MMP


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

Table of contents



us-gaap:AllocatedShareBasedCompensationExpense
us-gaap:AwardType

us-gaap:ComprehensiveIncomeNetOfTax
us-gaap:PartnerCapitalComponents

us-gaap:CostsAndExpenses

us-gaap:GainsLossesOnExtinguishmentOfDebt
us-gaap:DebtInstrument

us-gaap:GeneralAndAdministrativeExpense
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest

us-gaap:IncomeTaxExpenseBenefit

us-gaap:InterestExpenseDebt

us-gaap:OperatingIncomeLoss
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OtherNonoperatingIncomeExpense

us-gaap:ProfitLoss
us-gaap:PartnerCapitalComponents

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

us-gaap:Revenues
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:ProductOrService
us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, us-gaap:TimingOfTransferOfGoodOrService
us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:TimingOfTransferOfGoodOrService
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ProductOrService
us-gaap:ProductOrService, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:ProductOrService, us-gaap:TimingOfTransferOfGoodOrService

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

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:AssetsCurrent
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:AccountsReceivableNetCurrent
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

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

us-gaap:PropertyPlantAndEquipmentGross
us-gaap:BalanceSheetLocation, us-gaap:PropertyPlantAndEquipmentByType
us-gaap:PropertyPlantAndEquipmentByType

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment

us-gaap:PropertyPlantAndEquipmentNet

us-gaap:InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:Goodwill
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:IntangibleAssetsNetExcludingGoodwill

us-gaap:OperatingLeaseRightOfUseAsset
mmp:LeaseType
mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:OtherAssetsNoncurrent

us-gaap:AccountsPayableCurrent

us-gaap:LiabilitiesCurrent
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:OperatingLeaseLiabilityCurrent
mmp:LeaseType
mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:OtherAccruedLiabilitiesCurrent

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

us-gaap:LongTermDebtNoncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent
us-gaap:RetirementPlanType

us-gaap:OtherLiabilitiesNoncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent
mmp:LeaseType
mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo
mmp:LeaseType
mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree
mmp:LeaseType
mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour
mmp:LeaseType
mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive
mmp:LeaseType
mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive
mmp:LeaseType
mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:OperatingLeaseLiability
mmp:LeaseType
mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue
mmp:LeaseType
mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount
mmp:LeaseType
mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax
us-gaap:RetirementPlanType

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue
us-gaap:PartnerCapitalComponents

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:DepreciationDepletionAndAmortization
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:IncreaseDecreaseInAccountsPayable

us-gaap:IncreaseDecreaseInInventories

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:ProfitLoss
us-gaap:PartnerCapitalComponents

us-gaap:ShareBasedCompensation

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:PaymentsForRepurchaseOfCommonStock

mmp:AdditionalInvestmentinNonControlledEntities

mmp:AmortizationofExcessInvestmentandCapitalizedInterest

mmp:DisposalGroupIncludingDiscontinuedOperationCostsAndExpenses

mmp:OperatingMarginLoss
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

mmp:ProportionateShareOfEquityEarnings

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationOtherLongtermIncentivePlansRequisiteServicePeriodRecognition
us-gaap:PartnerCapitalComponents
us-gaap:DebtInstrument
us-gaap:AmortizationOfDebtDiscountPremium

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect

us-gaap:ContractWithCustomerLiabilityChangeInTimeframePerformanceObligationSatisfiedRevenueRecognized

us-gaap:CostDirectMaterial
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanInterestCost
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanOtherCosts
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1

us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1
us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanServiceCost

us-gaap:DefinedContributionPlanCostRecognized

us-gaap:DepreciationAndAmortizationDiscontinuedOperations
us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation, us-gaap:IncomeStatementLocation
us-gaap:DerivativeGainLossOnDerivativeNet
us-gaap:HedgingDesignation

us-gaap:DirectOperatingCosts
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold

us-gaap:DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense

us-gaap:DisposalGroupIncludingDiscontinuedOperationOperatingExpense

us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue
us-gaap:ProductOrService

us-gaap:EnvironmentalRemediationExpense

us-gaap:EquityMethodInvestmentDividendsOrDistributions

us-gaap:EquityMethodInvestmentSoldCarryingAmount

us-gaap:GainLossOnDispositionOfAssets1

us-gaap:GainLossOnSaleOfOtherAssets
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:FairValueByAssetClass

us-gaap:IncomeLossFromContinuingOperationsPerOutstandingLimitedPartnershipAndGeneralPartnershipUnitBasicAndDiluted

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTax

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerOutstandingLimitedPartnershipAndGeneralPartnershipUnitBasicAndDiluted

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

us-gaap:IncreaseDecreaseInAccountsAndOtherReceivables

us-gaap:IncreaseDecreaseInDeferredRevenue

us-gaap:IncreaseDecreaseInEmployeeRelatedLiabilities

us-gaap:IncreaseDecreaseInInterestPayableNet

us-gaap:IncreaseDecreaseInOtherAccountsPayable

us-gaap:IncreaseDecreaseInOtherAccruedLiabilities

us-gaap:IncreaseDecreaseInPropertyAndOtherTaxesPayable

us-gaap:InterestCostsCapitalizedAdjustment

us-gaap:InvestmentIncomeInterestAndDividend

us-gaap:LeaseCost
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:LimitedPartnersCapitalAccountDistributionAmount
us-gaap:StatementScenario
us-gaap:CreditFacility
us-gaap:LongTermDebtWeightedAverageInterestRateOverTime

us-gaap:MaturitiesOfSeniorDebt

us-gaap:NetIncomeLossNetOfTaxPerOutstandingLimitedPartnershipUnitDiluted

us-gaap:NetIncomeLossPerOutstandingLimitedPartnershipAndGeneralPartnershipUnitBasicAndDiluted

us-gaap:NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax

us-gaap:OperatingLeaseLeaseIncome
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax
us-gaap:RetirementPlanType

us-gaap:OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax
us-gaap:RetirementPlanType

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax
us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:HedgingDesignation

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax
us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:HedgingDesignation, us-gaap:IncomeStatementLocation

us-gaap:OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationNetOfTax
us-gaap:RetirementPlanType

us-gaap:OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
us-gaap:PartnerCapitalComponents

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax
us-gaap:RetirementPlanType

us-gaap:OtherOperatingIncomeExpenseNet
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:PartnersCapitalAccountDistributions
us-gaap:PartnerCapitalComponents

us-gaap:PartnersCapitalAccountUnitBasedCompensation
us-gaap:PartnerCapitalComponents

us-gaap:PartnersCapitalOther
us-gaap:PartnerCapitalComponents

us-gaap:PaymentsForProceedsFromHedgeFinancingActivities

us-gaap:PaymentsOfDebtExtinguishmentCosts

us-gaap:PaymentsOfDebtIssuanceCosts

us-gaap:PaymentsOfOrdinaryDividends

us-gaap:PaymentsRelatedToTaxWithholdingForShareBasedCompensation

us-gaap:PaymentsToAcquireInterestInJointVenture

us-gaap:PensionAndOtherPostretirementBenefitExpense

us-gaap:ProceedsFromIssuanceOfSeniorLongTermDebt

us-gaap:ProceedsFromRepaymentsOfCommercialPaper

us-gaap:ProceedsFromSaleOfProductiveAssets
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:FairValueByAssetClass
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:FairValueByAssetClass
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:SubsequentEventType

us-gaap:PropertyPlantAndEquipmentAdditions
us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:RevenueFromRelatedParties
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:StockRepurchasedDuringPeriodValue
us-gaap:PartnerCapitalComponents

us-gaap:UnrealizedGainLossOnDerivatives
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:WeightedAverageLimitedPartnershipUnitsOutstanding

us-gaap:WeightedAverageLimitedPartnershipUnitsOutstandingDiluted

dei:EntityCommonStockSharesOutstanding
us-gaap:TransactionType
mmp:AmountAfterOffset
us-gaap:RetirementPlanType
mmp:AmountofLiabilitiesandAccumulatedOtherComprehensiveLossRecognizedinConsolidatedBalanceSheet
us-gaap:StatementBusinessSegments
mmp:ContractedStorage
us-gaap:StatementBusinessSegments
mmp:ContractedStorageWhollyOwned
us-gaap:DebtInstrument
mmp:DebtInstrumentNotesAtPricePercentageOfPar

mmp:EnergyRelatedInventoryTransmix

mmp:EquityMethodInvestmentsUnamortizedExcessInvestmentNet
us-gaap:PropertyPlantAndEquipmentByType
mmp:OperatingLeaseRightOfUseAssetGross
us-gaap:StatementBusinessSegments
mmp:PipelineLength
us-gaap:StatementBusinessSegments
mmp:RevenueMarketsRegulatedByStateOrFERCPercentage
us-gaap:StatementBusinessSegments
mmp:RevenueShipmentsRegulatedByFERCPercentage
us-gaap:StatementBusinessSegments
mmp:StorageCapacity
us-gaap:StatementBusinessSegments
mmp:StorageCapacityWhollyOwned

us-gaap:AccountsAndOtherReceivablesNetCurrent
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:AccountsPayableOtherCurrent
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:AccountsPayableOtherCurrentAndNoncurrent
us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:AccountsReceivableRelatedPartiesCurrent

us-gaap:AccrualForEnvironmentalLossContingencies

us-gaap:AccrualForTaxesOtherThanIncomeTaxesCurrent

us-gaap:AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax

us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperation

us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent

us-gaap:BilledContractReceivables

us-gaap:ContractWithCustomerAssetNet

us-gaap:ContractWithCustomerLiability
us-gaap:CreditFacility
us-gaap:DebtInstrumentFaceAmount

us-gaap:DebtInstrumentUnamortizedDiscountPremiumNet

us-gaap:DeferredCompensationArrangementWithIndividualSharesAuthorizedForIssuance

us-gaap:DeferredFinanceCostsNet

us-gaap:DeferredRevenueCurrent
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedBenefitObligation
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditAfterTax
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmountsRecognizedInBalanceSheet
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationWeightedAverageInterestCreditingRate
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanBenefitObligation
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear
us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanFairValueOfPlanAssets
us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanFundedStatusOfPlan

us-gaap:DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear
us-gaap:DefinedBenefitPlanByPlanAssetCategories
us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage
us-gaap:StatementScenario, us-gaap:DefinedBenefitPlanByPlanAssetCategories

us-gaap:DefinedBenefitPlanUltimateHealthCareCostTrendRate1
us-gaap:DefinedBenefitPlanByPlanAssetCategories
us-gaap:DefinedBenefitPlanWeightedAverageAssetAllocations
us-gaap:TransactionType
us-gaap:DerivativeCollateralRightToReclaimCash
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation
us-gaap:DerivativeFairValueOfDerivativeAsset
us-gaap:HedgingDesignation
us-gaap:TransactionType
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation
us-gaap:DerivativeFairValueOfDerivativeLiability
us-gaap:HedgingDesignation
us-gaap:TransactionType
us-gaap:TransactionType
us-gaap:DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeLiabilities
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementBasis
us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship
us-gaap:DerivativeNonmonetaryNotionalAmount

us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsNotesAndLoansReceivableNet

us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsPayableCurrent

us-gaap:DisposalGroupIncludingDiscontinuedOperationAccruedLiabilitiesCurrent

us-gaap:DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent

us-gaap:DisposalGroupIncludingDiscontinuedOperationInventoryCurrent

us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets

us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities

us-gaap:DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent

us-gaap:EmployeeRelatedLiabilitiesCurrent

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
us-gaap:AwardType, us-gaap:PlanName

us-gaap:EnergyMarketingContractLiabilitiesCurrent

us-gaap:EnergyRelatedInventory

us-gaap:EnergyRelatedInventoryChemicals

us-gaap:EnergyRelatedInventoryNaturalGasLiquids

us-gaap:EnergyRelatedInventoryPetroleum
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentOwnershipPercentage
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:SubsequentEventType

us-gaap:FiniteLivedIntangibleAssetsAccumulatedAmortization

us-gaap:GoodFaithAndMarginDepositsWithBrokerDealers
us-gaap:TransactionType
us-gaap:BalanceSheetLocation, us-gaap:GuaranteeObligationsByNature
us-gaap:GuaranteesFairValueDisclosure
us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FairValueByMeasurementBasis

us-gaap:InterestPayableCurrentAndNoncurrent

us-gaap:InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet

us-gaap:InventoryCrudeOilProductsAndMerchandise

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths
mmp:LeaseType
mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:LessorOperatingLeasePaymentsToBeReceived

us-gaap:LessorOperatingLeasePaymentsToBeReceivedFiveYears

us-gaap:LessorOperatingLeasePaymentsToBeReceivedFourYears

us-gaap:LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths

us-gaap:LessorOperatingLeasePaymentsToBeReceivedThereafter

us-gaap:LessorOperatingLeasePaymentsToBeReceivedThreeYears

us-gaap:LessorOperatingLeasePaymentsToBeReceivedTwoYears
us-gaap:CreditFacility
us-gaap:LettersOfCreditOutstandingAmount
us-gaap:CreditFacility, us-gaap:LongtermDebtType

