Arrangements.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RestructuringReservePeriodExpense">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_LockUpPeriodRestrictionDiscount">
    <definition>Lock-up period restriction discount.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ShareIssuedAsPercentageOfParValueOfPreferenceSharesToBeIssued">
    <definition>Share issued as a percentage of par value of the preference shares to be issued.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AvailableForSaleSecuritiesDebtSecurities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsOther">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DurationOfFloatingRateNotePortfolio">
    <definition>Duration of the floating rate note portfolio.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DepreciationAndAmortization">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DividendsPayableCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_EarningsPerShareBasic">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DividendsCommonStockCash">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesPlanAssets">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_EquityMethodInvestmentOwnershipPercentage">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueAssetsMeasuredOnNonrecurringBasisUnobservableInputsDescriptionAndDevelopmentTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TrainingAndSupportServices">
    <definition>Training and support services.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_EarningsPerSharePolicyTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_AmountReceivedDueToCourtJudgement">
    <definition>Amount received due to court judgement.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_MinimumPercentageForManufacturingCostsOfTotalForecastedTransactions">
    <definition>Minimum percentage for manufacturing costs of the total forecasted transactions.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ExpectedTotalRevenueFromMultipleDeliverableAgreementsYearTwo">
    <definition>Expected Total Revenue from Multiple Deliverable Agreements, Year Two.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_IncreaseParentCapitalSurplusPurchaseNoncontrollingInterests">
    <definition>Increase in parent company's capital surplus for purchase of Noncontrolling interests.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PaymentsToAcquireMarketableSecurities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InterestPaid">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_FairValueOfIdentifiableAssetsAndAssumedLiabilitiesAcquiredTextBlock">
    <definition>Fair value of the identifiable assets and assumed liabilities acquired.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ScheduleOfAccumulatedOtherComprehensiveIncomeLossBeforeTaxEffectsTableTextBlock">
    <definition>Schedule of Accumulated other comprehensive income (loss) before tax effects table.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccrualForTaxesOtherThanIncomeTaxesCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ScheduleOfFiniteLivedIntangibleAssetsFutureAmortizationExpenseTextBlock">
    <definition>Tabular disclosure of the amount of amortization expense expected to be recorded in succeeding fiscal years for finite-lived intangible assets.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesOther">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledOnFailedVestingConditionsInPeriod">
    <definition>Share based compensation arrangement by share based payment award equity instruments other than options cancelled on failed vesting conditions in period.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InvestmentIncomeNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ComprehensiveIncomeLossPolicyTextBlock">
    <definition>Comprehensive income (loss).</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_FinancialCostOfFactoredAmounts">
    <definition>Financial Cost Of Factored Amounts.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueAssetsMeasuredOnRecurringBasisDerivativeFinancialInstrumentsAssets">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PrepaidExpenseCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SharesAcceleratedDuringPeriodUnderFirstTrancheOfLocalSubPlan">
    <definition>Shares accelerated during the period under First Tranche of The Local Sub Plan.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_MinorityInterest">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_AmountOfInterestAwardEntitledToRetain">
    <definition>Amount of Interest award entitled to retain.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CustomerAdvancesCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_MarketableSecuritiesNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_PaymentForPurchaseOfTangibleAssetSegmentInformationGeographicAreasTextBlock">
    <definition>Payment for purchase of tangible assets of operations by entities located within the indicated geographic areas.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherComprehensiveIncomeFinalizationOfPensionAndNonPensionPostretirementPlanValuationNetOfTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AdvertisingExpense">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RestructuringAndRelatedActivitiesDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RecordedUnconditionalPurchaseObligationDueAfterFifthYear">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CurrentIncomeTaxExpenseBenefit">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_SegmentReportingSegmentOperatingProfitLoss">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PropertyPlantAndEquipmentNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_MaximumPercentageOfTaxReductionFromTaxHolidays">
    <definition>Maximum Percentage of Tax reduction from Tax holidays.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TradeAccountsReceivableImpairmentCharges">
