MPLX


Line plots across dimensions of each concept
Line plots across concepts
Tables

Table of contents



us-gaap:AllocatedShareBasedCompensationExpense

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest
us-gaap:ProductOrService
us-gaap:CostOfGoodsAndServicesSold

us-gaap:CostsAndExpenses
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee
us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:GainsLossesOnExtinguishmentOfDebt

us-gaap:GeneralAndAdministrativeExpense
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:IncomeLossFromContinuingOperations

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee
us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest

us-gaap:IncomeTaxExpenseBenefit

us-gaap:IncomeTaxesPaidNet

us-gaap:InterestPaidNet

us-gaap:NetIncomeLoss
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:StatementClassOfStock

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest

us-gaap:OtherComprehensiveIncomeLossNetOfTax
us-gaap:RetirementPlanType, us-gaap:StatementEquityComponents

us-gaap:OtherNonoperatingIncomeExpense

us-gaap:ProfitLoss
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax
us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ProductOrService
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:Revenues
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee
us-gaap:MajorCustomers, us-gaap:StatementBusinessSegments

us-gaap:Assets
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:Liabilities

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:AssetsCurrent
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:AccountsReceivableNetCurrent

us-gaap:OtherAssetsCurrent
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee
us-gaap:AssetsNoncurrent

us-gaap:PropertyPlantAndEquipmentGross
mplx:MajorAssetClass, us-gaap:PropertyPlantAndEquipmentByType
mplx:NonRelatedParty, us-gaap:PropertyPlantAndEquipmentByType
us-gaap:PropertyPlantAndEquipmentByType
us-gaap:PropertyPlantAndEquipmentByType, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
mplx:NonRelatedParty, us-gaap:PropertyPlantAndEquipmentByType
us-gaap:PropertyPlantAndEquipmentByType
us-gaap:StatementBusinessSegments
us-gaap:AmortizationOfIntangibleAssets

us-gaap:PropertyPlantAndEquipmentNet
mplx:NonRelatedParty, us-gaap:PropertyPlantAndEquipmentByType
us-gaap:PropertyPlantAndEquipmentByType

us-gaap:Goodwill
us-gaap:BusinessCombinationSeparatelyRecognizedTransactions
us-gaap:BusinessCombinationSeparatelyRecognizedTransactions, us-gaap:StatementBusinessSegments
us-gaap:ReportingUnit
us-gaap:StatementBusinessSegments

us-gaap:IntangibleAssetsNetExcludingGoodwill
us-gaap:StatementBusinessSegments

us-gaap:FiniteLivedIntangibleAssetsNet

us-gaap:OperatingLeaseRightOfUseAsset
mplx:NonRelatedParty
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:OtherAssetsNoncurrent

us-gaap:AccountsPayableCurrent

us-gaap:AccruedLiabilitiesCurrent

us-gaap:DebtCurrent

us-gaap:LiabilitiesCurrent
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:OperatingLeaseLiabilityCurrent
mplx:NonRelatedParty
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:OtherLiabilitiesCurrent
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee
us-gaap:LiabilitiesNoncurrent

us-gaap:DebtAndCapitalLeaseObligations

us-gaap:LongTermDebtAndCapitalLeaseObligations

us-gaap:DeferredIncomeTaxLiabilitiesNet

us-gaap:OperatingLeaseLiabilityNoncurrent
mplx:NonRelatedParty
us-gaap:RelatedPartyTransactionsByRelatedParty
mplx:NonRelatedParty
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo
us-gaap:RelatedPartyTransactionsByRelatedParty
mplx:NonRelatedParty
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree
us-gaap:RelatedPartyTransactionsByRelatedParty
mplx:NonRelatedParty
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour
us-gaap:RelatedPartyTransactionsByRelatedParty
mplx:NonRelatedParty
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive
us-gaap:RelatedPartyTransactionsByRelatedParty
mplx:NonRelatedParty
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive
us-gaap:RelatedPartyTransactionsByRelatedParty
mplx:NonRelatedParty
us-gaap:OperatingLeaseLiability
us-gaap:RelatedPartyTransactionsByRelatedParty
mplx:NonRelatedParty
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue
us-gaap:RelatedPartyTransactionsByRelatedParty
mplx:NonRelatedParty
us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax
us-gaap:RetirementPlanType, us-gaap:StatementEquityComponents
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RetirementPlanType, us-gaap:StatementEquityComponents

us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders
us-gaap:StatementEquityComponents

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:AmortizationOfFinancingCosts
us-gaap:ConsolidationItems

us-gaap:DeferredIncomeTaxExpenseBenefit

us-gaap:IncreaseDecreaseInAccountsReceivable

us-gaap:IncreaseDecreaseInInventories

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetIncomeLoss
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:StatementClassOfStock

us-gaap:ProfitLoss
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:ProceedsFromIssuanceOfLongTermDebt

us-gaap:RepaymentsOfLongTermDebt
us-gaap:DebtInstrument, us-gaap:LongtermDebtType
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:DebtInstrumentInterestRateStatedPercentage
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType
dei:LegalEntity, us-gaap:Range, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
us-gaap:ConsolidationItems
mpc:AdjustedEBITDA
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ConsolidationItems
mpc:AdjustedEBITDAattributabletononcontrollinginterests

mpc:CapitalContributionByRelatedParty
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
mpc:CapitalExpenditure

mpc:ComprehensiveIncomeLossNetofTaxAttributabletoNonredeemableNoncontrollingInterest
us-gaap:AdjustmentsForNewAccountingPronouncements
mpc:ContractwithCustomerAssetIncreaseDecrease

mpc:CostOfRentalSalesAndOccupancyCosts

mpc:CostofRentalSalesandOccupancyCostsRelatedParties
us-gaap:AdjustmentsForNewAccountingPronouncements
mpc:DeferredRevenueNoncurrentPeriodIncreaseDecrease
us-gaap:AdjustmentsForNewAccountingPronouncements
mpc:DeferredRevenueNoncurrentRelatedPartyPeriodIncreaseDecrease
us-gaap:AdjustmentsForNewAccountingPronouncements
mpc:DeferredRevenueRelatedPartiesRevenueRecognized
us-gaap:AdjustmentsForNewAccountingPronouncements
mpc:DeferredRevenueRelatedPartyPeriodIncreaseDecrease
us-gaap:IncomeStatementLocation
mpc:DerivativeInstrumentsNotDesignatedasHedgingInstrumentsRealizedGainLossNet

mpc:EarningsPerUnitPotentiallyDilutiveUnits
us-gaap:DerivativeInstrumentRisk
mpc:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetAndLiabilitiesNetChangeInUnrealizedGainLossIncludedInEarningsContractHeld

mpc:IncreaseDecreaseInCapitalAccruals

mpc:InterestAndOtherFinancialCostsFromRelatedParties

mpc:InterestandOtherFinancialCosts

mpc:NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity
mpc:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:StatementEquityComponents

mpc:NonCashNetTransfersOfMaterialsAndSuppliesInventories

mpc:OperatingLeaseIncomeStatementLeaseRevenueRelatedParties
us-gaap:RelatedPartyTransactionsByRelatedParty

mpc:OtherComprehensiveIncomeLossPensionandOtherPostretirementBenefitPlansNetUnamortizedGainLossAdjustmentNetofTax

mpc:PartnersTotalSubsequentDistributionAmount
us-gaap:StatementClassOfStock
us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:StatementClassOfStock
mpc:PaymentsofDistributionsonPreferredUnits
us-gaap:ProductOrService
mpc:RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties
us-gaap:ProductOrService, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ProductOrService
mpc:RevenuefromContractwithCustomerexcludingAssessedTaxandNonASC606Revenue
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:RelatedPartyTransactionsByRelatedParty
mpc:SalesRevenueGoodsRelatedPartyNetZero
us-gaap:ConsolidationItems
mplx:AdjustedEBITDA
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ConsolidationItems
mplx:AdjustedEBITDAattributabletononcontrollinginterests

mplx:CapitalContributionByRelatedParty
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
mplx:CapitalExpenditure
us-gaap:AdjustmentsForNewAccountingPronouncements
mplx:ContractwithCustomerAssetIncreaseDecrease
us-gaap:AdjustmentsForNewAccountingPronouncements
mplx:DeferredRevenueNoncurrentPeriodIncreaseDecrease
us-gaap:AdjustmentsForNewAccountingPronouncements
mplx:DeferredRevenueNoncurrentRelatedPartyPeriodIncreaseDecrease
us-gaap:AdjustmentsForNewAccountingPronouncements
mplx:DeferredRevenueRelatedPartiesRevenueRecognized
us-gaap:AdjustmentsForNewAccountingPronouncements
mplx:DeferredRevenueRelatedPartyPeriodIncreaseDecrease
us-gaap:IncomeStatementLocation
mplx:DerivativeInstrumentsNotDesignatedasHedgingInstrumentsRealizedGainLossNet

mplx:DistributionsMadetoPartnersTotalCashDistributionDeclared

mplx:EarningsPerUnitPotentiallyDilutiveUnits
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel
mplx:FairValueInputsProbabilityOfRenewal
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel
mplx:FairValueInputsProbabilityofRenewalSecondTerm
us-gaap:DerivativeInstrumentRisk
mplx:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetAndLiabilitiesNetChangeInUnrealizedGainLossIncludedInEarningsContractHeld

mplx:IncreaseDecreaseInCapitalAccruals

mplx:InterestAndOtherFinancialCostsFromRelatedParties

mplx:InterestandOtherFinancialCosts

mplx:NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity
mplx:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:StatementEquityComponents

mplx:OtherComprehensiveIncomeLossPensionandOtherPostretirementBenefitPlansNetUnamortizedGainLossAdjustmentNetofTax
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RetirementPlanType, us-gaap:StatementEquityComponents
us-gaap:StatementClassOfStock
mplx:PartnersTotalSubsequentDistributionAmount
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:StatementClassOfStock
mplx:PaymentsofDistributionsonPreferredUnits
us-gaap:ProductOrService
mplx:RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties
us-gaap:ProductOrService, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ProductOrService
mplx:RevenuefromContractwithCustomerexcludingAssessedTaxandNonASC606Revenue
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:RelatedPartyTransactionsByRelatedParty
mplx:SalesRevenueGoodsRelatedPartyNetZero
us-gaap:AwardType
mplx:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsWeightedAverageGrantDateFairValueForfeited
us-gaap:AwardType
mplx:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsWeightedAverageGrantDateFairValueIssued

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect
us-gaap:AdjustmentsForNewAccountingPronouncements
us-gaap:ContractWithCustomerAssetReclassifiedToReceivable

us-gaap:CostsAndExpensesRelatedParty
us-gaap:AdjustmentsForNewAccountingPronouncements
us-gaap:DeferredRevenuePeriodIncreaseDecrease
us-gaap:AdjustmentsForNewAccountingPronouncements
us-gaap:DeferredRevenueRevenueRecognized1

us-gaap:Depreciation
us-gaap:StatementBusinessSegments

us-gaap:DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet
us-gaap:IncomeStatementLocation

us-gaap:DistributionMadeToLimitedPartnerCashDistributionsDeclared
dei:LegalEntity, us-gaap:PartnerCapitalComponents
mplx:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:StatementClassOfStock
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:SubsequentEventType
us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType
us-gaap:SubsequentEventType

us-gaap:DistributionMadeToLimitedPartnerCashDistributionsPaid
us-gaap:PreferredUnitsByName
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:StatementClassOfStock
us-gaap:DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:SubsequentEventType
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:StatementClassOfStock
us-gaap:DividendsPreferredStock

us-gaap:EquityMethodInvestmentDividendsOrDistributions
us-gaap:ConsolidationItems

us-gaap:EquityMethodInvestmentOtherThanTemporaryImpairment

us-gaap:ExtinguishmentOfDebtGainLossNetOfTax
us-gaap:DerivativeInstrumentRisk
us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInEarnings
us-gaap:DerivativeInstrumentRisk
us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationSettlements

us-gaap:GainLossOnDispositionOfAssets

us-gaap:GoodwillAndIntangibleAssetImpairment

us-gaap:GoodwillImpairmentLoss
us-gaap:StatementBusinessSegments

us-gaap:IncomeLossFromEquityMethodInvestments
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities

us-gaap:IncreaseDecreaseInDeferredRevenue

us-gaap:IncreaseDecreaseInDerivativeAssetsAndLiabilities

us-gaap:IncreaseDecreaseInDueFromRelatedPartiesCurrent

us-gaap:InterestCostsCapitalized

us-gaap:InterestExpenseDebtExcludingAmortization
us-gaap:IncomeStatementLocation
us-gaap:LaborAndRelatedExpense
us-gaap:IncomeStatementLocation, us-gaap:RelatedPartyTransactionsByRelatedParty
mplx:NonRelatedParty
us-gaap:LeaseIncome
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:DebtInstrument, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:LineOfCreditFacilityInterestRateDuringPeriod

us-gaap:LossContingencyDamagesPaidValue

us-gaap:LossContingencyDamagesSoughtValue

us-gaap:NetIncomeLossAllocatedToLimitedPartners
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:NetIncomeLossNetOfTaxPerOutstandingLimitedPartnershipUnitDiluted
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax

us-gaap:OperatingLeaseLeaseIncome
mpc:NonRelatedParty
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:OperatingLeasesIncomeStatementLeaseRevenue
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OtherCostAndExpenseOperating

us-gaap:OtherOperatingActivitiesCashFlowStatement

us-gaap:OtherOperatingIncome
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:PartnersCapitalAccountDistributions
mpc:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount
mplx:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:StatementClassOfStock
us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType
us-gaap:BusinessCombinationSeparatelyRecognizedTransactions
us-gaap:PartnersCapitalAccountUnitsRedeemed
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnersCapitalAccountUnitsUnitbasedCompensation

us-gaap:PaymentsForProceedsFromOtherInvestingActivities
us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:PaymentsOfDebtExtinguishmentCosts

us-gaap:PaymentsOfDebtIssuanceCosts

us-gaap:PaymentsToAcquireEquityMethodInvestments
us-gaap:StatementBusinessSegments

us-gaap:PaymentsToMinorityShareholders

us-gaap:ProceedsFromContributionsFromParent

us-gaap:ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital
us-gaap:DebtInstrument, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:ProceedsFromLinesOfCredit
dei:LegalEntity, us-gaap:DebtInstrument
us-gaap:ProceedsFromLongTermLinesOfCredit

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities

us-gaap:ProceedsFromRelatedPartyDebt
us-gaap:DebtInstrument, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:ProceedsFromSalesOfAssetsInvestingActivities
us-gaap:PropertyPlantAndEquipmentByType, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:PropertyPlantAndEquipmentAdditions

us-gaap:RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:RelatedPartyTransactionPurchasesFromRelatedParty
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:DebtInstrument, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:RepaymentsOfLinesOfCredit
dei:LegalEntity, us-gaap:DebtInstrument
us-gaap:RepaymentsOfLongTermLinesOfCredit

us-gaap:RepaymentsOfRelatedPartyDebt
us-gaap:DebtInstrument, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:RestructuringCharges
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:RevenueFromRelatedParties

us-gaap:RevenueNotFromContractWithCustomerOther
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:SalesTypeLeaseInterestIncome
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:SalesTypeLeaseRevenue
us-gaap:RelatedPartyTransactionsByRelatedParty, us-gaap:StatementBusinessSegments
us-gaap:ReclassificationType, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:SalesTypeLeaseSellingProfitLoss
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:SalesTypeLeaseVariableLeaseIncome
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
us-gaap:AwardDate, us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
us-gaap:AwardType
us-gaap:Range, us-gaap:AwardDate, us-gaap:AwardType
us-gaap:Range, us-gaap:AwardType
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted

us-gaap:StockRepurchasedAndRetiredDuringPeriodShares
us-gaap:SubsequentEventType
us-gaap:SubsequentEventType
us-gaap:StockRepurchasedAndRetiredDuringPeriodValue

us-gaap:StockholdersEquityChangeInReportingEntity
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:StockholdersEquityOther
mpc:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount
mplx:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:StatementEquityComponents

us-gaap:TaxesExcludingIncomeAndExciseTaxes
us-gaap:PreferredUnitsByName
us-gaap:TemporaryEquityNetIncome

us-gaap:TreasuryStockAcquiredAverageCostPerShare

us-gaap:UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic

us-gaap:UndistributedEarningsLossAvailableToCommonShareholdersBasic
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:HedgingDesignation
us-gaap:UnrealizedGainLossOnDerivativesAndCommodityContracts
us-gaap:HedgingDesignation, us-gaap:IncomeStatementLocation
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:WeightedAverageLimitedPartnershipUnitsOutstanding
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:WeightedAverageLimitedPartnershipUnitsOutstandingDiluted
us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:WriteOffOfDeferredDebtIssuanceCost

dei:EntityCommonStockSharesOutstanding

dei:EntityNumberOfEmployees

mpc:AccruedPropertyPlantAndEquipmentCurrent

mpc:CurrentAssetsRelatedParties

mpc:CurrentLiabilitiesRelatedParties
us-gaap:AdjustmentsForNewAccountingPronouncements
mpc:DeferredRevenueCurrentRelatedParties
us-gaap:AdjustmentsForNewAccountingPronouncements
mpc:DeferredRevenueNoncurrentRelatedParties
us-gaap:DeferredRevenueArrangementType, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:DeferredRevenueArrangementType, us-gaap:RelatedPartyTransactionsByRelatedParty
mpc:DeferredRevenueRelatedParties
mpc:CommodityType, us-gaap:DerivativeInstrumentRisk
mpc:EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiabilityIncludingInceptionValueAllocableToHostContract
us-gaap:StatementBusinessSegments
mpc:EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquityPortionRelatedToGoodwillandOtherAssetsNotAmortized
us-gaap:BusinessCombinationSeparatelyRecognizedTransactions
mpc:ExcessofFairValueoverBookValue
us-gaap:Range, us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel
mpc:FairValueInputsForwardCommodityPrice

mpc:LiabilitiesRelatedPartiesNoncurrent
dei:LegalEntity, us-gaap:DebtInstrument
mpc:LineofCreditFacilityRemainingBorrowingCapacityPercentage

mpc:NaturalGasOrNaturalGasLiquidsInStorage

mpc:OtherAssetsRelatedPartiesNoncurrent
us-gaap:BusinessCombinationSeparatelyRecognizedTransactions
mpc:PartnerCapitalUnitscontributedfairvalueassigned
us-gaap:RelatedPartyTransactionsByRelatedParty
mpc:SalestypeandDirectFinancingLeasesLeaseReceivablePaymentstobeReceivedCurrentYear
us-gaap:AwardType
mpc:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsWeightedAverageGrantDateFairValueOutstanding

mplx:AccruedPropertyPlantAndEquipmentCurrent

mplx:CommonStockMonetaryValueofSharesAuthorized

mplx:CurrentAssetsRelatedParties

mplx:CurrentLiabilitiesRelatedParties
us-gaap:AdjustmentsForNewAccountingPronouncements
mplx:DeferredRevenueCurrentRelatedParties
us-gaap:AdjustmentsForNewAccountingPronouncements
mplx:DeferredRevenueNoncurrentRelatedParties
us-gaap:DeferredRevenueArrangementType, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:DeferredRevenueArrangementType, us-gaap:RelatedPartyTransactionsByRelatedParty
mplx:DeferredRevenueRelatedParties
mplx:CommodityType, us-gaap:DerivativeInstrumentRisk
mplx:EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiabilityIncludingInceptionValueAllocableToHostContract
us-gaap:StatementBusinessSegments
mplx:EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquityPortionRelatedToGoodwillandOtherAssetsNotAmortized
us-gaap:BusinessCombinationSeparatelyRecognizedTransactions
mplx:ExcessofFairValueoverBookValue
us-gaap:Range, us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel
mplx:FairValueInputsForwardCommodityPrice

mplx:LiabilitiesRelatedPartiesNoncurrent
dei:LegalEntity, us-gaap:DebtInstrument
mplx:LineofCreditFacilityRemainingBorrowingCapacityPercentage

mplx:NaturalGasOrNaturalGasLiquidsInStorage
us-gaap:ProductOrService, us-gaap:RelatedPartyTransactionsByRelatedParty
mplx:NumberofRenewals
us-gaap:ProductOrService, us-gaap:RelatedPartyTransactionsByRelatedParty, us-gaap:TypeOfArrangement

mplx:OtherAssetsRelatedPartiesNoncurrent
us-gaap:BusinessCombinationSeparatelyRecognizedTransactions
mplx:PartnerCapitalUnitscontributedfairvalueassigned
us-gaap:RelatedPartyTransactionsByRelatedParty
mplx:SalestypeandDirectFinancingLeasesLeaseReceivablePaymentstobeReceivedCurrentYear
us-gaap:AwardType
mplx:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsWeightedAverageGrantDateFairValueOutstanding
us-gaap:AwardType
mplx:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionsConvertible
us-gaap:AwardType
mplx:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionsConvertibleWeightedAverageFairValue
us-gaap:AwardType
mplx:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionsVestedAndExpectedToVestOutstandingNumber
us-gaap:AwardType
mplx:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionsVestedAndExpectedToVestWeightedAverageFairValue
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:AccountsReceivableRelatedPartiesCurrent

us-gaap:AccrualForEnvironmentalLossContingencies

us-gaap:AllowanceForDoubtfulAccountsReceivable

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent

us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent
us-gaap:AdjustmentsForNewAccountingPronouncements
us-gaap:ContractWithCustomerAssetGross

us-gaap:ContractWithCustomerLiability
us-gaap:OtherCommitments
us-gaap:ContractualObligation
us-gaap:OtherCommitments
us-gaap:ContractualObligationDueAfterFifthYear
us-gaap:OtherCommitments
us-gaap:ContractualObligationDueInFifthYear
us-gaap:OtherCommitments
us-gaap:ContractualObligationDueInFourthYear
us-gaap:OtherCommitments
us-gaap:ContractualObligationDueInNextTwelveMonths
us-gaap:OtherCommitments
us-gaap:ContractualObligationDueInSecondYear
us-gaap:OtherCommitments
us-gaap:ContractualObligationDueInThirdYear
dei:LegalEntity, us-gaap:DebtInstrument
us-gaap:DebtInstrumentInterestRateEffectivePercentage

us-gaap:DebtInstrumentUnamortizedDiscount
us-gaap:TitleOfIndividual, us-gaap:AwardType
us-gaap:DeferredCompensationSharebasedArrangementsLiabilityCurrentAndNoncurrent

us-gaap:DeferredCreditsAndOtherLiabilitiesNoncurrent
us-gaap:AdjustmentsForNewAccountingPronouncements
us-gaap:DeferredRevenueCurrent

us-gaap:DeferredRevenueNoncurrent
us-gaap:AdjustmentsForNewAccountingPronouncements

us-gaap:DerivativeAverageForwardPrice
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation
us-gaap:DerivativeFairValueOfDerivativeLiability
us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:DerivativeLiabilities
us-gaap:FairValueByMeasurementFrequency

us-gaap:DueFromRelatedPartiesCurrent

us-gaap:DueFromRelatedPartiesNoncurrent
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:DueToRelatedPartiesCurrent
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:DueToRelatedPartiesNoncurrent
us-gaap:AwardType
us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions

us-gaap:EnergyRelatedInventoryNaturalGasLiquids
us-gaap:StatementBusinessSegments
us-gaap:EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquity
mpc:OwnershipType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentOwnershipPercentage
mplx:OwnershipType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:EquityMethodInvestments
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:StatementBusinessSegments
us-gaap:BusinessCombinationSeparatelyRecognizedTransactions
us-gaap:FairValueNetAssetLiability
us-gaap:DerivativeInstrumentRisk
us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs

us-gaap:FinanceLeaseLiability
dei:LegalEntity, us-gaap:LongtermDebtType
mplx:NonRelatedParty
us-gaap:LongtermDebtType
mplx:NonRelatedParty
us-gaap:FinanceLeaseLiabilityCurrent
mplx:NonRelatedParty
us-gaap:FinanceLeaseLiabilityNoncurrent

us-gaap:FinanceLeaseLiabilityPaymentsDue

us-gaap:FinanceLeaseLiabilityPaymentsDueAfterYearFive

us-gaap:FinanceLeaseLiabilityPaymentsDueNextTwelveMonths

us-gaap:FinanceLeaseLiabilityPaymentsDueYearFive

us-gaap:FinanceLeaseLiabilityPaymentsDueYearFour

us-gaap:FinanceLeaseLiabilityPaymentsDueYearThree

us-gaap:FinanceLeaseLiabilityPaymentsDueYearTwo

us-gaap:FinanceLeaseLiabilityUndiscountedExcessAmount
mplx:NonRelatedParty
us-gaap:FinanceLeaseWeightedAverageDiscountRatePercent

us-gaap:FiniteLivedIntangibleAssetsAccumulatedAmortization
us-gaap:StatementBusinessSegments

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFive

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFour

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearThree

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo

us-gaap:FiniteLivedIntangibleAssetsGross
us-gaap:StatementBusinessSegments

us-gaap:GoodwillGross
us-gaap:StatementBusinessSegments

us-gaap:GoodwillImpairedAccumulatedImpairmentLoss
us-gaap:StatementBusinessSegments

us-gaap:InterestPayableCurrentAndNoncurrent

us-gaap:InventoryGross
mplx:NonRelatedParty
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:LessorOperatingLeasePaymentsToBeReceivedFiveYears
mplx:NonRelatedParty
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:LessorOperatingLeasePaymentsToBeReceivedFourYears
mplx:NonRelatedParty
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths
mplx:NonRelatedParty
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:LessorOperatingLeasePaymentsToBeReceivedThereafter
mplx:NonRelatedParty
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:LessorOperatingLeasePaymentsToBeReceivedThreeYears
mplx:NonRelatedParty
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:LessorOperatingLeasePaymentsToBeReceivedTwoYears
mplx:NonRelatedParty
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:ReclassificationType
us-gaap:LessorSalesTypeLeaseAssumptionsAndJudgmentsValueOfUnderlyingAssetAmount

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent
mpc:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:LimitedPartnersCapitalAccountUnitsIssued
mplx:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty
mpc:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:LimitedPartnersCapitalAccountUnitsOutstanding
mplx:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:DebtInstrument
us-gaap:LineOfCredit
us-gaap:DebtInstrument, us-gaap:RelatedPartyTransactionsByRelatedParty
dei:LegalEntity, us-gaap:DebtInstrument
us-gaap:LineOfCreditFacilityRemainingBorrowingCapacity
us-gaap:FairValueByMeasurementBasis
us-gaap:LongTermDebtFairValue

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:NetInvestmentInLeaseCurrent
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:NetInvestmentInLeaseNoncurrent
mplx:NonRelatedParty
us-gaap:OperatingLeaseWeightedAverageDiscountRatePercent

us-gaap:OperatingLeasesFutureMinimumPaymentsReceivable
mplx:NonRelatedParty
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:OtherInventoriesSpareParts
us-gaap:FairValueByMeasurementBasis
us-gaap:OtherLiabilitiesFairValueDisclosure

us-gaap:PartnersCapital
mpc:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount
mplx:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:PartnersCapitalAccountUnits
us-gaap:PartnerTypeOfPartnersCapitalAccount

us-gaap:PartnersCapitalAttributableToNoncontrollingInterest

us-gaap:PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest
mpc:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount
mplx:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount
us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:StatementEquityComponents
dei:LegalEntity, us-gaap:StatementClassOfStock
us-gaap:PreferredUnitsOutstanding
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:PrepaidInsurance

us-gaap:PurchaseCommitmentRemainingMinimumAmountCommitted
us-gaap:Range
us-gaap:ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount

us-gaap:RevenueRemainingPerformanceObligation
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceived
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedFiveYears
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedFourYears
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedNextTwelveMonths
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedThereafter
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedThreeYears
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedTwoYears
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivableUndiscountedExcessAmount
us-gaap:ReclassificationType, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:SalesTypeLeaseLeaseReceivable
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:ReclassificationType, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:SalesTypeLeaseUnguaranteedResidualAsset
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber
us-gaap:PlanName
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized

us-gaap:StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1

us-gaap:TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests
us-gaap:PreferredUnitsByName

us-gaap:UnamortizedDebtIssuanceExpense

Plots across concepts


IncomeStatement
Other Comprehensive Income Loss Net Of Tax
Expenses
Other Nonoperating Income Expense
Balance Sheet
Cash And Cash Equivalents At Carrying Value
Assets
Cash And Cash Equivalents At Carrying Value
Current Assets
Cash And Cash Equivalents At Carrying Value
NonCurrent Assets
Other Assets Noncurrent
PropertyPlantAndEquipmentNet
Accumulated Depreciation Depletion And Amortization Property Plant And Equipment
Liabilities
Liabilities Current
Current Liabilities
Debt Current
Noncurrent Liabilities
Deferred Income Tax Liabilities Net
CashFlow
Net Cash Provided By Used In Financing Activities
NetCashProvidedByUsedInOperatingActivities
Increase Decrease In Inventories
NetCashProvidedByUsedInInvestingActivities
Net Cash Provided By Used In Investing Activities
NetCashProvidedByUsedInFinancingActivities
Net Cash Provided By Used In Financing Activities
FiniteLivedIntangibleAssets
Finite Lived Intangible Assets Accumulated Amortization
AccountsReceivable
Allowance For Doubtful Accounts Receivable Current