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent

us-gaap:LimitedPartnersCapitalAccount

us-gaap:LimitedPartnersCapitalAccountUnitsOutstanding
us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:LongTermDebtFairValue
us-gaap:FairValueByMeasurementBasis
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:LongTermInvestmentsAndReceivablesNet

us-gaap:NetInvestmentInLease

us-gaap:NetInvestmentInLeaseCurrent

us-gaap:NetInvestmentInLeaseNoncurrent

us-gaap:NotesAndLoansReceivableNetNoncurrent

us-gaap:OperatingLeaseWeightedAverageDiscountRatePercent
mmp:LeaseType

us-gaap:PartnersCapital
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee
us-gaap:PartnerCapitalComponents
us-gaap:PartnerCapitalComponents, us-gaap:RetirementPlanType
us-gaap:RetirementPlanType

us-gaap:PartnersCapitalAccountDistributionPerUnitOfLimitedPartnerInterest
us-gaap:StatementScenario
us-gaap:SubsequentEventType
us-gaap:RetirementPlanType
us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities
us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:ReceivablesFairValueDisclosure
us-gaap:FairValueByMeasurementBasis

us-gaap:RecordedThirdPartyEnvironmentalRecoveriesReceivable
us-gaap:BalanceSheetLocation

us-gaap:RestrictedCashAndCashEquivalentsNoncurrent

us-gaap:RevenueRemainingPerformanceObligation
us-gaap:StatementBusinessSegments

us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivable

us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceived

us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedFiveYears

us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedFourYears

us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedNextTwelveMonths

us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedThereafter

us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedThreeYears

us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedTwoYears

us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivableUndiscountedExcessAmount

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
us-gaap:AwardType

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant

us-gaap:StockRepurchaseProgramAuthorizedAmount1

us-gaap:UnbilledReceivablesCurrent

Plots across concepts


IncomeStatement
Income Loss From Continuing Operations 
Before Income Taxes Extraordinary Items Noncontrolling Interest
Expenses
Other Nonoperating Income Expense
Balance Sheet
Intangible Assets Net Excluding Goodwill
Assets
Operating Lease Right Of Use Asset
Current Assets
Other Assets Current
NonCurrent Assets
Other Assets Noncurrent
PropertyPlantAndEquipmentNet
Accumulated Depreciation Depletion And Amortization Property Plant And Equipment
Liabilities
Operating Lease Liability
Current Liabilities
Operating Lease Liability Current
Noncurrent Liabilities
Other Liabilities Noncurrent
CashFlow
Net Cash Provided By Used In Financing Activities
NetCashProvidedByUsedInOperatingActivities
Share Based Compensation
NetCashProvidedByUsedInInvestingActivities
Payments To Acquire Property Plant And Equipment
NetCashProvidedByUsedInFinancingActivities
Net Cash Provided By Used In Financing Activities
OperatingLeaseLiability
Operating Lease Liability Current
LesseeOperatingLeaseLiabilityPaymentsDue
Lessee Operating Lease Liability Undiscounted Excess Amount