    <definition>Trade Accounts Receivable, Impairment Charges.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanFundedStatusOfPlan">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TotalAuthorisedShareCapital">
    <definition>Total Authorised Share Capital.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_RealizedGainLossOnReductionInOperatingExpenses">
    <definition>Realized Gain Loss on  Reduction in Operating Expenses.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnAsset">
    <definition>Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Expected Long Term Return On Asset.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherComprehensiveIncomeAmortizationOfDefinedBenefitPlanTotalBeforeTax">
    <definition>Other Comprehensive Income Amortization of Defined Benefit Plan Total Before Tax.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ExpectedTrainingAndSupportServicesYearOne">
    <definition>Expected Training and Support Services, Year One</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_PurchaseAccountingResultsTextBlock">
    <definition>Purchase accounting results.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_InvestmentInIntangibleAndFinancialAssets">
    <definition>Investment in intangible and financial assets.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DebtInstrumentIssuedAmountDescription">
    <definition>Debt Instrument Issued Amount Description.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ReceivablesDueFromCustomerSoldWithoutRecourse">
    <definition>Receivables due from customer, sold without recourse.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfDerivativeInstrumentsIncludedInTradingActivitiesTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ChangeInFairValueIncludedInOciForAvailableForsaleMarketableSecurities">
    <definition>Change in fair value included in OCI for available for-sale marketable securities.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_DocumentPeriodEndDate">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_FairValueMeasurementWithUnobservableInputsReconciliationNonRecurringBasisAssetStillHeldGainLossIncludedInEarningsAtReportingDate">
    <definition>Fair value measurement with unobservable inputs reconciliation non recurring basis asset still held gain loss included in earnings at reporting date.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeTaxReconciliationTaxCreditsOther">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherIncomeAndExpensesNet">
    <definition>Other income and expenses, net.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ExpectedTotalRevenueFromMultipleDeliverableAgreementsYearThree">
    <definition>Expected Total Revenue From Multiple Deliverable Agreements, Year Three.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FiniteLivedIntangibleAssetsAverageUsefulLife">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_GoodwillGross">
    <definition>Gross amount, as of the balance sheet date, of the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable), in excess of the fair value of net assets acquired in one or more business combination transactions.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ImpairmentOfInvestments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_SalesRevenueGoodsNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DerivativeLiabilityNotDesignatedAsHedgingInstrumentFairValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherObligationDueInTwoYears">
    <definition>Other Obligation Due InTwo Years.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ShortTermDepositsTextBlock">
    <definition>Short-term deposits.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_EquityInterestInJointVenture">
    <definition>Equity interest in joint venture.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_UnrealizedGainOnPriceRiskCashFlowDerivativesBeforeTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxLiabilitiesRegulatoryAssets">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RecordedUnconditionalPurchaseObligationDueInThirdYear">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IntangibleAssetsDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ExpectedReducedEmployeeHeadcount">
    <definition>Expected Reduced Employee Headcount.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanEstimatedFutureEmployerContributionsInNextFiscalYear">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeTaxReconciliationPriorYearIncomeTaxes">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CommonStockSharesAuthorized">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_FairValueMeasurementWithUnobservableInputsReconciliationNonRecurringBasisImpairmentOnEquityMethodInvestment">
    <definition>Fair Value Measurement With Unobservable Inputs Reconciliation Non Recurring Basis Impairment on Equity method Investment.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxLiabilities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ShareCapitalPolicyTextBlock">
    <definition>Share capital.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_GoodwillImpairedAccumulatedImpairmentLoss">
    <definition>The accumulated impairment losses related to goodwill as of the balance sheet date.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherIncomeAndOtherExpenseDisclosureTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="dei_DocumentFiscalYearFocus">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_BusinessAcquisitionCostOfAcquiredEntityPurchasePrice">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanDebtSecurities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TransferOfTresuryShareToEmployeesUnderCompanysShareBasedRemuneration">
    <definition>Transfer Of Tresury Share To Employees Under Companys Share Based Remuneration.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock">