Tables

  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
 Cost Ratio us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:NonVIEsNANANA293.0NANANA392.0NANANANANANANANANANANANANANANANANANANANANANANANANA
 Cost Ratio us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:OtherVIEsNANANA175.0NANANA173.0NANANANANANANANANANANANANANANANANANANANANANANANANA
 Cost Ratio us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:OtherVIEsandNonVIEsNANANA468.0NANANA565.0NANANANANANANANANANANANANANANANANANANANANANANANANA
 Cost Ratio us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:NonVIEs█▁323.0284.0NANA303.0337.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Cost Ratio us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:OtherVIEs█▁173.0163.0NANA174.0-217.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Cost Ratio us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:OtherVIEsandNonVIEs█▁496.0447.0NANA477.0120.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Margin from Continuing Operations us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:NonVIEsNANANA293.0NANANA392.0NANANANANANANANANANANANANANANANANANANANANANANANANA
 Margin from Continuing Operations us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:OtherVIEsNANANA175.0NANANA173.0NANANANANANANANANANANANANANANANANANANANANANANANANA
 Margin from Continuing Operations us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:OtherVIEsandNonVIEsNANANA468.0NANANA565.0NANANANANANANANANANANANANANANANANANANANANANANANANA
 Margin from Continuing Operations us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:NonVIEs█▁323.0284.0NANA303.0337.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Margin from Continuing Operations us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:OtherVIEs█▁173.0163.0NANA174.0-217.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Margin from Continuing Operations us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:OtherVIEsandNonVIEs█▁496.0447.0NANA477.0120.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Net profit Margin us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:NonVIEsNANANA293.0NANANA392.0NANANANANANANANANANANANANANANANANANANANANANANANANA
 Net profit Margin us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:OtherVIEsNANANA175.0NANANA173.0NANANANANANANANANANANANANANANANANANANANANANANANANA
 Net profit Margin us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:OtherVIEsandNonVIEsNANANA468.0NANANA565.0NANANANANANANANANANANANANANANANANANANANANANANANANA
 Net profit Margin us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:NonVIEs█▁323.0284.0NANA303.0337.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Net profit Margin us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:OtherVIEs█▁173.0163.0NANA174.0-217.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Net profit Margin us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:OtherVIEsandNonVIEs█▁496.0447.0NANA477.0120.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
 TTM Greenblatt ROC _ _█████▁▅█▇█▇█▇▇▇▇▇▇▇▇▇▆▇▇▇▇▇▇▇▇▇715.0749.0701.0675.0655.0-2716.0-575.0693.0489.0507.0439.0519.0457.0427.0239.0218.0193.0187.0132.0143.012.0-41.019.841.951.445.936.243.143.055.736.1NANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:AllocatedShareBasedCompensationExpense ▂▂█▁▂▁▁▁▂▁▁▁▁▁▁▁▂-2.0-3.026.0-4.0-3.0-5.0-5.0-5.0-3.0-6.0-4.0-6.0-5.0-4.0-5.0-4.0-3.0NANANANANANANANANANANANANANANANA
us-gaap:ComprehensiveIncomeNetOfTax █████▁▅█▇█▇█▇▇▇▇▇▇706.0737.0692.0665.0648.0-2725.0-581.0629.0482.0504.0434.0510.0453.0419.0238.0216.0190.0150.0NANANANANANANANANANANANANANANA
us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest █████▁▅█▇█▇█▇▇▇▇▇▇715.0746.0701.0674.0655.0-2717.0-573.0689.0488.0510.0439.0516.0456.0421.0241.0217.0191.0187.0NANANANANANANANANANANANANANANA
 us-gaap:CostOfGoodsAndServicesSold us-gaap:ProductOrService us-gaap:NaturalGasMidstream█▆▃▃▁▂▄▂▃▄▅▅▄▄▄▃▂338.0276.0165.0152.087.0135.0197.0129.0166.0194.0213.0241.0204.0187.0210.0170.0140.0NANANANANANANANANANANANANANANANA
 us-gaap:CostOfGoodsAndServicesSold us-gaap:ProductOrService us-gaap:OilAndGasRefiningAndMarketing▅▅▆▆▆▇██▄▃▄▄▄▃▁▁▁293.0273.0320.0323.0315.0368.0390.0407.0233.0210.0268.0241.0233.0206.0147.0129.0139.0NANANANANANANANANANANANANANANANA
us-gaap:CostsAndExpenses ▄▄▄▄▃█▆▄▃▃▃▃▃▃▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁▁▁▁▁1464.01365.01329.01348.01203.03478.02662.01354.0970.0968.01049.01040.0970.0863.0750.0669.0636.0621.0517.0496.0488.0582.0219.2101.590.086.3100.693.889.681.089.184.087.0
 us-gaap:GainsLossesOnExtinguishmentOfDebt us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:SeniorNotesDueJanuary2025,mplx:FixedRateSeniorNotes█▁0.0-8.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:GeneralAndAdministrativeExpense ▇▇▇███▇█▅▆▆▆▆▅▅▅▄▅▄▄▄▄▄▂▁▁▁▁▁▁▁▁▁87.086.089.096.096.097.095.0102.069.082.074.076.072.069.067.059.057.058.046.046.049.052.046.321.117.918.717.715.315.915.913.313.013.9
us-gaap:IncomeLossFromContinuingOperations █████▁▅█▇▇▇▇▇▇▇▇▇▇▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆931.0974.0920.0899.0878.0-2486.0-346.0926.0659.0678.0666.0672.0608.0557.0335.0311.0280.0265.0197.0207.076.027.050.047.157.651.238.544.244.356.336.539.835.2
us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest █████▁▅█▇█▇█▇▇▇▇▇▇▇▇▇▆▇▇▇▇▇▇▇▇▇▇▇715.0749.0701.0675.0655.0-2716.0-575.0693.0489.0507.0439.0519.0457.0427.0239.0218.0193.0187.0132.0143.012.0-41.019.841.951.445.936.243.143.055.736.139.634.9
 us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:NonVIEsNANANA162.0NANANA253.0NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:OtherVIEsNANANA69.0NANANA81.0NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:OtherVIEsandNonVIEsNANANA231.0NANANA334.0NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:NonVIEs█▁170.0153.0NANA161.0205.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:OtherVIEs█▁63.056.0NANA76.0-321.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:OtherVIEsandNonVIEs█▁233.0209.0NANA237.0-116.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:IncomeTaxExpenseBenefit ▆▆▆▆▆▆▄█▆▄▆▇▆█▄▆▇▆▆▆▁▃▇▆▆▆▆▆▆▆▅▆▆0.01.01.01.00.00.0-2.04.01.0-2.00.03.01.04.0-2.01.02.00.00.00.0-8.0-4.01.90.10.00.0-0.20.00.10.0-0.70.40.1
us-gaap:IncomeTaxesPaidNet NANANA0.0NANANA0.0NANANA0.0NANANA2.0NANANANANANANANANANA-0.3NANANANANANA
us-gaap:InterestPaidNet ▅▅▅▅▅▅▅█▄▄▅▄▂▃▂▃▂▂▂▂▂▂▁▁▁▁▁▁▁▁▁▁183.0231.0190.0208.0213.0210.0187.0364.0141.0143.0191.0139.051.0103.056.0108.050.049.054.049.056.053.00.610.30.31.81.10.90.90.00.00.0NA
us-gaap:NetIncomeLoss █████▁▅█▇█▇█▇▇▇▇▇▇▇▇▇▆▇▇▇▇▇▇▇▇▇▇▇706.0739.0691.0665.0648.0-2724.0-581.0629.0482.0503.0434.0510.0453.0421.0238.0216.0190.0150.0133.0141.019.0-60.018.041.551.245.629.229.128.834.220.221.518.6
us-gaap:NetIncomeLossAttributableToNoncontrollingInterest ▄▄▄▄▃▄▄▄▃▃▃▃▂▂▂▂▂▂▁▂▂▁▁▁▁▁▄▆▆█▆▇▆9.09.09.09.07.08.08.08.06.06.05.06.03.02.03.01.01.01.0-1.02.01.00.00.20.30.20.37.214.014.121.516.617.716.2
us-gaap:OtherComprehensiveIncomeLossNetOfTax NANANA0.00.0-1.00.00.00.01.00.00.00.0-2.0NANANANANANANANANANANANANANANANANANANA
 us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:RetirementPlanType,us-gaap:StatementEquityComponents us-gaap:OtherPostretirementBenefitPlansDefinedBenefit,us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNANA0.00.00.0-1.00.00.00.01.00.00.00.0-1.0NANANANANANANANANANANANANANANANANANANA
us-gaap:OtherNonoperatingIncomeExpense ▆▅▇▆▆▆▇▆▇▇▁▆▇▆▆▇▇▇▇▇▇▇▇███-19.0-27.0-13.0-17.0-16.0-16.0-15.0-16.0-13.0-14.0-73.0-17.0-15.0-17.0-16.0-15.0-13.0-12.0-13.0-13.0-12.0-12.0-10.0-1.00.0-1.0NANANANANANANA
us-gaap:ProfitLoss █████▁▅█▇█▇█▇▇▇▇▇▇▇▇▇▆▇▇▇▇▇▇▇▇▇▇▇715.0748.0700.0674.0655.0-2716.0-573.0689.0488.0509.0439.0516.0456.0423.0241.0217.0191.0187.0132.0143.020.0-37.018.041.851.445.936.443.142.955.736.839.234.8
us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax ▇▇█▆▆▆█▆▅▅▆▅▅▄▄▄▄▃▃▃▂▃▁▁▁▁▁▁▁▁▁▁▁1896.01862.02249.01756.01592.01781.02316.01760.01276.01263.01715.01341.01231.01107.01085.0980.0916.0886.0714.0703.0564.0609.0257.0148.6147.6137.5132.0138.0133.9137.3125.6123.8122.2
us-gaap:Revenues ████▇▄██▆▆▆▆▅▅▄▄▃▃▃▃▂▂▁▁▁▁▁▁▁▁▁▁▁2395.02339.02249.02247.02081.0992.02316.02280.01629.01646.01715.01712.01578.01420.01085.0980.0916.0886.0714.0703.0564.0609.0257.0148.6147.6137.5132.0138.0133.9137.3125.6123.8122.2
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:Assets ▇▇▇▇▇▇██▅▅▅▅▅▄▄▄▄▄▄▄▄▄▄▁▁▁▁▁▁▁▁▁▁35773.036030.036414.036662.037022.037006.040430.041281.023746.023584.022779.022379.021412.021006.019500.019238.018601.018285.016646.016415.016079.015978.015677.01391.11382.61354.01214.51194.31181.41193.71208.51218.71217.7
us-gaap:Liabilities ████████▆▆▆▅▅▅▄▃▃▃▃▃▃▃▃▁▁▁▁▁▁▁▁▁▁22010.022212.022429.022599.022792.022682.022849.022421.015872.015651.014911.014423.013457.013028.08527.08152.07692.07585.05327.05261.05613.06323.06423.0898.0890.2878.0750.8361.0352.7372.694.496.989.1
us-gaap:LiabilitiesAndStockholdersEquity ▇▇▇▇▇▇██▅▅▅▅▅▄▄▄▄▄▄▄▄▄▄▁▁▁▁▁▁▁▁▁▁35773.036030.036414.036662.037022.037006.040430.041281.023746.023584.022779.022379.021412.021006.019500.019238.018601.018285.016646.016415.016079.015978.015677.01391.11382.61354.01214.51194.31181.41193.71208.51218.71217.7
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:AssetsCurrent ▇▇█▇▇▇██▄▅▅▅▄▄▃▃▅▅▄▄▃▃▃▁▂▂▁▁▁▁▁▁▁1332.01374.01515.01272.01386.01329.01484.01440.0786.0952.0897.0925.0774.0729.0559.0571.0843.0811.0740.0686.0486.0429.0474.0173.0214.7209.997.2105.5119.4128.0135.1155.6180.9
us-gaap:CashAndCashEquivalentsAtCarryingValue ▁▂▁▂▃▂▁▂▁▃▃▂▁▁▁▁█▇▇▆▂▁▂▃▄▄▂▂▂▂▂▃▄8.024.015.028.067.057.015.041.07.093.068.037.03.02.05.03.0293.0265.0234.0208.035.04.043.090.4130.4132.527.332.243.240.654.186.9115.3
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents ▁▁▁▂▂▂▁▂▁▃▃▂▁▁▁▁█▇▇8.024.015.028.067.057.015.041.07.093.076.039.09.06.09.09.0297.0268.0239.0NANANA52.0NANANANANANANANANANA
us-gaap:AccountsReceivableNetCurrent ▇▇▆▇█▇██▅▅▆▆▅▄▄▅▄▄▄▄▄▄▄▁▁▁▁▁▁▁▁▁▁538.0523.0452.0477.0562.0522.0593.0570.0335.0365.0417.0452.0363.0300.0292.0320.0284.0255.0297.0289.0265.0250.0244.011.812.68.610.28.910.912.212.214.312.8
us-gaap:OtherAssetsCurrent ▄▄▅▅▄▄█▅▃▃▄▃▄▃▃▃▃▃▃▃▂▃▄▁▁▁▁▁▁▂▁▁▁46.049.065.059.048.045.0110.065.034.034.046.037.041.033.037.032.031.031.033.033.024.028.050.04.17.36.17.06.98.211.08.92.33.3
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
 us-gaap:AssetsNoncurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:NonVIEsNANANA5024.05061.0NA5134.0NANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:AssetsNoncurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:OtherVIEsNANANA6398.05824.0NA5862.0NANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:AssetsNoncurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:OtherVIEsandNonVIEsNANANA11422.010885.0NA10996.0NANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:AssetsNoncurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:NonVIEs▁▆█4909.04967.04997.0NANANA5134.0NANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:AssetsNoncurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:OtherVIEs█▆▁7401.07266.06889.0NANANA5862.0NANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:AssetsNoncurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:OtherVIEsandNonVIEs█▇▁12310.012233.011886.0NANANA10996.0NANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:PropertyPlantAndEquipmentGross ████████▆▆▆▆▅▅▅▄▄▄▄▄▄▄▃▁▁▁▁▁▁▁▁▁▁26330.026937.026875.026919.026792.026587.026867.026328.019086.018689.018316.017778.016974.016454.014462.014054.013618.013410.011845.011551.011253.010964.010118.01496.71435.41396.31361.71326.71287.81279.71276.41261.31225.8
us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment ███▇▇▆▆▆▆▅▅▅▅▅▃▃▃▃▂▂▂▂▁▁▁▁▁▁▁▁▁▁▁5978.05941.05657.05304.05034.04758.04722.04436.04065.03873.03677.03507.03332.03163.02275.02132.01980.01999.01115.01014.0893.0769.0435.0387.5375.9365.3353.1344.1332.0320.7309.8305.1296.0
 us-gaap:AmortizationOfIntangibleAssets us-gaap:StatementBusinessSegments mpc:GatheringandProcessingNANANA23.023.029.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:AmortizationOfIntangibleAssets us-gaap:StatementBusinessSegments mplx:GatheringandProcessing▁█22.023.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:PropertyPlantAndEquipmentNet ▇███████▆▆▆▅▅▅▅▅▅▄▄▄▄▄▄▁▁▁▁▁▁▁▁▁▁20352.020996.021218.021615.021758.021829.022145.021892.015021.014816.014639.014271.013642.013291.012187.011922.011638.011411.010730.010537.010360.010195.09683.01109.21059.51031.01008.6982.6955.8959.0966.6956.2929.8
us-gaap:Goodwill ▆▆▆▆▆▆▇█▃▃▃▃▃▃▂▂▂▂▂▂▂▂▃▁▁▁▁▁▁▁▁▁▁7657.07657.07657.07657.07722.07722.09536.010735.02581.02581.02586.02586.02460.02460.02245.02245.02245.02245.02199.02199.02199.02200.02559.0104.7104.7104.7104.7104.7104.7104.7104.7104.7104.7
us-gaap:IntangibleAssetsNetExcludingGoodwill ▅▅▅▆▆▆██▁▁▁▁▁▁▁▁▂▂▂▂▂▂▁896.0927.0959.0991.01023.01055.01270.01309.0405.0414.0424.0434.0435.0444.0453.0463.0473.0482.0492.0501.0511.0520.0466.0NANANA0.0NANANANANANA
us-gaap:FiniteLivedIntangibleAssetsNet NA927.0959.0991.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OperatingLeaseRightOfUseAsset ▇▇▇▇████▆▆▁297.0296.0309.0323.0341.0352.0365.0366.0255.0262.00.0NANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OtherAssetsNoncurrent ██▆▆▇▆▇▇▅▅▅▅▅▄▄▃▃▃▂▂▂▂▂▁▁▂▁▁▁▁▁▁▁62.064.048.048.051.050.052.055.036.033.035.036.037.028.026.022.018.017.014.014.012.011.012.04.23.78.44.01.51.52.02.12.22.3
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:AccountsPayableCurrent ▅▅▅▅▅▅█▇▅▄▅▅▆▅▅▅▅▄▄▄▃▄▃▂▂▂▂▁▁▁▁▂▂158.0162.0152.0140.0145.0138.0242.0196.0134.0110.0162.0146.0172.0143.0151.0152.0144.0121.0123.0107.0102.0105.089.067.655.544.942.234.925.727.030.541.643.3
us-gaap:AccruedLiabilitiesCurrent █▇▄▃▁▁▄▄▂▄█258.0233.0194.0169.0138.0135.0187.0185.0148.0189.0250.0NANANA231.0202.0178.0194.0228.0193.0180.0159.0186.0NANANA11.0NANANANANANA
us-gaap:DebtCurrent ▁▁█▄▁▁▁▆▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁1.02.0764.0307.03.04.09.0510.06.01.01.01.01.01.01.01.01.01.01.01.01.01.01.00.80.80.80.80.80.80.80.70.70.7
us-gaap:LiabilitiesCurrent ▆▅█▆▅▅██▄▄▅▅▅▄▅▄▃▃▃▃▃▄▃▁▁▁▁▁▁▁▁▁▁1727.01196.02086.01531.01228.01214.02132.02232.01048.01029.01186.01204.01279.0876.01304.01048.0790.0712.0704.0670.0650.01045.0612.0135.5128.0115.0100.690.882.487.583.485.678.1
us-gaap:OperatingLeaseLiabilityCurrent ▇▇▇████▇▆▆▁63.063.063.065.069.067.066.061.047.046.00.0NANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OtherLiabilitiesCurrent ▃▃▃▃▂▂▂█▂▂▂█▇▆▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁178.0151.0150.0158.0143.0129.0136.0656.095.075.083.0665.0610.0445.038.041.029.026.024.018.017.014.012.02.73.67.01.71.83.21.71.41.61.1
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
 us-gaap:LiabilitiesNoncurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:NonVIEsNANANA857.0853.0NA822.0NANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LiabilitiesNoncurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:OtherVIEsNANANA1611.0656.0NA305.0NANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LiabilitiesNoncurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mpc:OtherVIEsandNonVIEsNANANA2468.01509.0NA1127.0NANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LiabilitiesNoncurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:NonVIEs█▆▁862.0853.0830.0NANANA822.0NANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LiabilitiesNoncurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:OtherVIEs█▃▁2379.02053.01904.0NANANA305.0NANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LiabilitiesNoncurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee mplx:OtherVIEsandNonVIEs█▃▁3241.02906.02734.0NANANA1127.0NANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:DebtAndCapitalLeaseObligations ████████▆▆▆▅▅▅▃▃▃▃▃▃▃▃▃▁▁▁▁▁▁▁▁▁▁19609.020445.020536.020757.020938.020864.020119.020120.014473.014283.013856.013357.012357.012357.07362.07277.07108.07108.04858.04858.04859.05185.05736.0759.1759.4759.6644.8265.0265.2280.410.510.710.9
us-gaap:LongTermDebtAndCapitalLeaseObligations ████████▆▆▆▅▅▅▃▃▃▃▃▂▂▃▃▁▁▁▁▁▁▁▁▁▁19234.020052.019375.020042.020556.020467.019704.019190.014030.013832.013392.012889.011874.011861.06945.06848.06666.06654.04422.04411.04400.04715.05255.0752.5752.6757.0644.0264.2264.4279.69.810.010.2
us-gaap:DeferredIncomeTaxLiabilitiesNet ▁▁██▁▁█11.011.012.012.011.011.012.0NANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OperatingLeaseLiabilityNoncurrent ▆▆▇▇▇▇██▆▆▁232.0230.0244.0258.0274.0284.0302.0309.0209.0216.00.0NANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo mplx:NonRelatedParty mplx:ThirdPartyNANA67.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo us-gaap:RelatedPartyTransactionsByRelatedParty mplx:MarathonPetroleumCorporationNANA14.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree mplx:NonRelatedParty mplx:ThirdPartyNANA57.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree us-gaap:RelatedPartyTransactionsByRelatedParty mplx:MarathonPetroleumCorporationNANA14.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour mplx:NonRelatedParty mplx:ThirdPartyNANA35.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour us-gaap:RelatedPartyTransactionsByRelatedParty mplx:MarathonPetroleumCorporationNANA14.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive mplx:NonRelatedParty mplx:ThirdPartyNANA19.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive us-gaap:RelatedPartyTransactionsByRelatedParty mplx:MarathonPetroleumCorporationNANA14.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive mplx:NonRelatedParty mplx:ThirdPartyNANA115.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive us-gaap:RelatedPartyTransactionsByRelatedParty mplx:MarathonPetroleumCorporationNANA591.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax NANA-15.0-16.0-16.0-16.0-15.0-15.0-15.0-15.0-16.0-16.0-16.0-16.0-14.0NANANA0.0NANANANANANANANANANANANANANA
 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:RetirementPlanType,us-gaap:StatementEquityComponents us-gaap:OtherPostretirementBenefitPlansDefinedBenefit,us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNANA-2.0-2.0-2.0-2.0-1.0-1.0-1.0-1.0-2.0-2.0-2.0-2.0-1.0NANANA0.0NANANANANANANANANANANANANANA
 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:RetirementPlanType,us-gaap:StatementEquityComponents us-gaap:PensionPlansDefinedBenefit,us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNANA-13.0-14.0-14.0-14.0-14.0-14.0-14.0-14.0-14.0-14.0-14.0-14.0-13.0NANANA0.0NANANANANANANANANANANANANANA
 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName mpc:LoopLlcandExplorerPipelineNANANA-16.0-16.0-16.0-15.0-15.0-15.0-15.0-16.0-16.0-16.0-16.0-14.0-14.0NANA0.0NANANANANANANANANANANANANANA
us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders ▄▄10.010.0NA9.08.09.0NA8.06.06.07.04.03.03.03.02.00.02.00.02.00.01.00.50.20.20.18.712.510.914.9NA25.022.1
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:NetCashProvidedByUsedInOperatingActivities ▇▆▆▇▆▆▆█▅▄▅▄▅▃▃▃▃▃▂▂▂▂▁▁▁▁▁▁▁▁▁▁▁1365.01124.01185.01222.01105.01009.01092.01538.0834.0618.0799.0737.0840.0450.0569.0494.0467.0377.0356.0339.0298.0295.054.157.069.458.556.561.956.571.945.158.561.9
us-gaap:NetCashProvidedByUsedInInvestingActivities ▇█▇▇▆▆▄▃▅▅▅▃▆▆▆▆▆▃▆▆▇▇▁██████████-155.0-90.0-202.0-283.0-415.0-362.0-874.0-1014.0-600.0-575.0-659.0-1073.0-464.0-490.0-470.0-433.0-451.0-953.0-363.0-323.0-286.0-240.0-1378.9-54.9-34.9-29.3-32.0-33.7-2.8-6.6-32.6-40.2-31.6
us-gaap:NetCashProvidedByUsedInFinancingActivities ▁▂▂▂▃▃▄▃▄▄▄▅▃▅▄▃▄▆▅▅▄▄█▄▄▅▄▄▄▄▄▄▄-1226.0-1025.0-996.0-978.0-680.0-605.0-244.0-499.0-320.0-26.0-103.0366.0-373.037.0-97.0-351.012.0607.033.0157.019.0-94.01277.7-42.1-36.676.0-29.4-39.2-51.1-78.8-45.3-46.7-142.9
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:AmortizationOfFinancingCosts ███▇▇▆▆▂▆▆▆▇▆▇▇▆▆▆▆▅▆▅▃▁▁▁18.017.017.015.015.014.013.03.013.013.014.015.014.016.015.013.013.012.012.011.012.011.04.00.01.00.0NANANANANANANA
us-gaap:DeferredIncomeTaxExpenseBenefit NANA0.00.0-1.00.0-3.03.00.0-2.01.02.01.04.0-3.01.01.00.0-1.0-3.0-9.0-4.03.00.0-1.00.00.0NANANA-0.4NANA
us-gaap:IncreaseDecreaseInAccountsReceivable ▅▇▄▂▆▁▅▆▃▂▃█▇▅▃▆▅▂▅▅▅▄▅▄▄▄▄▄▄▄▄▄▄16.067.07.0-38.040.0-71.021.044.0-25.0-57.0-35.086.063.08.0-28.037.027.0-44.08.024.015.05.027.4-0.84.0-1.61.3-2.0-1.30.0-2.11.5-1.2
us-gaap:IncreaseDecreaseInInventories ▂█▅▄█▂▆▅▄▂▁▅▆▂▃▄▄▃▅▄▅▃▃▃▃▃-3.011.04.01.010.0-3.06.04.02.0-3.0-5.05.07.0-2.00.01.02.00.04.01.04.0-1.0-1.00.00.00.0NANANANANANANA
us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet ▂▅▇▅▁█▆▁▄▁▄▄▄▄-2.01.03.01.0-3.04.02.0-3.00.0-3.00.00.00.00.0NANANANANANANANANANANANANANANANANANANA
us-gaap:NetCashProvidedByUsedInOperatingActivities ▇▆▆▇▆▆▆█▅▄▅▄▅▃▃▃▃▃▂▂▂▂▁▁▁▁▁▁▁▁▁▁▁1365.01124.01185.01222.01105.01009.01092.01538.0834.0618.0799.0737.0840.0450.0569.0494.0467.0377.0356.0339.0298.0295.054.157.069.458.556.561.956.571.945.158.561.9
us-gaap:NetIncomeLoss █████▁▅█▇█▇█▇▇▇▇▇▇▇▇▇▆▇▇▇▇▇▇▇▇▇▇▇706.0739.0691.0665.0648.0-2724.0-581.0629.0482.0503.0434.0510.0453.0421.0238.0216.0190.0150.0133.0141.019.0-60.018.041.551.245.629.229.128.834.220.221.518.6
us-gaap:ProfitLoss █████▁▅█▇█▇█▇▇▇▇▇▇▇▇▇▆▇▇▇▇▇▇▇▇▇▇▇715.0748.0700.0674.0655.0-2716.0-573.0689.0488.0509.0439.0516.0456.0423.0241.0217.0191.0187.0132.0143.020.0-37.018.041.851.445.936.443.142.955.736.839.234.8
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:NetCashProvidedByUsedInInvestingActivities ▇█▇▇▆▆▄▃▅▅▅▃▆▆▆▆▆▃▆▆▇▇▁██████████-155.0-90.0-202.0-283.0-415.0-362.0-874.0-1014.0-600.0-575.0-659.0-1073.0-464.0-490.0-470.0-433.0-451.0-953.0-363.0-323.0-286.0-240.0-1378.9-54.9-34.9-29.3-32.0-33.7-2.8-6.6-32.6-40.2-31.6
us-gaap:PaymentsToAcquirePropertyPlantAndEquipment ▂▂▃▃▄▄▇█▅▅▅▅▄▅▄▄▄▃▄▄▃▃▂▁▁▁▁▁▁▁▁▁▁109.0126.0201.0274.0329.0379.0688.0836.0427.0457.0536.0521.0407.0455.0407.0352.0372.0280.0332.0305.0278.0291.0142.959.035.029.731.533.98.15.125.540.231.6
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:NetCashProvidedByUsedInFinancingActivities ▁▂▂▂▃▃▄▃▄▄▄▅▃▅▄▃▄▆▅▅▄▄█▄▄▅▄▄▄▄▄▄▄-1226.0-1025.0-996.0-978.0-680.0-605.0-244.0-499.0-320.0-26.0-103.0366.0-373.037.0-97.0-351.012.0607.033.0157.019.0-94.01277.7-42.1-36.676.0-29.4-39.2-51.1-78.8-45.3-46.7-142.9
us-gaap:ProceedsFromIssuanceOfLongTermDebt ▁█890.01910.0NA3490.01175.01325.0500.06399.01450.0825.02451.01125.00.09610.0250.0420.00.02241.00.00.0128.0306.0961.80.00.0528.2890.00.00.0270.0NANANA
us-gaap:RepaymentsOfLongTermDebt ▁█1726.02020.0NA3690.01101.0581.0501.05762.01261.0400.01999.0126.00.04655.0165.0250.00.01.00.01.0454.0857.01025.30.30.2415.2510.30.215.20.20.10.20.2
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mpc:MPLXLP,mpc:SeniorNotesDueAugust2030,us-gaap:SeniorNotesNANANA2.65e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mpc:MPLXLP,mpc:SeniorNotesDueMarch2026,us-gaap:SeniorNotesNANANA1.75e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mpc:MPLXLP,mpc:SeniorNotesDueOctober2022,us-gaap:SeniorNotesNANANA6.25e-06NANA6.25e-086.25e-08NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:MPLXLP,mplx:SeniorNotesDueApril2038,us-gaap:SeniorNotesNANA4.5e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:MPLXLP,mplx:SeniorNotesDueApril2048,us-gaap:SeniorNotesNANA4.7e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:MPLXLP,mplx:SeniorNotesDueApril2058,us-gaap:SeniorNotesNANA4.9000000000000005e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:MPLXLP,mplx:SeniorNotesDueAugust2030,us-gaap:SeniorNotesNANA2.65e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:MPLXLP,mplx:SeniorNotesDueDecember2024,us-gaap:SeniorNotesNANA4.875e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:MPLXLP,mplx:SeniorNotesDueFebruary2025,us-gaap:SeniorNotesNANA4e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:MPLXLP,mplx:SeniorNotesDueFebruary2029,us-gaap:SeniorNotesNANA4.8e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:MPLXLP,mplx:SeniorNotesDueFebruary2049,us-gaap:SeniorNotesNANA5.5e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:MPLXLP,mplx:SeniorNotesDueJuly2023,us-gaap:SeniorNotesNANA4.5e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:MPLXLP,mplx:SeniorNotesDueJune2025,us-gaap:SeniorNotesNANA4.875e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:MPLXLP,mplx:SeniorNotesDueMarch2023,us-gaap:SeniorNotesNANA3.375e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:MPLXLP,mplx:SeniorNotesDueMarch2026,us-gaap:SeniorNotesNANA1.75e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:MPLXLP,mplx:SeniorNotesDueMarch2027,us-gaap:SeniorNotesNANA4.125e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:MPLXLP,mplx:SeniorNotesDueMarch2028,us-gaap:SeniorNotesNANA4e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:MPLXLP,mplx:SeniorNotesDueMarch2047,us-gaap:SeniorNotesNANA5.2e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument,us-gaap:LongtermDebtType,us-gaap:SubsequentEventType mplx:MPLXLP,mplx:SeniorNotesDueJanuary2025,us-gaap:SeniorNotes,us-gaap:SubsequentEventNANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:Range,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:ANDXLP,srt:Maximum,mplx:SeniorNotesDueJanuary2025,us-gaap:SeniorNotesNANA5.25e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:Range,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:ANDXLP,srt:Minimum,mplx:SeniorNotesDueDecember2022,us-gaap:SeniorNotesNANA3.5e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:Range,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:MarkWest,srt:Maximum,mplx:SeniorNotesDueJune2025,us-gaap:SeniorNotesNANA4.875e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:Range,us-gaap:DebtInstrument,us-gaap:LongtermDebtType mplx:MarkWest,srt:Minimum,mplx:SeniorNotesDueJuly2023,us-gaap:SeniorNotesNANA4.5e-06NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA

Allocated Share Based Compensation Expense

us-gaap:AllocatedShareBasedCompensationExpense

us-gaap:AllocatedShareBasedCompensationExpense


Allocated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value-2.0-3.026-4.0-3.0-5.0-5.0-5.0-3.0-6.0-4.0-6.0-5.0-4.0-5.0-4.0-3.0
Percentage of AllocatedShareBasedCompensationExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.1-0.21.2-0.2-0.2-0.3-0.2-0.3-0.2-0.5-0.2-0.4-0.4-0.4-0.5-0.4-0.3

Comprehensive Income Net Of Tax

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTax


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value706737692665648-2725.0-581.0629482504434510453419238216190150
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax37.239.630.837.940.7-153.0-25.135.737.839.925.338.036.837.921.922.020.716.9

Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value715746701674655-2717.0-573.0689488510439516456421241217191187
Percentage of ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax37.740.131.238.441.1-152.6-24.739.138.240.425.638.537.038.022.222.120.921.1

Cost Of Goods And Services Sold

us-gaap:CostOfGoodsAndServicesSold us-gaap:ProductOrService

us-gaap:CostOfGoodsAndServicesSold

us-gaap:NaturalGasMidstream


Cost
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value33827616515287135197129166194213241204187210170140
Percentage of CostOfGoodsAndServicesSold100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax17.814.87.38.75.57.68.57.313.015.412.418.016.616.919.417.315.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:NaturalGasMidstream0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OilAndGasRefiningAndMarketing


Cost
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value293273320323315368390407233210268241233206147129139
Percentage of CostOfGoodsAndServicesSold86.798.9193.9212.5362.1272.6198.0315.5140.4108.2125.8100.0114.2110.270.075.999.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax15.514.714.218.419.820.716.823.118.316.615.618.018.918.613.513.215.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OilAndGasRefiningAndMarketing0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Costs And Expenses

us-gaap:CostsAndExpenses

us-gaap:CostsAndExpenses


Costs
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value1464136513291348120334782662135497096810491040970863750669636621517496488582219101908610093898189848779
Percentage of CostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax77.273.359.176.875.6195.3114.976.976.076.661.277.678.878.069.168.369.470.172.470.686.595.685.368.361.062.876.268.066.959.00.067.971.20.0

us-gaap:CostsAndExpenses us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

mpc:NonVIEs


Costs
Period End2020-09-302019-09-30
Value131139
Percentage of CostsAndExpenses9.710.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax7.57.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:NonVIEs0.00.0

mpc:OtherVIEs


Costs
Period End2020-09-302019-09-30
Value10692
Percentage of CostsAndExpenses7.96.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.05.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:OtherVIEs0.00.0

mpc:OtherVIEsandNonVIEs


Costs
Period End2020-09-302019-09-30
Value237231
Percentage of CostsAndExpenses17.617.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax13.513.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:OtherVIEsandNonVIEs0.00.0

mplx:NonVIEs


Costs
Period End2021-06-302021-03-312020-06-302020-03-31
Value153131142132
Percentage of CostsAndExpenses10.59.611.83.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax8.17.08.97.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:NonVIEs0.00.00.00.0

mplx:OtherVIEs


Costs
Period End2021-06-302021-03-312020-06-302020-03-31
Value11010798104
Percentage of CostsAndExpenses7.57.88.13.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax5.85.76.25.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:OtherVIEs0.00.00.00.0

mplx:OtherVIEsandNonVIEs


Costs
Period End2021-06-302021-03-312020-06-302020-03-31
Value263238240236
Percentage of CostsAndExpenses18.017.420.06.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax13.912.815.113.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:OtherVIEsandNonVIEs0.00.00.00.0

Gains Losses On Extinguishment Of Debt

us-gaap:GainsLossesOnExtinguishmentOfDebt us-gaap:DebtInstrument, us-gaap:LongtermDebtType

us-gaap:GainsLossesOnExtinguishmentOfDebt

mplx:SeniorNotesDueJanuary2025, mplx:FixedRateSeniorNotes


Gains
Period End2021-06-302021-03-31
Value0-8000000.0
Percentage of GainsLossesOnExtinguishmentOfDebt0.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.0-0.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:SeniorNotesDueJanuary2025 mplx:FixedRateSeniorNotes0.00.0

General And Administrative Expense

us-gaap:GeneralAndAdministrativeExpense

us-gaap:GeneralAndAdministrativeExpense


General
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value878689969697951026982747672696759575846464952462117181715151513131313
Percentage of GeneralAndAdministrativeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.64.64.05.56.05.44.15.85.46.54.35.75.86.26.26.06.26.56.46.58.78.518.014.212.113.613.411.111.911.60.010.511.40.0

us-gaap:GeneralAndAdministrativeExpense us-gaap:RelatedPartyTransactionsByRelatedParty

mplx:MarathonPetroleumCorporation


General
Period End2021-06-302021-03-312020-06-302020-03-31
Value63576864
Percentage of GeneralAndAdministrativeExpense72.466.370.866.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.33.14.33.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:MarathonPetroleumCorporation0.00.00.00.0

Income Loss From Continuing Operations

us-gaap:IncomeLossFromContinuingOperations

us-gaap:IncomeLossFromContinuingOperations


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value931974920899878-2486.0-346.09266596786666726085573353112802651972077627504757513844445636393535
Percentage of IncomeLossFromContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax49.152.340.951.255.2-139.6-14.952.651.653.738.850.149.450.330.931.730.629.927.629.413.54.419.531.739.037.229.232.033.141.00.032.128.80.0

Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value715749701675655-2716.0-575.069348950743951945742723921819318713214312-41.0194151453643435536393435
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax37.740.231.238.441.1-152.5-24.839.438.340.125.638.737.138.622.022.221.121.118.520.32.1-6.77.728.234.833.427.431.232.140.60.032.028.60.0

Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest

mpc:NonVIEs


Income
Period End2020-09-302019-09-30
Value162253
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.214.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:NonVIEs0.00.0

mpc:OtherVIEs


Income
Period End2020-09-302019-09-30
Value6981
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest42.632.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.94.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:OtherVIEs0.00.0

mpc:OtherVIEsandNonVIEs


Income
Period End2020-09-302019-09-30
Value231334
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest142.6132.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax13.219.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:OtherVIEsandNonVIEs0.00.0

mplx:NonVIEs


Income
Period End2021-06-302021-03-312020-06-302020-03-31
Value170153161205
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest0.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.08.210.111.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:NonVIEs0.00.00.00.0

mplx:OtherVIEs


Income
Period End2021-06-302021-03-312020-06-302020-03-31
Value635676-321.0
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest0.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.33.04.8-18.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:OtherVIEs0.00.00.00.0

mplx:OtherVIEsandNonVIEs


Income
Period End2021-06-302021-03-312020-06-302020-03-31
Value233209237-116.0
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest0.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax12.311.214.9-6.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:OtherVIEsandNonVIEs0.00.00.00.0

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit

us-gaap:IncomeTaxExpenseBenefit


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-09-30
Value01000000.01000000.01000000.000-2000000.04000000.01000000.0-2000000.003000000.01000000.04000000.0-2000000.01000000.02000000.0000-8000000.0-4000000.01900000.0100000.000-200000.00100000.00-700000.0400000.0100000.00-100000.0
Percentage of IncomeTaxExpenseBenefit0.0100.0100.0100.00.00.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.00.00.00.0100.0100.0100.0100.00.00.0100.00.0100.00.0100.0100.0100.00.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.00.10.00.10.00.0-0.10.20.1-0.20.00.20.10.4-0.20.10.20.00.00.0-1.4-0.70.70.10.00.0-0.20.00.10.00.00.30.10.00.0

Income Taxes Paid Net

us-gaap:IncomeTaxesPaidNet

us-gaap:IncomeTaxesPaidNet


Income
Period End2020-09-302019-09-302018-09-302017-09-302014-12-31
Value0002000000.0-300000.0
Percentage of IncomeTaxesPaidNet0.00.00.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.00.00.00.2-0.2

Interest Paid Net

us-gaap:InterestPaidNet

us-gaap:InterestPaidNet


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value18323119020821321018736414114319113951103561085049544956530.6100.31.81.10.90.90.00.00.0
Percentage of InterestPaidNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.712.48.411.813.411.88.120.711.111.311.110.44.19.35.211.05.55.57.67.09.98.70.26.90.21.30.80.70.70.00.00.0

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value706739691665648-2724.0-581.062948250343451045342123821619015013314119-60.018415145292928342021181713
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax37.239.730.737.940.7-152.9-25.135.737.839.825.338.036.838.021.922.020.716.918.620.13.4-9.97.027.934.733.222.121.121.524.90.017.415.20.00.0

us-gaap:NetIncomeLoss us-gaap:PartnerTypeOfPartnersCapitalAccount

mpc:LimitedPartnersCommonUnits


Net
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312013-09-30
Value635617-2755.0-612.059944048341449143340512611499726274-35.0-99.01833212015139.910
Percentage of NetIncomeLoss95.595.2101.1105.395.291.396.095.496.395.696.252.952.852.148.046.652.5-184.2165.0100.079.541.043.952.147.149.048.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax36.238.8-154.7-26.434.034.538.224.136.635.236.611.611.610.88.18.710.5-6.2-16.37.022.214.214.511.59.90.08.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:LimitedPartnersCommonUnits0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

mplx:LimitedPartnersCommonUnits


Net
Period End2021-06-302021-03-312020-06-302020-03-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value675708617-2755.0322120151313159.7109.89.66.5
Percentage of NetIncomeLoss95.695.895.2101.179.042.644.151.747.147.244.448.048.852.754.549.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax35.638.038.8-154.722.114.814.611.49.910.211.10.08.58.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:LimitedPartnersCommonUnits0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:StatementClassOfStock

us-gaap:PreferredPartner, us-gaap:SeriesAPreferredStock


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value21202020212020202120201920
Percentage of NetIncomeLoss3.02.72.93.03.2-0.7-3.43.24.44.04.63.74.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.11.10.91.11.31.10.91.11.61.61.21.41.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:PreferredPartner us-gaap:SeriesAPreferredStock0.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PreferredPartner, us-gaap:SeriesBPreferredStock


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value10.01110.010.010.0111110.021
Percentage of NetIncomeLoss1.41.51.41.51.5-0.4-1.91.64.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.50.60.40.60.60.60.50.61.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:PreferredPartner us-gaap:SeriesBPreferredStock0.00.00.00.00.00.00.00.00.0

Net Income Loss Attributable To Noncontrolling Interest

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value9.09.09.09.07.08.08.08.06.06.05.06.03.02.03.01.01.01.0-1.02.01.00.00.20.30.20.37.214142116171617
Percentage of NetIncomeLossAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.50.50.40.50.40.40.30.50.50.50.30.40.20.20.30.10.10.1-0.10.30.20.00.10.20.10.25.510.110.515.70.014.313.30.0

Other Comprehensive Income Loss Net Of Tax

us-gaap:OtherComprehensiveIncomeLossNetOfTax

us-gaap:OtherComprehensiveIncomeLossNetOfTax


Other
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value00-1000000.00001000000.0000-2000000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax0.00.0100.00.00.00.0100.00.00.00.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.00.0-0.10.00.00.00.10.00.00.0-0.2

us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:RetirementPlanType, us-gaap:StatementEquityComponents

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Other
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value000-1000000.00001000000.0000-1000000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax0.00.00.0100.00.00.00.0100.00.00.00.050.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.00.00.0-0.10.00.00.00.10.00.00.0-0.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OtherPostretirementBenefitPlansDefinedBenefit us-gaap:AccumulatedDefinedBenefitPlansAdjustment0.00.00.00.00.00.00.00.00.00.00.00.0

Other Nonoperating Income Expense

us-gaap:OtherNonoperatingIncomeExpense

us-gaap:OtherNonoperatingIncomeExpense


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-19000000.0-27000000.0-13000000.0-17000000.0-16000000.0-16000000.0-15000000.0-16000000.0-13000000.0-14000000.0-73000000.0-17000000.0-15000000.0-17000000.0-16000000.0-15000000.0-13000000.0-12000000.0-13000000.0-13000000.0-12000000.0-12000000.0-10000000.0-1000000.00-1000000.0
Percentage of OtherNonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-1.0-1.5-0.6-1.0-1.0-0.9-0.6-0.9-1.0-1.1-4.3-1.3-1.2-1.5-1.5-1.5-1.4-1.4-1.8-1.8-2.1-2.0-3.9-0.70.0-0.7

Profit Loss

us-gaap:ProfitLoss

us-gaap:ProfitLoss


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value715748700674655-2716.0-573.068948850943951645642324121719118713214320-37.0184151453643425536393435
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax37.740.231.138.441.1-152.5-24.739.138.240.325.638.537.038.222.222.120.921.118.520.33.5-6.17.028.134.833.427.631.232.040.60.031.728.50.0

us-gaap:ProfitLoss us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

mpc:NonVIEs


Profit
Period End2020-09-302019-09-30
Value145222
Percentage of ProfitLoss21.532.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax8.312.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:NonVIEs0.00.0

mpc:OtherVIEs


Profit
Period End2020-09-302019-09-30
Value5365
Percentage of ProfitLoss7.99.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.03.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:OtherVIEs0.00.0

mpc:OtherVIEsandNonVIEs


Profit
Period End2020-09-302019-09-30
Value198287
Percentage of ProfitLoss29.441.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax11.316.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:OtherVIEsandNonVIEs0.00.0

mplx:NonVIEs


Profit
Period End2021-06-302021-03-312020-06-302020-03-31
Value143140146186
Percentage of ProfitLoss20.018.722.3-6.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax7.57.59.210.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:NonVIEs0.00.00.00.0

mplx:OtherVIEs


Profit
Period End2021-06-302021-03-312020-06-302020-03-31
Value416454-337.0
Percentage of ProfitLoss5.78.68.212.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax2.23.43.4-18.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:OtherVIEs0.00.00.00.0

mplx:OtherVIEsandNonVIEs


Profit
Period End2021-06-302021-03-312020-06-302020-03-31
Value184204200-151.0
Percentage of ProfitLoss25.727.330.55.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.711.012.6-8.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:OtherVIEsandNonVIEs0.00.00.00.0

Revenue From Contract With Customer Excluding Assessed Tax

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
Value189618622249175615921781231617601276126317151341123111071085980916886714703564609257148147137132138133137125123122
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, us-gaap:Product, mpc:GatheringandProcessing


Revenue
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value234151222283207204244304311267253280219193
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax13.39.512.512.211.816.019.317.723.221.722.925.822.321.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax13.39.512.512.211.816.019.317.723.221.722.925.822.321.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:Product mpc:GatheringandProcessing100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, us-gaap:Product, mpc:LogisticsandStorage


Revenue
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value9.0211934224.03.04.05.03.02.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.51.31.11.51.20.30.20.20.40.20.20.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.51.31.11.51.20.30.20.20.40.20.20.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:Product mpc:LogisticsandStorage100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:OperatingSegments, us-gaap:Product, mplx:GatheringandProcessing


Revenue
Period End2021-06-302021-03-312020-06-302020-03-31
Value407397151222
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax21.521.39.512.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax21.521.39.512.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:Product mplx:GatheringandProcessing100.0100.0100.0100.0

us-gaap:OperatingSegments, us-gaap:Product, mplx:LogisticsandStorage


Revenue
Period End2021-06-302021-03-312020-06-302020-03-31
Value4.04.02119
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.20.21.31.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.20.21.31.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:Product mplx:LogisticsandStorage100.0100.0100.0100.0

us-gaap:OperatingSegments, us-gaap:Service, mpc:GatheringandProcessing


Revenue
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value524489536561555415404420422378354279268254
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax29.830.730.124.231.532.532.024.531.530.732.025.727.327.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax29.830.730.124.231.532.532.024.531.530.732.025.727.327.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:Service mpc:GatheringandProcessing100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, us-gaap:Service, mpc:LogisticsandStorage


Revenue
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value9899311004978976653612607602581499313307302
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax56.358.556.442.255.551.248.535.444.947.245.128.831.333.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax56.358.556.442.255.551.248.535.444.947.245.128.831.333.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:Service mpc:LogisticsandStorage100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, us-gaap:Service, mplx:GatheringandProcessing


Revenue
Period End2021-06-302021-03-312020-06-302020-03-31
Value493508489536
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax26.027.330.730.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax26.027.330.730.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:Service mplx:GatheringandProcessing100.0100.0100.0100.0

us-gaap:OperatingSegments, us-gaap:Service, mplx:LogisticsandStorage


Revenue
Period End2021-06-302021-03-312020-06-302020-03-31
Value9929539311004
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax52.351.258.556.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax52.351.258.556.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:Service mplx:LogisticsandStorage100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService

us-gaap:Product


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value304282182165120169230171168202250239206207278217191
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax16.015.18.19.47.59.59.99.713.216.014.617.816.718.725.622.120.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax16.015.18.19.47.59.59.99.713.216.014.617.816.718.725.622.120.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:Product100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Service


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value578589618604563612633632448438456456410382311299286
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax30.531.627.534.435.434.427.335.935.134.726.634.033.334.528.730.531.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax30.531.627.534.435.434.427.335.935.134.726.634.033.334.528.730.531.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:Service100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ServiceOther


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value76775341223954262634445951440.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.04.12.42.31.42.22.31.52.02.72.64.44.14.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.04.12.42.31.42.22.31.52.02.72.64.44.14.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ServiceOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:Service, mpc:GatheringandProcessing


Revenue
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value517486528547537415404420422378354
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax29.430.529.623.630.532.532.024.531.530.732.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax29.430.529.623.630.532.532.024.531.530.732.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:Service mpc:GatheringandProcessing100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Service, mpc:LogisticsandStorage


Revenue
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value8777848695333436343228
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax5.04.84.73.75.42.62.72.12.52.62.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax5.04.84.73.75.42.62.72.12.52.62.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:Service mpc:LogisticsandStorage100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Service, mplx:GatheringandProcessing


Revenue
Period End2021-06-302021-03-312020-06-302020-03-31
Value487505486528
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax25.727.130.529.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax25.727.130.529.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:Service mplx:GatheringandProcessing100.0100.0100.0100.0

us-gaap:Service, mplx:LogisticsandStorage


Revenue
Period End2021-06-302021-03-312020-06-302020-03-31
Value91847784
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.84.54.84.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.84.54.84.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:Service mplx:LogisticsandStorage100.0100.0100.0100.0

us-gaap:ServiceOther, mpc:GatheringandProcessing


Revenue
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value4122395426263444595144
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax2.31.42.22.31.52.02.72.64.44.14.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax2.31.42.22.31.52.02.72.64.44.14.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ServiceOther mpc:GatheringandProcessing100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ServiceOther, mplx:GatheringandProcessing


Revenue
Period End2021-06-302021-03-312020-06-302020-03-31
Value76772239
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.04.11.42.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.04.11.42.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ServiceOther mplx:GatheringandProcessing100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:StatementBusinessSegments

mpc:GatheringandProcessing


Revenue
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value758640758844762619648717734647606
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax43.240.242.636.443.348.551.341.854.752.654.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax43.240.242.636.443.348.551.341.854.752.654.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:GatheringandProcessing100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mpc:LogisticsandStorage


Revenue
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value99895210231012998657615611607584501
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax56.859.857.443.756.751.548.735.645.347.445.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax56.859.857.443.756.751.548.735.645.347.445.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:LogisticsandStorage100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mplx:GatheringandProcessing


Revenue
Period End2021-06-302021-03-312020-06-302020-03-31
Value900905640758
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax47.548.640.242.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax47.548.640.242.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:GatheringandProcessing100.0100.0100.0100.0

mplx:LogisticsandStorage


Revenue
Period End2021-06-302021-03-312020-06-302020-03-31
Value9969579521023
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax52.551.459.857.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax52.551.459.857.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:LogisticsandStorage100.0100.0100.0100.0

Revenues

us-gaap:Revenues

us-gaap:Revenues


Revenues
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
Value23952339224922472081992231622801629164617151712157814201085980916886714703564609257148147137132138133137125123122
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax126.3125.6100.0128.0130.755.7100.0129.5127.7130.3100.0127.7128.2128.3100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Revenues us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mpc:GatheringandProcessing


Revenuesus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value913791-374.0947901744780852859756824739670603598590568530498
Percentage of Revenues40.638.0-37.740.939.545.747.449.750.247.958.068.168.465.867.582.680.894.081.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax52.049.7-21.040.951.258.361.849.764.161.474.468.168.465.867.582.680.894.081.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mpc:GatheringandProcessing0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, mpc:LogisticsandStorage


Revenuesus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value13341290136613691379885866863853822658397389384357217216211211-51.0214213201
Percentage of Revenues59.462.0137.759.160.554.352.650.349.852.146.336.639.741.940.330.430.737.434.6-19.8144.0144.3146.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax76.081.076.759.178.469.468.650.363.666.859.436.639.741.940.330.430.737.434.6-19.8144.0144.3146.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mpc:LogisticsandStorage0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, mplx:GatheringandProcessing


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value10361045791-374.0
Percentage of Revenues43.344.738.0-37.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax54.656.149.7-21.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mplx:GatheringandProcessing0.00.00.00.0

us-gaap:OperatingSegments, mplx:LogisticsandStorage


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value1359129412901366
Percentage of Revenues56.755.362.0137.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax71.769.581.076.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mplx:LogisticsandStorage0.00.00.00.0

us-gaap:Revenues us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

mpc:NonVIEs


Revenuesus-gaap:
Period End2020-09-302019-09-30
Value293392
Percentage of Revenues13.017.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax16.722.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:NonVIEs0.00.0

mpc:OtherVIEs


Revenuesus-gaap:
Period End2020-09-302019-09-30
Value175173
Percentage of Revenues7.87.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax10.09.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:OtherVIEs0.00.0

mpc:OtherVIEsandNonVIEs


Revenuesus-gaap:
Period End2020-09-302019-09-30
Value468565
Percentage of Revenues20.824.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax26.732.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:OtherVIEsandNonVIEs0.00.0

mplx:NonVIEs


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value323284303337
Percentage of Revenues13.512.114.634.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax17.015.319.018.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:NonVIEs0.00.00.00.0

mplx:OtherVIEs


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value173163174-217.0
Percentage of Revenues7.27.08.4-21.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.18.810.9-12.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:OtherVIEs0.00.00.00.0

mplx:OtherVIEsandNonVIEs


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value496447477120
Percentage of Revenues20.719.122.912.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax26.224.030.06.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:OtherVIEsandNonVIEs0.00.00.00.0

us-gaap:Revenues us-gaap:MajorCustomers, us-gaap:StatementBusinessSegments

mpc:ThirdParty, mpc:GatheringandProcessing


Revenuesus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value858748425893843716757825828731703
Percentage of Revenues38.235.942.838.637.044.046.048.148.446.349.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax48.947.023.938.647.956.159.948.161.759.463.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:ThirdParty mpc:GatheringandProcessing0.00.00.00.00.00.00.00.00.00.00.0

mpc:ThirdParty, mpc:LogisticsandStorage


Revenuesus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value139146158162182948286827174
Percentage of Revenues6.27.015.97.08.05.85.05.04.84.55.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax7.99.28.97.010.37.46.55.06.15.86.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:ThirdParty mpc:LogisticsandStorage0.00.00.00.00.00.00.00.00.00.00.0

mplx:ThirdParty, mplx:GatheringandProcessing


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value988989748-425.0
Percentage of Revenues41.342.335.9-42.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax52.153.147.0-23.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:ThirdParty mplx:GatheringandProcessing0.00.00.00.0

mplx:ThirdParty, mplx:LogisticsandStorage


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value138129146158
Percentage of Revenues5.85.57.015.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax7.36.99.28.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:ThirdParty mplx:LogisticsandStorage0.00.00.00.0

Assets

us-gaap:Assets

us-gaap:Assets


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value3577336030364143666237022370064043041281237462358422779223792141221006195001923818601182851664616415160791597815677139113821354121411941181119312081218121713111301
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mpc:GatheringandProcessing


Assetsus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-31
Value15490156471605819605206611665616451161451585015427150461488414715144891430714297141851412714186142460.0
Percentage of Assets42.342.343.448.550.070.169.870.970.872.071.676.376.577.978.285.986.487.988.890.90.0
Percentage of Assets42.342.343.448.550.070.169.870.970.872.071.676.376.577.978.285.986.487.988.890.90.0
Percentage of Assets us-gaap:OperatingSegments mpc:GatheringandProcessing100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

us-gaap:OperatingSegments, mpc:LogisticsandStorage


Assetsus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-31
Value21144213082089120810205797083704065666492598259584611452038193713211520221952179214311214
Percentage of Assets57.757.656.551.549.929.829.928.829.027.928.423.623.520.520.312.712.312.111.29.1100.0
Percentage of Assets57.757.656.551.549.929.829.928.829.027.928.423.623.520.520.312.712.312.111.29.1100.0
Percentage of Assets us-gaap:OperatingSegments mpc:LogisticsandStorage100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, mplx:GatheringandProcessing


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312019-12-31
Value14896152191546119605
Percentage of Assets41.642.242.548.5
Percentage of Assets41.642.242.548.5
Percentage of Assets us-gaap:OperatingSegments mplx:GatheringandProcessing100.0100.0100.0100.0

us-gaap:OperatingSegments, mplx:LogisticsandStorage


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312019-12-31
Value20869207872093820810
Percentage of Assets58.357.757.551.5
Percentage of Assets58.357.757.551.5
Percentage of Assets us-gaap:OperatingSegments mplx:LogisticsandStorage100.0100.0100.0100.0

Liabilities

us-gaap:Liabilities

us-gaap:Liabilities


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value22010222122242922599227922268222849224211587215651149111442313457130288527815276927585532752615613632364238988908787503613523729496897574
Percentage of Liabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets61.561.661.661.661.661.356.554.366.866.465.564.462.862.043.742.441.441.532.032.034.939.641.064.664.464.861.830.229.931.27.88.07.35.85.7

Liabilities And Stockholders Equity

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:LiabilitiesAndStockholdersEquity


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value3577336030364143666237022370064043041281237462358422779223792141221006195001923818601182851664616415160791597815677139113821354121411941181119312081218121713111301
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Assets Current

us-gaap:AssetsCurrent

us-gaap:AssetsCurrent


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value1332137415151272138613291484144078695289792577472955957184381174068648642947417321420997105119128135155180295283
Percentage of AssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.73.84.23.53.73.63.73.53.34.03.94.13.63.52.93.04.54.44.44.23.02.73.012.415.515.58.08.810.110.711.212.814.922.521.8

us-gaap:AssetsCurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

mpc:NonVIEs


Assets
Period End2020-09-302020-06-302019-12-31
Value367317330
Percentage of AssetsCurrent28.922.922.2
Percentage of Assets1.00.90.8
Percentage of Assets mpc:NonVIEs0.00.00.0

mpc:OtherVIEs


Assets
Period End2020-09-302020-06-302019-12-31
Value774357534
Percentage of AssetsCurrent60.825.836.0
Percentage of Assets2.11.01.3
Percentage of Assets mpc:OtherVIEs0.00.00.0

mpc:OtherVIEsandNonVIEs


Assets
Period End2020-09-302020-06-302019-12-31
Value1141674864
Percentage of AssetsCurrent89.748.658.2
Percentage of Assets3.11.82.1
Percentage of Assets mpc:OtherVIEsandNonVIEs0.00.00.0

mplx:NonVIEs


Assets
Period End2021-06-302021-03-312020-12-312019-12-31
Value464321318330
Percentage of AssetsCurrent34.823.421.022.2
Percentage of Assets1.30.90.90.8
Percentage of Assets mplx:NonVIEs0.00.00.00.0

mplx:OtherVIEs


Assets
Period End2021-06-302021-03-312020-12-312019-12-31
Value355312530534
Percentage of AssetsCurrent26.722.735.036.0
Percentage of Assets1.00.91.51.3
Percentage of Assets mplx:OtherVIEs0.00.00.00.0

mplx:OtherVIEsandNonVIEs


Assets
Period End2021-06-302021-03-312020-12-312019-12-31
Value819633848864
Percentage of AssetsCurrent61.546.156.058.2
Percentage of Assets2.31.82.32.1
Percentage of Assets mplx:OtherVIEsandNonVIEs0.00.00.00.0

Cash And Cash Equivalents At Carrying Value

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:CashAndCashEquivalentsAtCarryingValue


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value8.0241528675715417.09368373.02.05.03.0293265234208354.043901301322732434054861152272160.1
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.10.00.10.20.20.00.10.00.40.30.20.00.00.00.01.61.41.41.30.20.00.36.59.49.82.22.73.73.44.57.19.517.416.70.0

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value8.0241528675715417.09376399.06.09.09.029726823952
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.10.00.10.20.20.00.10.00.40.30.20.00.00.00.01.61.51.40.3

Accounts Receivable Net Current

us-gaap:AccountsReceivableNetCurrent

us-gaap:AccountsReceivableNetCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value53852345247756252259357033536541745236330029232028425529728926525024411128.6108.910121214121417
Percentage of AccountsReceivableNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.51.51.21.31.51.41.51.41.41.51.82.01.71.41.51.71.51.41.81.81.61.61.60.80.90.60.80.70.91.01.01.21.11.11.4