Tables

  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
 Operating Margin us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,mmp:CrudeOilPipelineandTerminalsSegment█▇▇█▇▇██████▇▇▆▆▆▅▅▆▅▅▆▅▅▄▄▄▄▃▃▂▂▁165.759149.136142.311163.554146.254155.499160.618162.861164.51156.807158.404161.247155.084136.713132.458132.378131.332111.29112.208129.279103.798106.255122.38699.2498.96789.58790.22983.74184.45872.49868.09852.88844.39726.387NANANANANANANANANANANANA
 Operating Margin us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,mmp:RefinedProductsSegment▅▅▄▃▁▇▅▄▅▃█▃▄▅▅▃▄▄▄▂▂▂▃▃▂▃▅▃▂▅▄▂▂▂489.073513.749445.482436.64315.735628.889530.341445.669489.896422.573659.51430.311442.35493.465495.647396.558439.959482.404452.478373.391370.277368.746433.576431.581343.034389.416528.424393.106368.823503.946466.499349.408358.718364.774NANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
 TTM Greenblatt ROC _ _▆▆▅▆▄▇▇▇▇▅█▆▆▆▆▅▆▆▅▅▅▄▅▆▄▄▆▅▃▆▅▃▄▃▄▁▃▂▄▂▂▂▃266.875279.484239.95266.597200.686326.769338.337320.479300.742244.146360.846295.573266.168271.994290.081229.701261.458271.473258.578233.949226.527215.998246.376289.67207.763219.811295.087225.837178.218275.089223.47154.624184.457142.505182.6879.284167.281122.813199.004137.753128.666116.72172.599NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:AllocatedShareBasedCompensationExpense ▄▄▅▂▄▁▂▅█▄▆▆▇▅▅▃▅▄▄▄▃▅5.3814.6796.4051.1694.2560.1551.4356.77310.894.9147.4417.93310.0476.6326.4583.4666.574.1474.6214.6783.4096.65NANANANANANANANANA4.2175.4264.8568.4815.5474.1652.8435.9592.7345.2673.75NANANANA
us-gaap:ComprehensiveIncomeNetOfTax ▃▂▂▂▁▃▃▃▃▂▄█▂▂▂▂▂▂▃▂▂▂▂▃▂▂▂▂▁▃▂▁▁294.924223.851164.034213.961137.987279.87272.313261.361240.372205.217311.781603.887219.155216.189194.416200.824210.635227.319229.963192.575179.934195.408205.667248.82180.81169.015193.703196.996147.94238.844204.766125.67154.102NA147.89464.276141.30894.33574.019105.692107.64890.10286.35153.437102.44366.254
us-gaap:CostsAndExpenses ▅▅▄▄▂▇▆▄▅▅█▄▅▅▅▄▄▄▄▃▂▃▃▂▂▂▄▂▃▃▃▂▁▂▃▁▂▄429.261420.179382.779367.939297.324499.186450.514385.927436.718422.985555.111396.242420.433441.323426.039374.298383.558392.047383.49336.409307.709321.446343.502303.083304.322311.869387.311297.409320.183343.983355.081291.586260.191291.967318.601248.334283.724372.318NANANANANANANANA
us-gaap:GainsLossesOnExtinguishmentOfDebt NANA0.00.0-12.8930.00.00.00.0-8.270.00.00.00.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:GainsLossesOnExtinguishmentOfDebt us-gaap:DebtInstrument mmp:FourPointTwoFivePercentageNotesDueTwoThousandTwentyOneNANA25.8NA-12.9NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:GeneralAndAdministrativeExpense █▆█▄▅▄▆▇▇▆▆▆▇▆▆▄▅▅▄▄▄▅▅▄▄▄▅▄▅▄▄▃▄▃▃▂▂▂▃▁▂▂▃▂▁▂56.08946.5856.38638.01642.16836.90847.11651.15652.38345.99547.04847.38953.2946.55644.84137.20243.39340.28136.59935.834.54240.87440.27737.61237.94235.49838.66735.37739.30934.93536.42332.75533.26230.05632.69427.55125.41423.74428.32820.4725.28124.5928.27223.62420.17823.242
us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest ▃▂▂▂▁▃▃▃▃▂▄█▂▂▃▂▂▂▂▂▂▂265.333222.107184.685212.462134.432288.32285.432273.138254.884208.832310.484596.143215.525211.844239.047199.426211.308223.58214.215195.289188.544207.941NANANANANANANANANANANANANANANA94.07NANANA90.53NANANANA
us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest 264.899NANANA129.919NANANANANANANANANANANANANANANANANANANANANANANANA243.775191.455126.227155.453113.715154.41351.107138.70294.07110.731110.687103.484NANANANANA
us-gaap:IncomeTaxExpenseBenefit ▆▇▇▇▇▇▄▆▇▇▁█▇▇▇▇▇▇▇▇▇▇0.4340.7890.7650.8240.5890.756-1.0130.11.1811.169-3.5881.6091.1160.9341.1520.9260.9080.8440.9240.7380.6850.871NANANANANANANANANANANANANANANA0.5460.4690.4470.4850.4650.4710.1480.2290.523
us-gaap:InterestExpenseDebt ▆▆▆▆█▆▆▆▅▇▆▆▆▆▆▅▅▅▅▅▅▄▄▄▄▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂▂▂▁▁56.98156.97954.76254.21269.25955.955.80153.7551.40660.16652.44455.13356.7556.65256.04551.89551.54651.21251.61450.16348.68643.72442.75339.77939.75636.60734.85534.99337.26536.41635.16831.85231.7231.72330.62729.11329.11829.12329.06327.33225.98826.48626.76825.31622.52121.774
us-gaap:OperatingIncomeLoss ▆▆▅▆▄▇▇▇▇▅█▆▆▆▆▅▆▆▅▅▅▄▅▆▄▄▆▅▃▆▅▃▄▃▄▁▃▂▄▂▂▂▃▁▂▁266.875279.484239.95266.597200.686326.769338.337320.479300.742244.146360.846295.573266.168271.994290.081229.701261.458271.473258.578233.949226.527215.998246.376289.67207.763219.811295.087225.837178.218275.089223.47154.624184.457142.505182.6879.284167.281122.813199.004137.753128.666116.72172.59982.251124.72186.307
us-gaap:OtherNonoperatingIncomeExpense ▁▆▅▅▅▆▅▅▄▅▅▅▆▃▆▆▅▅▆▇▆▇▅▅█▆▃▆▆▆-14.828-1.059-1.456-1.455-1.446-0.807-2.608-2.602-4.57-2.05-3.569-1.6940.119-8.724-0.377-0.549-2.043-1.170.6843.3241.9252.27-3.539-1.7066.539-0.279-8.5730.00.00.0NANANANANANANANANANANANA0.0-0.75NANA
us-gaap:ProfitLoss ▃▂▂▂▁▃▃▃▃▂▄█▂▂▃▂▂▂▂▂▂▂280.417221.318183.92211.638133.843287.564286.445273.038253.703207.663314.072594.534214.409210.91237.895198.5210.4222.736213.291194.551187.859207.07NANANANANANANANANANANANANANANA93.524110.262110.24102.99990.06587.95756.637102.45264.534
us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax ▇▇▅▅▃▆█▆▇▇▇▆▇▇▇▅▆▆▆▅▄▄▅▅▄▄▇▄▄▆▅▃▃▃▄▁▃▄▄▃▂▃▂▂▃▁666.407687.574585.663576.254459.284626.276739.995607.956676.188654.073682.546634.577654.328661.442673.299572.848619.44642.074614.915551.782518.897519.816573.048577.232487.543522.09667.07521.601496.446618.606577.438443.835443.912432.421503.195325.869449.527493.483486.933435.51383.327442.897398.491406.201423.06329.695
us-gaap:Revenues ▅▅▄▅▃▇▆▅▆▅█▅▅▆▆▄▅▅▅▄▄▄▄▄▃▄▅▄▃▅▄▃▃▂▃▁▃▃▃▂▂▃▂▂▂▁653.643661.073586.324598.264460.408782.806740.682656.596701.699628.935865.683638.02644.091678.779673.299572.848619.44642.074614.915551.782518.897519.816573.048577.232487.543522.09667.07521.601496.446618.606577.438443.835443.912432.421503.195325.869449.527493.483486.933435.51383.327442.897398.491406.201423.06329.695
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:Assets ████████▇▇▇▇▇▆▆▆▆▆▆▆▅▅▄▄▄▄▄▃▃▃▃▂▂▂▂▂▂▁▁▁▁▁▁8292.6628248.2288196.9828140.1968104.998185.3058437.7298392.1868005.447844.5517747.5377595.6687538.3027376.0497394.3757103.4476930.7226829.8796772.0736919.7856448.2046392.3146041.5675966.1835732.0565605.1175517.2855311.3965124.2595143.7824820.8124548.0054388.0684405.7134420.0674105.3574074.9894009.7944045.0014006.6983849.163796.8373717.9NANANA
 us-gaap:Liabilities us-gaap:EquityMethodInvestmentNonconsolidatedInvestee us-gaap:EquityMethodInvestmentsNANA201.153NANANA221.452NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LiabilitiesAndStockholdersEquity ████████▇▇▇▇▇▆▆▆▆▆▆▆▅▅▄▄▄▄▄▃▃▃▃▂▂▂▂▂▂▁▁▁▁▁▁8292.6628248.2288196.9828140.1968104.998185.3058437.7298392.1868005.447844.5517747.5377595.6687538.3027376.0497394.3757103.4476930.7226829.8796772.0736919.7856448.2046392.3146041.5675966.1835732.0565605.1175517.2855311.3965124.2595143.7824820.8124548.0054388.0684405.7134420.0674105.3574074.9894009.7944045.0014006.6983849.163796.8373717.9NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:AssetsCurrent █▃▂▁▁▂▃▄▂▂▄▅▂▃▄▂▁▁▂▄▂▃▁▂▁▂▂▂▂▄▂▂▃▄▅▃▄▄▄▄▃▂▂1022.273478.145405.193341.243317.244426.99459.408567.844407.018438.188646.343672.007425.538493.192611.839407.428325.656302.428370.394648.275385.582515.531338.854358.156332.701395.65402.667401.98358.458567.042396.733387.281464.319585.495700.278500.47591.85566.448612.19607.521458.567428.278384.583NANANA
us-gaap:CashAndCashEquivalentsAtCarryingValue ▆▁▁▁▁▄▂▄▁▁▆▆▁▃▅▁▁▁▁▇▂▅▂▁▂▂▁▁▁▅▂▁▄▆█▃▆▄▅▅▁▂▁▃▂▁257.974.07313.0368.5412.863139.25458.03135.4863.0713.496218.283217.4232.46774.197176.0681.3815.4717.05514.701291.09734.263209.99228.7319.00729.0352.81317.06314.8530.731196.6325.23514.228119.491221.003328.278100.491233.716151.642209.62198.06512.99228.5327.48377.01735.0946.916
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents ▇▁▁▁▁▄▃▅▂▂█▇▃▃▅▁▁266.37812.95122.44720.3339.156149.55784.599191.49231.24650.529309.261260.23104.05774.197176.0681.3815.471NA14.701NANANA28.731NANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:AccountsReceivableNetCurrent ▇█▅▅▃▃▆▇█▇▄▇▅▄█▇▅▂▄▆▃▃▂▅▂▄▂▄▃▄▅▅▃▅▃▄▂▄▂▃▁▃▃134.115142.948109.136109.05192.88494.563125.44131.746139.611134.12104.164137.618106.679105.089138.779128.765113.23382.021105.689126.14193.32989.66283.893113.7684.71596.784.465106.49591.691101.292116.295107.7186.676110.75691.114106.20882.201103.05282.49789.83870.07486.72692.192NANANA
us-gaap:OtherAssetsCurrent ▄▄▅▄▃▄▄▅▄▄▆▇█▇▇▇▇▄▄▅▅▅▄▄▄▃▃▄▄▃▅▃▂▂▂▂▂▁▁▁▂▁▁39.06442.96744.39235.78731.93839.74340.23745.63138.5839.76758.14366.22175.28266.44663.39662.24766.12342.31839.96652.646.30543.8843.41839.93740.89331.61934.33139.10736.6233.96946.73531.29624.50521.07123.50219.10721.70712.77613.41211.99819.59212.63711.774NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
 us-gaap:AssetsNoncurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee us-gaap:EquityMethodInvestmentsNANA2846.747NANANA2768.696NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:PropertyPlantAndEquipmentGross ▇███████▇▇▇▇▆▆▆▆▆▆▅▅▅▅▅▄▄▄▄▃▃▃▃▂▂▂▂▂▁▁▁▁▁▁▁7986.7388370.2088352.8258319.48243.1068166.1258431.2278248.1818024.8457808.9527628.5927570.7597443.0957346.4957235.4687121.8567048.5026905.3736783.7376657.3056470.3566302.1996166.7665998.285832.3385642.9045533.9355174.1075089.2775017.7864986.754764.3254581.6034495.2324408.554287.8154173.154105.9514080.4844027.643996.6093948.7823894.61NANANA
us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment ███▇▇▇▇▇▇▇▆▆▆▆▆▆▅▅▅▅▄▄▄▄▄▄▃▃▃▃▃▃▂▂▂▂▂▂▂▁▁▁▁2047.5632143.842091.1342036.3511971.2681919.0142027.1931983.6941935.3011883.3581830.4111835.8241783.0361732.4861682.6331638.3511592.0351545.0011507.9961471.2631428.4261388.691347.5371317.631278.8651243.311204.6011182.3611146.551104.1911070.4921039.1391005.766974.345943.248910.852883.467853.66830.762801.709771.347743.174716.054NANANA
us-gaap:PropertyPlantAndEquipmentNet ▇███████▇▇▇▇▆▆▆▆▆▆▆▅▅▅▅▄▄▄▃▃▃▃▃▂▂▂▂▁▁▁▁▁▁▁▁5939.1756226.3686261.6916283.0496271.8386247.1116404.0346264.4876089.5445925.5945798.1815734.9355660.0595614.0095552.8355483.5055456.4675360.3725275.7415186.0425041.934913.5094819.2294680.654553.4734399.5944329.3343991.7463942.7273913.5953916.2583725.1863575.8373520.8873465.3023376.9633289.6833252.2913249.7223225.9313225.2623205.6083178.556NANANA
us-gaap:InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures ▅████▇██▇▇▆▅█▇▆▆▅▅▅▄▄▃▃▃▂▁▁1002.9891203.3391213.8561211.0791207.671190.8031240.5511206.041165.0281128.6261076.3061005.3921210.2591126.7731082.5111066.94976.456976.419931.255912.419850.401800.38765.628753.568666.451636.618613.867NANANA360.852NANANA107.356NANANANANANANANANANANA
us-gaap:Goodwill ▆███████████████████████████████████████▁▁▁50.12152.8352.8352.8352.8352.8353.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.2653.26239.96139.96139.925NANANA
us-gaap:IntangibleAssetsNetExcludingGoodwill ▇▇▇▇▇▇▇▇▇████████████▇▁▁▁▁▁▁▂▂▂▂▂▂▃▃▃▃▃▃▃▃▃43.6244.27244.92545.57846.56347.2347.89848.56549.23349.951.17451.6652.11852.56352.76452.84552.92551.86551.97652.10252.33744.8821.8562.5353.2143.8934.5735.2525.9316.617.297.9698.6599.39813.27413.65514.03514.5115.17615.8416.50617.17216.924NANANA
us-gaap:OperatingLeaseRightOfUseAsset ██▇▆▇▇▇▇▇▇▁187.231194.463166.078152.082158.855165.512171.868162.463167.456172.1050.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OtherAssetsNoncurrent ▃▃▃▃▃▃▂▂▃▃▂▂▂▂▂▂▆██▂▂▃▂▅▄▄▃▂▁▁▁▁▁▁▁▂▁▁▁▁▁▁▁17.96218.34320.24320.69322.1823.1213.35912.73224.42119.19910.45112.08711.60312.12813.4912.30343.42662.30265.57710.15711.06815.57714.83338.49728.54828.46724.30410.31.9063.4264.2693.0692.0761.7251.88913.023.0222.1972.4373.6874.683.0033.209NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:AccountsPayableCurrent ▄▄▄▅▄▆▆█▇▇▅▅▅▅▄▄▄▃▃▄▄▄▄▅▃▃▃▃▂▂▂▃▃▄▄▃▂▁▂▂▁▁▁122.711102.199100.022124.612119.678147.893150.992205.41179.734192.969138.735137.169125.216129.283104.852120.99103.191.69177.248101.012118.484102.858104.094123.81395.8191.02297.13184.63672.0573.41776.32683.1981.636111.449112.00298.14167.23548.54266.38468.13148.95846.60441.425NANANA
us-gaap:LiabilitiesCurrent ▄▃▃▃▃█▄▄▄▄▄█▅▅▆▅▂▂▃▄▅▄▅▃▂▂▃▂▂▄▄▄▃▂▂▂▁▁▁▁▁▁▁642.023560.763558.574531.619521.151139.644666.876680.645618.271623.368676.5561127.064782.738788.54836.51809.714456.575397.599481.656683.849713.662679.094713.072468.562383.205418.887536.155393.653346.626604.15638.276641.76579.361382.073392.62369.29299.273272.259311.055296.693273.014319.314275.047NANANA
us-gaap:OperatingLeaseLiabilityCurrent ███████▇▇▇▁25.73526.66127.53327.17727.25126.69926.22122.99722.47723.2640.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OtherAccruedLiabilitiesCurrent ▇█▄▅▃▃▅▆▄▅▄▅▄▅▆▇▃▂▃▁▁▁▂▁▁▂▂▃▂▂▄▄▃▄▄▄▃▄▃▃▃▅▃128.507137.97679.16679.38852.8952.34890.788108.88476.45994.43175.48280.19564.01785.26696.159119.57246.80337.79351.625.15622.48121.66531.33920.40821.62937.95344.35554.44937.75543.05563.03369.70249.16478.32272.04970.52655.14267.50559.858.1746.26184.63547.324NANANA
us-gaap:OtherLiabilitiesCurrent ▆▃▅▅▅▇▇▆▆▅▄▃▃▆▅▄▃▃▄▄▆▆▅▃▄▅█▃▂▄▃▄▃▂▃▂▁▁▂▁▁▃▃66.67935.91750.78350.25854.35172.55873.20559.560.57254.81948.65737.87333.60361.54156.5444.06536.01540.86448.43143.05864.23561.8951.09934.93244.66950.13480.92840.60631.91947.11141.14643.07833.58928.62832.83631.51619.14421.36228.73522.42121.12339.47932.428NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
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us-gaap:LongTermDebtNoncurrent █████▆▇▇▇▆▆▅▇▆▆▆▆▆▆▆▅▄▄▄▄▄▃▃▃▂▂▁▁▂▂▁4979.6874996.1424978.6914900.3114792.6494155.4374706.0754705.7754407.7934279.6764211.383718.6074392.0274272.7474273.5184051.4114231.9124203.084087.1924073.5023574.8983552.0323189.2873407.1143326.9363183.752982.8953003.7072910.4962691.2882435.3162236.7612140.0832391.7182393.4082146.749NANA2151.775NANANANANANANA
us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent ▇██▇▇▇▇▆▆▆▆▆▆▆▅▃▃▃▃▃▄▄▃▃▄▄▃▂▂▂▂▃▃▃▃▃▃▃▃▂▁▁▁152.111165.145163.776142.154143.459145.709145.992131.676133.513124.652122.58125.088127.849131.248111.30566.4168.44470.77771.46170.41681.86384.38577.55168.68179.80780.74175.15541.13354.04655.73651.63763.03671.22772.48168.13461.08369.77171.31967.0842.94431.70431.87528.965NANANA
us-gaap:OtherLiabilitiesNoncurrent ▇▆▅▅▆▆▆▅▅▄█▆▇▃▃▃▂▂▂▃▂▂▂▂▂▂▃▃▃▂▂▂▂▁▁▂▁▂▂▁▂▂▂68.46960.32954.65255.90458.7261.3259.73555.08548.96840.29582.2464.42569.52634.76430.3529.79927.13727.07325.86829.40826.41223.43824.16224.84623.84323.42729.06929.44328.16719.6621.80220.06817.73415.25916.38221.41115.28323.65919.90512.50922.51623.01217.597NANANA
us-gaap:OperatingLeaseLiabilityNoncurrent ██▇▆▇▇▇▇▇▇▁164.583168.817137.483121.764134.274139.218144.023135.689146.726148.6030.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo NANA30.528NANANA31.27329.03628.93929.969NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo mmp:LeaseType mmp:ThirdPartyNANA20.609NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
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us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree NANA30.773NANANA28.78827.96727.84828.362NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
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us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour NANA26.599NANANA28.26725.48225.3625.48NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
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us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive NANA42.787NANANA50.60671.55971.14967.338NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
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  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
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 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:RetirementPlanType us-gaap:OtherPostretirementBenefitPlansDefinedBenefitNANA-10.409NANA-8.259-8.378-6.045-6.105-5.338-5.409-5.889-6.036-6.437-6.597-7.319-7.481-7.681-7.881-6.07-5.433NA-3.945NANANA-1.696NANANANANANANANANANANANANANANANANANANA
 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:RetirementPlanType us-gaap:PensionPlansDefinedBenefitNANA-117.782NANA-101.447-104.739-92.131-93.876-87.37-88.602-94.738-96.352-98.261-97.226-52.488-54.138-56.236-58.584-58.727-60.045NA-62.279NANANA-63.257NANANANANANANANANANANANANANANANANANANA
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  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:NetCashProvidedByUsedInOperatingActivities ▆▄▄▄▃▆▆▆▆▃█▅▅▄▅▄▅▄▅▄▃▃▆▅▄▃▆▄▃▄▄▃▃▃▄▁▄▁▂▃▁▂▂▂▂▁352.716240.239267.273276.852178.632384.621398.582352.037364.004206.556489.169299.715286.164277.902314.106222.161307.083265.328325.045231.927197.5209.568345.588309.285223.736191.083393.986235.959207.282270.074251.459179.234172.229169.778232.84973.756248.74589.741151.181208.08770.67147.385108.767102.587139.96573.337
us-gaap:NetCashProvidedByUsedInInvestingActivities ▆▄▃▃▃▅▂▂▂▂▂█▃▃▃▃▃▃▃▂▂▂▂▂▂▃▂▃▂▂▁▂▃▃▃▃▄▄▄▄▄▃▃▁▃▄228.997-31.161-88.982-91.462-150.596131.793-272.504-232.574-280.28-221.894-220.693423.926-162.256-160.233-154.476-95.408-139.636-181.103-175.254-268.744-214.337-199.031-203.977-242.976-229.25-134.566-221.183-171.478-234.84-202.483-304.75-269.475-159.204-148.617-147.251-107.857-71.11-41.863-52.691-49.164-58.965-97.921-118.363-353.63-78.113-40.054
us-gaap:NetCashProvidedByUsedInFinancingActivities ▃▄▄▄▄▂▄▆▅▄▄▁▅▄▆▅▄▅▂█▄▇▅▅▅▅▄▅▄▆▆▅▅▅▇▅▅▅▅▆▅▅▅█▅▅-328.286-218.574-176.177-174.213-168.437-451.456-232.97140.783-103.007-243.394-219.445-567.468-94.048-219.5415.057-130.843-169.031-91.871-426.187293.651-158.892170.724-121.887-86.332-18.269-20.767-170.593-50.359-168.341103.80464.298-15.022-114.537-128.436142.189-99.124-95.561-105.856-86.93526.15-27.245-28.415-59.938292.966-33.674-30.535
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:DepreciationDepletionAndAmortization ▃▄▅▅▄▄▅▄▄▄█▄▄▃▃▃▃▃▃▃▃▃▃▂▂▂▂▂▃▂▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁▁52.25858.12864.7871.82258.5463.53465.10656.62762.5361.871103.35156.22853.61951.87950.52749.90948.89647.29844.00547.08143.30243.75442.63242.04340.4441.69739.27938.05446.89737.51136.44235.2734.18636.33233.32431.69231.48631.5130.91830.23430.66429.36329.20827.40325.71526.342
us-gaap:IncreaseDecreaseInAccountsPayable █▇▅▅▆▆▁▆█▆▄▆▅█▄▆▆▆▄▅▆▅▄▆▇▅▃▆▅▆▅▅▄▇▆▅▆▃▄█▆▆▄▇▃█19.0210.235-4.815-3.2724.3867.926-30.2516.90419.2012.909-6.3528.655-0.61419.457-6.6222.4445.8577.275-10.273-3.2758.0731.052-8.1193.8212.757-4.351-17.4015.997-2.4742.961.0461.278-11.63211.313.665-4.9586.981-16.863-7.06720.2924.4052.596-7.4399.852-14.46919.85
us-gaap:IncreaseDecreaseInInventories ▆▇▇▆▇▁▅▇▅▆▆▅▅▆▆█▄▆▆▄▇▆▅▅▅▆▄▆▅▆▅▆▆▅▆▆▅▅▆▄█▆▆▅▄█13.32145.38438.35612.64945.231-112.007-21.55333.045-22.1419.3136.369-4.212-12.40913.64213.58349.311-26.97712.0511.367-33.41924.3421.22-4.313-24.739-1.0293.187-44.71313.533-21.29323.011-21.2610.5812.752-16.7361.1725.049-24.5-18.6931.74-28.87661.4378.15113.133-5.525-33.84349.642
us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet ▁▆▄▅▇▅▄▇▆▃▅▅█▃▄▅▇▄▄▇▇▄▃▅█▄▃▆▇▃▆▆▅▅▆▅▆▅▆▄▇▄▅▄▆▄-45.0768.003-12.508-0.84524.0952.536-8.06216.2428.09-21.583-1.7812.63431.26-25.406-10.8041.97817.137-7.618-12.46724.55619.569-9.896-23.067-2.90626.553-9.83-28.66711.48622.894-25.58811.51711.442-1.166-5.9155.731-5.2513.759-4.7264.017-9.44717.436-8.5372.173-9.1626.709-8.718
us-gaap:NetCashProvidedByUsedInOperatingActivities ▆▄▄▄▃▆▆▆▆▃█▅▅▄▅▄▅▄▅▄▃▃▆▅▄▃▆▄▃▄▄▃▃▃▄▁▄▁▂▃▁▂▂▂▂▁352.716240.239267.273276.852178.632384.621398.582352.037364.004206.556489.169299.715286.164277.902314.106222.161307.083265.328325.045231.927197.5209.568345.588309.285223.736191.083393.986235.959207.282270.074251.459179.234172.229169.778232.84973.756248.74589.741151.181208.08770.67147.385108.767102.587139.96573.337
us-gaap:ProfitLoss ▃▂▂▂▁▃▃▃▃▂▄█▂▂▃▂▂▂▂▂▂▂280.417221.318183.92211.638133.843287.564286.445273.038253.703207.663314.072594.534214.409210.91237.895198.5210.4222.736213.291194.551187.859207.07NANANANANANANANANANANANANANANA93.524110.262110.24102.99990.06587.95756.637102.45264.534
us-gaap:ShareBasedCompensation ▄▄▅▂▄▁▂▅█▄▆▆▇▅▅▃▅▄▄▄▃▅▇▄▅▄▇▄▆▄▇▄▄▄▆▅▄▃▅▃▄▃▆▄▂▄5.3814.6796.4051.1694.2560.1551.4356.77310.894.9147.4417.93310.0476.6326.4583.4666.574.1474.6214.6783.4096.659.0194.6875.7884.7519.5534.9787.6655.0889.5844.2175.4264.8568.4815.5474.1652.8435.9592.7345.2673.757.4174.5731.954.959
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:NetCashProvidedByUsedInInvestingActivities ▆▄▃▃▃▅▂▂▂▂▂█▃▃▃▃▃▃▃▂▂▂▂▂▂▃▂▃▂▂▁▂▃▃▃▃▄▄▄▄▄▃▃▁▃▄228.997-31.161-88.982-91.462-150.596131.793-272.504-232.574-280.28-221.894-220.693423.926-162.256-160.233-154.476-95.408-139.636-181.103-175.254-268.744-214.337-199.031-203.977-242.976-229.25-134.566-221.183-171.478-234.84-202.483-304.75-269.475-159.204-148.617-147.251-107.857-71.11-41.863-52.691-49.164-58.965-97.921-118.363-353.63-78.113-40.054
us-gaap:PaymentsToAcquirePropertyPlantAndEquipment ▁▁▂▂▃▅▆▇█▆▅▄▄▃▄▄▄▄▅▆▅▄▅▄▄▄▄▃▂▂▃▃▃▃▄▄▂▁▂▁▁▂▂▂▂▁37.45329.95268.40478.953119.546172.671225.385230.943281.226206.436177.937154.878119.97199.471140.43136.735139.989141.515156.349207.677170.611139.522189.891155.412147.331128.517129.20588.10278.84370.29594.088108.50491.21889.947124.153121.91770.95937.13956.50247.8945.05450.21960.72862.80856.3341.553
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:NetCashProvidedByUsedInFinancingActivities ▃▄▄▄▄▂▄▆▅▄▄▁▅▄▆▅▄▅▂█▄▇▅▅▅▅▄▅▄▆▆▅▅▅▇▅▅▅▅▆▅▅▅█▅▅-328.286-218.574-176.177-174.213-168.437-451.456-232.97140.783-103.007-243.394-219.445-567.468-94.048-219.5415.057-130.843-169.031-91.871-426.187293.651-158.892170.724-121.887-86.332-18.269-20.767-170.593-50.359-168.341103.80464.298-15.022-114.537-128.436142.189-99.124-95.561-105.856-86.93526.15-27.245-28.415-59.938292.966-33.674-30.535
us-gaap:PaymentsForRepurchaseOfCommonStock NANA24.9949.9680.0201.982NANA0.00.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31