    <definition>Schedule of Effective Income Tax Rate Reconciliation.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherObligationDueInFourYears">
    <definition>Other Obligation Due in Four Years.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherComprehensiveIncomeAvailableForSaleSecuritiesAdjustmentNetOfTaxPeriodIncreaseDecrease">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CurrentFederalTaxExpenseBenefit">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_MinorityInterestDecreaseFromRedemptions">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_TreasuryStockValueAcquiredCostMethod">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_NoncontrollingInterestInCompanysBusinessContributed">
    <definition>Noncontrolling interest in the Company's business contributed.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_NetIncomeLossAttributableToNoncontrollingInterest">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DebtInstrumentInterestRateStatedPercentage">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_LossContingencyEvaluatedByPlaintiff">
    <definition>Loss contingency evaluated by plaintiff.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FutureAmortizationExpenseYearFour">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RepaymentsOfConvertibleDebt">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherObligation">
    <definition>Other Obligation.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherObligationDueInFiveYears">
    <definition>Other Obligation Due in Five Years.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalEquityInstrumentsOtherThanOptionsNonVestedNumber">
    <definition>Share based compensation arrangement by share based payment award additional equity instruments other than options non vested number.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherPayablesAndAccruedLiabilitiesTextBlock">
    <definition>Other Payables And Accrued Liabilities.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherComprehensiveIncomeOfDefinedBenefitPlanEffectOfCurtailmentSettlementForActuarialGainsLossesBeforeTax">
    <definition>Other Comprehensive Income Of Defined Benefit Plan Effect Of Curtailment Settlement For Actuarial Gains Losses Before Tax.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ReceivablesFromEquityInvestments">
    <definition>Receivables from equity investments.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanBenefitsPaid">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SegmentReportingFormerReportableSegmentOperatingProfitLoss">
    <definition>Segment Reporting, Former Reportable Segment, Operating Profit (Loss).</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeTaxHolidayIncomeTaxBenefitsPerShare">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FiniteLivedIntangibleAssetsGross">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FairValueAssetsMeasuredOnRecurringBasisTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccruedSalariesCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OtherAssetsNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DeferredGainOnRemainingDerivativeInstrumentsRecordedInAccumulatedOtherComprehensiveIncome">
    <definition>Deferred gain on the remaining derivative instruments recorded in Accumulated Other Comprehensive Income.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SharesAcceleratedDuringPeriodUnderSecodTrancheOfEmployeePlan">
    <definition>Shares accelerated during period under Secod Tranche of Employee Plan.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AvailableForSaleSecuritiesEquitySecuritiesNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AssetsCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncreaseDecreaseInRestrictedCash">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_AdditionalSharesGrantedToSelectedEmployeeDesignatedByManagingBoardOfCompanyAsPartOfPlan">
    <definition>Additional Shares Granted to Selected Employee designated by the Managing Board of the Company as Part of the Plan.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CommonStockValueOutstanding">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TransactionsWithNoncontrollingInterestsTextBlock">
    <definition>Transactions with noncontrolling interests.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CommonStockDividendsPerShareCashPaid">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CommonStockValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_NetProceedsFromSaleOfStockReceivedOnInvestmentDivestiture">
    <definition>Net proceeds from sale of stock received on investment divestiture.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ResearchAndDevelopmentExpense">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_TreasuryStockSharesAcquired">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InventoryWorkInProcessNetOfReserves">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DerivativeGainLossOnDerivativeNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SharesAcceleratedDuringPeriodUnderThirdTranche">
    <definition>Shares Accelerated during the period under Third Tranche.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_BusinessAcquisitionPurchasePriceAllocationCurrentAssetsCashAndCashEquivalents">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredFederalIncomeTaxExpenseBenefit">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_CouponRateOfNote">
    <definition>Coupon rate of Note</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsByMajorClassTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AllocatedShareBasedCompensationExpense">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_RepurchasedOfFacilityPercent">
    <definition>Repurchased of facility, percent</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ConstructiveObligationsPolicyTextBlock">
    <definition>Provisions.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherPayablesAndAccruedLiabilities">
    <definition>Other payables and accrued liabilities.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_UnrealizedGainLossOnForeignCurrencyDerivativesNetBeforeTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_EquityMethodInvestmentsTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_AmountOfChargeRepresentsProportionalShareOfLossReported">
    <definition>Amount of Charge represents Proportional share of loss reported.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ExpectedTrainingAndSupportServicesYearThree">
    <definition>Expected Training And Support Services, Year Three.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_FairValueMeasurementWithUnobservableInputsReconciliationNonRecurringBasisAssetValue">
    <definition>Fair Value Measurement With Unobservable Inputs Reconciliation Non Recurring Basis Asset Value.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PaymentsToAcquireInterestInSubsidiariesAndAffiliates">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_CumulativeProbabilityThresholdForRealizationOfIncomeTaxBenefits">
    <definition>Cumulative probability threshold for realization of income tax benefits.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TotalFinancialAndNonFinancialAssetsMeasuredAtFairValueOnNonRecurringBasis">
    <definition>Total Financial And Non Financial Assets Measured At fair Value On Non recurring Basis.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVested">
    <definition>Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_AdditionalSharesGrantedForFreeToEmployees">
    <definition>Additional Shares granted for free to Employees.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SharesAcceleratedDuringPeriodUnderThirdTrancheOfLocalSubPlan">
    <definition>Shares accelerated during period under Third Tranche of Local Sub Plan.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DerivativeInstrumentsDesignatedAsCashFlowHedgeTextBlock">
    <definition>Derivative instruments designated as Cash Flow hedge.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ClassificationOfPrePayrollTaxAndSocialContributionStockBasedCompensationExpenseIncludedInConsolidatedStatementsOfIncomeTextBlock">
    <definition>Classification of pre-payroll tax and social contribution stock-based compensation expense included in the consolidated statements of income.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ChangesInCarryingAmountOfGoodwillTextBlock">
    <definition>Changes in the carrying amount of goodwill.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ProceedsFromSaleOfEquityMethodInvestments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_RelatedPartyTransactionOtherIncomeAndExpensesFromTransactionsWithRelatedParty">
    <definition>Other income and expenses from transactions with related party realized during the period.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsInYearFour">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageNominalValuePerShare">
    <definition>Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Nominal Value Per Share</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanBenefitObligation">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanCurtailments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_PaymentsForProceedsFromDerivatives">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock">
    <definition>Schedule of Income Before Income Tax Domestic and Foreign.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_FiniteLivedIntangibleAssetsUsefulLifeMaximum">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_GoodwillAcquiredDuringPeriod">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherComprehensiveIncomeNetGainLossGeneratedArisingBeforeTax">
    <definition>Other Comprehensive Income Net Gain Loss Generated Arising Before Tax.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RecordedUnconditionalPurchaseObligationDueInSecondYear">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RepaymentsOfLongTermDebt">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherObligationDueInThreeYears">
    <definition>Other Obligation Due In Three Years.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxAssetsNet">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_TotalObligationDueCurrent">
    <definition>Total Obligation Due, Current.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanRealEstate">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ValuationAllowancesAndReservesTranslationAdjustment">
    <definition>Valuation Allowances and Reserves, Translation Adjustment.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_InterestOnParValueOfPortfolio">
    <definition>Interest on par value of the portfolio.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DeferredTaxAssetsRegulatoryAssetsAndLiabilities">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_IncomeTaxReconciliationImpactOfUncertainTaxPositions">
    <definition>Income Tax Reconciliation Impact Of Uncertain Tax Positions.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_UnrealizedGainOnCashFlowDerivativesBeforeTax">
    <definition>Unrealized Gain On Cash Flow Derivatives Before Tax.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DefinedBenefitPlanTransferIn">
    <definition>Defined Benefit Plan Transfer In.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_IncomeLossFromEquityMethodInvestmentsNetOfCost">
    <definition>Income Loss From Equity Method Investments Net Of Cost.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_NotionalAmountOfForeignCurrencyCashFlowHedgeDerivativesShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit">
    <definition>Notional Amount Of Foreign Currency Cash Flow Hedge Derivatives Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Upper Range Limit.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_FederalDistrictCourtInNewYorkIssuedRulingAffirmingUnanimousArbitrationAwardIncludingCollectedInterest">