Other Assets Current

us-gaap:OtherAssetsCurrent

us-gaap:OtherAssetsCurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value464965594845110653434463741333732313133332428504.17.36.17.06.98.2118.92.33.32.42.6
Percentage of OtherAssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.10.10.20.20.10.10.30.20.10.10.20.20.20.20.20.20.20.20.20.20.10.20.30.30.50.50.60.60.70.90.70.20.30.20.2

us-gaap:OtherAssetsCurrent us-gaap:RelatedPartyTransactionsByRelatedParty

mpc:MarathonPetroleumCorporation


Other
Period End2020-09-302020-06-302019-12-312019-09-302018-12-31
Value1.01.00.06.00.0
Percentage of OtherAssetsCurrent1.72.10.09.20.0
Percentage of Assets0.00.00.00.00.0
Percentage of Assets mpc:MarathonPetroleumCorporation0.00.00.00.00.0

mplx:MarathonPetroleumCorporation


Other
Period End2021-06-302021-03-312020-12-31
Value2.01.01.0
Percentage of OtherAssetsCurrent4.32.01.5
Percentage of Assets0.00.00.0
Percentage of Assets mplx:MarathonPetroleumCorporation0.00.00.0

Assets Noncurrent

us-gaap:AssetsNoncurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:AssetsNoncurrent

mpc:NonVIEs


Assets
Period End2020-09-302020-06-302019-12-31
Value502450615134
Percentage of AssetsNoncurrent100.0100.0100.0
Percentage of Assets13.713.712.7
Percentage of Assets mpc:NonVIEs0.00.00.0

mpc:OtherVIEs


Assets
Period End2020-09-302020-06-302019-12-31
Value639858245862
Percentage of AssetsNoncurrent127.3115.1114.2
Percentage of Assets17.515.714.5
Percentage of Assets mpc:OtherVIEs0.00.00.0

mpc:OtherVIEsandNonVIEs


Assets
Period End2020-09-302020-06-302019-12-31
Value114221088510996
Percentage of AssetsNoncurrent227.3215.1214.2
Percentage of Assets31.229.427.2
Percentage of Assets mpc:OtherVIEsandNonVIEs0.00.00.0

mplx:NonVIEs


Assets
Period End2021-06-302021-03-312020-12-312019-12-31
Value4909496749975134
Percentage of AssetsNoncurrent0.00.00.0100.0
Percentage of Assets13.713.813.712.7
Percentage of Assets mplx:NonVIEs0.00.00.00.0

mplx:OtherVIEs


Assets
Period End2021-06-302021-03-312020-12-312019-12-31
Value7401726668895862
Percentage of AssetsNoncurrent0.00.00.0114.2
Percentage of Assets20.720.218.914.5
Percentage of Assets mplx:OtherVIEs0.00.00.00.0

mplx:OtherVIEsandNonVIEs


Assets
Period End2021-06-302021-03-312020-12-312019-12-31
Value12310122331188610996
Percentage of AssetsNoncurrent0.00.00.0214.2
Percentage of Assets34.434.032.627.2
Percentage of Assets mplx:OtherVIEsandNonVIEs0.00.00.00.0

Property Plant And Equipment Gross

us-gaap:PropertyPlantAndEquipmentGross

us-gaap:PropertyPlantAndEquipmentGross


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value2633026937268752691926792265872686726328190861868918316177781697416454144621405413618134101184511551112531096410118149614351396136113261287127912761261122511961186
Percentage of PropertyPlantAndEquipmentGross100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets73.674.873.873.472.471.866.563.880.479.280.479.479.378.374.273.173.273.371.270.470.068.664.5107.6103.8103.1112.1111.1109.0107.2105.6103.5100.791.291.2

us-gaap:PropertyPlantAndEquipmentGross mplx:MajorAssetClass, us-gaap:PropertyPlantAndEquipmentByType

mplx:Bargesandtowingvessels, us-gaap:EquipmentLeasedToOtherParty


Property
Period End2020-12-312019-12-31
Value129906
Percentage of PropertyPlantAndEquipmentGross0.53.4
Percentage of Assets0.42.2
Percentage of Assets mplx:Bargesandtowingvessels us-gaap:EquipmentLeasedToOtherParty0.00.0

mplx:GasGatheringAndTransmissionEquipmentAndFacilities, us-gaap:EquipmentLeasedToOtherParty


Property
Period End2020-12-312019-12-31
Value990980
Percentage of PropertyPlantAndEquipmentGross3.73.6
Percentage of Assets2.72.4
Percentage of Assets mplx:GasGatheringAndTransmissionEquipmentAndFacilities us-gaap:EquipmentLeasedToOtherParty0.00.0

mplx:LandBuildingOfficeEquipmentAndOther, us-gaap:EquipmentLeasedToOtherParty


Property
Period End2020-12-312019-12-31
Value171198
Percentage of PropertyPlantAndEquipmentGross0.60.7
Percentage of Assets0.50.5
Percentage of Assets mplx:LandBuildingOfficeEquipmentAndOther us-gaap:EquipmentLeasedToOtherParty0.00.0

mplx:PipelinesAndRelatedAssets, us-gaap:EquipmentLeasedToOtherParty


Property
Period End2020-12-312019-12-31
Value834745
Percentage of PropertyPlantAndEquipmentGross3.12.8
Percentage of Assets2.31.8
Percentage of Assets mplx:PipelinesAndRelatedAssets us-gaap:EquipmentLeasedToOtherParty0.00.0

mplx:ProcessingFractionationAndStorageFacilities, us-gaap:EquipmentLeasedToOtherParty


Property
Period End2020-12-312019-12-31
Value867855
Percentage of PropertyPlantAndEquipmentGross3.23.2
Percentage of Assets2.42.1
Percentage of Assets mplx:ProcessingFractionationAndStorageFacilities us-gaap:EquipmentLeasedToOtherParty0.00.0

mplx:Refineriesandrelatedassets, us-gaap:EquipmentLeasedToOtherParty


Property
Period End2020-12-312019-12-31
Value16802320
Percentage of PropertyPlantAndEquipmentGross6.38.6
Percentage of Assets4.65.7
Percentage of Assets mplx:Refineriesandrelatedassets us-gaap:EquipmentLeasedToOtherParty0.00.0

mplx:Terminalsandrelatedassets, us-gaap:EquipmentLeasedToOtherParty


Property
Period End2020-12-312019-12-31
Value1276943
Percentage of PropertyPlantAndEquipmentGross4.73.5
Percentage of Assets3.52.3
Percentage of Assets mplx:Terminalsandrelatedassets us-gaap:EquipmentLeasedToOtherParty0.00.0

us-gaap:PropertyPlantAndEquipmentGross mplx:NonRelatedParty, us-gaap:PropertyPlantAndEquipmentByType

mplx:ThirdParty, mplx:FinanceLease


Property
Period End2020-12-312019-12-31
Value1746
Percentage of PropertyPlantAndEquipmentGross0.10.2
Percentage of Assets0.00.1
Percentage of Assets mplx:ThirdParty mplx:FinanceLease0.00.0

us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType

us-gaap:EquipmentLeasedToOtherParty


Property
Period End2020-12-312019-12-31
Value59476947
Percentage of PropertyPlantAndEquipmentGross22.125.9
Percentage of Assets16.317.2
Percentage of Assets us-gaap:EquipmentLeasedToOtherParty0.00.0

us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType, us-gaap:StatementBusinessSegments

mpc:Bargesandtowingvessels, mpc:LogisticsandStorage


Property
Period End2020-09-302020-06-302020-03-312019-12-31
Value961960960906
Percentage of PropertyPlantAndEquipmentGross3.63.63.63.4
Percentage of Assets2.62.62.62.2
Percentage of Assets mpc:Bargesandtowingvessels mpc:LogisticsandStorage0.00.00.00.0

mpc:GasGatheringAndTransmissionEquipmentAndFacilities, mpc:GatheringandProcessing


Property
Period End2020-09-302020-06-302020-03-312019-12-31
Value7413737473497159
Percentage of PropertyPlantAndEquipmentGross27.527.527.626.6
Percentage of Assets20.219.919.917.7
Percentage of Assets mpc:GasGatheringAndTransmissionEquipmentAndFacilities mpc:GatheringandProcessing0.00.00.00.0

mpc:LandBuildingOfficeEquipmentAndOther, mpc:GatheringandProcessing


Property
Period End2020-09-302020-06-302020-03-312019-12-31
Value509489491484
Percentage of PropertyPlantAndEquipmentGross1.91.81.81.8
Percentage of Assets1.41.31.31.2
Percentage of Assets mpc:LandBuildingOfficeEquipmentAndOther mpc:GatheringandProcessing0.00.00.00.0

mpc:LandBuildingOfficeEquipmentAndOther, mpc:LogisticsandStorage


Property
Period End2020-09-302020-06-302020-03-312019-12-31
Value1576183418271817
Percentage of PropertyPlantAndEquipmentGross5.96.86.96.8
Percentage of Assets4.35.04.94.5
Percentage of Assets mpc:LandBuildingOfficeEquipmentAndOther mpc:LogisticsandStorage0.00.00.00.0

mpc:PipelinesAndRelatedAssets, mpc:LogisticsandStorage


Property
Period End2020-09-302020-06-302020-03-312019-12-31
Value6001571956375572
Percentage of PropertyPlantAndEquipmentGross22.321.321.220.7
Percentage of Assets16.415.415.213.8
Percentage of Assets mpc:PipelinesAndRelatedAssets mpc:LogisticsandStorage0.00.00.00.0

mpc:ProcessingFractionationAndStorageFacilities, mpc:GatheringandProcessing


Property
Period End2020-09-302020-06-302020-03-312019-12-31
Value5944592356055545
Percentage of PropertyPlantAndEquipmentGross22.122.121.120.6
Percentage of Assets16.216.015.113.7
Percentage of Assets mpc:ProcessingFractionationAndStorageFacilities mpc:GatheringandProcessing0.00.00.00.0

mpc:Refineriesandrelatedassets, mpc:LogisticsandStorage


Property
Period End2020-09-302020-06-302020-03-312019-12-31
Value2196232423082870
Percentage of PropertyPlantAndEquipmentGross8.28.78.710.7
Percentage of Assets6.06.36.27.1
Percentage of Assets mpc:Refineriesandrelatedassets mpc:LogisticsandStorage0.00.00.00.0

mpc:Terminalsandrelatedassets, mpc:LogisticsandStorage


Property
Period End2020-09-302020-06-302020-03-312019-12-31
Value1534128111761109
Percentage of PropertyPlantAndEquipmentGross5.74.84.44.1
Percentage of Assets4.23.53.22.7
Percentage of Assets mpc:Terminalsandrelatedassets mpc:LogisticsandStorage0.00.00.00.0

mplx:Bargesandtowingvessels, mplx:LogisticsandStorage


Property
Period End2021-06-302021-03-312020-12-312019-12-31
Value965965965906
Percentage of PropertyPlantAndEquipmentGross3.73.63.63.4
Percentage of Assets2.72.72.72.2
Percentage of Assets mplx:Bargesandtowingvessels mplx:LogisticsandStorage0.00.00.00.0

mplx:GasGatheringAndTransmissionEquipmentAndFacilities, mplx:GatheringandProcessing


Property
Period End2021-06-302021-03-312020-12-312019-12-31
Value7574755975477159
Percentage of PropertyPlantAndEquipmentGross28.828.128.126.6
Percentage of Assets21.221.020.717.7
Percentage of Assets mplx:GasGatheringAndTransmissionEquipmentAndFacilities mplx:GatheringandProcessing0.00.00.00.0

mplx:LandBuildingOfficeEquipmentAndOther, mplx:GatheringandProcessing


Property
Period End2021-06-302021-03-312020-12-312019-12-31
Value511510507484
Percentage of PropertyPlantAndEquipmentGross1.91.91.91.8
Percentage of Assets1.41.41.41.2
Percentage of Assets mplx:LandBuildingOfficeEquipmentAndOther mplx:GatheringandProcessing0.00.00.00.0

mplx:LandBuildingOfficeEquipmentAndOther, mplx:LogisticsandStorage


Property
Period End2021-06-302021-03-312020-12-312019-12-31
Value1575158415841817
Percentage of PropertyPlantAndEquipmentGross6.05.95.96.8
Percentage of Assets4.44.44.34.5
Percentage of Assets mplx:LandBuildingOfficeEquipmentAndOther mplx:LogisticsandStorage0.00.00.00.0

mplx:PipelinesAndRelatedAssets, mplx:LogisticsandStorage


Property
Period End2021-06-302021-03-312020-12-312019-12-31
Value6045604560265572
Percentage of PropertyPlantAndEquipmentGross23.022.422.420.7
Percentage of Assets16.916.816.513.8
Percentage of Assets mplx:PipelinesAndRelatedAssets mplx:LogisticsandStorage0.00.00.00.0

mplx:ProcessingFractionationAndStorageFacilities, mplx:GatheringandProcessing


Property
Period End2021-06-302021-03-312020-12-312019-12-31
Value5726572557215545
Percentage of PropertyPlantAndEquipmentGross21.721.321.320.6
Percentage of Assets16.015.915.713.7
Percentage of Assets mplx:ProcessingFractionationAndStorageFacilities mplx:GatheringandProcessing0.00.00.00.0

mplx:Refineriesandrelatedassets, mplx:LogisticsandStorage


Property
Period End2021-06-302021-03-312020-12-312019-12-31
Value1789233523332870
Percentage of PropertyPlantAndEquipmentGross6.88.78.710.7
Percentage of Assets5.06.56.47.1
Percentage of Assets mplx:Refineriesandrelatedassets mplx:LogisticsandStorage0.00.00.00.0

mplx:Terminalsandrelatedassets, mplx:LogisticsandStorage


Property
Period End2021-06-302021-03-312020-12-312019-12-31
Value1652164916431109
Percentage of PropertyPlantAndEquipmentGross6.36.16.14.1
Percentage of Assets4.64.64.52.7
Percentage of Assets mplx:Terminalsandrelatedassets mplx:LogisticsandStorage0.00.00.00.0

us-gaap:AssetUnderConstruction, mpc:GatheringandProcessing


Property
Period End2020-09-302020-06-302020-03-312019-12-31
Value382368616745
Percentage of PropertyPlantAndEquipmentGross1.41.42.32.8
Percentage of Assets1.01.01.71.8
Percentage of Assets us-gaap:AssetUnderConstruction mpc:GatheringandProcessing0.00.00.00.0

us-gaap:AssetUnderConstruction, mpc:LogisticsandStorage


Property
Period End2020-09-302020-06-302020-03-312019-12-31
Value403520618660
Percentage of PropertyPlantAndEquipmentGross1.51.92.32.5
Percentage of Assets1.11.41.71.6
Percentage of Assets us-gaap:AssetUnderConstruction mpc:LogisticsandStorage0.00.00.00.0

us-gaap:AssetUnderConstruction, mplx:GatheringandProcessing


Property
Period End2021-06-302021-03-312020-12-312019-12-31
Value276288287745
Percentage of PropertyPlantAndEquipmentGross1.01.11.12.8
Percentage of Assets0.80.80.81.8
Percentage of Assets us-gaap:AssetUnderConstruction mplx:GatheringandProcessing0.00.00.00.0

us-gaap:AssetUnderConstruction, mplx:LogisticsandStorage


Property
Period End2021-06-302021-03-312020-12-312019-12-31
Value217277262660
Percentage of PropertyPlantAndEquipmentGross0.81.01.02.5
Percentage of Assets0.60.80.71.6
Percentage of Assets us-gaap:AssetUnderConstruction mplx:LogisticsandStorage0.00.00.00.0

us-gaap:PropertyPlantAndEquipmentGross us-gaap:StatementBusinessSegments

mpc:GatheringandProcessing


Property
Period End2020-09-302020-06-302020-03-312019-12-31
Value14248141541406113933
Percentage of PropertyPlantAndEquipmentGross52.952.852.951.9
Percentage of Assets38.938.238.034.5
Percentage of Assets mpc:GatheringandProcessing0.00.00.00.0

mpc:LogisticsandStorage


Property
Period End2020-09-302020-06-302020-03-312019-12-31
Value12671126381252612934
Percentage of PropertyPlantAndEquipmentGross47.147.247.148.1
Percentage of Assets34.634.133.832.0
Percentage of Assets mpc:LogisticsandStorage0.00.00.00.0

mplx:GatheringandProcessing


Property
Period End2021-06-302021-03-312020-12-312019-12-31
Value14087140821406213933
Percentage of PropertyPlantAndEquipmentGross53.552.352.351.9
Percentage of Assets39.439.138.634.5
Percentage of Assets mplx:GatheringandProcessing0.00.00.00.0

mplx:LogisticsandStorage


Property
Period End2021-06-302021-03-312020-12-312019-12-31
Value12243128551281312934
Percentage of PropertyPlantAndEquipmentGross46.547.747.748.1
Percentage of Assets34.235.735.232.0
Percentage of Assets mplx:LogisticsandStorage0.00.00.00.0

Accumulated Depreciation Depletion And Amortization Property Plant And Equipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value59785941565753045034475847224436406538733677350733323163227521321980199911151014893769435387375365353344332320309305296287276
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets16.716.515.514.513.612.911.710.717.116.416.115.715.615.111.711.110.610.96.76.25.64.82.827.927.227.029.128.828.126.925.625.024.321.921.2

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment mplx:NonRelatedParty, us-gaap:PropertyPlantAndEquipmentByType

mplx:ThirdParty, mplx:FinanceLease


Accumulated
Period End2020-12-312019-12-31
Value8.019
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment0.10.4
Percentage of Assets0.00.0
Percentage of Assets mplx:ThirdParty mplx:FinanceLease0.00.0

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap:PropertyPlantAndEquipmentByType

us-gaap:EquipmentLeasedToOtherParty


Accumulated
Period End2020-12-312019-12-31
Value20072355
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment35.549.9
Percentage of Assets5.55.8
Percentage of Assets us-gaap:EquipmentLeasedToOtherParty0.00.0

Amortization Of Intangible Assets

us-gaap:AmortizationOfIntangibleAssets us-gaap:StatementBusinessSegments

us-gaap:AmortizationOfIntangibleAssets

mpc:GatheringandProcessing


Amortization
Period End2020-09-302020-06-302020-03-31
Value232329
Percentage of AmortizationOfIntangibleAssets100.0100.0100.0
Percentage of Assets0.00.00.0
Percentage of Assets mpc:GatheringandProcessing0.00.00.0

mplx:GatheringandProcessing


Amortization
Period End2021-06-302021-03-31
Value2223
Percentage of AmortizationOfIntangibleAssets0.00.0
Percentage of Assets0.00.0
Percentage of Assets mplx:GatheringandProcessing0.00.0

Property Plant And Equipment Net

us-gaap:PropertyPlantAndEquipmentNet

us-gaap:PropertyPlantAndEquipmentNet


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value2035220996212182161521758218292214521892150211481614639142711364213291121871192211638114111073010537103601019596831109105910311008982955959966956929909910
Percentage of PropertyPlantAndEquipmentNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets56.958.358.359.058.859.054.853.063.362.864.363.863.763.362.562.062.662.464.564.264.463.861.879.776.676.183.082.380.980.380.078.576.469.369.9

us-gaap:PropertyPlantAndEquipmentNet mplx:NonRelatedParty, us-gaap:PropertyPlantAndEquipmentByType

mplx:ThirdParty, mplx:FinanceLease


Property
Period End2020-12-312019-12-31
Value9.027
Percentage of PropertyPlantAndEquipmentNet0.00.1
Percentage of Assets0.00.1
Percentage of Assets mplx:ThirdParty mplx:FinanceLease0.00.0

us-gaap:PropertyPlantAndEquipmentNet us-gaap:PropertyPlantAndEquipmentByType

us-gaap:EquipmentLeasedToOtherParty


Property
Period End2020-12-312019-12-31
Value39404592
Percentage of PropertyPlantAndEquipmentNet18.620.7
Percentage of Assets10.811.4
Percentage of Assets us-gaap:EquipmentLeasedToOtherParty0.00.0

Goodwill

us-gaap:Goodwill

us-gaap:Goodwill


Goodwill
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value765776577657765777227722953610735258125812586258624602460224522452245224521992199219922002559104104104104104104104104104104104104
Percentage of Goodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets21.421.321.020.920.920.923.626.010.910.911.411.611.511.711.511.712.112.313.213.413.713.816.37.57.67.78.68.88.98.88.78.68.68.08.0

us-gaap:Goodwill us-gaap:BusinessCombinationSeparatelyRecognizedTransactions

mpc:WesternRefiningWholesaleWesternRefiningProductTransport


Goodwillus-gaap:
Period End2020-07-31
Value65
Percentage of Goodwill0.0
Percentage of Assets0.0
Percentage of Assets mpc:WesternRefiningWholesaleWesternRefiningProductTransport0.0

mplx:WesternRefiningWholesaleWesternRefiningProductTransport


Goodwillus-gaap:
Period End2020-07-31
Value65
Percentage of Goodwill0.0
Percentage of Assets0.0
Percentage of Assets mplx:WesternRefiningWholesaleWesternRefiningProductTransport0.0

us-gaap:Goodwill us-gaap:BusinessCombinationSeparatelyRecognizedTransactions, us-gaap:StatementBusinessSegments

mpc:WesternRefiningWholesaleWesternRefiningProductTransport, mpc:LogisticsandStorage


Goodwillus-gaap:
Period End2020-07-31
Value65
Percentage of Goodwill0.0
Percentage of Assets0.0
Percentage of Assets mpc:WesternRefiningWholesaleWesternRefiningProductTransport mpc:LogisticsandStorage0.0

us-gaap:Goodwill us-gaap:ReportingUnit

mplx:CrudeGathering


Goodwillus-gaap:
Period End2020-12-31
Value1100
Percentage of Goodwill14.4
Percentage of Assets3.0
Percentage of Assets mplx:CrudeGathering0.0

us-gaap:Goodwill us-gaap:StatementBusinessSegments

mpc:LogisticsandStorage


Goodwillus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312018-12-312017-12-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-31
Value7657772277227722503162116116116116105105
Percentage of Goodwill100.0100.0100.081.019.57.25.35.35.35.34.1100.3
Percentage of Assets20.920.920.919.12.20.80.70.70.70.70.78.6
Percentage of Assets mpc:LogisticsandStorage0.00.00.00.00.00.00.00.00.00.00.00.0

mplx:LogisticsandStorage


Goodwillus-gaap:
Period End2021-06-302021-03-312020-12-312019-12-312018-12-31
Value76577657765777227234
Percentage of Goodwill100.0100.0100.081.0279.7
Percentage of Assets21.421.321.019.131.8
Percentage of Assets mplx:LogisticsandStorage0.00.00.00.00.0

Intangible Assets Net Excluding Goodwill

us-gaap:IntangibleAssetsNetExcludingGoodwill

us-gaap:IntangibleAssetsNetExcludingGoodwill


Intangible
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-31
Value89692795999110231055127013094054144244344354444534634734824925015115204660.0
Percentage of IntangibleAssetsNetExcludingGoodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets2.52.62.62.72.82.93.13.21.71.81.91.92.02.12.32.42.52.63.03.13.23.33.00.0

us-gaap:IntangibleAssetsNetExcludingGoodwill us-gaap:StatementBusinessSegments

mpc:GatheringandProcessing


Intangible
Period End2020-09-302020-06-302020-03-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value7808038261032415453492466
Percentage of IntangibleAssetsNetExcludingGoodwill78.778.578.381.397.9100.0100.0100.0
Percentage of Assets2.12.22.22.61.82.33.03.0
Percentage of Assets mpc:GatheringandProcessing0.00.00.00.00.00.00.00.0

mpc:LogisticsandStorage


Intangible
Period End2020-09-302020-06-302020-03-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value2112202292389.00.00.00.0
Percentage of IntangibleAssetsNetExcludingGoodwill21.321.521.718.72.10.00.00.0
Percentage of Assets0.60.60.60.60.00.00.00.0
Percentage of Assets mpc:LogisticsandStorage0.00.00.00.00.00.00.00.0

mplx:GatheringandProcessing


Intangible
Period End2021-06-302021-03-312020-12-312019-12-31
Value7127347571032
Percentage of IntangibleAssetsNetExcludingGoodwill79.579.278.981.3
Percentage of Assets2.02.02.12.6
Percentage of Assets mplx:GatheringandProcessing0.00.00.00.0

mplx:LogisticsandStorage


Intangible
Period End2021-06-302021-03-312020-12-312019-12-31
Value184193202238
Percentage of IntangibleAssetsNetExcludingGoodwill20.520.821.118.7
Percentage of Assets0.50.50.60.6
Percentage of Assets mplx:LogisticsandStorage0.00.00.00.0

Finite Lived Intangible Assets Net

us-gaap:FiniteLivedIntangibleAssetsNet

us-gaap:FiniteLivedIntangibleAssetsNet


Finite
Period End2021-03-312020-12-312020-09-30
Value927959991
Percentage of FiniteLivedIntangibleAssetsNet100.0100.0100.0
Percentage of Assets2.62.62.7

Operating Lease Right Of Use Asset

us-gaap:OperatingLeaseRightOfUseAsset

us-gaap:OperatingLeaseRightOfUseAsset


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value2972963093233413523653662552620.0
Percentage of OperatingLeaseRightOfUseAsset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets0.80.80.80.90.91.00.90.91.11.10.0

us-gaap:OperatingLeaseRightOfUseAsset mplx:NonRelatedParty

mplx:ThirdParty


Operating
Period End2020-12-312019-12-31
Value309365
Percentage of OperatingLeaseRightOfUseAsset100.0100.0
Percentage of Assets0.80.9
Percentage of Assets mplx:ThirdParty0.00.0

us-gaap:OperatingLeaseRightOfUseAsset us-gaap:RelatedPartyTransactionsByRelatedParty

mpc:MarathonPetroleumCorporation


Operating
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value2312312312322322322320.0
Percentage of OperatingLeaseRightOfUseAsset71.567.765.663.663.491.088.50.0
Percentage of Assets0.60.60.60.60.61.01.00.0
Percentage of Assets mpc:MarathonPetroleumCorporation0.00.00.00.00.00.00.00.0

mplx:MarathonPetroleumCorporation


Operating
Period End2021-06-302021-03-312020-12-312019-12-31
Value230230231232
Percentage of OperatingLeaseRightOfUseAsset77.477.774.863.6
Percentage of Assets0.60.60.60.6
Percentage of Assets mplx:MarathonPetroleumCorporation0.00.00.00.0

Other Assets Noncurrent

us-gaap:OtherAssetsNoncurrent

us-gaap:OtherAssetsNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value62644848515052553633353637282622181714141211124.23.78.44.01.51.52.02.12.22.32.52.8
Percentage of OtherAssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.20.20.10.10.10.10.10.10.20.10.20.20.20.10.10.10.10.10.10.10.10.10.10.30.30.60.30.10.10.20.20.20.20.20.2

Accounts Payable Current

us-gaap:AccountsPayableCurrent

us-gaap:AccountsPayableCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value15816215214014513824219613411016214617214315115214412112310710210589675544423425273041433439
Percentage of AccountsPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.40.40.40.40.40.40.60.50.60.50.70.70.80.70.80.80.80.70.70.70.60.70.64.94.03.33.52.92.22.32.53.43.62.63.0

Accrued Liabilities Current

us-gaap:AccruedLiabilitiesCurrent

us-gaap:AccruedLiabilitiesCurrent


Accrued
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-31
Value25823319416913813518718514818925023120217819422819318015918611
Percentage of AccruedLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.70.60.50.50.40.40.50.40.60.81.11.21.11.01.11.41.21.11.01.20.9

Debt Current

us-gaap:DebtCurrent

us-gaap:DebtCurrent


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value1.02.07643073.04.09.05106.01.01.01.01.01.01.01.01.01.01.01.01.01.01.00.80.80.80.80.80.80.80.70.70.70.70.7
Percentage of DebtCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.02.10.80.00.00.01.20.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.10.10.10.10.10.10.10.10.10.10.10.1

Liabilities Current

us-gaap:LiabilitiesCurrent

us-gaap:LiabilitiesCurrent


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value17271196208615311228121421322232104810291186120412798761304104879071270467065010456121351281151009082878385786463
Percentage of LiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets4.83.35.74.23.33.35.35.44.44.45.25.46.04.26.75.44.23.94.24.14.06.53.99.79.38.58.37.67.07.36.97.06.44.94.9

us-gaap:LiabilitiesCurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

mpc:NonVIEs


Liabilities
Period End2020-09-302020-06-302019-12-31
Value194181245
Percentage of LiabilitiesCurrent12.714.711.5
Percentage of Assets0.50.50.6
Percentage of Assets mpc:NonVIEs0.00.00.0

mpc:OtherVIEs


Liabilities
Period End2020-09-302020-06-302019-12-31
Value304265192
Percentage of LiabilitiesCurrent19.921.69.0
Percentage of Assets0.80.70.5
Percentage of Assets mpc:OtherVIEs0.00.00.0

mpc:OtherVIEsandNonVIEs


Liabilities
Period End2020-09-302020-06-302019-12-31
Value498446437
Percentage of LiabilitiesCurrent32.536.320.5
Percentage of Assets1.41.21.1
Percentage of Assets mpc:OtherVIEsandNonVIEs0.00.00.0

mplx:NonVIEs


Liabilities
Period End2021-06-302021-03-312020-12-312019-12-31
Value281194187245
Percentage of LiabilitiesCurrent16.316.29.011.5
Percentage of Assets0.80.50.50.6
Percentage of Assets mplx:NonVIEs0.00.00.00.0

mplx:OtherVIEs


Liabilities
Period End2021-06-302021-03-312020-12-312019-12-31
Value183338323192
Percentage of LiabilitiesCurrent10.628.315.59.0
Percentage of Assets0.50.90.90.5
Percentage of Assets mplx:OtherVIEs0.00.00.00.0

mplx:OtherVIEsandNonVIEs


Liabilities
Period End2021-06-302021-03-312020-12-312019-12-31
Value464532510437
Percentage of LiabilitiesCurrent26.944.524.420.5
Percentage of Assets1.31.51.41.1
Percentage of Assets mplx:OtherVIEsandNonVIEs0.00.00.00.0