Allocated Share Based Compensation Expense

us-gaap:AllocatedShareBasedCompensationExpense

us-gaap:AllocatedShareBasedCompensationExpense


Allocated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value5.3814.6796.4051.1694.2560.1551.4356.773104.9147.4417.933106.6326.4583.4666.574.1474.6214.6783.4096.654.2175.4264.8568.4815.5474.1652.8435.9592.7345.2673.75
Percentage of AllocatedShareBasedCompensationExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.80.70.00.20.90.00.01.11.60.80.01.31.51.00.00.61.10.60.80.80.71.31.01.21.11.71.70.90.61.20.61.40.8

us-gaap:AllocatedShareBasedCompensationExpense us-gaap:AwardType

us-gaap:PerformanceShares


Allocated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value2.6542.2164.334-1.1211.821-1.947-0.2035.1629.3173.6446.5527.0879.1655.9245.7042.7285.913.481
Percentage of AllocatedShareBasedCompensationExpense49.347.467.7-95.942.8-1256.1-14.176.285.674.288.189.391.289.388.378.790.083.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.40.30.0-0.20.4-0.30.00.81.40.60.01.11.40.90.00.51.00.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:PerformanceShares0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PhantomShareUnitsPSUs


Allocated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value2.7272.4632.0712.292.4352.1021.6381.6111.5731.270.8890.8460.8820.7080.7540.7380.660.6660.6020.5930.4810.576
Percentage of AllocatedShareBasedCompensationExpense50.752.632.3195.957.21356.1114.123.814.425.811.910.78.810.711.721.310.016.113.012.714.18.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.40.40.00.40.50.30.00.30.20.20.00.10.10.10.00.10.10.10.10.10.10.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:PhantomShareUnitsPSUs0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Comprehensive Income Net Of Tax