    <definition>Federal district court in New York issued a ruling affirming the unanimous arbitration award including collected interest.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RestructuringCharges">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SegmentReportingProductSegmentsOperatingProfitLoss">
    <definition>Segment Reporting, Product Segments, Operating Profit (Loss).</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SustainabilityThresholdForUncertainTaxPosition">
    <definition>Sustainability Threshold for Uncertain Tax Position.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanInterestCost">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncreaseDecreaseInInventories">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanContributionsByPlanParticipants">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanContributionsByEmployer">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ProfitLoss">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RestructuringSettlementAndImpairmentProvisions">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_LongTermReceivablesFromThirdParty">
    <definition>Long-term receivables from third party.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ConvertibleDebt">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalEquityInstrumentsOtherThanOptionsVestedInPeriodUnderFirstTranche">
    <definition>Share based compensation arrangement by share based payment award additional equity instruments other than options vested in period under first tranche.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ReceivablesPolicyTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ResearchAndDevelopmentExpendituresPolicyTextBlock">
    <definition>Research and Development Expenditures Policy.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_GainLossOnSaleOfEquityMethodInvestments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ProceedsFromSaleOfCurrentMarketableSecurities">
    <definition>Proceeds From Sale Of Current Marketable Securities.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_InterestReceivableCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_LegalInflationaryIndex">
    <definition>Legal inflationary index.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_FairValueMeasurementWithUnobservableInputsReconciliationNonRecurringBasisAssetPurchasesSalesIssuancesSettlements">
    <definition>Fair Value Measurement With Unobservable Inputs Reconciliation Non Recurring Basis Purchases, Sales, Issuances, Settlements.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DerivativeAssetNotDesignatedAsHedgingInstrumentFairValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_IncomeTaxReconciliationValuationAllowanceAdjustments">
    <definition>Income Tax Reconciliation Valuation Allowance Adjustments.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_UnsecuredDebt">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_CurrentForeignTaxExpenseBenefit">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_DeferredTaxAssetsOnTaxLossCarryforwardsAndInvestmentCreditsExpirationYearFour">
    <definition>Deferred tax assets on tax loss carryforwards and investment credits expiration Year Four.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillAmount">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_UnrecognizedTaxBenefits">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ContingencyPremiumPaidOnZeroCostCollars">
    <definition>Contingency premium paid on zero-cost collars.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_GoodwillTranslationAndPurchaseAccountingAdjustments">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_SharesAcceleratedDuringPeriodUnderThirdTrancheOfEmployeePlan">
    <definition>Shares accelerated during period under Third Tranche of Employee Plan.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_RestructuringReserveCurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_ScheduleOfDebtInstrumentsTextBlock">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OperatingIncomeLossByProductSegmentTextBlock">
    <definition>Operating income (loss) by product segment.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_MinimumPercentageForResearchAndDevelopmentAndCorporateCostsOfTotalForecastedTransactions">
    <definition>Minimum percentage for Research and development and Corporate costs of the total forecasted transactions.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_BusinessCombinationCashReceived">
    <definition>Business Combination Cash Received.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_GainsLossesOnExtinguishmentOfDebt">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_ObligationsForCapacityRights">
    <definition>Obligations for capacity rights.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherReceivablesAndAssetTextBlock">
    <definition>Other receivables and asset.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_IncomeTaxReconciliationTaxCreditsResearch">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_WeightedAverageAssumptionsUsedInDeterminationOfBenefitObligationAndPlanAssetTextBlock">
    <definition>Weighted average assumptions used in the determination of the benefit obligation and the plan asset.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="stm_OtherObligationDueCurrent">
    <definition>Other Obligation Due, Current.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AssetsNoncurrent">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
  <Element Id="us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses">
    <definition>No authoritative reference available.</definition>
    <reference>No authoritative reference available.</reference>
  </Element>
</DefinitionAndReference>