Operating Lease Liability Current

us-gaap:OperatingLeaseLiabilityCurrent

us-gaap:OperatingLeaseLiabilityCurrent


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value636363656967666147460.0
Percentage of OperatingLeaseLiabilityCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets0.20.20.20.20.20.20.20.10.20.20.0

us-gaap:OperatingLeaseLiabilityCurrent mplx:NonRelatedParty

mplx:ThirdParty


Operating
Period End2020-12-312019-12-31
Value6366
Percentage of OperatingLeaseLiabilityCurrent100.0100.0
Percentage of Assets0.20.2
Percentage of Assets mplx:ThirdParty0.00.0

us-gaap:OperatingLeaseLiabilityCurrent us-gaap:RelatedPartyTransactionsByRelatedParty

mpc:MarathonPetroleumCorporation


Operating
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value1.01.01.01.01.01.01.00.0
Percentage of OperatingLeaseLiabilityCurrent1.51.41.51.51.62.12.20.0
Percentage of Assets0.00.00.00.00.00.00.00.0
Percentage of Assets mpc:MarathonPetroleumCorporation0.00.00.00.00.00.00.00.0

Other Liabilities Current

us-gaap:OtherLiabilitiesCurrent

us-gaap:OtherLiabilitiesCurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value1781511501581431291366569575836656104453841292624181714122.73.67.01.71.83.21.71.41.61.12.63.0
Percentage of OtherLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.50.40.40.40.40.30.31.60.40.30.43.02.82.10.20.20.20.10.10.10.10.10.10.20.30.50.10.20.30.10.10.10.10.20.2

Liabilities Noncurrent

us-gaap:LiabilitiesNoncurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:LiabilitiesNoncurrent

mpc:NonVIEs


Liabilities
Period End2020-09-302020-06-302019-12-31
Value857853822
Percentage of LiabilitiesNoncurrent100.0100.0100.0
Percentage of Assets2.32.32.0
Percentage of Assets mpc:NonVIEs0.00.00.0

mpc:OtherVIEs


Liabilities
Period End2020-09-302020-06-302019-12-31
Value1611656305
Percentage of LiabilitiesNoncurrent188.076.937.1
Percentage of Assets4.41.80.8
Percentage of Assets mpc:OtherVIEs0.00.00.0

mpc:OtherVIEsandNonVIEs


Liabilities
Period End2020-09-302020-06-302019-12-31
Value246815091127
Percentage of LiabilitiesNoncurrent288.0176.9137.1
Percentage of Assets6.74.12.8
Percentage of Assets mpc:OtherVIEsandNonVIEs0.00.00.0

mplx:NonVIEs


Liabilities
Period End2021-06-302021-03-312020-12-312019-12-31
Value862853830822
Percentage of LiabilitiesNoncurrent0.00.00.0100.0
Percentage of Assets2.42.42.32.0
Percentage of Assets mplx:NonVIEs0.00.00.00.0

mplx:OtherVIEs


Liabilities
Period End2021-06-302021-03-312020-12-312019-12-31
Value237920531904305
Percentage of LiabilitiesNoncurrent0.00.00.037.1
Percentage of Assets6.75.75.20.8
Percentage of Assets mplx:OtherVIEs0.00.00.00.0

mplx:OtherVIEsandNonVIEs


Liabilities
Period End2021-06-302021-03-312020-12-312019-12-31
Value3241290627341127
Percentage of LiabilitiesNoncurrent0.00.00.0137.1
Percentage of Assets9.18.17.52.8
Percentage of Assets mplx:OtherVIEsandNonVIEs0.00.00.00.0

Debt And Capital Lease Obligations

us-gaap:DebtAndCapitalLeaseObligations

us-gaap:DebtAndCapitalLeaseObligations


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value19609204452053620757209382086420119201201447314283138561335712357123577362727771087108485848584859518557367597597596442652652801010101111
Percentage of DebtAndCapitalLeaseObligations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets54.856.756.456.656.656.449.848.760.960.660.859.757.758.837.837.838.238.929.229.630.232.536.654.654.956.153.122.222.423.50.90.90.90.80.9

Long Term Debt And Capital Lease Obligations

us-gaap:LongTermDebtAndCapitalLeaseObligations

us-gaap:LongTermDebtAndCapitalLeaseObligations


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value19234200521937520042205562046719704191901403013832133921288911874118616945684866666654442244114400471552557527527576442642642799.810.0101010
Percentage of LongTermDebtAndCapitalLeaseObligations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets53.855.753.254.755.555.348.746.559.158.658.857.655.556.535.635.635.836.426.626.927.429.533.554.154.455.953.022.122.423.40.80.80.80.80.8

Deferred Income Tax Liabilities Net

us-gaap:DeferredIncomeTaxLiabilitiesNet

us-gaap:DeferredIncomeTaxLiabilitiesNet


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value11111212111112
Percentage of DeferredIncomeTaxLiabilitiesNet100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.0

Operating Lease Liability Noncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value2322302442582742843023092092160.0
Percentage of OperatingLeaseLiabilityNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets0.60.60.70.70.70.80.70.70.90.90.0

us-gaap:OperatingLeaseLiabilityNoncurrent mplx:NonRelatedParty

mplx:ThirdParty


Operating
Period End2020-12-312019-12-31
Value244302
Percentage of OperatingLeaseLiabilityNoncurrent100.0100.0
Percentage of Assets0.70.7
Percentage of Assets mplx:ThirdParty0.00.0

us-gaap:OperatingLeaseLiabilityNoncurrent us-gaap:RelatedPartyTransactionsByRelatedParty

mpc:MarathonPetroleumCorporation


Operating
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value2302302302302312312310.0
Percentage of OperatingLeaseLiabilityNoncurrent89.183.981.076.274.8110.5106.90.0
Percentage of Assets0.60.60.60.60.61.01.00.0
Percentage of Assets mpc:MarathonPetroleumCorporation0.00.00.00.00.00.00.00.0

mplx:MarathonPetroleumCorporation


Operating
Period End2021-06-302021-03-312020-12-312019-12-31
Value229229229230
Percentage of OperatingLeaseLiabilityNoncurrent98.799.693.976.2
Percentage of Assets0.60.60.60.6
Percentage of Assets mplx:MarathonPetroleumCorporation0.00.00.00.0

Lessee Operating Lease Liability Payments Due Year Two

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo mplx:NonRelatedParty

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo

mplx:ThirdParty


Lessee
Period End2020-12-31
Value67
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo100.0
Percentage of Assets0.2
Percentage of Assets mplx:ThirdParty0.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo us-gaap:RelatedPartyTransactionsByRelatedParty

mplx:MarathonPetroleumCorporation


Lessee
Period End2020-12-31
Value14
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo20.9
Percentage of Assets0.0
Percentage of Assets mplx:MarathonPetroleumCorporation0.0

Lessee Operating Lease Liability Payments Due Year Three

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree mplx:NonRelatedParty

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree

mplx:ThirdParty


Lessee
Period End2020-12-31
Value57
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearThree100.0
Percentage of Assets0.2
Percentage of Assets mplx:ThirdParty0.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree us-gaap:RelatedPartyTransactionsByRelatedParty

mplx:MarathonPetroleumCorporation


Lessee
Period End2020-12-31
Value14
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearThree24.6
Percentage of Assets0.0
Percentage of Assets mplx:MarathonPetroleumCorporation0.0

Lessee Operating Lease Liability Payments Due Year Four

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour mplx:NonRelatedParty

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour

mplx:ThirdParty


Lessee
Period End2020-12-31
Value35
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFour100.0
Percentage of Assets0.1
Percentage of Assets mplx:ThirdParty0.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour us-gaap:RelatedPartyTransactionsByRelatedParty

mplx:MarathonPetroleumCorporation


Lessee
Period End2020-12-31
Value14
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFour40.0
Percentage of Assets0.0
Percentage of Assets mplx:MarathonPetroleumCorporation0.0

Lessee Operating Lease Liability Payments Due Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive mplx:NonRelatedParty

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive

mplx:ThirdParty


Lessee
Period End2020-12-31
Value19
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFive100.0
Percentage of Assets0.1
Percentage of Assets mplx:ThirdParty0.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive us-gaap:RelatedPartyTransactionsByRelatedParty

mplx:MarathonPetroleumCorporation


Lessee
Period End2020-12-31
Value14
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFive73.7
Percentage of Assets0.0
Percentage of Assets mplx:MarathonPetroleumCorporation0.0

Lessee Operating Lease Liability Payments Due After Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive mplx:NonRelatedParty

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive

mplx:ThirdParty


Lessee
Period End2020-12-31
Value115
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive100.0
Percentage of Assets0.3
Percentage of Assets mplx:ThirdParty0.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive us-gaap:RelatedPartyTransactionsByRelatedParty

mplx:MarathonPetroleumCorporation


Lessee
Period End2020-12-31
Value591
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive513.9
Percentage of Assets1.6
Percentage of Assets mplx:MarathonPetroleumCorporation0.0

Operating Lease Liability

us-gaap:OperatingLeaseLiability mplx:NonRelatedParty

us-gaap:OperatingLeaseLiability

mplx:ThirdParty


Operating
Period End2020-12-312019-12-31
Value307368
Percentage of OperatingLeaseLiability100.0100.0
Percentage of Assets0.80.9
Percentage of Assets mplx:ThirdParty0.00.0

us-gaap:OperatingLeaseLiability us-gaap:RelatedPartyTransactionsByRelatedParty

mplx:MarathonPetroleumCorporation


Operating
Period End2020-12-312019-12-31
Value230231
Percentage of OperatingLeaseLiability74.962.8
Percentage of Assets0.60.6
Percentage of Assets mplx:MarathonPetroleumCorporation0.00.0

Lessee Operating Lease Liability Payments Due

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue mplx:NonRelatedParty

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue

mplx:ThirdParty


Lessee
Period End2020-12-31
Value369
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue100.0
Percentage of Assets1.0
Percentage of Assets mplx:ThirdParty0.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue us-gaap:RelatedPartyTransactionsByRelatedParty

mplx:MarathonPetroleumCorporation


Lessee
Period End2020-12-31
Value661
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue179.1
Percentage of Assets1.8
Percentage of Assets mplx:MarathonPetroleumCorporation0.0

Lessee Operating Lease Liability Undiscounted Excess Amount

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount mplx:NonRelatedParty

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount

mplx:ThirdParty


Lessee
Period End2020-12-31
Value62
Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount100.0
Percentage of Assets0.2
Percentage of Assets mplx:ThirdParty0.0

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount us-gaap:RelatedPartyTransactionsByRelatedParty

mplx:MarathonPetroleumCorporation


Lessee
Period End2020-12-31
Value431
Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount695.2
Percentage of Assets1.2
Percentage of Assets mplx:MarathonPetroleumCorporation0.0

Accumulated Other Comprehensive Income Loss Net Of Tax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax


Accumulated
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value-15000000.0-16000000.0-16000000.0-16000000.0-15000000.0-15000000.0-15000000.0-15000000.0-16000000.0-16000000.0-16000000.0-16000000.0-14000000.00
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.0-0.1-0.1-0.1-0.1-0.1-0.1-0.10.0

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:RetirementPlanType, us-gaap:StatementEquityComponents

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Accumulated
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value-2000000.0-2000000.0-2000000.0-2000000.0-1000000.0-1000000.0-1000000.0-1000000.0-2000000.0-2000000.0-2000000.0-2000000.0-1000000.00
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax13.312.512.512.56.76.76.76.712.512.512.512.57.10.0
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.00.0
Percentage of Assets us-gaap:OtherPostretirementBenefitPlansDefinedBenefit us-gaap:AccumulatedDefinedBenefitPlansAdjustment0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PensionPlansDefinedBenefit, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Accumulated
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value-13000000.0-14000000.0-14000000.0-14000000.0-14000000.0-14000000.0-14000000.0-14000000.0-14000000.0-14000000.0-14000000.0-14000000.0-13000000.00
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax86.787.587.587.593.393.393.393.387.587.587.587.592.90.0
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.0-0.1-0.1-0.1-0.1-0.1-0.1-0.10.0
Percentage of Assets us-gaap:PensionPlansDefinedBenefit us-gaap:AccumulatedDefinedBenefitPlansAdjustment0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

mpc:LoopLlcandExplorerPipeline


Accumulated
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-31
Value-16000000.0-16000000.0-16000000.0-15000000.0-15000000.0-15000000.0-15000000.0-16000000.0-16000000.0-16000000.0-16000000.0-14000000.0-14000000.00
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.10.0
Percentage of Assets mpc:LoopLlcandExplorerPipeline0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

mplx:LoopLlcandExplorerPipeline


Accumulated
Period End2021-06-302021-03-312020-12-312020-06-302020-03-312019-12-31
Value-17000000.0-17000000.0-15000000.0-16000000.0-16000000.0-15000000.0
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax0.00.0100.0100.0100.0100.0
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets mplx:LoopLlcandExplorerPipeline0.00.00.00.00.00.0

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RetirementPlanType, us-gaap:StatementEquityComponents

mplx:LoopLlcandExplorerPipeline, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Accumulated
Period End2021-06-302021-03-312020-12-312020-06-302020-03-312019-12-31
Value-2000000.0-2000000.0-2000000.0-2000000.0-2000000.0-1000000.0
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax0.00.013.312.512.56.7
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets mplx:LoopLlcandExplorerPipeline us-gaap:OtherPostretirementBenefitPlansDefinedBenefit us-gaap:AccumulatedDefinedBenefitPlansAdjustment0.00.00.00.00.00.0

mplx:LoopLlcandExplorerPipeline, us-gaap:PensionPlansDefinedBenefit, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Accumulated
Period End2021-06-302021-03-312020-12-312020-06-302020-03-312019-12-31
Value-15000000.0-15000000.0-13000000.0-14000000.0-14000000.0-14000000.0
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax0.00.086.787.587.593.3
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets mplx:LoopLlcandExplorerPipeline us-gaap:PensionPlansDefinedBenefit us-gaap:AccumulatedDefinedBenefitPlansAdjustment0.00.00.00.00.00.0

Minority Interest Decrease From Distributions To Noncontrolling Interest Holders

us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders

us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders


Minority
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-31
Value10.010.09.08.09.08.06.06.07.04.03.03.03.02.00.02.00.02.00.01.00.50.20.20.18.7121014252212
Percentage of MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders us-gaap:StatementEquityComponents

us-gaap:NoncontrollingInterest


Minority
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value10.010.09.08.09.08.06.06.07.04.03.03.03.02.00.02.0
Percentage of MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:NoncontrollingInterest0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value13651124118512221105100910921538834618799737840450569494467377356339298295545769585661567145586146
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax72.060.452.769.669.456.747.287.465.448.946.655.068.240.752.450.451.042.649.948.252.848.421.138.447.042.542.844.942.252.435.947.350.70.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-155.0-90.0-202.0-283.0-415.0-362.0-874.0-1014.0-600.0-575.0-659.0-1073.0-464.0-490.0-470.0-433.0-451.0-953.0-363.0-323.0-286.0-240.0-1378.9-54.9-34.9-29.3-32.0-33.7-2.8-6.6-32.6-40.2-31.6-9.2
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-8.2-4.8-9.0-16.1-26.1-20.3-37.7-57.6-47.0-45.5-38.4-80.0-37.7-44.3-43.3-44.2-49.2-107.6-50.8-45.9-50.7-39.4-536.5-36.9-23.6-21.3-24.2-24.4-2.1-4.8-26.0-32.5-25.90.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-1226.0-1025.0-996.0-978.0-680.0-605.0-244.0-499.0-320.0-26.0-103.0366-373.037-97.0-351.0126073315719-94.01277-42.1-36.676-29.4-39.2-51.1-78.8-45.3-46.7-142.9-26.3
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-64.7-55.0-44.3-55.7-42.7-34.0-10.5-28.4-25.1-2.1-6.027.3-30.33.3-8.9-35.81.368.54.622.33.4-15.4497.2-28.3-24.855.3-22.3-28.4-38.2-57.4-36.1-37.7-116.90.0

Amortization Of Financing Costs

us-gaap:AmortizationOfFinancingCosts

us-gaap:AmortizationOfFinancingCosts


Amortization
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value181717151514133.013131415141615131312121112114.00.01.00.0
Percentage of AmortizationOfFinancingCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.0

us-gaap:AmortizationOfFinancingCosts us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Amortization
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value18171515141310.0131314141516151313
Percentage of AmortizationOfFinancingCosts100.0100.0100.0100.0100.0100.0333.3100.0100.0100.093.3107.1100.0100.0100.0100.0

Deferred Income Tax Expense Benefit

us-gaap:DeferredIncomeTaxExpenseBenefit

us-gaap:DeferredIncomeTaxExpenseBenefit


Deferred
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value00-1000000.00-3000000.03000000.00-2000000.01000000.02000000.01000000.04000000.0-3000000.01000000.01000000.00-1000000.0-3000000.0-9000000.0-4000000.03000000.00-1000000.000-400000.0
Percentage of DeferredIncomeTaxExpenseBenefit0.00.0100.00.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.00.0100.00.00.0100.0

Increase Decrease In Accounts Receivable

us-gaap:IncreaseDecreaseInAccountsReceivable

us-gaap:IncreaseDecreaseInAccountsReceivable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value16677.0-38.040-71.02144-25.0-57.0-35.086638.0-28.03727-44.08.024155.027-0.84.0-1.61.3-2.0-1.30.0-2.11.5-1.2-3.6
Percentage of IncreaseDecreaseInAccountsReceivable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0

Increase Decrease In Inventories

us-gaap:IncreaseDecreaseInInventories

us-gaap:IncreaseDecreaseInInventories


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-3.0114.01.010.0-3.06.04.02.0-3.0-5.05.07.0-2.00.01.02.00.04.01.04.0-1.0-1.00.00.00.0
Percentage of IncreaseDecreaseInInventories100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.00.0100.0100.0100.0100.0100.00.00.00.0

Increase Decrease In Other Operating Capital Net

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-2000000.01000000.03000000.01000000.0-3000000.04000000.02000000.0-3000000.00-3000000.00000
Percentage of IncreaseDecreaseInOtherOperatingCapitalNet100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.00.00.00.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value13651124118512221105100910921538834618799737840450569494467377356339298295545769585661567145586146
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax72.060.452.769.669.456.747.287.465.448.946.655.068.240.752.450.451.042.649.948.252.848.421.138.447.042.542.844.942.252.435.947.350.70.0

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value706739691665648-2724.0-581.062948250343451045342123821619015013314119-60.018415145292928342021181713
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax37.239.730.737.940.7-152.9-25.135.737.839.825.338.036.838.021.922.020.716.918.620.13.4-9.97.027.934.733.222.121.121.524.916.117.415.20.00.0

us-gaap:NetIncomeLoss us-gaap:PartnerTypeOfPartnersCapitalAccount

mpc:LimitedPartnersCommonUnits


Net
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312013-09-30
Value635617-2755.0-612.059944048341449143340512611499726274-35.0-99.01833212015139.910
Percentage of NetIncomeLoss95.595.2101.1105.395.291.396.095.496.395.696.252.952.852.148.046.652.5-184.2165.0100.079.541.043.952.147.149.048.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax36.238.8-154.7-26.434.034.538.224.136.635.236.611.611.610.88.18.710.5-6.2-16.37.022.214.214.511.59.97.98.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:LimitedPartnersCommonUnits0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

mplx:LimitedPartnersCommonUnits


Net
Period End2021-06-302021-03-312020-06-302020-03-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value675708617-2755.0322120151313159.7109.89.66.5
Percentage of NetIncomeLoss95.695.895.2101.179.042.644.151.747.147.244.448.048.852.754.549.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax35.638.038.8-154.722.114.814.611.49.910.211.17.78.58.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:LimitedPartnersCommonUnits0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:StatementClassOfStock

us-gaap:PreferredPartner, us-gaap:SeriesAPreferredStock


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value21202020212020202120201920
Percentage of NetIncomeLoss3.02.72.93.03.2-0.7-3.43.24.44.04.63.74.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.11.10.91.11.31.10.91.11.61.61.21.41.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:PreferredPartner us-gaap:SeriesAPreferredStock0.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PreferredPartner, us-gaap:SeriesBPreferredStock


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value10.01110.010.010.0111110.021
Percentage of NetIncomeLoss1.41.51.41.51.5-0.4-1.91.64.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.50.60.40.60.60.60.50.61.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:PreferredPartner us-gaap:SeriesBPreferredStock0.00.00.00.00.00.00.00.00.0

Profit Loss

us-gaap:ProfitLoss

us-gaap:ProfitLoss


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value715748700674655-2716.0-573.068948850943951645642324121719118713214320-37.0184151453643425536393435
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax37.740.231.138.441.1-152.5-24.739.138.240.325.638.537.038.222.222.120.921.118.520.33.5-6.17.028.134.833.427.631.232.040.629.331.728.50.0

us-gaap:ProfitLoss us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

mpc:NonVIEs


Profit
Period End2020-09-302019-09-30
Value145222
Percentage of ProfitLoss21.532.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax8.312.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:NonVIEs0.00.0

mpc:OtherVIEs


Profit
Period End2020-09-302019-09-30
Value5365
Percentage of ProfitLoss7.99.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.03.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:OtherVIEs0.00.0

mpc:OtherVIEsandNonVIEs


Profit
Period End2020-09-302019-09-30
Value198287
Percentage of ProfitLoss29.441.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax11.316.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mpc:OtherVIEsandNonVIEs0.00.0

mplx:NonVIEs


Profit
Period End2021-06-302021-03-312020-06-302020-03-31
Value143140146186
Percentage of ProfitLoss20.018.722.3-6.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax7.57.59.210.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:NonVIEs0.00.00.00.0

mplx:OtherVIEs


Profit
Period End2021-06-302021-03-312020-06-302020-03-31
Value416454-337.0
Percentage of ProfitLoss5.78.68.212.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax2.23.43.4-18.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:OtherVIEs0.00.00.00.0

mplx:OtherVIEsandNonVIEs


Profit
Period End2021-06-302021-03-312020-06-302020-03-31
Value184204200-151.0
Percentage of ProfitLoss25.727.330.55.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.711.012.6-8.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mplx:OtherVIEsandNonVIEs0.00.00.00.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-155.0-90.0-202.0-283.0-415.0-362.0-874.0-1014.0-600.0-575.0-659.0-1073.0-464.0-490.0-470.0-433.0-451.0-953.0-363.0-323.0-286.0-240.0-1378.9-54.9-34.9-29.3-32.0-33.7-2.8-6.6-32.6-40.2-31.6-9.2
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-8.2-4.8-9.0-16.1-26.1-20.3-37.7-57.6-47.0-45.5-38.4-80.0-37.7-44.3-43.3-44.2-49.2-107.6-50.8-45.9-50.7-39.4-536.5-36.9-23.6-21.3-24.2-24.4-2.1-4.8-26.0-32.5-25.90.0

Payments To Acquire Property Plant And Equipment

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value10912620127432937968883642745753652140745540735237228033230527829114259352931338.15.12540319.2
Percentage of PaymentsToAcquirePropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-1226.0-1025.0-996.0-978.0-680.0-605.0-244.0-499.0-320.0-26.0-103.0366-373.037-97.0-351.0126073315719-94.01277-42.1-36.676-29.4-39.2-51.1-78.8-45.3-46.7-142.9-26.3
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-64.7-55.0-44.3-55.7-42.7-34.0-10.5-28.4-25.1-2.1-6.027.3-30.33.3-8.9-35.81.368.54.622.33.4-15.4497.2-28.3-24.855.3-22.3-28.4-38.2-57.4-36.1-37.7-116.90.0

Proceeds From Issuance Of Long Term Debt

us-gaap:ProceedsFromIssuanceOfLongTermDebt

us-gaap:ProceedsFromIssuanceOfLongTermDebt


Proceeds
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-31
Value890191034901175132550063991450825245111250.096102504200.022410.00.01283069610.00.05288900.00.02700.0
Percentage of ProceedsFromIssuanceOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.00.0100.00.00.0100.0100.0100.00.00.0100.0100.00.00.0100.00.0

Repayments Of Long Term Debt

us-gaap:RepaymentsOfLongTermDebt

us-gaap:RepaymentsOfLongTermDebt


Repayments
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value17262020369011015815015762126140019991260.046551652500.01.00.01.045485710250.30.24155100.2150.20.10.20.20.2
Percentage of RepaymentsOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.00.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RepaymentsOfLongTermDebt us-gaap:DebtInstrument, us-gaap:LongtermDebtType

mplx:FloatingRateSeniorNotesDueSeptember2021, us-gaap:SeniorNotes


Repayments
Period End2020-09-14
Value1000
Percentage of RepaymentsOfLongTermDebt0.0

Debt Instrument Interest Rate Stated Percentage

us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType

us-gaap:DebtInstrumentInterestRateStatedPercentage

mpc:MPLXLP, mpc:SeniorNotesDueAugust2030, us-gaap:SeniorNotes


Debt
Period End2020-09-30
Value2.65
Percentage of DebtInstrumentInterestRateStatedPercentage100.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mpc:MPLXLP mpc:SeniorNotesDueAugust2030 us-gaap:SeniorNotes0.0

mpc:MPLXLP, mpc:SeniorNotesDueMarch2026, us-gaap:SeniorNotes


Debt
Period End2020-09-30
Value1.75
Percentage of DebtInstrumentInterestRateStatedPercentage66.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mpc:MPLXLP mpc:SeniorNotesDueMarch2026 us-gaap:SeniorNotes0.0

mpc:MPLXLP, mpc:SeniorNotesDueOctober2022, us-gaap:SeniorNotes


Debt
Period End2020-09-302019-12-312019-09-30
Value6.250.06250.0625
Percentage of DebtInstrumentInterestRateStatedPercentage235.80.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations mpc:MPLXLP mpc:SeniorNotesDueOctober2022 us-gaap:SeniorNotes0.00.00.0

mplx:MPLXLP, mplx:SeniorNotesDueApril2038, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value4.5
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MPLXLP mplx:SeniorNotesDueApril2038 us-gaap:SeniorNotes0.0

mplx:MPLXLP, mplx:SeniorNotesDueApril2048, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value4.7
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MPLXLP mplx:SeniorNotesDueApril2048 us-gaap:SeniorNotes0.0

mplx:MPLXLP, mplx:SeniorNotesDueApril2058, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value4.9
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MPLXLP mplx:SeniorNotesDueApril2058 us-gaap:SeniorNotes0.0

mplx:MPLXLP, mplx:SeniorNotesDueAugust2030, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value2.65
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MPLXLP mplx:SeniorNotesDueAugust2030 us-gaap:SeniorNotes0.0

mplx:MPLXLP, mplx:SeniorNotesDueDecember2024, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value4.875
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MPLXLP mplx:SeniorNotesDueDecember2024 us-gaap:SeniorNotes0.0

mplx:MPLXLP, mplx:SeniorNotesDueFebruary2025, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value4.0
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MPLXLP mplx:SeniorNotesDueFebruary2025 us-gaap:SeniorNotes0.0

mplx:MPLXLP, mplx:SeniorNotesDueFebruary2029, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value4.8
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MPLXLP mplx:SeniorNotesDueFebruary2029 us-gaap:SeniorNotes0.0

mplx:MPLXLP, mplx:SeniorNotesDueFebruary2049, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value5.5
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MPLXLP mplx:SeniorNotesDueFebruary2049 us-gaap:SeniorNotes0.0

mplx:MPLXLP, mplx:SeniorNotesDueJuly2023, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value4.5
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MPLXLP mplx:SeniorNotesDueJuly2023 us-gaap:SeniorNotes0.0

mplx:MPLXLP, mplx:SeniorNotesDueJune2025, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value4.875
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MPLXLP mplx:SeniorNotesDueJune2025 us-gaap:SeniorNotes0.0

mplx:MPLXLP, mplx:SeniorNotesDueMarch2023, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value3.375
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MPLXLP mplx:SeniorNotesDueMarch2023 us-gaap:SeniorNotes0.0

mplx:MPLXLP, mplx:SeniorNotesDueMarch2026, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value1.75
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MPLXLP mplx:SeniorNotesDueMarch2026 us-gaap:SeniorNotes0.0

mplx:MPLXLP, mplx:SeniorNotesDueMarch2027, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value4.125
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MPLXLP mplx:SeniorNotesDueMarch2027 us-gaap:SeniorNotes0.0

mplx:MPLXLP, mplx:SeniorNotesDueMarch2028, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value4.0
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MPLXLP mplx:SeniorNotesDueMarch2028 us-gaap:SeniorNotes0.0

mplx:MPLXLP, mplx:SeniorNotesDueMarch2047, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value5.2
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MPLXLP mplx:SeniorNotesDueMarch2047 us-gaap:SeniorNotes0.0

us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType

mplx:MPLXLP, mplx:SeniorNotesDueJanuary2025, us-gaap:SeniorNotes, us-gaap:SubsequentEvent


Debt
Period End2021-01-15
Value5.25
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MPLXLP mplx:SeniorNotesDueJanuary2025 us-gaap:SeniorNotes us-gaap:SubsequentEvent0.0

us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity, us-gaap:Range, us-gaap:DebtInstrument, us-gaap:LongtermDebtType

mplx:ANDXLP, srt:Maximum, mplx:SeniorNotesDueJanuary2025, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value5.25
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:ANDXLP srt:Maximum mplx:SeniorNotesDueJanuary2025 us-gaap:SeniorNotes0.0

mplx:ANDXLP, srt:Minimum, mplx:SeniorNotesDueDecember2022, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value3.5
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:ANDXLP srt:Minimum mplx:SeniorNotesDueDecember2022 us-gaap:SeniorNotes0.0

mplx:MarkWest, srt:Maximum, mplx:SeniorNotesDueJune2025, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value4.875
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MarkWest srt:Maximum mplx:SeniorNotesDueJune2025 us-gaap:SeniorNotes0.0

mplx:MarkWest, srt:Minimum, mplx:SeniorNotesDueJuly2023, us-gaap:SeniorNotes


Debt
Period End2020-12-31
Value4.5
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations mplx:MarkWest srt:Minimum mplx:SeniorNotesDueJuly2023 us-gaap:SeniorNotes0.0

Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod us-gaap:AwardType

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod

us-gaap:PerformanceShares


Share
Period End2021-06-302021-03-312020-12-31
Value0375730.00
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod0.0100.00.0

mpc:AdjustedEBITDA us-gaap:ConsolidationItems

mpc:AdjustedEBITDA

us-gaap:OperatingSegments


Adjusted
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value13351227129413191165920930911937867760569538474
Percentage of AdjustedEBITDA100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mpc:AdjustedEBITDA us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mpc:GatheringandProcessing


Adjusted
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value442388422466399351371364390341323338320290
Percentage of AdjustedEBITDA33.131.632.635.334.238.239.940.041.639.342.559.459.561.2

us-gaap:OperatingSegments, mpc:LogisticsandStorage


Adjusted
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value893839872853766569559547547526437231218184
Percentage of AdjustedEBITDA66.968.467.464.765.861.860.160.058.460.757.540.640.538.8

mpc:AdjustedEBITDAattributabletononcontrollinginterests us-gaap:ConsolidationItems

mpc:AdjustedEBITDAattributabletononcontrollinginterests

us-gaap:MaterialReconcilingItems


Adjusted
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value10.08.09.09.09.07.07.05.07.04.02.03.02.02.0
Percentage of AdjustedEBITDAattributabletononcontrollinginterests100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mpc:CapitalContributionByRelatedParty

mpc:CapitalContributionByRelatedParty


Capital
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value136.022529513150.00.00.010460.06630.0120.02100.015
Percentage of CapitalContributionByRelatedParty100.0100.0100.0100.0100.0100.00.00.00.0100.00.0100.00.0100.00.0100.00.0100.0

mpc:CapitalContributionByRelatedParty us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty

mpc:LimitedPartnersCommonUnits, mpc:MarathonPetroleumCorporation


Capital
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value136.02252920.00.0
Percentage of CapitalContributionByRelatedParty100.0100.0100.099.00.00.0

mpc:CapitalExpenditure us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

mpc:CapitalExpenditure

us-gaap:OperatingSegments, mpc:GatheringandProcessing


Capital
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value131110134250321326306
Percentage of CapitalExpenditure100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, mpc:LogisticsandStorage


Capital
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value118108184360272230198
Percentage of CapitalExpenditure90.198.2137.3144.084.770.664.7

mpc:ComprehensiveIncomeLossNetofTaxAttributabletoNonredeemableNoncontrollingInterest

mpc:ComprehensiveIncomeLossNetofTaxAttributabletoNonredeemableNoncontrollingInterest


Comprehensive
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value9.07.08.08.08.06.06.05.06.03.02.03.01.01.01.0
Percentage of ComprehensiveIncomeLossNetofTaxAttributabletoNonredeemableNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mpc:ContractwithCustomerAssetIncreaseDecrease us-gaap:AdjustmentsForNewAccountingPronouncements

mpc:ContractwithCustomerAssetIncreaseDecrease

us-gaap:AccountingStandardsUpdate201409


Contractwith
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value117.0-27.0112.09.0-17.0
Percentage of ContractwithCustomerAssetIncreaseDecrease100.0100.0100.0100.0100.0100.0100.0

mpc:CostOfRentalSalesAndOccupancyCosts

mpc:CostOfRentalSalesAndOccupancyCosts


Cost
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value333335383728374132332918191312141114145.00.00.00.0
Percentage of CostOfRentalSalesAndOccupancyCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0

mpc:CostofRentalSalesandOccupancyCostsRelatedParties

mpc:CostofRentalSalesandOccupancyCostsRelatedParties


Costof
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value32414641452.03.03.01.00.01.01.00.01.00.00.00.01.0
Percentage of CostofRentalSalesandOccupancyCostsRelatedParties100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.00.0100.00.00.00.0100.0

mpc:DeferredRevenueNoncurrentPeriodIncreaseDecrease us-gaap:AdjustmentsForNewAccountingPronouncements

mpc:DeferredRevenueNoncurrentPeriodIncreaseDecrease

us-gaap:AccountingStandardsUpdate201409


Deferred
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value145.06.08.012131.0
Percentage of DeferredRevenueNoncurrentPeriodIncreaseDecrease100.0100.0100.0100.0100.0100.0100.0

mpc:DeferredRevenueNoncurrentRelatedPartyPeriodIncreaseDecrease us-gaap:AdjustmentsForNewAccountingPronouncements

mpc:DeferredRevenueNoncurrentRelatedPartyPeriodIncreaseDecrease

us-gaap:AccountingStandardsUpdate201409


Deferred
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-5000000.0-3000000.01000000.0-2000000.07000000.0-2000000.00
Percentage of DeferredRevenueNoncurrentRelatedPartyPeriodIncreaseDecrease100.0100.0100.0100.0100.0100.00.0

mpc:DeferredRevenueRelatedPartiesRevenueRecognized us-gaap:AdjustmentsForNewAccountingPronouncements

mpc:DeferredRevenueRelatedPartiesRevenueRecognized

us-gaap:AccountingStandardsUpdate201409


Deferred
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-31000000.0-13000000.0-16000000.0-17000000.0-20000000.0-14000000.0-16000000.0
Percentage of DeferredRevenueRelatedPartiesRevenueRecognized100.0100.0100.0100.0100.0100.0100.0

mpc:DeferredRevenueRelatedPartyPeriodIncreaseDecrease us-gaap:AdjustmentsForNewAccountingPronouncements

mpc:DeferredRevenueRelatedPartyPeriodIncreaseDecrease

us-gaap:AccountingStandardsUpdate201409


Deferred
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value29361221169.09.0
Percentage of DeferredRevenueRelatedPartyPeriodIncreaseDecrease100.0100.0100.0100.0100.0100.0100.0

mpc:DerivativeInstrumentsNotDesignatedasHedgingInstrumentsRealizedGainLossNet us-gaap:IncomeStatementLocation

mpc:DerivativeInstrumentsNotDesignatedasHedgingInstrumentsRealizedGainLossNet

mpc:Purchasedproductcosts


Derivative
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value-2000000.0-1000000.0-1000000.0-1000000.0-2000000.0-1000000.0-2000000.0-2000000.0-4000000.0-3000000.0-3000000.0-3000000.0-2000000.0-2000000.0-2000000.0-1000000.0-1000000.0-2000000.0-1000000.0
Percentage of DerivativeInstrumentsNotDesignatedasHedgingInstrumentsRealizedGainLossNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mpc:EarningsPerUnitPotentiallyDilutiveUnits

mpc:EarningsPerUnitPotentiallyDilutiveUnits


Earnings
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value1000000.001000000.001000000.01000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.0-8000000.01000000.0010000000.0
Percentage of EarningsPerUnitPotentiallyDilutiveUnits100.00.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.0100.0100.00.0100.0

mpc:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetAndLiabilitiesNetChangeInUnrealizedGainLossIncludedInEarningsContractHeld us-gaap:DerivativeInstrumentRisk

mpc:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetAndLiabilitiesNetChangeInUnrealizedGainLossIncludedInEarningsContractHeld

us-gaap:EmbeddedDerivativeFinancialInstruments


Fair
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-09-302015-06-30
Value-11.0-6.013-10.09.0-2.0-5.013-19.0-10.03.0-2.0-10.0-1.08.0-11.0-4.0-8.0-3.0-4.0-8.0
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetAndLiabilitiesNetChangeInUnrealizedGainLossIncludedInEarningsContractHeld100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mpc:IncreaseDecreaseInCapitalAccruals

mpc:IncreaseDecreaseInCapitalAccruals


Increase
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-25.0-111.0-61.0-79.018-11.0-74.014-25.0121-6.01622312.0-20.01.014-20.07.05.08.05.0
Percentage of IncreaseDecreaseInCapitalAccruals100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mpc:InterestAndOtherFinancialCostsFromRelatedParties

mpc:InterestAndOtherFinancialCostsFromRelatedParties


Interest
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value0.01.03.03.05.01.01.01.02.01.01.01.01.00.00.00.00.00.01.00.00.00.00.0
Percentage of InterestAndOtherFinancialCostsFromRelatedParties0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.0100.00.00.00.00.0

mpc:InterestandOtherFinancialCosts

mpc:InterestandOtherFinancialCosts


Interestand
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value223208216216223157158167139136114818074
Percentage of InterestandOtherFinancialCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mpc:NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity

mpc:NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity


Net
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value654634-2736.0669467489419497436407225201174171116127
Percentage of NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mpc:NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity mpc:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount

mpc:Public, mpc:LimitedPartnersCommonUnits


Net
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-236.0-229.01022222-168.0-176.0-1183.0179-157.018089857255
Percentage of NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity-36.1-36.1-37.433.2-36.0-36.0-282.336.0-36.044.239.642.341.432.2

mpc:NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity us-gaap:PartnerTypeOfPartnersCapitalAccount

us-gaap:PreferredClassB


Net
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value10.010.0117.00.00.0
Percentage of NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity1.51.6-0.41.00.00.0

mpc:NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty

mpc:LimitedPartnersCommonUnits, mpc:MarathonPetroleumCorporation


Net
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-399.0-388.01733380-293.0-307.0-1889.0312-276.022525292717
Percentage of NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity-61.0-61.2-63.356.8-62.7-62.8-450.862.8-63.355.311.114.415.59.9

mpc:NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity us-gaap:StatementEquityComponents

us-gaap:NoncontrollingInterest


Net
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value9.07.08.08.06.06.05.06.03.02.03.01.01.01.0
Percentage of NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity1.41.1-0.31.21.31.21.21.20.70.51.30.50.60.6

mpc:NonCashNetTransfersOfMaterialsAndSuppliesInventories

mpc:NonCashNetTransfersOfMaterialsAndSuppliesInventories


Non
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value00-1000000.01000000.0001000000.0001000000.01000000.001000000.0-1000000.06000000.09000000.000-5000000.05000000.0000300000.0200000.0
Percentage of NonCashNetTransfersOfMaterialsAndSuppliesInventories0.00.0100.0100.00.00.0100.00.00.0100.0100.00.0100.0100.0100.0100.00.00.0100.0100.00.00.00.0100.0100.0

mpc:OperatingLeaseIncomeStatementLeaseRevenueRelatedParties

mpc:OperatingLeaseIncomeStatementLeaseRevenueRelatedParties


Operating
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value241237234292293158193193190190145727070673029292626252525
Percentage of OperatingLeaseIncomeStatementLeaseRevenueRelatedParties100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mpc:OperatingLeaseIncomeStatementLeaseRevenueRelatedParties us-gaap:RelatedPartyTransactionsByRelatedParty

mpc:MarathonPetroleumCorporation


Operating
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value2412372342922931581931931901901457270706730292938262525
Percentage of OperatingLeaseIncomeStatementLeaseRevenueRelatedParties100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0146.2100.0100.0100.0

mpc:OtherComprehensiveIncomeLossPensionandOtherPostretirementBenefitPlansNetUnamortizedGainLossAdjustmentNetofTax

mpc:OtherComprehensiveIncomeLossPensionandOtherPostretirementBenefitPlansNetUnamortizedGainLossAdjustmentNetofTax


Other
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value00-1000000.00001000000.0000-2000000.00000
Percentage of OtherComprehensiveIncomeLossPensionandOtherPostretirementBenefitPlansNetUnamortizedGainLossAdjustmentNetofTax0.00.0100.00.00.00.0100.00.00.00.0100.00.00.00.00.0

mpc:PartnersTotalSubsequentDistributionAmount

mpc:PartnersTotalSubsequentDistributionAmount


Partners
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312013-09-30
Value745746759734734543526517483-31.03363112791224923115612947423330262222
Percentage of PartnersTotalSubsequentDistributionAmount100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mpc:PartnersTotalSubsequentDistributionAmount us-gaap:StatementClassOfStock

mpc:LimitedPartnersCommonUnits


Partners
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312013-09-30
Value71571572871670469252351450749746724723221819818517917215614938191816131111
Percentage of PartnersTotalSubsequentDistributionAmount96.095.895.90.095.994.396.30.096.496.196.7-796.869.070.171.01541.771.974.5100.0115.580.945.254.553.350.050.050.0

us-gaap:PreferredClassA


Partners
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2021202020212020192016
Percentage of PartnersTotalSubsequentDistributionAmount2.72.82.60.02.72.93.70.03.63.93.3

us-gaap:PreferredClassB


Partners
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value10.010.0111110.0210.00.00.00.0
Percentage of PartnersTotalSubsequentDistributionAmount1.31.31.40.01.42.90.00.00.00.0

mpc:PartnersTotalSubsequentDistributionAmount us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType

us-gaap:PreferredClassB, us-gaap:SubsequentEvent


Partners
Period End2020-08-17
Value21
Percentage of PartnersTotalSubsequentDistributionAmount0.0

mpc:PaymentsofDistributionsonPreferredUnits us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:StatementClassOfStock

mpc:PaymentsofDistributionsonPreferredUnits

us-gaap:PreferredPartner, us-gaap:SeriesAPreferredStock


Paymentsof
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value2021202021202019
Percentage of PaymentsofDistributionsonPreferredUnits100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PreferredPartner, us-gaap:SeriesBPreferredStock


Paymentsof
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value200.0210.0210.00.00.0
Percentage of PaymentsofDistributionsonPreferredUnits100.00.0105.00.0100.00.00.00.0

mpc:RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties us-gaap:ProductOrService

mpc:RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties

us-gaap:Product


Revenuefrom
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value373033333214111418134.02.02.02.0
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Service


Revenuefrom
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value909857928906899620578571568549471281276270
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties2456.82856.72812.12745.52809.44428.65254.54078.63155.64223.111775.014050.013800.013500.0

mpc:RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties us-gaap:ProductOrService, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:Product, mpc:MarathonPetroleumCorporation


Revenuefrom
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value37303331321441521813
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties100.0100.0100.093.9100.0100.0372.7371.4100.0100.0

us-gaap:Service, mpc:MarathonPetroleumCorporation


Revenuefrom
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value908857927906899620803816568549
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties2454.12856.72809.12745.52809.44428.67300.05828.63155.64223.1

us-gaap:Service, us-gaap:OtherAffiliates


Revenuefrom
Period End2020-09-302020-06-302020-03-312019-06-302019-03-31
Value1.00.01.00.00.0
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties2.70.03.00.00.0

mpc:RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:Product, mpc:GatheringandProcessing


Revenuefrom
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value3526292424129.01216113.0
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties94.686.787.972.775.085.781.885.788.984.675.0

us-gaap:Product, mpc:LogisticsandStorage


Revenuefrom
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2.04.04.09.08.02.02.02.02.02.01.0
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties5.413.312.127.325.014.318.214.311.115.425.0

us-gaap:Service, mpc:GatheringandProcessing


Revenuefrom
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value7.03.08.014180.00.00.00.00.00.0
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties18.910.024.242.456.20.00.00.00.00.00.0

us-gaap:Service, mpc:LogisticsandStorage


Revenuefrom
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value902854920892881620578571568549471
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties2437.82846.72787.92703.02753.14428.65254.54078.63155.64223.111775.0

mpc:RevenuefromContractwithCustomerexcludingAssessedTaxandNonASC606Revenue us-gaap:ProductOrService

mpc:RevenuefromContractwithCustomerexcludingAssessedTaxandNonASC606Revenue

us-gaap:Product


Revenuefrom
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value165120169230171168202243240208206
Percentage of RevenuefromContractwithCustomerexcludingAssessedTaxandNonASC606Revenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mpc:RevenuefromContractwithCustomerexcludingAssessedTaxandNonASC606Revenue us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:Product, mpc:GatheringandProcessing


Revenuefrom
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value158103154205157166201241237207205
Percentage of RevenuefromContractwithCustomerexcludingAssessedTaxandNonASC606Revenue95.885.891.189.191.898.899.599.298.899.599.5

us-gaap:Product, mpc:LogisticsandStorage


Revenuefrom
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value7.0171525142.01.02.03.01.01.0
Percentage of RevenuefromContractwithCustomerexcludingAssessedTaxandNonASC606Revenue4.214.28.910.98.21.20.50.81.20.50.5

mpc:SalesRevenueGoodsRelatedPartyNetZero us-gaap:RelatedPartyTransactionsByRelatedParty

mpc:SalesRevenueGoodsRelatedPartyNetZero

mpc:MarathonPetroleumCorporation


Sales
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value1075217330130111886112137112798163535721137.05.0
Percentage of SalesRevenueGoodsRelatedPartyNetZero100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mplx:AdjustedEBITDA us-gaap:ConsolidationItems

mplx:AdjustedEBITDA

us-gaap:OperatingSegments


Adjusted
Period End2021-06-302021-03-312020-06-302020-03-31
Value1374135212271294
Percentage of AdjustedEBITDA100.0100.0100.0100.0

mplx:AdjustedEBITDA us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mplx:GatheringandProcessing


Adjusted
Period End2021-06-302021-03-312020-06-302020-03-31
Value427456388422
Percentage of AdjustedEBITDA31.133.731.632.6

us-gaap:OperatingSegments, mplx:LogisticsandStorage


Adjusted
Period End2021-06-302021-03-312020-06-302020-03-31
Value947896839872
Percentage of AdjustedEBITDA68.966.368.467.4

mplx:AdjustedEBITDAattributabletononcontrollinginterests us-gaap:ConsolidationItems

mplx:AdjustedEBITDAattributabletononcontrollinginterests

us-gaap:MaterialReconcilingItems


Adjusted
Period End2021-06-302021-03-312020-06-302020-03-31
Value10.010.08.09.0
Percentage of AdjustedEBITDAattributabletononcontrollinginterests100.0100.0100.0100.0

mplx:CapitalContributionByRelatedParty

mplx:CapitalContributionByRelatedParty


Capital
Period End2021-06-302021-03-312020-06-302020-03-31
Value1227.06.0225
Percentage of CapitalContributionByRelatedParty100.0100.0100.0100.0

mplx:CapitalContributionByRelatedParty us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty

mplx:LimitedPartnersCommonUnits, mplx:MarathonPetroleumCorporation


Capital
Period End2021-06-302021-03-312020-06-302020-03-31
Value1227.06.0225
Percentage of CapitalContributionByRelatedParty100.0100.0100.0100.0

mplx:CapitalExpenditure us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

mplx:CapitalExpenditure

us-gaap:OperatingSegments, mplx:GatheringandProcessing


Capital
Period End2021-06-302021-03-312020-06-302020-03-31
Value3630110134
Percentage of CapitalExpenditure100.0100.0100.0100.0

us-gaap:OperatingSegments, mplx:LogisticsandStorage


Capital
Period End2021-06-302021-03-312020-06-302020-03-31
Value7659108184
Percentage of CapitalExpenditure211.1196.798.2137.3

mplx:ContractwithCustomerAssetIncreaseDecrease us-gaap:AdjustmentsForNewAccountingPronouncements

mplx:ContractwithCustomerAssetIncreaseDecrease

us-gaap:AccountingStandardsUpdate201409


Contractwith
Period End2021-06-302021-03-312020-06-302020-03-31
Value2000000.0-27000000.07000000.0-27000000.0
Percentage of ContractwithCustomerAssetIncreaseDecrease100.0100.0100.0100.0

mplx:DeferredRevenueNoncurrentPeriodIncreaseDecrease us-gaap:AdjustmentsForNewAccountingPronouncements

mplx:DeferredRevenueNoncurrentPeriodIncreaseDecrease

us-gaap:AccountingStandardsUpdate201409


Deferred
Period End2021-06-302021-03-312020-06-302020-03-31
Value5.04.05.06.0
Percentage of DeferredRevenueNoncurrentPeriodIncreaseDecrease100.0100.0100.0100.0

mplx:DeferredRevenueNoncurrentRelatedPartyPeriodIncreaseDecrease us-gaap:AdjustmentsForNewAccountingPronouncements

mplx:DeferredRevenueNoncurrentRelatedPartyPeriodIncreaseDecrease

us-gaap:AccountingStandardsUpdate201409


Deferred
Period End2021-06-302021-03-312020-06-302020-03-31
Value-4000000.0-4000000.0-3000000.01000000.0
Percentage of DeferredRevenueNoncurrentRelatedPartyPeriodIncreaseDecrease100.0100.0100.0100.0

mplx:DeferredRevenueRelatedPartiesRevenueRecognized us-gaap:AdjustmentsForNewAccountingPronouncements

mplx:DeferredRevenueRelatedPartiesRevenueRecognized

us-gaap:AccountingStandardsUpdate201409


Deferred
Period End2021-06-302021-03-312020-06-302020-03-31
Value-30000000.0-20000000.0-13000000.0-16000000.0
Percentage of DeferredRevenueRelatedPartiesRevenueRecognized100.0100.0100.0100.0

mplx:DeferredRevenueRelatedPartyPeriodIncreaseDecrease us-gaap:AdjustmentsForNewAccountingPronouncements

mplx:DeferredRevenueRelatedPartyPeriodIncreaseDecrease

us-gaap:AccountingStandardsUpdate201409


Deferred
Period End2021-06-302021-03-312020-06-302020-03-31
Value16213612
Percentage of DeferredRevenueRelatedPartyPeriodIncreaseDecrease100.0100.0100.0100.0

mplx:DerivativeInstrumentsNotDesignatedasHedgingInstrumentsRealizedGainLossNet us-gaap:IncomeStatementLocation

mplx:DerivativeInstrumentsNotDesignatedasHedgingInstrumentsRealizedGainLossNet

mplx:Purchasedproductcosts


Derivative
Period End2021-06-302021-03-312020-06-302020-03-31
Value-3000000.0-3000000.0-1000000.0-1000000.0
Percentage of DerivativeInstrumentsNotDesignatedasHedgingInstrumentsRealizedGainLossNet100.0100.0100.0100.0

mplx:DistributionsMadetoPartnersTotalCashDistributionDeclared

mplx:DistributionsMadetoPartnersTotalCashDistributionDeclared


Distributions
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value744745746759747734734543332726252322212013
Percentage of DistributionsMadetoPartnersTotalCashDistributionDeclared100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mplx:EarningsPerUnitPotentiallyDilutiveUnits

mplx:EarningsPerUnitPotentiallyDilutiveUnits


Earnings
Period End2021-06-302021-03-312020-06-302020-03-312012-03-31
Value1000000.01000000.01000000.01000000.00
Percentage of EarningsPerUnitPotentiallyDilutiveUnits100.0100.0100.0100.00.0

mplx:FairValueInputsProbabilityOfRenewal us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel

mplx:FairValueInputsProbabilityOfRenewal

us-gaap:EmbeddedDerivativeFinancialInstruments, us-gaap:FairValueInputsLevel3


Fair
Period End2021-06-302021-03-31
Value0100.0
Percentage of FairValueInputsProbabilityOfRenewal0.0100.0

mplx:FairValueInputsProbabilityofRenewalSecondTerm us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel

mplx:FairValueInputsProbabilityofRenewalSecondTerm

us-gaap:EmbeddedDerivativeFinancialInstruments, us-gaap:FairValueInputsLevel3


Fair
Period End2021-06-302021-03-31
Value0100.0
Percentage of FairValueInputsProbabilityofRenewalSecondTerm0.0100.0

mplx:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetAndLiabilitiesNetChangeInUnrealizedGainLossIncludedInEarningsContractHeld us-gaap:DerivativeInstrumentRisk

mplx:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetAndLiabilitiesNetChangeInUnrealizedGainLossIncludedInEarningsContractHeld

us-gaap:EmbeddedDerivativeFinancialInstruments


Fair
Period End2021-06-302021-03-312020-06-302020-03-31
Value-39.0-5.0-6.013
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetAndLiabilitiesNetChangeInUnrealizedGainLossIncludedInEarningsContractHeld100.0100.0100.0100.0

mplx:IncreaseDecreaseInCapitalAccruals

mplx:IncreaseDecreaseInCapitalAccruals


Increase
Period End2021-06-302021-03-312020-06-302020-03-31
Value3.0-37.0-111.0-61.0
Percentage of IncreaseDecreaseInCapitalAccruals100.0100.0100.0100.0

mplx:InterestAndOtherFinancialCostsFromRelatedParties

mplx:InterestAndOtherFinancialCostsFromRelatedParties


Interest
Period End2021-06-302020-06-302020-03-31
Value2.01.03.0
Percentage of InterestAndOtherFinancialCostsFromRelatedParties100.0100.0100.0

mplx:InterestandOtherFinancialCosts

mplx:InterestandOtherFinancialCosts


Interestand
Period End2021-06-302021-03-312020-06-302020-03-31
Value198220208216
Percentage of InterestandOtherFinancialCosts100.0100.0100.0100.0

mplx:NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity

mplx:NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value693729634-2736.0
Percentage of NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity100.0100.0100.0100.0

mplx:NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity mplx:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount

mplx:Public, mplx:LimitedPartnersCommonUnits


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value-251.0-266.0-229.01022
Percentage of NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity-36.2-36.5-36.1-37.4

mplx:NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity us-gaap:PartnerTypeOfPartnersCapitalAccount

us-gaap:SeriesBPreferredStock


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value10.01110.011
Percentage of NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity1.41.51.6-0.4

mplx:NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty

mplx:LimitedPartnersCommonUnits, mplx:MarathonPetroleumCorporation


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value-423.0-443.0-388.01733
Percentage of NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity-61.0-60.8-61.2-63.3

mplx:NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity us-gaap:StatementEquityComponents

us-gaap:NoncontrollingInterest


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value9.09.07.08.0
Percentage of NetIncomeLossIncludingPortionAttributabletoNoncontrollingInterestExcludingPortionAttributabletoTemporaryEquity1.31.21.1-0.3

mplx:OtherComprehensiveIncomeLossPensionandOtherPostretirementBenefitPlansNetUnamortizedGainLossAdjustmentNetofTax

mplx:OtherComprehensiveIncomeLossPensionandOtherPostretirementBenefitPlansNetUnamortizedGainLossAdjustmentNetofTax


Other
Period End2021-06-302021-03-312020-06-302020-03-31
Value0-2000000.00-1000000.0
Percentage of OtherComprehensiveIncomeLossPensionandOtherPostretirementBenefitPlansNetUnamortizedGainLossAdjustmentNetofTax0.0100.00.0100.0

mplx:OtherComprehensiveIncomeLossPensionandOtherPostretirementBenefitPlansNetUnamortizedGainLossAdjustmentNetofTax us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

mplx:LoopLlcandExplorerPipeline


Other
Period End2021-06-302021-03-312020-06-302020-03-31
Value0-2000000.00-1000000.0
Percentage of OtherComprehensiveIncomeLossPensionandOtherPostretirementBenefitPlansNetUnamortizedGainLossAdjustmentNetofTax0.0100.00.0100.0

mplx:OtherComprehensiveIncomeLossPensionandOtherPostretirementBenefitPlansNetUnamortizedGainLossAdjustmentNetofTax us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RetirementPlanType, us-gaap:StatementEquityComponents

mplx:LoopLlcandExplorerPipeline, us-gaap:PensionPlansDefinedBenefit, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Other
Period End2021-06-302021-03-31
Value0-2000000.0
Percentage of OtherComprehensiveIncomeLossPensionandOtherPostretirementBenefitPlansNetUnamortizedGainLossAdjustmentNetofTax0.0100.0

mplx:PartnersTotalSubsequentDistributionAmount us-gaap:StatementClassOfStock

mplx:PartnersTotalSubsequentDistributionAmount

us-gaap:PreferredClassA


Partners
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value2020212020202120
Percentage of PartnersTotalSubsequentDistributionAmount100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PreferredClassB


Partners
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value10.010.010.0111110.021
Percentage of PartnersTotalSubsequentDistributionAmount50.050.047.655.055.050.0100.0

mplx:PaymentsofDistributionsonPreferredUnits us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:StatementClassOfStock

mplx:PaymentsofDistributionsonPreferredUnits

us-gaap:PreferredPartner, us-gaap:SeriesAPreferredStock


Paymentsof
Period End2021-06-302021-03-312020-06-302020-03-31
Value21202120
Percentage of PaymentsofDistributionsonPreferredUnits100.0100.0100.0100.0

us-gaap:PreferredPartner, us-gaap:SeriesBPreferredStock


Paymentsof
Period End2021-06-302021-03-312020-06-302020-03-31
Value0.0210.021
Percentage of PaymentsofDistributionsonPreferredUnits0.0105.00.0105.0

mplx:RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties us-gaap:ProductOrService

mplx:RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties

us-gaap:Product


Revenuefrom
Period End2021-06-302021-03-312020-06-302020-03-31
Value31423033
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties100.0100.0100.0100.0

us-gaap:Service


Revenuefrom
Period End2021-06-302021-03-312020-06-302020-03-31
Value907872857928
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties2925.82076.22856.72812.1

mplx:RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties us-gaap:ProductOrService, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:Product, mplx:MarathonPetroleumCorporation


Revenuefrom
Period End2021-06-302021-03-312020-06-302020-03-31
Value31423033
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties100.0100.0100.0100.0

us-gaap:Service, mplx:MarathonPetroleumCorporation


Revenuefrom
Period End2021-06-302021-03-312020-06-302020-03-31
Value907871857927
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties2925.82073.82856.72809.1

us-gaap:Service, us-gaap:OtherAffiliates


Revenuefrom
Period End2021-06-302021-03-312020-06-302020-03-31
Value0.01.00.01.0
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties0.02.40.03.0

mplx:RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:Product, mplx:GatheringandProcessing