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTax


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value29422316421313727927226124020531160321921619420021022722919217919520524818016919319614723820412515414764141947410510790865310266
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax44.332.60.037.130.044.70.043.035.531.40.095.233.532.70.035.134.035.437.434.934.737.635.943.137.132.429.037.829.838.635.528.334.729.419.731.419.115.224.328.120.321.713.224.220.1

us-gaap:ComprehensiveIncomeNetOfTax us-gaap:PartnerCapitalComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value142.533-19.8862.3234.144-7.694-14.132-11.677-13.331-2.446-2.2919.3534.7465.279
Percentage of ComprehensiveIncomeNetOfTax4.91.1-12.11.13.0-2.7-5.2-4.5-5.5-1.2-0.71.52.22.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax2.20.40.00.40.9-1.20.0-1.9-2.0-0.40.01.50.70.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:LimitedPartner


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value280221183211133287286273253207314594214210
Percentage of ComprehensiveIncomeNetOfTax95.198.9112.198.997.0102.7105.2104.5105.5101.2100.798.597.897.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax42.132.20.036.729.145.90.044.937.531.70.093.732.831.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:LimitedPartner0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Costs And Expenses

us-gaap:CostsAndExpenses

us-gaap:CostsAndExpenses


Costs
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value429420382367297499450385436422555396420441426374383392383336307321343303304311387297320343355291260291318248283372
Percentage of CostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax64.461.10.063.964.779.70.063.564.664.70.062.464.366.70.065.361.961.162.461.059.361.859.952.562.459.758.157.064.555.661.565.758.667.563.376.263.175.4

Gains Losses On Extinguishment Of Debt

us-gaap:GainsLossesOnExtinguishmentOfDebt

us-gaap:GainsLossesOnExtinguishmentOfDebt


Gains
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
Value0.00.0-12.8930.00.00.00.0-8.270.00.00.00.0
Percentage of GainsLossesOnExtinguishmentOfDebt0.00.0100.00.00.00.00.0100.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.00.0-2.80.00.00.00.0-1.30.00.00.00.0

us-gaap:GainsLossesOnExtinguishmentOfDebt us-gaap:DebtInstrument

mmp:FourPointTwoFivePercentageNotesDueTwoThousandTwentyOne


Gains
Period End2020-12-312020-06-30
Value25-12.9
Percentage of GainsLossesOnExtinguishmentOfDebt0.0100.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.0-2.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mmp:FourPointTwoFivePercentageNotesDueTwoThousandTwentyOne0.00.0

General And Administrative Expense

us-gaap:GeneralAndAdministrativeExpense

us-gaap:GeneralAndAdministrativeExpense


General
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value56465638423647515245474753464437434036353440403737353835393436323330322725232820252428232023
Percentage of GeneralAndAdministrativeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax8.46.80.06.69.25.90.08.47.77.00.07.58.17.00.06.57.06.36.06.56.77.97.06.57.86.85.86.87.95.66.37.47.57.06.58.55.74.85.84.76.65.67.15.84.87.0

us-gaap:GeneralAndAdministrativeExpense us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mmp:CrudeOilPipelineandTerminalsSegment


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
Value1512151011101213141213121311119.26611108.8868.4939.1469.789.0659.8189.0318.0868.2317.6357.6975.9945.7545.14.9154.127
Percentage of GeneralAndAdministrativeExpense28.127.927.427.727.327.827.426.726.927.428.526.925.225.624.824.925.524.924.323.726.523.922.526.123.822.821.321.619.617.215.815.614.813.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax2.41.90.01.82.51.60.02.22.11.90.02.02.11.80.01.61.81.61.41.51.81.91.61.71.91.51.21.51.61.01.01.11.11.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:CrudeOilPipelineandTerminalsSegment10.59.80.07.49.17.90.09.89.99.10.09.09.79.70.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, mmp:RefinedProductsSegment


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
Value40334027302627303127272833282723262422222025252223222522252324222321
Percentage of GeneralAndAdministrativeExpense71.972.172.672.372.772.259.259.959.260.358.860.762.362.062.064.061.661.862.764.259.362.063.959.163.063.765.763.964.665.967.169.470.070.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.14.90.04.86.74.30.05.04.64.20.04.55.14.40.04.24.33.93.74.24.04.94.53.94.94.33.84.35.13.74.25.15.24.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:RefinedProductsSegment7.86.00.06.39.25.40.07.26.35.90.06.47.05.80.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312012-03-312011-03-31
Value2652221842121342882852732542083105962152112391992112232141951882079490
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax39.832.30.036.929.346.00.044.937.731.90.093.932.932.00.034.834.134.834.835.436.340.019.120.4

Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest


Income
Period End2021-06-302020-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value2641292431911261551131545113894110110103
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax39.828.339.433.228.435.026.330.715.730.919.122.725.427.0

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit

us-gaap:IncomeTaxExpenseBenefit


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value434000.0789000.0765000.0824000.0589000.0756000.0-1013000.0100000.01181000.01169000.0-3588000.01609000.01116000.0934000.01152000.0926000.0908000.0844000.0924000.0738000.0685000.0871000.0546000.0469000.0447000.0485000.0465000.0471000.0148000.0229000.0523000.0
Percentage of IncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.10.10.00.10.10.10.00.00.20.20.00.30.20.10.00.20.10.10.20.10.10.20.10.10.10.10.10.10.00.10.2

Interest Expense Debt

us-gaap:InterestExpenseDebt

us-gaap:InterestExpenseDebt


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value56565454695555535160525556565651515151504843423939363434373635313131302929292927252626252221
Percentage of InterestExpenseDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax8.68.30.09.415.18.90.08.87.69.20.08.78.78.60.09.18.38.08.49.19.48.47.56.98.27.05.26.77.55.96.17.27.17.36.18.96.55.96.06.36.86.06.76.25.36.6

Operating Income Loss

us-gaap:OperatingIncomeLoss

us-gaap:OperatingIncomeLoss


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value266279239266200326338320300244360295266271290229261271258233226215246289207219295225178275223154184142182791671221991371281161728212486
Percentage of OperatingIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax40.040.60.046.343.752.20.052.744.537.30.046.640.741.10.040.142.242.342.142.443.741.643.050.242.642.144.243.335.944.538.734.841.633.036.324.337.224.940.931.633.626.443.320.229.526.2

us-gaap:OperatingIncomeLoss us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mmp:CrudeOilPipelineandTerminalsSegment


Operating
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
Value747978961009312012513011210212512510311793828193807881767589687255595050393011
Percentage of OperatingIncomeLoss27.828.332.636.350.328.735.739.343.446.028.542.647.337.940.640.931.529.936.034.634.837.531.026.043.131.124.724.733.118.522.825.916.57.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax11.111.50.016.822.015.00.020.719.317.20.019.919.215.60.016.413.312.615.114.715.215.613.313.118.413.110.910.711.98.28.89.06.92.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:CrudeOilPipelineandTerminalsSegment49.459.50.068.380.172.20.090.491.280.90.088.990.984.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, mmp:RefinedProductsSegment


Operating
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
Value19220016116999233202177158108242155127153160122160169143132131120153194100137203154105208162102133117
Percentage of OperatingIncomeLoss72.271.767.463.749.771.359.855.452.644.567.252.648.056.555.353.361.562.455.456.558.255.762.367.348.362.568.968.659.175.972.666.172.382.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax28.929.10.029.521.737.20.029.223.416.60.024.519.523.20.021.425.926.423.324.025.423.226.833.820.626.330.529.721.233.828.123.030.027.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:RefinedProductsSegment37.236.00.038.929.846.80.041.732.223.10.034.426.931.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Other Nonoperating Income Expense

us-gaap:OtherNonoperatingIncomeExpense

us-gaap:OtherNonoperatingIncomeExpense


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312010-12-312010-09-30
Value-14828000.0-1059000.0-1456000.0-1455000.0-1446000.0-807000.0-2608000.0-2602000.0-4570000.0-2050000.0-3569000.0-1694000.0119000.0-8724000.0-377000.0-549000.0-2043000.0-1170000.0684000.03324000.01925000.02270000.0-3539000.0-1706000.06539000.0-279000.0-8573000.00000-750000.0
Percentage of OtherNonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-2.2-0.20.0-0.3-0.3-0.10.0-0.4-0.7-0.30.0-0.30.0-1.30.0-0.1-0.3-0.20.10.60.40.4-0.6-0.31.3-0.1-1.30.00.00.00.0-0.2

Profit Loss

us-gaap:ProfitLoss

us-gaap:ProfitLoss


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2802211832111332872862732532073145942142102371982102222131941872079311011010290875610264
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax42.132.20.036.729.145.90.044.937.531.70.093.732.831.90.034.734.034.734.735.336.239.819.022.625.326.920.322.113.924.219.6

us-gaap:ProfitLoss us-gaap:PartnerCapitalComponents

us-gaap:LimitedPartner


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value280221183211133287286273253207314594214210
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax42.132.20.036.729.145.90.044.937.531.70.093.732.831.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:LimitedPartner0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Revenue From Contract With Customer Excluding Assessed Tax

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value666687585576459626739607676654682634654661673572619642614551518519573577487522667521496618577443443432503325449493486435383442398406423329
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems

us-gaap:IntersegmentElimination


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-30
Value-1.189-1.812-1.469-1.93-1.581-1.582-1.582-1.556-1.341-0.938-0.938-0.923-0.915-0.915-0.915-0.901-0.893-0.694-0.606-0.2010.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.2-0.3-0.3-0.3-0.3-0.3-0.2-0.3-0.2-0.1-0.1-0.1-0.1-0.1-0.1-0.2-0.1-0.1-0.1-0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.2-0.3-0.3-0.3-0.3-0.3-0.2-0.3-0.2-0.1-0.1-0.1-0.1-0.1-0.1-0.2-0.1-0.1-0.1-0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:IntersegmentElimination100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

us-gaap:OperatingSegments, mmp:CrudeOilPipelineandTerminalsSegment


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value149132122141125129138139143138134141138122
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax22.519.320.924.627.420.718.822.921.221.219.622.321.118.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax22.519.320.924.627.420.718.822.921.221.219.622.321.118.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:CrudeOilPipelineandTerminalsSegment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, mmp:RefinedProductsSegment