Revenuefrom
Period End2021-06-302021-03-312020-06-302020-03-31
Value28392629
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties90.392.986.787.9

us-gaap:Product, mplx:LogisticsandStorage


Revenuefrom
Period End2021-06-302021-03-312020-06-302020-03-31
Value3.03.04.04.0
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties9.77.113.312.1

us-gaap:Service, mplx:GatheringandProcessing


Revenuefrom
Period End2021-06-302021-03-312020-06-302020-03-31
Value6.03.03.08.0
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties19.47.110.024.2

us-gaap:Service, mplx:LogisticsandStorage


Revenuefrom
Period End2021-06-302021-03-312020-06-302020-03-31
Value901869854920
Percentage of RevenuefromContractwithCustomerExcludingAssessedTaxRelatedParties2906.52069.02846.72787.9

mplx:RevenuefromContractwithCustomerexcludingAssessedTaxandNonASC606Revenue us-gaap:ProductOrService

mplx:RevenuefromContractwithCustomerexcludingAssessedTaxandNonASC606Revenue

us-gaap:Product


Revenuefrom
Period End2021-06-302021-03-312020-06-302020-03-31
Value304282120169
Percentage of RevenuefromContractwithCustomerexcludingAssessedTaxandNonASC606Revenue100.0100.0100.0100.0

mplx:RevenuefromContractwithCustomerexcludingAssessedTaxandNonASC606Revenue us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:Product, mplx:GatheringandProcessing


Revenuefrom
Period End2021-06-302021-03-312020-06-302020-03-31
Value303281103154
Percentage of RevenuefromContractwithCustomerexcludingAssessedTaxandNonASC606Revenue99.799.685.891.1

us-gaap:Product, mplx:LogisticsandStorage


Revenuefrom
Period End2021-06-302021-03-312020-06-302020-03-31
Value1.01.01715
Percentage of RevenuefromContractwithCustomerexcludingAssessedTaxandNonASC606Revenue0.30.414.28.9

mplx:SalesRevenueGoodsRelatedPartyNetZero us-gaap:RelatedPartyTransactionsByRelatedParty

mplx:SalesRevenueGoodsRelatedPartyNetZero

mplx:MarathonPetroleumCorporation


Sales
Period End2021-06-302021-03-312020-06-302020-03-31
Value17716852173
Percentage of SalesRevenueGoodsRelatedPartyNetZero100.0100.0100.0100.0

mplx:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsWeightedAverageGrantDateFairValueForfeited us-gaap:AwardType

mplx:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsWeightedAverageGrantDateFairValueForfeited

us-gaap:PhantomShareUnitsPSUs


Share
Period End2021-06-302021-03-31
Value0.133.09
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsWeightedAverageGrantDateFairValueForfeited100.0100.0

mplx:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsWeightedAverageGrantDateFairValueIssued us-gaap:AwardType

mplx:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsWeightedAverageGrantDateFairValueIssued

us-gaap:PhantomShareUnitsPSUs


Share
Period End2021-06-302021-03-31
Value0.5729.73
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsWeightedAverageGrantDateFairValueIssued100.0100.0

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect


Cash
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-16.09.0-39.010.042-26.025-86.01737303.0-3.00.0-288.02929
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0

us-gaap:ContractWithCustomerAssetReclassifiedToReceivable us-gaap:AdjustmentsForNewAccountingPronouncements

us-gaap:ContractWithCustomerAssetReclassifiedToReceivable

us-gaap:AccountingStandardsUpdate201409


Contract
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-1000000.00-1000000.000-1000000.0-1000000.00
Percentage of ContractWithCustomerAssetReclassifiedToReceivable100.00.0100.00.00.0100.0100.00.0

us-gaap:CostsAndExpensesRelatedParty

us-gaap:CostsAndExpensesRelatedParty


Costs
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value26329728027633730323921223222822317712511410910778847876262624232623232425232321
Percentage of CostsAndExpensesRelatedParty100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredRevenuePeriodIncreaseDecrease us-gaap:AdjustmentsForNewAccountingPronouncements

us-gaap:DeferredRevenuePeriodIncreaseDecrease

us-gaap:AccountingStandardsUpdate201409


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value177.06.08.03.05.06.07.03.01.0
Percentage of DeferredRevenuePeriodIncreaseDecrease100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredRevenueRevenueRecognized1 us-gaap:AdjustmentsForNewAccountingPronouncements

us-gaap:DeferredRevenueRevenueRecognized1

us-gaap:AccountingStandardsUpdate201409


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-16000000.0-1000000.0-2000000.0-1000000.0-2000000.0-3000000.0-3000000.0-1000000.0-2000000.0-1000000.0
Percentage of DeferredRevenueRevenueRecognized1100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Depreciation

us-gaap:Depreciation


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value318329385346321325338302214211201201188176168164164187139138137132501212121212121212121111
Percentage of Depreciation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Depreciation us-gaap:StatementBusinessSegments

mpc:GatheringandProcessing


Depreciationus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value182183-187.0-208.0-189.0-144.0-141.0-132.0-139.0-127.0-128.0
Percentage of Depreciation52.657.0-57.5-61.5-62.6-67.3-66.8-65.7-69.2-67.6-72.7

mpc:LogisticsandStorage


Depreciationus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value164138-138.0-130.0-113.0-70.0-70.0-69.0-62.0-61.0-48.0
Percentage of Depreciation47.443.0-42.5-38.5-37.4-32.7-33.2-34.3-30.8-32.4-27.3

mplx:GatheringandProcessing


Depreciationus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value182182183187
Percentage of Depreciation57.255.357.057.5

mplx:LogisticsandStorage


Depreciationus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value136147138138
Percentage of Depreciation42.844.743.042.5

us-gaap:DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet

us-gaap:DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value-39.0-6.0-4.0-12.0-7.014-7.09.0-1.0-6.027-22.0-12.04.0-17.0-21.01.013-25.0-2.0-13.0-4.0
Percentage of DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet us-gaap:IncomeStatementLocation

mpc:Purchasedproductcosts


Derivative
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value-12.0-7.014-7.09.0-1.0-6.019-20.0-11.03.0-14.0-11.0-1.07.0-11.0-4.0-10.0-2.0
Percentage of DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet100.0100.0100.0100.0100.0100.0100.070.490.991.775.082.452.4-100.053.844.0200.076.950.0

mplx:Purchasedproductcosts


Derivative
Period End2021-06-302021-03-312020-06-302020-03-31
Value-39.0-6.0-7.014
Percentage of DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet100.0100.0100.0100.0

us-gaap:DistributionMadeToLimitedPartnerCashDistributionsDeclared

us-gaap:DistributionMadeToLimitedPartnerCashDistributionsDeclared


Distribution
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value73673874474574675974773473454353452651748336233631127925824923120019046413633272625-152.7222120-13.3
Percentage of DistributionMadeToLimitedPartnerCashDistributionsDeclared100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DistributionMadeToLimitedPartnerCashDistributionsDeclared dei:LegalEntity, us-gaap:PartnerCapitalComponents

mpc:MPLXLP, mpc:TexNewMexunits


Distribution
Period End2020-09-302020-06-302020-03-312018-12-31
Value5.02.00.00.0
Percentage of DistributionMadeToLimitedPartnerCashDistributionsDeclared0.70.30.00.0

us-gaap:DistributionMadeToLimitedPartnerCashDistributionsDeclared mplx:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount

mplx:Public, mplx:LimitedPartnersCommonUnits


Distribution
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value269270270270270266261191
Percentage of DistributionMadeToLimitedPartnerCashDistributionsDeclared36.236.236.235.636.136.235.635.2

us-gaap:DistributionMadeToLimitedPartnerCashDistributionsDeclared us-gaap:PartnerTypeOfPartnersCapitalAccount

mpc:LimitedPartnersCommonUnits


Distribution
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312013-09-30
Value71571572871670469252351450749746724723221819818517917215614938191816131111
Percentage of DistributionMadeToLimitedPartnerCashDistributionsDeclared96.095.895.995.995.994.396.396.396.496.196.768.269.070.171.071.771.974.578.078.481.745.748.848.547.3-7.548.9

mplx:LimitedPartnersCommonUnits


Distribution
Period End2021-06-302021-03-312020-06-302020-03-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value70570771572837191716131212-74.8111010-6.5
Percentage of DistributionMadeToLimitedPartnerCashDistributionsDeclared95.895.895.895.981.145.948.250.047.347.948.449.048.948.849.348.9

us-gaap:DistributionMadeToLimitedPartnerCashDistributionsDeclared us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty

mplx:LimitedPartnersCommonUnits, mplx:MarathonPetroleumCorporation


Distribution
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value445445445458446438431332
Percentage of DistributionMadeToLimitedPartnerCashDistributionsDeclared59.859.759.760.359.759.758.761.1

us-gaap:DistributionMadeToLimitedPartnerCashDistributionsDeclared us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:StatementClassOfStock

us-gaap:PreferredPartner, us-gaap:SeriesAPreferredStock


Distribution
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value21202020212020202120201920
Percentage of DistributionMadeToLimitedPartnerCashDistributionsDeclared2.92.72.72.72.82.62.72.72.93.73.73.63.9

us-gaap:PreferredPartner, us-gaap:SeriesBPreferredStock


Distribution
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value10.01110.010.010.0111110.0210.00.00.00.0
Percentage of DistributionMadeToLimitedPartnerCashDistributionsDeclared1.41.51.31.31.31.41.51.42.90.00.00.00.0

us-gaap:DistributionMadeToLimitedPartnerCashDistributionsDeclared us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:SubsequentEventType

mpc:LimitedPartnersCommonUnits, us-gaap:SubsequentEvent


Distribution
Period End2020-10-272020-07-282020-04-282019-10-252019-07-222019-04-292018-10-26
Value715715728704692523507
Percentage of DistributionMadeToLimitedPartnerCashDistributionsDeclared0.00.00.00.00.00.00.0

mplx:LimitedPartnersCommonUnits, us-gaap:SubsequentEvent


Distribution
Period End2021-07-272021-04-27
Value705707
Percentage of DistributionMadeToLimitedPartnerCashDistributionsDeclared0.00.0

us-gaap:DistributionMadeToLimitedPartnerCashDistributionsDeclared us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType

us-gaap:PreferredClassB, us-gaap:SubsequentEvent


Distribution
Period End2021-02-16
Value21
Percentage of DistributionMadeToLimitedPartnerCashDistributionsDeclared0.0

us-gaap:DistributionMadeToLimitedPartnerCashDistributionsDeclared us-gaap:SubsequentEventType

us-gaap:SubsequentEvent


Distribution
Period End2021-01-282020-01-232019-01-252018-07-252018-04-252018-01-262017-10-252017-07-262017-04-262017-01-252016-10-252016-07-222016-04-192016-01-252015-10-202015-07-212015-04-202015-01-202014-10-212014-07-222014-04-222014-01-232013-10-312013-07-31
Value71471551449746734632029426324223322220018946413633272625232221
Percentage of DistributionMadeToLimitedPartnerCashDistributionsDeclared0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:DistributionMadeToLimitedPartnerCashDistributionsPaid

us-gaap:DistributionMadeToLimitedPartnerCashDistributionsPaid


Distribution
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value708713722717728717704693523515507498467347320295263242233221201190464136332726252322212013
Percentage of DistributionMadeToLimitedPartnerCashDistributionsPaid100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DistributionMadeToLimitedPartnerCashDistributionsPaid us-gaap:PreferredUnitsByName

mpc:SeriesAConvertiblePreferredUnits


Distribution
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2021202021202019191716
Percentage of DistributionMadeToLimitedPartnerCashDistributionsPaid2.82.92.82.83.03.83.93.73.83.64.6

mplx:SeriesAConvertiblePreferredUnits


Distribution
Period End2021-06-302021-03-31
Value2120
Percentage of DistributionMadeToLimitedPartnerCashDistributionsPaid3.02.8

us-gaap:DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:StatementClassOfStock

us-gaap:DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit

mplx:ANDXLP, us-gaap:PreferredPartner, us-gaap:SeriesBPreferredStock


Distribution
Period End2021-06-302021-03-31
Value068.75
Percentage of DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit0.0100.0

us-gaap:DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit us-gaap:PartnerTypeOfPartnersCapitalAccount

mpc:LimitedPartnersCommonUnits


Distribution
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value0.68750.68750.68750.68750.67750.66750.65750.64750.63750.62750.61750.60750.58750.56250.540.520.5150.510.5050.50.470.440.410.38250.35750.34250.32750.31250.2975
Percentage of DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

mplx:LimitedPartnersCommonUnits


Distribution
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value0.68750.68750.68750.68750.68750.67750.66750.65750.470.440.410.38250.35750.34250.32750.31250.29750.2850.27250.1769
Percentage of DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit us-gaap:SubsequentEventType

us-gaap:SubsequentEvent


Distribution
Period End2021-07-272021-04-272021-01-282020-10-272020-07-282020-04-282020-01-232019-10-252019-07-222019-04-292019-01-252018-10-262018-07-252018-04-252018-01-262017-10-252017-07-262017-04-262017-01-252016-10-252016-07-222016-04-192016-01-252015-10-202015-07-212015-04-202015-01-202014-10-212014-07-222014-04-222014-01-232013-10-312013-07-31
Value0.68750.68750.68750.68750.68750.68750.68750.67750.66750.65750.64750.63750.62750.61750.60750.58750.56250.540.520.5150.510.5050.50.470.440.410.38250.35750.34250.32750.31250.29750.285
Percentage of DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:DividendsPreferredStock us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:StatementClassOfStock

us-gaap:DividendsPreferredStock

us-gaap:PreferredPartner, us-gaap:SeriesAPreferredStock


Dividends
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value212020202120202021202019
Percentage of DividendsPreferredStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PreferredPartner, us-gaap:SeriesBPreferredStock


Dividends
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value10.01110.010.010.01110.07.00.00.00.00.0
Percentage of DividendsPreferredStock47.655.050.050.047.655.050.035.00.00.00.00.0

us-gaap:EquityMethodInvestmentDividendsOrDistributions

us-gaap:EquityMethodInvestmentDividendsOrDistributions


Equity
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value1201191091241071191461591191011211041076810570333337334038150.00.00.0
Percentage of EquityMethodInvestmentDividendsOrDistributions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:EquityMethodInvestmentDividendsOrDistributions us-gaap:ConsolidationItems

us-gaap:MaterialReconcilingItems


Equity
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value121121130130115124163145120108133112112901006533
Percentage of EquityMethodInvestmentDividendsOrDistributions100.8101.7119.3104.8107.5104.2111.691.2100.8106.9109.9107.7104.7132.495.292.9100.0

us-gaap:EquityMethodInvestmentOtherThanTemporaryImpairment

us-gaap:EquityMethodInvestmentOtherThanTemporaryImpairment


Equity
Period End2021-06-302020-12-312020-09-302020-06-302020-03-31
Value6.00.00.012641264
Percentage of EquityMethodInvestmentOtherThanTemporaryImpairment100.00.00.0100.0100.0

us-gaap:ExtinguishmentOfDebtGainLossNetOfTax

us-gaap:ExtinguishmentOfDebtGainLossNetOfTax


Extinguishment
Period End2021-06-302021-03-312020-09-30
Value0.01214
Percentage of ExtinguishmentOfDebtGainLossNetOfTax0.0100.0100.0

us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInEarnings us-gaap:DerivativeInstrumentRisk

us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInEarnings

us-gaap:EmbeddedDerivativeFinancialInstruments


Fair
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value-39.0-6.0-4.0-12.0-7.014-7.09.0-1.0-6.018-19.0-11.03.0-15.0-12.00.08.0-12.0-6.0-7.0-4.0
Percentage of FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInEarnings100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0

us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationSettlements us-gaap:DerivativeInstrumentRisk

us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationSettlements

us-gaap:EmbeddedDerivativeFinancialInstruments


Fair
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value3.03.02.02.01.01.01.02.01.02.03.03.03.03.03.03.01.02.02.02.01.02.0
Percentage of FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationSettlements100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:GainLossOnDispositionOfAssets

us-gaap:GainLossOnDispositionOfAssets


Gain
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-312014-09-302013-12-312013-09-30
Value-3000000.00-1000000.003000000.0-1000000.05000000.0-1000000.0-1000000.0-1000000.000-1000000.0001000000.001000000.000-800000.000000
Percentage of GainLossOnDispositionOfAssets100.00.0100.00.0100.0100.0100.0100.0100.0100.00.00.0100.00.00.0100.00.0100.00.00.0100.00.00.00.00.00.0

us-gaap:GoodwillAndIntangibleAssetImpairment

us-gaap:GoodwillAndIntangibleAssetImpairment


Goodwill
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-06-302019-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value420.00.00.021650.00.00.00.00.00.00.00.01.01290.00.00.00.0
Percentage of GoodwillAndIntangibleAssetImpairment100.00.00.00.0100.00.00.00.00.00.00.00.00.0100.0100.00.00.00.00.0

us-gaap:GoodwillImpairmentLoss

us-gaap:GoodwillImpairmentLoss


Goodwill
Period End2020-12-312020-09-302020-06-302020-03-312019-11-302019-11-292016-12-312016-09-302016-06-302016-03-31
Value0.00.00.018144111560.00.01.0129
Percentage of GoodwillImpairmentLoss0.00.00.0100.0100.0100.00.00.0100.0100.0

us-gaap:GoodwillImpairmentLoss us-gaap:StatementBusinessSegments

mpc:GatheringandProcessing


Goodwill
Period End2020-09-302020-06-302020-03-312016-12-312016-09-302016-06-302016-03-31
Value0.00.018140.00.01.0129
Percentage of GoodwillImpairmentLoss0.00.0100.00.00.0100.0100.0

us-gaap:IncomeLossFromEquityMethodInvestments

us-gaap:IncomeLossFromEquityMethodInvestments


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value6670768389-1184.0359573706564506149231.05.0-2.06.0-83.05.03.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of IncomeLossFromEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IncomeLossFromEquityMethodInvestments us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mpc:GatheringandProcessing


Income
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value4749-1234.0-6.03526292221141720161.0
Percentage of IncomeLossFromEquityMethodInvestments56.655.1104.2-17.136.835.641.433.832.828.027.940.869.6100.0

us-gaap:OperatingSegments, mpc:LogisticsandStorage


Income
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value3640504160474143433644297.00.0
Percentage of IncomeLossFromEquityMethodInvestments43.444.9-4.2117.163.264.458.666.267.272.072.159.230.40.0

us-gaap:OperatingSegments, mplx:GatheringandProcessing


Income
Period End2021-06-302021-03-312020-06-302020-03-31
Value313449-1234.0
Percentage of IncomeLossFromEquityMethodInvestments47.048.655.1104.2

us-gaap:OperatingSegments, mplx:LogisticsandStorage


Income
Period End2021-06-302021-03-312020-06-302020-03-31
Value35364050
Percentage of IncomeLossFromEquityMethodInvestments53.051.444.9-4.2

us-gaap:IncomeLossFromEquityMethodInvestments us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

mpc:NonVIEs


Income
Period End2020-09-302019-09-30
Value4360
Percentage of IncomeLossFromEquityMethodInvestments51.863.2

mpc:OtherVIEs


Income
Period End2020-09-302019-09-30
Value4035
Percentage of IncomeLossFromEquityMethodInvestments48.236.8

mpc:OtherVIEsandNonVIEs


Income
Period End2020-09-302019-09-30
Value8395
Percentage of IncomeLossFromEquityMethodInvestments100.0100.0

mplx:NonVIEs


Income
Period End2021-06-302021-03-312020-06-302020-03-31
Value32314538
Percentage of IncomeLossFromEquityMethodInvestments48.544.350.6-3.2

mplx:OtherVIEs


Income
Period End2021-06-302021-03-312020-06-302020-03-31
Value343944-1222.0
Percentage of IncomeLossFromEquityMethodInvestments51.555.749.4103.2

us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities

us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value5126637540-142.022-5.02.0-78.0-51.032163-44.0422243-59.0414133-15.0-8.7-1.69.35.0-0.42.70.5-2.3-5.31.68.2-7.1
Percentage of IncreaseDecreaseInAccountsPayableAndAccruedLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInDeferredRevenue

us-gaap:IncreaseDecreaseInDeferredRevenue


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value192427362227422915149.0149.07.09.09.08.07.0
Percentage of IncreaseDecreaseInDeferredRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInDerivativeAssetsAndLiabilities

us-gaap:IncreaseDecreaseInDerivativeAssetsAndLiabilities


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-36.0-3.0-2.0-10.0-6.015-6.0110.0-7.026-16.0-9.09.0-9.0-19.04.018-15.0-3.0-13.0-12.06.00.00.00.0
Percentage of IncreaseDecreaseInDerivativeAssetsAndLiabilities100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:IncreaseDecreaseInDueFromRelatedPartiesCurrent

us-gaap:IncreaseDecreaseInDueFromRelatedPartiesCurrent


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-109.08.028-9.0-79.0521540-39.0147-63.017-31.0127-2.0-39.0-40.0189.0-9.017-23.03.4-2.92.45.1-8.00.5-1.4-6.3-2.0-5.2-8.7-3.0
Percentage of IncreaseDecreaseInDueFromRelatedPartiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestCostsCapitalized

us-gaap:InterestCostsCapitalized


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-03-31
Value5.05.08.08.010.01315139.07.06.09.09.09.08.06.0117.07.07.07.07.02.01.01.01.01.0
Percentage of InterestCostsCapitalized100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestExpenseDebtExcludingAmortization

us-gaap:InterestExpenseDebtExcludingAmortization


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value1951982052072062112112121561561531341351127977746652515255204.06.05.0
Percentage of InterestExpenseDebtExcludingAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LaborAndRelatedExpense us-gaap:IncomeStatementLocation

us-gaap:LaborAndRelatedExpense

mpc:PurchasesFromRelatedParties


Labor
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value297280276303313278
Percentage of LaborAndRelatedExpense100.0100.0100.0100.0100.0100.0

mplx:RentalCostOfSales


Labor
Period End2021-06-302020-06-30
Value3233
Percentage of LaborAndRelatedExpense0.011.8

mplx:Rentalcostofsalesrelatedparties


Labor
Period End2021-03-312020-03-31
Value3235
Percentage of LaborAndRelatedExpense0.012.7

us-gaap:LaborAndRelatedExpense us-gaap:IncomeStatementLocation, us-gaap:RelatedPartyTransactionsByRelatedParty

mpc:GeneralandAdministrativeExpenseRelatedParty, mpc:MarathonPetroleumCorporation


Labor
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-09-30
Value63686469594350293027232725242527
Percentage of LaborAndRelatedExpense21.224.323.20.019.513.718.00.00.00.00.00.00.00.00.00.0

mpc:PurchasesFromRelatedParties, mpc:MarathonPetroleumCorporation


Labor
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312013-09-30
Value29327627133229723921214513613311410597919264807370-23.034333319172019
Percentage of LaborAndRelatedExpense98.798.698.20.098.076.476.30.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

mpc:PurchasesFromRelatedParties, us-gaap:OtherAffiliates


Labor
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value4.04.05.05.06.05.05.06.00.0
Percentage of LaborAndRelatedExpense1.31.41.80.02.01.61.80.00.0

mpc:Rentalcostofsalesrelatedparties, mpc:MarathonPetroleumCorporation


Labor
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value32414641452.03.02.00.00.01.00.00.01.00.0
Percentage of LaborAndRelatedExpense10.814.616.70.014.90.61.10.00.00.00.00.00.00.00.0

mplx:Rentalcostofsalesrelatedparties, mplx:MarathonPetroleumCorporation


Labor
Period End2021-06-302021-03-312020-06-302020-03-31
Value23394146
Percentage of LaborAndRelatedExpense0.00.014.616.7

us-gaap:LeaseIncome mplx:NonRelatedParty

us-gaap:LeaseIncome

mplx:ThirdParty


Lease
Period End2021-06-302021-03-312020-06-302020-03-31
Value68686663
Percentage of LeaseIncome100.0100.0100.0100.0

us-gaap:LeaseIncome us-gaap:RelatedPartyTransactionsByRelatedParty

mplx:MarathonPetroleumCorporation


Lease
Period End2021-06-302021-03-312020-06-302020-03-31
Value144202195186
Percentage of LeaseIncome211.8297.1295.5295.2

us-gaap:LineOfCreditFacilityInterestRateDuringPeriod us-gaap:DebtInstrument, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:LineOfCreditFacilityInterestRateDuringPeriod

mpc:RelatedPartyRevolvingCreditAgreement, mpc:MPCInvestment


Line
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value2.3527-0.0010.02833-0.00199-0.00205-0.001430.039880.000650.001980.001370.030730.00056
Percentage of LineOfCreditFacilityInterestRateDuringPeriod100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mplx:RelatedPartyRevolvingCreditAgreement, mplx:MPCInvestment


Line
Period End2021-06-302021-03-31
Value-0.0171.371
Percentage of LineOfCreditFacilityInterestRateDuringPeriod0.00.0

us-gaap:LossContingencyDamagesPaidValue

us-gaap:LossContingencyDamagesPaidValue


Loss
Period End2021-03-31
Value4000000.0
Percentage of LossContingencyDamagesPaidValue100.0

us-gaap:LossContingencyDamagesSoughtValue

us-gaap:LossContingencyDamagesSoughtValue


Loss
Period End2020-12-31
Value0.0
Percentage of LossContingencyDamagesSoughtValue0.0

us-gaap:NetIncomeLossAllocatedToLimitedPartners

us-gaap:NetIncomeLossAllocatedToLimitedPartners


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value675708661635617-2755.0-611.060246148341449143340512611499726274-36.0-99.0-19.93244412727273319211817
Percentage of NetIncomeLossAllocatedToLimitedPartners100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NetIncomeLossNetOfTaxPerOutstandingLimitedPartnershipUnitDiluted us-gaap:PartnerTypeOfPartnersCapitalAccount

us-gaap:NetIncomeLossNetOfTaxPerOutstandingLimitedPartnershipUnitDiluted

mpc:LimitedPartnersCommonUnits


Net
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value0.610.58-2.6-0.580.610.550.610.520.620.550.610.310.290.260.190.170.21-0.11-0.33-0.140.410.50.460.380.370.370.410.260.29
Percentage of NetIncomeLossNetOfTaxPerOutstandingLimitedPartnershipUnitDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mplx:LimitedPartnersCommonUnits


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value0.660.680.630.610.58-2.6-0.580.610.550.610.410.50.460.380.370.370.410.270.290.260.260.18
Percentage of NetIncomeLossNetOfTaxPerOutstandingLimitedPartnershipUnitDiluted0.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0103.8100.00.00.00.0

us-gaap:NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax us-gaap:PartnerTypeOfPartnersCapitalAccount

us-gaap:NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax

mpc:LimitedPartnersCommonUnits


Net
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value0.610.58-2.6-0.580.610.560.610.520.620.550.610.310.290.260.20.170.22-0.11-0.33-0.140.410.50.460.380.370.370.410.260.29
Percentage of NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mplx:LimitedPartnersCommonUnits


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value0.660.680.630.610.58-2.6-0.580.610.560.610.410.50.460.380.370.370.410.270.290.260.260.18
Percentage of NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax0.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0103.8100.00.00.00.0

us-gaap:OperatingLeaseLeaseIncome

us-gaap:OperatingLeaseLeaseIncome


Operating
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302019-06-30
Value999998966163216
Percentage of OperatingLeaseLeaseIncome100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingLeaseLeaseIncome mpc:NonRelatedParty

mpc:ThirdParty


Operating
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value706663636865
Percentage of OperatingLeaseLeaseIncome0.067.365.6100.031.50.0

us-gaap:OperatingLeaseLeaseIncome us-gaap:RelatedPartyTransactionsByRelatedParty

mpc:MarathonPetroleumCorporation


Operating
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value208195186247248246279
Percentage of OperatingLeaseLeaseIncome0.0199.0193.8404.9393.7113.90.0

mplx:MarathonPetroleumCorporation


Operating
Period End2021-06-302021-03-312020-06-302020-03-31
Value168242237234
Percentage of OperatingLeaseLeaseIncome169.7244.4241.8243.8

us-gaap:OperatingLeasesIncomeStatementLeaseRevenue

us-gaap:OperatingLeasesIncomeStatementLeaseRevenue


Operating
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value102102989697999094978984796969706980777170160.00.00.0
Percentage of OperatingLeasesIncomeStatementLeaseRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:OperatingLeasesIncomeStatementLeaseRevenue us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mpc:GatheringandProcessing


Operating
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value9489888988848891888479706870
Percentage of OperatingLeasesIncomeStatementLeaseRevenue92.290.891.791.888.993.393.693.898.9100.0100.0101.498.6100.0

us-gaap:OperatingSegments, mpc:LogisticsandStorage


Operating
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value249246242300304164199199191190145717170
Percentage of OperatingLeasesIncomeStatementLeaseRevenue244.1251.0252.1309.3307.1182.2211.7205.2214.6226.2183.5102.9102.9100.0

us-gaap:OperatingSegments, mplx:GatheringandProcessing


Operating
Period End2021-06-302021-03-312020-06-302020-03-31
Value91928988
Percentage of OperatingLeasesIncomeStatementLeaseRevenue0.00.090.891.7

us-gaap:OperatingSegments, mplx:LogisticsandStorage


Operating
Period End2021-06-302021-03-312020-06-302020-03-31
Value176249246242
Percentage of OperatingLeasesIncomeStatementLeaseRevenue0.00.0251.0252.1

us-gaap:OtherCostAndExpenseOperating

us-gaap:OtherCostAndExpenseOperating


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value02000000.03000000.01000000.01000000.001000000.00000
Percentage of OtherCostAndExpenseOperating0.0100.0100.0100.0100.00.0100.00.00.00.00.0

us-gaap:OtherOperatingActivitiesCashFlowStatement

us-gaap:OtherOperatingActivitiesCashFlowStatement


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value1415-3.0-20.0-4.030-14.0270.0-4.0509.0-17.03.0-15.01116162.0-3.06.015150.72.5-1.41.51.8-1.3-0.52.01.4-3.42.4
Percentage of OtherOperatingActivitiesCashFlowStatement100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherOperatingIncome

us-gaap:OtherOperatingIncome


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value3.01.00.02.02.01.06.02.05.00.0-1.03.01.04.01.02.01.02.01.02.01.02.03.81.41.41.41.11.51.11.51.31.00.91.2
Percentage of OtherOperatingIncome100.0100.00.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherOperatingIncome us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mpc:GatheringandProcessing