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value517556464436334498556426491471505451474495
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax77.780.979.475.872.979.575.270.172.672.074.171.272.574.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax77.780.979.475.872.979.575.270.172.672.074.171.272.574.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:RefinedProductsSegment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Revenues

us-gaap:Revenues

us-gaap:Revenues


Revenues
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value653661586598460782740656701628865638644678673572619642614551518519573577487522667521496618577443443432503325449493486435383442398406423329
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax98.196.1100.1103.8100.2125.0100.1108.0103.896.2126.8100.598.4102.6100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Revenues us-gaap:ConsolidationItems

us-gaap:IntersegmentElimination


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-30
Value-1.189-1.812-1.469-1.93-1.581-1.582-1.582-1.556-1.341-0.938-0.938-0.923-0.915-0.915-0.915-0.901-0.893-0.694-0.606-0.2010.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Revenues-0.2-0.3-0.3-0.3-0.3-0.2-0.2-0.2-0.2-0.1-0.1-0.1-0.1-0.1-0.1-0.2-0.1-0.1-0.1-0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.2-0.3-0.3-0.3-0.3-0.3-0.2-0.3-0.2-0.1-0.1-0.1-0.1-0.1-0.1-0.2-0.1-0.1-0.1-0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:IntersegmentElimination100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Revenues us-gaap:ConsolidationItems, us-gaap:ProductOrService

us-gaap:IntersegmentElimination, us-gaap:Service


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-1.189-1.812-1.469-1.93-1.581-1.582-1.582-1.556-1.341-0.938-0.938-0.923-0.915-0.915-0.915-0.901
Percentage of Revenues-0.2-0.3-0.3-0.3-0.3-0.2-0.2-0.2-0.2-0.1-0.1-0.1-0.1-0.1-0.1-0.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.2-0.3-0.3-0.3-0.3-0.3-0.2-0.3-0.2-0.1-0.1-0.1-0.1-0.1-0.1-0.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:IntersegmentElimination us-gaap:Service0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

us-gaap:OperatingSegments, us-gaap:Product, mmp:CrudeOilPipelineandTerminalsSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value4329125.1938.8146.1348.9298.3435.2955.7131412136.4390.17712
Percentage of Revenues6.64.42.20.91.90.81.21.30.80.91.72.02.10.90.02.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.54.22.20.91.91.01.21.40.80.92.12.02.01.00.02.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:Product mmp:CrudeOilPipelineandTerminalsSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, us-gaap:Product, mmp:RefinedProductsSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value14920111611434312226134183155358129150232208107
Percentage of Revenues22.930.519.919.17.540.030.620.526.124.741.420.423.434.330.918.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax22.529.320.019.87.550.030.622.227.123.752.520.523.135.230.918.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:Product mmp:RefinedProductsSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, us-gaap:ProductAndServiceOther, mmp:CrudeOilPipelineandTerminalsSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value3.6853.7523.743.7093.8033.7073.7473.5923.6463.4863.5043.4633.8494.0163.6393.703
Percentage of Revenues0.60.60.60.60.80.50.50.50.50.60.40.50.60.60.50.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.60.50.60.60.80.60.50.60.50.50.50.50.60.60.50.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:ProductAndServiceOther mmp:CrudeOilPipelineandTerminalsSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, us-gaap:ProductAndServiceOther, mmp:RefinedProductsSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value1.6091.551.5941.5791.5131.5840.4330.4320.470.4120.5120.3510.3520.2970.3530.353
Percentage of Revenues0.20.20.30.30.30.20.10.10.10.10.10.10.10.00.10.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.20.20.30.30.30.30.10.10.10.10.10.10.10.00.10.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:ProductAndServiceOther mmp:RefinedProductsSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, us-gaap:Service, mmp:CrudeOilPipelineandTerminalsSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value118116125154133145147150155147140145137126128116
Percentage of Revenues18.217.621.425.929.018.620.023.022.223.516.222.721.418.619.120.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax17.816.921.426.829.123.320.024.823.022.620.622.921.119.119.120.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:Service mmp:CrudeOilPipelineandTerminalsSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, us-gaap:Service, mmp:RefinedProductsSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value337310326320279314303310306267300300291260287289
Percentage of Revenues51.747.055.853.660.840.240.947.343.642.534.747.045.238.442.750.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax50.745.255.855.760.950.241.051.145.340.844.047.344.539.442.750.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:Service mmp:RefinedProductsSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

us-gaap:OperatingSegments, mmp:AncillaryServices, mmp:CrudeOilPipelineandTerminalsSegment, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value7.6117.9466.196.828127.8457.4747.1646.6116.0216.0786.2788.1995.035
Percentage of Revenues1.21.21.11.12.61.01.01.10.91.00.71.01.30.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.11.21.11.22.61.31.01.21.00.90.91.01.30.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:AncillaryServices mmp:CrudeOilPipelineandTerminalsSegment us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, mmp:AncillaryServices, mmp:RefinedProductsSegment, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value3131313228322829282527282825
Percentage of Revenues4.94.75.45.56.24.13.84.54.04.13.24.54.43.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.84.55.55.76.25.13.84.84.24.04.14.54.33.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:AncillaryServices mmp:RefinedProductsSegment us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, mmp:LeaseRevenue, mmp:CrudeOilPipelineandTerminalsSegment, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value1817191918191919171615161612
Percentage of Revenues2.82.73.33.24.12.52.62.92.52.71.82.52.61.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax2.82.63.33.34.13.12.63.22.62.62.32.52.51.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:LeaseRevenue mmp:CrudeOilPipelineandTerminalsSegment us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, mmp:LeaseRevenue, mmp:RefinedProductsSegment, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value3.9954.1476.435.3153.778.1622.9262.1032.8893.2452.9262.6412.4663.109
Percentage of Revenues0.60.61.10.90.81.00.40.30.40.50.30.40.40.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.60.61.10.90.81.30.40.30.40.50.40.40.40.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:LeaseRevenue mmp:RefinedProductsSegment us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, mmp:Storage, mmp:CrudeOilPipelineandTerminalsSegment, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value2929313244383535343431292829
Percentage of Revenues4.64.45.45.59.75.04.85.45.05.53.74.64.44.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.54.35.55.79.76.24.85.85.25.24.74.64.44.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:Storage mmp:CrudeOilPipelineandTerminalsSegment us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, mmp:Storage, mmp:RefinedProductsSegment, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value4449474950572625252625252425
Percentage of Revenues6.87.48.08.311.07.33.63.93.64.22.93.93.93.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.77.18.18.611.09.23.64.23.84.03.74.03.83.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:Storage mmp:RefinedProductsSegment us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, mmp:Terminalling, mmp:CrudeOilPipelineandTerminalsSegment, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value3.2186.1176.7615.6510.482.5394.6773.1764.7235.2463.8372.5280.00.0
Percentage of Revenues0.50.91.20.90.10.30.60.50.70.80.40.40.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.50.91.21.00.10.40.60.50.70.80.60.40.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:Terminalling mmp:CrudeOilPipelineandTerminalsSegment us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, mmp:Terminalling, mmp:RefinedProductsSegment, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value2532314136404547484043465039
Percentage of Revenues3.95.05.46.97.95.26.17.26.96.45.17.27.95.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.84.85.57.27.96.46.17.87.26.26.47.37.75.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:Terminalling mmp:RefinedProductsSegment us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, mmp:Transportation, mmp:CrudeOilPipelineandTerminalsSegment, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value5955619057778185918582918479
Percentage of Revenues9.18.310.415.112.59.911.013.113.013.59.614.313.211.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.08.010.515.612.512.311.014.113.513.012.114.413.012.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:Transportation mmp:CrudeOilPipelineandTerminalsSegment us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, mmp:Transportation, mmp:RefinedProductsSegment, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value232193209192160176200205201171200197184166
Percentage of Revenues35.529.335.732.134.822.527.131.328.727.223.230.928.724.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax34.828.135.833.434.928.127.133.929.826.129.431.128.225.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:Transportation mmp:RefinedProductsSegment us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, us-gaap:Product, mmp:CrudeOilPipelineandTerminalsSegment, us-gaap:TransferredAtPointInTime


Revenuesus-gaap:
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
Value4329125.1938.8146.1348.9298.3435.2955.7131412136.439
Percentage of Revenues6.64.42.20.91.90.81.21.30.80.91.72.02.10.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.54.22.20.91.91.01.21.40.80.92.12.02.01.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:Product mmp:CrudeOilPipelineandTerminalsSegment us-gaap:TransferredAtPointInTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, us-gaap:Product, mmp:RefinedProductsSegment, us-gaap:TransferredAtPointInTime


Revenuesus-gaap:
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
Value14920111611434312226134183155358129150232
Percentage of Revenues22.930.519.919.17.540.030.620.526.124.741.420.423.434.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax22.529.320.019.87.550.030.622.227.123.752.520.523.135.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:Product mmp:RefinedProductsSegment us-gaap:TransferredAtPointInTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, us-gaap:Service, mmp:CrudeOilPipelineandTerminalsSegment, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value118116125154133145147150155147140145137126
Percentage of Revenues18.217.621.425.929.018.620.023.022.223.516.222.721.418.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax17.816.921.426.829.123.320.024.823.022.620.622.921.119.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:Service mmp:CrudeOilPipelineandTerminalsSegment us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, us-gaap:Service, mmp:RefinedProductsSegment, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value337310326320279314303310306267300300291260
Percentage of Revenues51.747.055.853.660.840.240.947.343.642.534.747.045.238.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax50.745.255.855.760.950.241.051.145.340.844.047.344.539.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:Service mmp:RefinedProductsSegment us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Revenues us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:TimingOfTransferOfGoodOrService

us-gaap:IntersegmentElimination, mmp:Storage, us-gaap:TransferredOverTime


Revenuesus-gaap:
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-1.189-1.812-1.469-1.93-1.581-1.582-1.582-1.556-1.341-0.938-0.938-0.923-0.915-0.915
Percentage of Revenues-0.2-0.3-0.3-0.3-0.3-0.2-0.2-0.2-0.2-0.1-0.1-0.1-0.1-0.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.2-0.3-0.3-0.3-0.3-0.3-0.2-0.3-0.2-0.1-0.1-0.1-0.1-0.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:IntersegmentElimination mmp:Storage us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IntersegmentElimination, us-gaap:Service, us-gaap:TransferredOverTime


Revenuesus-gaap:
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-1.189-1.812-1.469-1.93-1.581-1.582-1.582-1.556-1.341-0.938-0.938-0.923-0.915-0.915
Percentage of Revenues-0.2-0.3-0.3-0.3-0.3-0.2-0.2-0.2-0.2-0.1-0.1-0.1-0.1-0.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.2-0.3-0.3-0.3-0.3-0.3-0.2-0.3-0.2-0.1-0.1-0.1-0.1-0.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:IntersegmentElimination us-gaap:Service us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

us-gaap:OperatingSegments, mmp:CrudeOilPipelineandTerminalsSegment


Revenuesus-gaap:
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
Value1651491421631461551601621641561581611551361321321311111121291031061229998899083847268524426
Percentage of Revenues25.422.624.327.331.819.921.724.823.424.918.325.324.120.119.723.121.217.318.223.420.020.421.417.220.317.213.516.117.011.711.811.910.06.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax24.921.724.328.431.824.821.726.824.324.023.225.423.720.719.723.121.217.318.223.420.020.421.417.220.317.213.516.117.011.711.811.910.06.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:CrudeOilPipelineandTerminalsSegment110.6112.2116.4115.5116.1119.8115.6116.9115.0112.9118.2113.8112.1111.60.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, mmp:RefinedProductsSegment


Revenuesus-gaap:
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
Value489513445436315628530445489422659430442493495396439482452373370368433431343389528393368503466349358364
Percentage of Revenues74.877.776.073.068.680.371.667.969.867.276.267.468.772.773.669.271.075.173.667.771.470.975.774.870.474.679.275.474.381.580.878.780.884.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax73.474.776.175.868.7100.471.773.372.464.696.667.867.674.673.669.271.075.173.667.771.470.975.774.870.474.679.275.474.381.580.878.780.884.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments mmp:RefinedProductsSegment94.592.395.8100.094.3126.395.3104.699.789.7130.495.393.299.60.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Revenues us-gaap:ProductOrService

us-gaap:Product


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value19323012911943319238144189162374144166241209121
Percentage of Revenues29.534.922.220.09.440.832.222.127.125.943.322.625.935.631.121.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax29.033.522.220.79.451.032.223.828.124.954.922.825.536.531.121.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:Product0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ProductAndServiceOther


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value5.2945.3025.3345.2885.3165.2915.385.3575.3055.1485.2274.8425.0465.254.7974.903
Percentage of Revenues0.80.80.90.91.20.70.70.80.80.80.60.80.80.80.70.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.80.80.90.91.20.80.70.90.80.80.80.80.80.80.70.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductAndServiceOther0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Service


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value455425451473411458497506506460486488472431458446
Percentage of Revenues69.764.376.979.289.458.667.177.172.273.356.176.673.363.668.278.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax68.361.877.082.289.773.267.283.374.970.471.277.072.265.368.278.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:Service0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Revenues us-gaap:ProductOrService, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:Service, mmp:Bridgetex, us-gaap:EquityMethodInvestee


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value12109.5389.323121010101010109.99.6979.8649.19.1
Percentage of Revenues2.01.61.61.62.81.41.51.61.51.61.21.61.51.51.41.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.91.61.61.62.81.71.51.81.51.61.51.61.51.51.41.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:Service mmp:Bridgetex us-gaap:EquityMethodInvestee0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Service, mmp:DoubleEaglePipelineLlc, us-gaap:EquityMethodInvestee


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value0.8570.9760.9010.9951.4211.61.41.5821.5721.6591.31.01.3431.5441.61.3
Percentage of Revenues0.10.10.20.20.30.20.20.20.20.30.20.20.20.20.20.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.10.10.20.20.30.30.20.30.20.30.20.20.20.20.20.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:Service mmp:DoubleEaglePipelineLlc us-gaap:EquityMethodInvestee0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Service, mmp:SaddlehornPipelineCompany, us-gaap:EquityMethodInvestee


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value0.5790.580.7720.580.5650.5660.5650.5660.5510.5520.60.50.5380.5380.50.5
Percentage of Revenues0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:Service mmp:SaddlehornPipelineCompany us-gaap:EquityMethodInvestee0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Revenues us-gaap:ProductOrService, us-gaap:TimingOfTransferOfGoodOrService

mmp:AncillaryServices, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value3939383940404443413840404237
Percentage of Revenues6.15.96.56.68.95.16.06.65.96.24.76.46.65.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax5.95.76.56.98.96.46.07.26.15.96.06.56.55.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mmp:AncillaryServices us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

mmp:LeaseRevenue, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value2221252422272625242422222319
Percentage of Revenues3.43.34.44.14.93.53.63.93.53.92.63.63.62.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.43.24.44.24.94.43.64.23.73.73.33.63.52.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mmp:LeaseRevenue us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

mmp:Storage, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value7376778093949393939590878588
Percentage of Revenues11.211.613.213.420.412.112.614.313.315.110.513.713.313.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax11.011.113.313.920.415.112.715.413.814.513.313.713.113.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mmp:Storage us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

mmp:Terminalling, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value2838384636425051534648495140
Percentage of Revenues4.35.96.67.88.05.56.87.97.77.45.67.77.95.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.35.76.68.18.06.96.98.58.07.17.17.87.86.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mmp:Terminalling us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

mmp:Transportation, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value291248270282217253281291292256283288269246
Percentage of Revenues44.637.646.247.247.332.338.044.441.740.732.745.241.836.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax43.836.146.249.047.440.438.148.043.339.241.545.441.237.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax mmp:Transportation us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Product, us-gaap:TransferredAtPointInTime


Revenuesus-gaap:
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
Value19323012911943319238144189162374144166241
Percentage of Revenues29.534.922.220.09.440.832.222.127.125.943.322.625.935.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax29.033.522.220.79.451.032.223.828.124.954.922.825.536.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:Product us-gaap:TransferredAtPointInTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Service, us-gaap:TransferredOverTime


Revenuesus-gaap:
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
Value455425451473411458497506506460486488472431
Percentage of Revenues69.764.376.979.289.458.667.177.172.273.356.176.673.363.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax68.361.877.082.289.773.267.283.374.970.471.277.072.265.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:Service us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Assets

us-gaap:Assets

us-gaap:Assets


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value82928248819681408104818584378392800578447747759575387376739471036930682967726919644863926041596657325605551753115124514348204548438844054420410540744009404540063849379637173163
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment


Assetsus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312014-09-302013-12-312012-12-312011-12-31
Value9013125620659595690109357237
Percentage of Assets1.11.63.32.80.91.01.01.72.38.15.9
Percentage of Assets1.11.63.32.80.91.01.01.72.38.15.9
Percentage of Assets us-gaap:CorporateNonSegment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments


Assetsus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312014-09-302013-12-312012-12-312011-12-31
Value81068306749171886712598254605220471140623807
Percentage of Assets98.998.496.797.299.199.099.098.397.791.994.1
Percentage of Assets98.998.496.797.299.199.099.098.397.791.994.1
Percentage of Assets us-gaap:OperatingSegments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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

us-gaap:OperatingSegments, mmp:CrudeOilPipelineandTerminalsSegment


Assetsus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312014-09-302013-12-312012-12-312011-12-31
Value283627912710281726312313193717321252875432
Percentage of Assets34.633.135.038.138.938.335.132.626.019.810.7
Percentage of Assets34.633.135.038.138.938.335.132.626.019.810.7
Percentage of Assets us-gaap:OperatingSegments mmp:CrudeOilPipelineandTerminalsSegment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, mmp:RefinedProductsSegment


Assetsus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312014-09-302013-12-312012-12-312011-12-31
Value52694302371534993289299128752849281125302736
Percentage of Assets64.351.048.047.348.649.552.153.658.357.367.7
Percentage of Assets64.351.048.047.348.649.552.153.658.357.367.7
Percentage of Assets us-gaap:OperatingSegments mmp:RefinedProductsSegment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:EquityMethodInvestments


Assetsus-gaap:
Period End2020-12-312019-12-31
Value30903028
Percentage of Assets37.735.9
Percentage of Assets37.735.9
Percentage of Assets us-gaap:EquityMethodInvestments100.0100.0

Liabilities

us-gaap:Liabilities us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:Liabilities

us-gaap:EquityMethodInvestments


Liabilitiesus-gaap:
Period End2020-12-312019-12-31
Value201221
Percentage of Liabilities100.0100.0
Percentage of Assets2.52.6
Percentage of Assets us-gaap:EquityMethodInvestments6.57.3

Liabilities And Stockholders Equity

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:LiabilitiesAndStockholdersEquity


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value82928248819681408104818584378392800578447747759575387376739471036930682967726919644863926041596657325605551753115124514348204548438844054420410540744009404540063849379637173163
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Assets Current

us-gaap:AssetsCurrent

us-gaap:AssetsCurrent


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value1022478405341317426459567407438646672425493611407325302370648385515338358332395402401358567396387464585700500591566612607458428384323
Percentage of AssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets12.35.84.94.23.95.25.46.85.15.68.38.85.66.78.35.74.74.45.59.46.08.15.66.05.87.17.37.67.011.08.28.510.613.315.812.214.514.115.115.211.911.310.310.2

us-gaap:AssetsCurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:EquityMethodInvestments


Assets
Period End2020-12-312019-12-31
Value243260
Percentage of AssetsCurrent60.256.6
Percentage of Assets3.03.1
Percentage of Assets us-gaap:EquityMethodInvestments7.98.6

Cash And Cash Equivalents At Carrying Value

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:CashAndCashEquivalentsAtCarryingValue


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-312007-12-31
Value2574.073138.5412.863139581353.07132182172.467741761.3815.4717.0551429134209289.007295217140.731196251411922132810023315120919812287.48377356.9164.168370.938
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.10.00.20.10.01.70.71.60.00.22.82.90.01.02.40.00.10.10.24.20.53.30.50.20.50.90.30.30.03.80.50.32.75.07.42.45.73.85.24.90.30.80.20.00.00.00.10.00.0

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312015-12-31
Value2661222209.156149841913150309260104741761.3815.4711428
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.20.20.30.20.11.81.02.30.40.64.03.41.41.02.40.00.10.20.5

Accounts Receivable Net Current

us-gaap:AccountsReceivableNetCurrent

us-gaap:AccountsReceivableNetCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value13414210910992941251311391341041371061051381281138210512693898311384968410691101116107861109110682103828970869272
Percentage of AccountsReceivableNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.61.71.31.31.11.21.51.61.71.71.31.81.41.41.91.81.61.21.61.81.41.41.41.91.51.71.52.01.82.02.42.42.02.52.12.62.02.62.02.21.82.32.52.3

us-gaap:AccountsReceivableNetCurrent us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:Bridgetex, us-gaap:EquityMethodInvestee


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-03-312018-12-312018-09-30
Value2.8350.2630.3550.3820.2730.3660.3920.3850.2840.30.2
Percentage of AccountsReceivableNetCurrent2.10.20.30.40.30.40.30.30.20.30.1
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets mmp:Bridgetex us-gaap:EquityMethodInvestee0.00.00.00.00.00.00.00.00.00.00.0

mmp:DoubleEaglePipelineLlc, us-gaap:EquityMethodInvestee


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value0.2040.310.2770.2860.480.5920.4450.440.5690.5830.50.30.5
Percentage of AccountsReceivableNetCurrent0.20.20.30.30.50.60.40.30.40.40.50.20.4
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets mmp:DoubleEaglePipelineLlc us-gaap:EquityMethodInvestee0.00.00.00.00.00.00.00.00.00.00.00.00.0

mmp:PowderSpringsLogisticsLLC, us-gaap:EquityMethodInvestee


Accounts
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-06-30
Value0.0070.1010.0470.3070.1610.144
Percentage of AccountsReceivableNetCurrent0.00.10.10.30.10.1
Percentage of Assets0.00.00.00.00.00.0
Percentage of Assets mmp:PowderSpringsLogisticsLLC us-gaap:EquityMethodInvestee0.00.00.00.00.00.0

mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Accounts
Period End2020-09-302020-06-302020-03-312019-12-312019-09-30
Value0.4970.7681.2160.9410.753
Percentage of AccountsReceivableNetCurrent0.50.81.30.80.6
Percentage of Assets0.00.00.00.00.0
Percentage of Assets mmp:SeabrookLogisticsLLC us-gaap:EquityMethodInvestee0.00.00.00.00.0

Other Assets Current

us-gaap:OtherAssetsCurrent

us-gaap:OtherAssetsCurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value3942443531394045383958667566636266423952464343394031343936334631242123192112131119121114
Percentage of OtherAssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.50.50.50.40.40.50.50.50.50.50.80.91.00.90.90.91.00.60.60.80.70.70.70.70.70.60.60.70.70.71.00.70.60.50.50.50.50.30.30.30.50.30.30.5

Assets Noncurrent

us-gaap:AssetsNoncurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:AssetsNoncurrent

us-gaap:EquityMethodInvestments


Assets
Period End2020-12-312019-12-31
Value28462768
Percentage of AssetsNoncurrent100.0100.0
Percentage of Assets34.732.8
Percentage of Assets us-gaap:EquityMethodInvestments92.191.4

Property Plant And Equipment Gross

us-gaap:PropertyPlantAndEquipmentGross

us-gaap:PropertyPlantAndEquipmentGross


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value79868370835283198243816684318248802478087628757074437346723571217048690567836657647063026166599858325642553351745089501749864764458144954408428741734105408040273996394838943398
Percentage of PropertyPlantAndEquipmentGross100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets96.3101.5101.9102.2101.799.899.998.3100.299.598.599.798.799.697.9100.3101.7101.1100.296.2100.398.6102.1100.5101.7100.7100.397.499.397.6103.4104.8104.4102.099.7104.4102.4102.4100.9100.5103.8104.0104.8107.4

us-gaap:PropertyPlantAndEquipmentGross us-gaap:BalanceSheetLocation, us-gaap:PropertyPlantAndEquipmentByType

mmp:CapitalizedInterest, us-gaap:PropertyPlantAndEquipmentOtherTypes


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value988667574331353324
Percentage of PropertyPlantAndEquipmentGross1.21.00.90.80.60.50.60.70.6
Percentage of Assets1.21.00.90.80.60.50.60.70.5
Percentage of Assets mmp:CapitalizedInterest us-gaap:PropertyPlantAndEquipmentOtherTypes0.00.00.00.00.00.00.00.00.0

us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType

us-gaap:BuildingAndBuildingImprovements


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value12612511911410188454137
Percentage of PropertyPlantAndEquipmentGross1.51.51.61.61.51.40.80.80.9
Percentage of Assets1.51.51.51.61.51.50.80.90.9
Percentage of Assets us-gaap:BuildingAndBuildingImprovements0.00.00.00.00.00.00.00.00.0

us-gaap:ConstructionInProgress


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value125515395389500476314165247
Percentage of PropertyPlantAndEquipmentGross1.56.15.25.47.47.75.73.35.6
Percentage of Assets1.56.15.15.37.47.95.73.45.6
Percentage of Assets us-gaap:ConstructionInProgress0.00.00.00.00.00.00.00.00.0

us-gaap:Containers


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value20852206205918971829168411981141975
Percentage of PropertyPlantAndEquipmentGross25.026.227.026.227.027.321.722.922.1
Percentage of Assets25.426.226.625.727.027.921.723.722.1
Percentage of Assets us-gaap:Containers0.00.00.00.00.00.00.00.00.0

us-gaap:Land


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value385336303303339275757883
Percentage of PropertyPlantAndEquipmentGross4.64.04.04.25.04.51.41.61.9
Percentage of Assets4.74.03.94.15.04.61.41.61.9
Percentage of Assets us-gaap:Land0.00.00.00.00.00.00.00.00.0

us-gaap:OtherEnergyEquipment


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value200620441875170313501217826716645
Percentage of PropertyPlantAndEquipmentGross24.024.324.623.519.919.714.914.414.6
Percentage of Assets24.524.224.223.019.920.215.014.914.6
Percentage of Assets us-gaap:OtherEnergyEquipment0.00.00.00.00.00.00.00.00.0

us-gaap:Pipelines


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value332729172614258124572249715593479
Percentage of PropertyPlantAndEquipmentGross39.834.634.335.736.236.512.911.910.9
Percentage of Assets40.634.633.834.936.337.213.012.310.8
Percentage of Assets us-gaap:Pipelines0.00.00.00.00.00.00.00.00.0

us-gaap:PropertyPlantAndEquipmentOtherTypes


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value296284261244206175126115105
Percentage of PropertyPlantAndEquipmentGross3.53.43.43.43.02.82.32.32.4
Percentage of Assets3.63.43.43.33.02.92.32.42.4
Percentage of Assets us-gaap:PropertyPlantAndEquipmentOtherTypes0.00.00.00.00.00.00.00.00.0