Other
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value141314201615151517136.0-1.01.00.01.00.01.00.00.0
Percentage of OtherOperatingIncome700.0650.01400.0333.3800.0300.00.0-1500.0566.71300.0150.0-100.050.00.050.00.050.00.00.0

us-gaap:OperatingSegments, mpc:LogisticsandStorage


Other
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value5152511617171110.01212121211121215161819-27.0192018
Percentage of OtherOperatingIncome2550.02600.05100.0266.7850.0340.00.0-1000.0400.01200.0300.01200.0550.01200.0600.01500.0800.01800.0950.0-710.51357.11428.61285.7

us-gaap:OperatingSegments, mplx:GatheringandProcessing


Other
Period End2021-06-302021-03-312020-06-302020-03-31
Value14141314
Percentage of OtherOperatingIncome466.71400.0650.01400.0

us-gaap:OperatingSegments, mplx:LogisticsandStorage


Other
Period End2021-06-302021-03-312020-06-302020-03-31
Value16521451
Percentage of OtherOperatingIncome533.35200.0700.05100.0

us-gaap:PartnersCapitalAccountDistributions

us-gaap:PartnersCapitalAccountDistributions


Partners
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value707735736728738715523515507498467347320295263242233221201190464136332726252322212013
Percentage of PartnersCapitalAccountDistributions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PartnersCapitalAccountDistributions mpc:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount

mpc:Public, mpc:LimitedPartnersCommonUnits


Partners
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value271270271262191188185-182.0179176170163149140
Percentage of PartnersCapitalAccountDistributions36.837.136.736.636.536.536.5-36.538.350.753.155.356.757.9

us-gaap:PartnersCapitalAccountDistributions mplx:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount

mplx:Public, mplx:LimitedPartnersCommonUnits


Partners
Period End2021-06-302021-03-312020-06-302020-03-31
Value262269270271
Percentage of PartnersCapitalAccountDistributions37.136.637.136.7

us-gaap:PartnersCapitalAccountDistributions us-gaap:PartnerTypeOfPartnersCapitalAccount

us-gaap:PreferredClassB


Partners
Period End2020-12-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value0.0200.021210.00.0
Percentage of PartnersCapitalAccountDistributions0.02.70.02.82.90.00.0

us-gaap:SeriesBPreferredStock


Partners
Period End2021-06-302021-03-312020-03-31
Value0.02121
Percentage of PartnersCapitalAccountDistributions0.02.92.8

us-gaap:PartnersCapitalAccountDistributions us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty

mpc:LimitedPartnersCommonUnits, mpc:MarathonPetroleumCorporation


Partners
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value445458446432332327322-316.028817147564945
Percentage of PartnersCapitalAccountDistributions60.562.960.460.463.563.563.5-63.561.749.314.719.018.618.6

mplx:LimitedPartnersCommonUnits, mplx:MarathonPetroleumCorporation


Partners
Period End2021-06-302021-03-312020-06-302020-03-31
Value445445458446
Percentage of PartnersCapitalAccountDistributions62.960.562.960.4

us-gaap:PartnersCapitalAccountDistributions us-gaap:StatementClassOfStock

us-gaap:PreferredClassB


Partners
Period End2020-08-17
Value21
Percentage of PartnersCapitalAccountDistributions0.0

us-gaap:SeriesBPreferredStock


Partners
Period End2021-02-16
Value21
Percentage of PartnersCapitalAccountDistributions0.0

us-gaap:PartnersCapitalAccountDistributions us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType

us-gaap:SeriesBPreferredStock, us-gaap:SubsequentEvent


Partners
Period End2021-08-16
Value21
Percentage of PartnersCapitalAccountDistributions0.0

us-gaap:PartnersCapitalAccountUnitsRedeemed us-gaap:BusinessCombinationSeparatelyRecognizedTransactions

us-gaap:PartnersCapitalAccountUnitsRedeemed

mpc:WesternRefiningWholesaleWesternRefiningProductTransport


Partners
Period End2020-07-31
Value18
Percentage of PartnersCapitalAccountUnitsRedeemed100.0

mplx:WesternRefiningWholesaleWesternRefiningProductTransport


Partners
Period End2020-07-31
Value18
Percentage of PartnersCapitalAccountUnitsRedeemed100.0

us-gaap:PartnersCapitalAccountUnitsUnitbasedCompensation us-gaap:PartnerTypeOfPartnersCapitalAccount

us-gaap:PartnersCapitalAccountUnitsUnitbasedCompensation

mplx:LimitedPartnersCommonUnits


Partners
Period End2021-06-302021-03-31
Value39864.0143250.0
Percentage of PartnersCapitalAccountUnitsUnitbasedCompensation100.0100.0

us-gaap:PaymentsForProceedsFromOtherInvestingActivities

us-gaap:PaymentsForProceedsFromOtherInvestingActivities


Payments
Period End2021-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-1000000.0-1000000.00-3000000.00000-1000000.0-3000000.03000000.01000000.0-2000000.01000000.01000000.0-2000000.0-3000000.03600000.0-2700000.01500000.0-400000.0500000.0-200000.0-5300000.01500000.07300000.0000
Percentage of PaymentsForProceedsFromOtherInvestingActivities100.0100.00.0100.00.00.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:PaymentsOfDebtExtinguishmentCosts us-gaap:DebtInstrument, us-gaap:LongtermDebtType

us-gaap:PaymentsOfDebtExtinguishmentCosts

mplx:SeniorNotesDueJanuary2025, mplx:FixedRateSeniorNotes


Payments
Period End2021-06-302021-03-31
Value0.020
Percentage of PaymentsOfDebtExtinguishmentCosts0.0100.0

us-gaap:PaymentsOfDebtIssuanceCosts

us-gaap:PaymentsOfDebtIssuanceCosts


Payments
Period End2020-12-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312012-10-31
Value2.00.0200.00.0230.00.0534.04.00.0210.00.00.00.06.60.00.63.82.70.00.00.02.4
Percentage of PaymentsOfDebtIssuanceCosts100.00.0100.00.00.0100.00.00.0100.0100.0100.00.0100.00.00.00.00.0100.00.0100.0100.0100.00.00.00.0100.0

us-gaap:PaymentsToAcquireEquityMethodInvestments

us-gaap:PaymentsToAcquireEquityMethodInvestments


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value49352222131912191841821281261037438715086554311710.029140.00.00.0
Percentage of PaymentsToAcquireEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:PaymentsToAcquireEquityMethodInvestments us-gaap:StatementBusinessSegments

mpc:GatheringandProcessing


Payments
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value1857-37.0-755.076127-128.0
Percentage of PaymentsToAcquireEquityMethodInvestments81.843.5-40.7-344.741.369.8-100.0

mpc:LogisticsandStorage


Payments
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value4.074-54.0-452.09561-7.0
Percentage of PaymentsToAcquireEquityMethodInvestments18.256.5-59.3-206.451.633.5-5.5

mplx:GatheringandProcessing


Payments
Period End2021-06-302021-03-312020-06-302020-03-31
Value36265737
Percentage of PaymentsToAcquireEquityMethodInvestments73.574.343.540.7

mplx:LogisticsandStorage


Payments
Period End2021-06-302021-03-312020-06-302020-03-31
Value139.07454
Percentage of PaymentsToAcquireEquityMethodInvestments26.525.756.559.3

us-gaap:PaymentsToMinorityShareholders

us-gaap:PaymentsToMinorityShareholders


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value10.010.0119.08.09.010.08.06.06.07.04.03.03.03.02.00.02.00.02.00.01.00.50.20.20.18.612101422252212
Percentage of PaymentsToMinorityShareholders100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromContributionsFromParent

us-gaap:ProceedsFromContributionsFromParent


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-312016-12-312015-12-312013-09-302013-06-302013-03-31
Value10.07.016146.014222416120.00.00.00.00.00.00.0
Percentage of ProceedsFromContributionsFromParent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.00.00.0

us-gaap:ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital

us-gaap:ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital


Proceeds
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value112.04169160.00.02.00.01.0150.02.00.04.0200.00.0
Percentage of ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital100.0100.0100.0100.0100.00.00.0100.00.0100.0100.00.0100.00.0100.0100.00.00.0

us-gaap:ProceedsFromLinesOfCredit us-gaap:DebtInstrument, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:ProceedsFromLinesOfCredit

mpc:RelatedPartyRevolvingCreditAgreement, mpc:MPCInvestment


Proceeds
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value216210411667160538692215851160012007484521571
Percentage of ProceedsFromLinesOfCredit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromLongTermLinesOfCredit dei:LegalEntity, us-gaap:DebtInstrument

us-gaap:ProceedsFromLongTermLinesOfCredit

mplx:MPLXLP, mplx:MPLXRevolvingCreditFacilitydueJuly2024


Proceeds
Period End2021-06-302021-03-31
Value8901910
Percentage of ProceedsFromLongTermLinesOfCredit100.0100.0

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value1000000.0-3000000.0-2000000.0-3000000.0-3000000.0-2000000.0-1000000.0-4000000.0-4000000.0-4000000.0-3000000.0-2000000.0-3000000.0-3000000.0-4000000.0-1000000.0-2000000.0-5000000.0-2000000.0-1000000.00-1000000.00000
Percentage of ProceedsFromPaymentsForOtherFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.00.00.00.0

us-gaap:ProceedsFromRelatedPartyDebt

us-gaap:ProceedsFromRelatedPartyDebt


Proceeds
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value13942162104116671605464222158511567123570845215408170.01231736241614373010.00.00.0
Percentage of ProceedsFromRelatedPartyDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:ProceedsFromRelatedPartyDebt us-gaap:DebtInstrument, us-gaap:RelatedPartyTransactionsByRelatedParty

mplx:RelatedPartyRevolvingCreditAgreement, mplx:MPCInvestment


Proceeds
Period End2021-06-302021-03-312020-06-302020-03-31
Value2194224110411667
Percentage of ProceedsFromRelatedPartyDebt0.00.0100.0100.0

us-gaap:ProceedsFromSalesOfAssetsInvestingActivities

us-gaap:ProceedsFromSalesOfAssetsInvestingActivities


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-312016-09-302015-12-312015-09-302014-12-312014-09-302013-12-31
Value4.0702.0114.039166.01.07.03.01.02.02.03.01.01.00.0-0.40.00.00.00.2
Percentage of ProceedsFromSalesOfAssetsInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.00.00.0100.0

us-gaap:PropertyPlantAndEquipmentAdditions us-gaap:PropertyPlantAndEquipmentByType, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:PropertyPlantAndEquipmentAdditions

us-gaap:AssetUnderConstruction, mpc:MarathonPetroleumCorporation


Property
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312013-09-30
Value29153642483841424641229.0111210.09.0119.09.04.03.04.02.03.91.92.12.4
Percentage of PropertyPlantAndEquipmentAdditions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AssetUnderConstruction, mplx:MarathonPetroleumCorporation


Property
Period End2021-06-302021-03-312020-06-302020-03-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value151215363.24.12.13.41.91.40.82.12.41.81.7
Percentage of PropertyPlantAndEquipmentAdditions0.00.0100.0100.0106.7102.5105.087.2100.00.00.0100.0100.00.00.0

us-gaap:RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty

us-gaap:RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty


Related
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value276564636364303127262626242323222522232628248.26.36.46.16.15.86.05.15.44.65.23.6
Percentage of RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty us-gaap:RelatedPartyTransactionsByRelatedParty

mpc:MarathonPetroleumCorporation


Related
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312013-09-30
Value484848131410.010.010.01110.010.010.09.010.01113141617-28.01818166.05.55.54.3
Percentage of RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty76.276.275.043.345.237.038.538.542.341.743.543.540.940.050.056.553.857.170.8-341.5285.7281.2262.398.494.8101.993.5

mplx:MarathonPetroleumCorporation


Related
Period End2021-06-302021-03-312020-06-302020-03-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value114910.0486.16.05.85.85.55.74.85.14.34.93.3
Percentage of RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty40.775.415.975.096.893.895.195.194.895.094.194.493.594.291.7

us-gaap:OtherAffiliates


Related
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value16161615151617174.02.04.00.02.01.0-9.04.07.03.01.01.03.01.0-1.00.00.0
Percentage of RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty59.324.625.023.823.825.056.754.814.87.715.40.08.34.3-39.118.228.013.64.33.810.74.2-12.20.00.0

us-gaap:RelatedPartyTransactionPurchasesFromRelatedParty

us-gaap:RelatedPartyTransactionPurchasesFromRelatedParty


Related
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value2972982802764.00.00.01.06.01.00.01.0381.0
Percentage of RelatedPartyTransactionPurchasesFromRelatedParty100.0100.0100.0100.0100.00.00.0100.0100.0100.00.0100.0100.0100.0

us-gaap:RelatedPartyTransactionPurchasesFromRelatedParty us-gaap:RelatedPartyTransactionsByRelatedParty

mplx:MarathonPetroleumCorporation


Related
Period End2021-06-302021-03-312020-06-302020-03-31
Value293294276271
Percentage of RelatedPartyTransactionPurchasesFromRelatedParty98.798.798.698.2

us-gaap:OtherAffiliates


Related
Period End2021-06-302021-03-312020-06-302020-03-31
Value4.04.04.05.0
Percentage of RelatedPartyTransactionPurchasesFromRelatedParty1.31.31.41.8

us-gaap:RepaymentsOfLinesOfCredit us-gaap:DebtInstrument, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:RepaymentsOfLinesOfCredit

mpc:RelatedPartyRevolvingCreditAgreement, mpc:MPCInvestment


Repayments
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value216210412261113637882171851150014005628381373
Percentage of RepaymentsOfLinesOfCredit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RepaymentsOfLongTermLinesOfCredit dei:LegalEntity, us-gaap:DebtInstrument

us-gaap:RepaymentsOfLongTermLinesOfCredit

mplx:MPLXLP, mplx:MPLXRevolvingCreditFacilitydueJuly2024


Repayments
Period End2021-06-302021-03-31
Value17251250
Percentage of RepaymentsOfLongTermLinesOfCredit100.0100.0

us-gaap:RepaymentsOfRelatedPartyDebt

us-gaap:RepaymentsOfRelatedPartyDebt


Repayments
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value13942162104122611136456121718511566134859583813566150.01231736285410072930.00.00.0
Percentage of RepaymentsOfRelatedPartyDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:RepaymentsOfRelatedPartyDebt us-gaap:DebtInstrument, us-gaap:RelatedPartyTransactionsByRelatedParty

mplx:RelatedPartyRevolvingCreditAgreement, mplx:MPCInvestment


Repayments
Period End2021-06-302021-03-312020-06-302020-03-31
Value1701224110412261
Percentage of RepaymentsOfRelatedPartyDebt0.00.0100.0100.0

us-gaap:RestructuringCharges

us-gaap:RestructuringCharges


Restructuring
Period End2020-12-312020-09-30
Value1.036
Percentage of RestructuringCharges100.0100.0

us-gaap:RestructuringCharges us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mpc:GatheringandProcessing


Restructuring
Period End2020-09-30
Value9.0
Percentage of RestructuringCharges25.0

us-gaap:OperatingSegments, mpc:LogisticsandStorage


Restructuring
Period End2020-09-30
Value27
Percentage of RestructuringCharges75.0

us-gaap:RestructuringCharges us-gaap:RelatedPartyTransactionsByRelatedParty

mpc:MPCInvestment


Restructuring
Period End2020-09-30
Value36
Percentage of RestructuringCharges100.0

us-gaap:RevenueFromRelatedParties

us-gaap:RevenueFromRelatedParties


Revenue
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value6.09.02.02.09.00.00.01.02.00.02.01.02.05.0122123114114114108113100979789
Percentage of RevenueFromRelatedParties100.0100.0100.0100.0100.00.00.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueNotFromContractWithCustomerOther

us-gaap:RevenueNotFromContractWithCustomerOther


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value499477482491489-789.0460520493527
Percentage of RevenueNotFromContractWithCustomerOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:SalesTypeLeaseInterestIncome us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:SalesTypeLeaseInterestIncome

mpc:MarathonPetroleumCorporation


Sales
Period End2020-09-302020-06-302019-09-30
Value37383.0
Percentage of SalesTypeLeaseInterestIncome100.0100.0100.0

mplx:MarathonPetroleumCorporation


Sales
Period End2021-06-302021-03-312020-06-302020-03-31
Value135373838
Percentage of SalesTypeLeaseInterestIncome0.00.0100.00.0

us-gaap:SalesTypeLeaseRevenue us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:SalesTypeLeaseRevenue

mplx:MarathonPetroleumCorporation


Sales
Period End2021-06-302020-06-30
Value13638
Percentage of SalesTypeLeaseRevenue100.0100.0

us-gaap:SalesTypeLeaseRevenue us-gaap:RelatedPartyTransactionsByRelatedParty, us-gaap:StatementBusinessSegments

mplx:MarathonPetroleumCorporation, mplx:LogisticsandStorage


Sales
Period End2021-06-302020-06-30
Value13638
Percentage of SalesTypeLeaseRevenue100.0100.0

us-gaap:SalesTypeLeaseSellingProfitLoss us-gaap:ReclassificationType, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:SalesTypeLeaseSellingProfitLoss

us-gaap:ReclassificationOther, mplx:MarathonPetroleumCorporation


Sales
Period End2021-06-30
Value112
Percentage of SalesTypeLeaseSellingProfitLoss100.0

us-gaap:SalesTypeLeaseVariableLeaseIncome us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:SalesTypeLeaseVariableLeaseIncome

mpc:MarathonPetroleumCorporation


Sales
Period End2020-09-302020-06-302019-09-30
Value1000000.001000000.0
Percentage of SalesTypeLeaseVariableLeaseIncome100.00.0100.0

mplx:MarathonPetroleumCorporation


Sales
Period End2021-06-30
Value1000000.0
Percentage of SalesTypeLeaseVariableLeaseIncome0.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod us-gaap:AwardType

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod

us-gaap:PerformanceShares


Share
Period End2021-06-302021-03-312020-12-31
Value01761.011250.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod0.0100.0100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue us-gaap:AwardDate, us-gaap:AwardType

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue

mpc:A2018, mpc:PerformanceUnitsMarketCondition


Share
Period End2020-09-302020-06-302020-03-31
Value000.45
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue0.00.0100.0

mpc:A2020, mpc:PerformanceUnitsMarketCondition


Share
Period End2020-09-302020-06-302020-03-31
Value000.8
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue0.00.0177.8

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue us-gaap:AwardType

us-gaap:PhantomShareUnitsPSUs


Share
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value0.0924.88-0.23-0.12-1.0620.49-0.34-0.12-0.0133.09-0.1-0.5-1.0537.910.060.05-0.0129.32-45.16-1.01-0.6681.83
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue0.00.00.00.00.04553.30.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue us-gaap:Range, us-gaap:AwardDate, us-gaap:AwardType

srt:Maximum, mpc:A2018, mpc:PerformanceUnitPerformanceCondition


Share
Period End2020-09-302020-06-302020-03-31
Value002.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue0.00.0444.4

srt:Maximum, mpc:A2020, mpc:PerformanceUnitPerformanceCondition


Share
Period End2020-09-302020-06-302020-03-31
Value002.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue0.00.0444.4

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue us-gaap:Range, us-gaap:AwardType

srt:Maximum, mplx:PerformanceUnitPerformanceCondition


Share
Period End2021-06-302021-03-31
Value02.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue0.00.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod us-gaap:AwardType

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod

us-gaap:PerformanceShares


Share
Period End2021-06-302021-03-312020-12-31
Value01347200.00
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod0.0100.00.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised us-gaap:AwardType

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised

us-gaap:PhantomShareUnitsPSUs


Share
Period End2021-06-302021-03-312020-12-31
Value58312.0143090.0127980.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised100.0100.0100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures us-gaap:AwardType

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures

us-gaap:PhantomShareUnitsPSUs


Share
Period End2021-06-302021-03-312020-12-31
Value60.01270.012018.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures100.0100.0100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted us-gaap:AwardType

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted

us-gaap:PhantomShareUnitsPSUs


Share
Period End2021-06-302021-03-312020-12-312019-12-312014-03-312013-09-302013-06-302013-03-31
Value13977.0321930.022561.011973.044192.03268.03299.065844.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StockRepurchasedAndRetiredDuringPeriodShares

us-gaap:StockRepurchasedAndRetiredDuringPeriodShares


Stock
Period End2021-06-302021-03-31
Value5.6570176.272981
Percentage of StockRepurchasedAndRetiredDuringPeriodShares100.0100.0

us-gaap:StockRepurchasedAndRetiredDuringPeriodShares us-gaap:SubsequentEventType

us-gaap:SubsequentEvent


Stock
Period End2021-07-022021-04-052021-01-04
Value0.1262930.29140.099406
Percentage of StockRepurchasedAndRetiredDuringPeriodShares0.00.00.0

us-gaap:StockRepurchasedAndRetiredDuringPeriodValue us-gaap:SubsequentEventType

us-gaap:StockRepurchasedAndRetiredDuringPeriodValue

us-gaap:SubsequentEvent


Stock
Period End2021-07-022021-04-052021-01-04
Value4.07.02.0
Percentage of StockRepurchasedAndRetiredDuringPeriodValue100.0100.0100.0

us-gaap:StockholdersEquityChangeInReportingEntity

us-gaap:StockholdersEquityChangeInReportingEntity


Stockholders
Period End2020-09-302019-09-302018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-90.00.00.00.00.00.00.00.00.00.0
Percentage of StockholdersEquityChangeInReportingEntity100.00.00.00.00.00.00.00.00.00.0

us-gaap:StockholdersEquityChangeInReportingEntity us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty

mpc:LimitedPartnersCommonUnits, mpc:MarathonPetroleumCorporation


Stockholders
Period End2020-09-302019-09-302018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-90.071990.00.00.05172-824.07460.0923
Percentage of StockholdersEquityChangeInReportingEntity100.00.00.00.00.00.00.00.00.00.0

us-gaap:StockholdersEquityOther

us-gaap:StockholdersEquityOther


Stockholders
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-06-302017-03-31
Value2.0-3.01.02.01.04.02.03.03.03.04.01.03.0-1.0
Percentage of StockholdersEquityOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StockholdersEquityOther mpc:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount

mpc:Public, mpc:LimitedPartnersCommonUnits


Stockholders
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-06-302017-03-31
Value2.01.02.05.02.02.03.04.03.02.04.0-2.0
Percentage of StockholdersEquityOther200.050.0200.0125.0100.066.7100.0133.375.0200.0133.3200.0

us-gaap:StockholdersEquityOther mplx:NonRelatedParty, us-gaap:PartnerTypeOfPartnersCapitalAccount

mplx:Public, mplx:LimitedPartnersCommonUnits


Stockholders
Period End2021-06-302020-06-302020-03-31
Value1.01.02.0
Percentage of StockholdersEquityOther50.050.0200.0

us-gaap:StockholdersEquityOther us-gaap:PartnerTypeOfPartnersCapitalAccount, us-gaap:RelatedPartyTransactionsByRelatedParty

mpc:LimitedPartnersCommonUnits, mpc:MarathonPetroleumCorporation


Stockholders
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-1.01.00.0-1.00.00.00.0-1.01.00.0
Percentage of StockholdersEquityOther-100.050.00.0-25.00.00.00.0-33.325.00.0

mplx:LimitedPartnersCommonUnits, mplx:MarathonPetroleumCorporation


Stockholders
Period End2021-06-302021-03-312020-06-30
Value1.0-1.01.0
Percentage of StockholdersEquityOther50.033.350.0

us-gaap:StockholdersEquityOther us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-03-312020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-2.00.0-1.00.00.01.00.00.00.0-2.0
Percentage of StockholdersEquityOther66.70.0-100.00.00.033.30.00.00.0-200.0

us-gaap:TaxesExcludingIncomeAndExciseTaxes

us-gaap:TaxesExcludingIncomeAndExciseTaxes


Taxes
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value3432313330312929191917201718141413131110.011114.5-0.73.03.21.71.71.91.91.31.41.81.7
Percentage of TaxesExcludingIncomeAndExciseTaxes100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:TemporaryEquityNetIncome us-gaap:PreferredUnitsByName

us-gaap:TemporaryEquityNetIncome

mplx:SeriesAConvertiblePreferredUnits


Temporary
Period End2021-06-302021-03-31
Value2120
Percentage of TemporaryEquityNetIncome100.0100.0

us-gaap:TreasuryStockAcquiredAverageCostPerShare

us-gaap:TreasuryStockAcquiredAverageCostPerShare


Treasury
Period End2021-06-302021-03-31
Value1.2424.78
Percentage of TreasuryStockAcquiredAverageCostPerShare100.0100.0

us-gaap:UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic

us-gaap:UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic


Undistributed
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312012-12-31
Value-53000000.0-80000000.0-98000000.0-3483000000.0-1328000000.0-105000000.0-252000000.0-40000000.0-100000000.0-16000000.0-64000000.0-62000000.0-124000000.0-120000000.0-121000000.0-129000000.0-200000.0
Percentage of UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UndistributedEarningsLossAvailableToCommonShareholdersBasic

us-gaap:UndistributedEarningsLossAvailableToCommonShareholdersBasic


Undistributed
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-30000000.01000000.0-53000000.0-80000000.0-98000000.0-3483000000.0-1328000000.0-105000000.0-252000000.0-40000000.0-100000000.0-16000000.0-64000000.0-62000000.0-124000000.0-120000000.0-121000000.0-129000000.0
Percentage of UndistributedEarningsLossAvailableToCommonShareholdersBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UndistributedEarningsLossAvailableToCommonShareholdersBasic us-gaap:PartnerTypeOfPartnersCapitalAccount

mpc:LimitedPartnersCommonUnits


Undistributed
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-80000000.0-98000000.0-3483000000.0-1328000000.0-105000000.0-252000000.0-40000000.0-100000000.0-16000000.0-64000000.0-62000000.0-121000000.0-118000000.0-119000000.0-126000000.0
Percentage of UndistributedEarningsLossAvailableToCommonShareholdersBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.097.698.398.397.7

mplx:LimitedPartnersCommonUnits


Undistributed
Period End2021-06-302021-03-312020-06-302020-03-31
Value-30000000.01000000.0-98000000.0-3483000000.0
Percentage of UndistributedEarningsLossAvailableToCommonShareholdersBasic100.0100.0100.0100.0

us-gaap:UnrealizedGainLossOnDerivativesAndCommodityContracts us-gaap:HedgingDesignation

us-gaap:UnrealizedGainLossOnDerivativesAndCommodityContracts

us-gaap:Nondesignated


Unrealized
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-10.0-6.015-6.0110.0-4.023-17.0-8.07.0
Percentage of UnrealizedGainLossOnDerivativesAndCommodityContracts100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0

us-gaap:UnrealizedGainLossOnDerivativesAndCommodityContracts us-gaap:HedgingDesignation, us-gaap:IncomeStatementLocation

us-gaap:Nondesignated, mpc:Purchasedproductcosts


Unrealized
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-10.0-6.015-6.0110.0-4.021-16.0-8.06.0
Percentage of UnrealizedGainLossOnDerivativesAndCommodityContracts100.0100.0100.0100.0100.00.0100.091.394.1100.085.7

us-gaap:Nondesignated, mplx:Purchasedproductcosts


Unrealized
Period End2021-06-302021-03-312020-06-302020-03-31
Value-36.0-3.0-6.015
Percentage of UnrealizedGainLossOnDerivativesAndCommodityContracts0.00.0100.0100.0

us-gaap:WeightedAverageLimitedPartnershipUnitsOutstanding us-gaap:PartnerTypeOfPartnersCapitalAccount

us-gaap:WeightedAverageLimitedPartnershipUnitsOutstanding

mpc:LimitedPartnersCommonUnits


Weighted
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312013-09-30
Value10461059105851974794794117947946617.03943773627.0341331300238043430.0370.037
Percentage of WeightedAverageLimitedPartnershipUnitsOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.0100.0

mplx:LimitedPartnersCommonUnits


Weighted
Period End2021-06-302021-03-312020-06-302020-03-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value10291037105910588043430.43737370.037373737
Percentage of WeightedAverageLimitedPartnershipUnitsOutstanding0.00.0100.0100.0100.5100.9100.70.0100.00.00.00.0100.00.00.00.0

us-gaap:WeightedAverageLimitedPartnershipUnitsOutstandingDiluted us-gaap:PartnerTypeOfPartnersCapitalAccount

us-gaap:WeightedAverageLimitedPartnershipUnitsOutstandingDiluted

mpc:LimitedPartnersCommonUnits


Weighted
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312013-09-30
Value10471059105852975795795117947946617.039538236714346331300248043430.3370.037
Percentage of WeightedAverageLimitedPartnershipUnitsOutstandingDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0

mplx:LimitedPartnersCommonUnits


Weighted
Period End2021-06-302021-03-312020-06-302020-03-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value10291037105910588043430.33737370.037373737
Percentage of WeightedAverageLimitedPartnershipUnitsOutstandingDiluted0.00.0100.0100.0100.5100.9100.9100.0100.00.00.00.0100.00.00.00.0

us-gaap:WriteOffOfDeferredDebtIssuanceCost us-gaap:DebtInstrument, us-gaap:LongtermDebtType

us-gaap:WriteOffOfDeferredDebtIssuanceCost

mplx:SeniorNotesDueJanuary2025, mplx:FixedRateSeniorNotes


Write
Period End2021-06-302021-03-31
Value0.012
Percentage of WriteOffOfDeferredDebtIssuanceCost0.0100.0

dei:EntityCommonStockSharesOutstanding

dei:EntityCommonStockSharesOutstanding


Entity
Period End2021-07-302021-04-302021-02-152020-10-29
Value1025102910371040
Percentage of EntityCommonStockSharesOutstanding100.0100.0100.0100.0

dei:EntityNumberOfEmployees

dei:EntityNumberOfEmployees


Entity
Period End2020-12-31
Value2050.0
Percentage of EntityNumberOfEmployees100.0

mpc:AccruedPropertyPlantAndEquipmentCurrent

mpc:AccruedPropertyPlantAndEquipmentCurrent


Accrued
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-31
Value12115423428334622724929419418317113813215716314016617
Percentage of AccruedPropertyPlantAndEquipmentCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mpc:CurrentAssetsRelatedParties

mpc:CurrentAssetsRelatedParties


Current
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value591594600656660333386290
Percentage of CurrentAssetsRelatedParties100.0100.0100.0100.0100.0100.0100.0100.0

mpc:CurrentLiabilitiesRelatedParties

mpc:CurrentLiabilitiesRelatedParties


Current
Period End2020-09-302020-06-302020-03-312019-12-312019-09-30