Accumulated Depreciation Depletion And Amortization Property Plant And Equipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value204721432091203619711919202719831935188318301835178317321682163815921545150714711428138813471317127812431204118211461104107010391005974943910883853830801771743716617
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets24.726.025.525.024.323.424.023.624.224.023.624.223.723.522.823.123.022.622.321.322.221.722.322.122.322.221.822.322.421.522.222.822.922.121.322.221.721.320.520.020.019.619.319.5

Property Plant And Equipment Net

us-gaap:PropertyPlantAndEquipmentNet

us-gaap:PropertyPlantAndEquipmentNet


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value59396226626162836271624764046264608959255798573456605614555254835456536052755186504149134819468045534399432939913942391339163725357535203465337632893252324932253225320531782780
Percentage of PropertyPlantAndEquipmentNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets71.675.576.477.277.476.375.974.676.175.574.875.575.176.175.177.278.778.577.974.978.276.979.878.579.478.578.575.276.976.181.281.981.579.978.482.380.781.180.380.583.884.485.587.9

Investments In Affiliates Subsidiaries Associates And Joint Ventures

us-gaap:InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures

us-gaap:InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures


Investments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-312012-12-31
Value1002120312131211120711901240120611651128107610051210112610821066976976931912850800765753666636613360107
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets12.114.614.814.914.914.514.714.414.614.413.913.216.115.314.615.014.114.313.813.213.212.512.712.611.611.411.17.52.4

us-gaap:InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mmp:CrudeOilPipelineandTerminalsSegment


Investments
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value78481878396188673959934591
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures64.666.072.888.895.296.697.795.985.4
Percentage of Assets9.69.710.113.013.112.210.97.22.1
Percentage of Assets us-gaap:OperatingSegments mmp:CrudeOilPipelineandTerminalsSegment27.729.328.934.133.732.031.027.610.5

us-gaap:OperatingSegments, mmp:RefinedProductsSegment


Investments
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value42924372931120.00.00.0
Percentage of InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures35.42.03.52.73.31.60.00.00.0
Percentage of Assets5.20.30.50.40.50.20.00.00.0
Percentage of Assets us-gaap:OperatingSegments mmp:RefinedProductsSegment8.10.61.00.80.90.40.00.00.0

Goodwill

us-gaap:Goodwill

us-gaap:Goodwill


Goodwill
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value5052525252525353535353535353535353535353535353535353535353535353535353535353535339393914
Percentage of Goodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.60.60.60.60.70.60.60.60.70.70.70.70.70.70.70.70.80.80.80.80.80.80.90.90.91.01.01.01.01.01.11.21.21.21.21.31.31.31.31.31.01.11.10.5

us-gaap:Goodwill us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mmp:RefinedProductsSegment


Goodwillus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value40383838383838383838
Percentage of Goodwill77.172.072.072.072.072.072.072.072.072.0
Percentage of Assets0.50.50.50.50.60.60.70.80.90.9
Percentage of Assets us-gaap:OperatingSegments mmp:RefinedProductsSegment0.80.91.01.11.21.31.31.41.51.4

Intangible Assets Net Excluding Goodwill

us-gaap:IntangibleAssetsNetExcludingGoodwill

us-gaap:IntangibleAssetsNetExcludingGoodwill


Intangible
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value434444454647474849495151525252525251515252441.8562.5353.2143.8934.5735.2525.9316.617.297.9698.6599.3981313141415151617165.896
Percentage of IntangibleAssetsNetExcludingGoodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.50.50.50.60.60.60.60.60.60.60.70.70.70.70.70.70.80.80.80.80.80.70.00.00.10.10.10.10.10.10.20.20.20.20.30.30.30.40.40.40.40.50.50.2

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
Value1871941661521581651711621671720.0
Percentage of OperatingLeaseRightOfUseAsset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets2.32.42.01.92.02.02.01.92.12.20.0

us-gaap:OperatingLeaseRightOfUseAsset mmp:LeaseType

mmp:ThirdParty


Operating
Period End2020-12-312019-12-31
Value10398
Percentage of OperatingLeaseRightOfUseAsset62.157.2
Percentage of Assets1.31.2
Percentage of Assets mmp:ThirdParty0.00.0

us-gaap:OperatingLeaseRightOfUseAsset mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:RelatedParty, mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Operating
Period End2020-12-312019-12-31
Value6273
Percentage of OperatingLeaseRightOfUseAsset37.942.8
Percentage of Assets0.80.9
Percentage of Assets mmp:RelatedParty mmp:SeabrookLogisticsLLC us-gaap:EquityMethodInvestee0.00.0

us-gaap:OperatingLeaseRightOfUseAsset us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

mmp:NA


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value13013410386909398
Percentage of OperatingLeaseRightOfUseAsset69.669.262.156.756.756.757.2
Percentage of Assets1.61.61.31.11.11.11.2
Percentage of Assets mmp:NA0.00.00.00.00.00.00.0

us-gaap:OperatingLeaseRightOfUseAsset us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value56596265687173
Percentage of OperatingLeaseRightOfUseAsset30.430.837.943.343.343.342.8
Percentage of Assets0.70.70.80.80.80.90.9
Percentage of Assets mmp:SeabrookLogisticsLLC us-gaap:EquityMethodInvestee0.00.00.00.00.00.00.0

Other Assets Noncurrent

us-gaap:OtherAssetsNoncurrent

us-gaap:OtherAssetsNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value171820202223131224191012111213124362651011151438282824101.9063.4264.2693.0692.0761.7251.889133.0222.1972.4373.6874.683.0033.2094.335
Percentage of OtherAssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.20.20.20.30.30.30.20.20.30.20.10.20.20.20.20.20.60.91.00.10.20.20.20.60.50.50.40.20.00.10.10.10.00.00.00.30.10.10.10.10.10.10.10.1

Accounts Payable Current

us-gaap:AccountsPayableCurrent

us-gaap:AccountsPayableCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value1221021001241191471502051791921381371251291041201039177101118102104123959197847273768381111112986748666848464137
Percentage of AccountsPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.51.21.21.51.51.81.82.42.22.51.81.81.71.81.41.71.51.31.11.51.81.61.72.11.71.61.81.61.41.41.61.81.92.52.52.41.61.21.61.71.31.21.11.2

Liabilities Current

us-gaap:LiabilitiesCurrent

us-gaap:LiabilitiesCurrent


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value64256055853152111396666806186236761127782788836809456397481683713679713468383418536393346604638641579382392369299272311296273319275229
Percentage of LiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets7.76.86.86.56.413.97.98.17.77.98.714.810.410.711.311.46.65.87.19.911.110.611.87.96.77.59.77.46.811.713.214.113.28.78.99.07.36.87.77.47.18.47.47.3

us-gaap:LiabilitiesCurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:EquityMethodInvestments


Liabilities
Period End2020-12-312019-12-31
Value143160
Percentage of LiabilitiesCurrent25.724.1
Percentage of Assets1.81.9
Percentage of Assets us-gaap:EquityMethodInvestments4.65.3

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
Value252627272726262222230.0
Percentage of OperatingLeaseLiabilityCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets0.30.30.30.30.30.30.30.30.30.30.0

us-gaap:OperatingLeaseLiabilityCurrent mmp:LeaseType

mmp:ThirdParty


Operating
Period End2020-12-312019-12-31
Value1715
Percentage of OperatingLeaseLiabilityCurrent62.157.7
Percentage of Assets0.20.2
Percentage of Assets mmp:ThirdParty0.00.0

us-gaap:OperatingLeaseLiabilityCurrent mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:RelatedParty, mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Operating
Period End2020-12-312019-12-31
Value1011
Percentage of OperatingLeaseLiabilityCurrent37.942.3
Percentage of Assets0.10.1
Percentage of Assets mmp:RelatedParty mmp:SeabrookLogisticsLLC us-gaap:EquityMethodInvestee0.00.0

us-gaap:OperatingLeaseLiabilityCurrent us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

mmp:NA


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value17171715151415
Percentage of OperatingLeaseLiabilityCurrent67.564.762.157.856.355.757.7
Percentage of Assets0.20.20.20.20.20.20.2
Percentage of Assets mmp:NA0.00.00.00.00.00.00.0

us-gaap:OperatingLeaseLiabilityCurrent us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value8.3699.4041011111111
Percentage of OperatingLeaseLiabilityCurrent32.535.337.942.243.744.342.3
Percentage of Assets0.10.10.10.10.10.10.1
Percentage of Assets mmp:SeabrookLogisticsLLC us-gaap:EquityMethodInvestee0.00.00.00.00.00.00.0

Other Accrued Liabilities Current

us-gaap:OtherAccruedLiabilitiesCurrent

us-gaap:OtherAccruedLiabilitiesCurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value12813779795252901087694758064859611946375125222131202137445437436369497872705567595846844736
Percentage of OtherAccruedLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.51.71.01.00.70.61.11.31.01.21.01.10.81.21.31.70.70.60.80.40.30.30.50.30.40.70.81.00.70.81.31.51.11.81.61.71.41.71.51.51.22.21.31.2

Other Liabilities Current

us-gaap:OtherLiabilitiesCurrent

us-gaap:OtherLiabilitiesCurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value6635505054727359605448373361564436404843646151344450804031474143332832311921282221393222
Percentage of OtherLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.80.40.60.60.70.90.90.70.80.70.60.50.40.80.80.60.50.60.70.61.01.00.80.60.80.91.50.80.60.90.90.90.80.60.70.80.50.50.70.60.51.00.90.7

Liabilities Noncurrent

us-gaap:LiabilitiesNoncurrent us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:LiabilitiesNoncurrent

us-gaap:EquityMethodInvestments


Liabilities
Period End2020-12-312019-12-31
Value5760
Percentage of LiabilitiesNoncurrent100.0100.0
Percentage of Assets0.70.7
Percentage of Assets us-gaap:EquityMethodInvestments1.92.0

Long Term Debt Noncurrent

us-gaap:LongTermDebtNoncurrent

us-gaap:LongTermDebtNoncurrent


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-31
Value4979499649784900479241554706470544074279421137184392427242734051423142034087407335743552318934073326318329823003291026912435223621402391239321462151
Percentage of LongTermDebtNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets60.060.660.760.259.150.855.856.155.154.654.449.058.357.957.857.061.161.560.458.955.455.652.857.158.056.854.156.656.852.350.549.248.854.354.152.353.2

Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value1521651631421431451451311331241221251271311116668707170818477687980754154555163717268616971674231312822
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.82.02.01.71.81.81.71.61.71.61.61.61.71.81.50.91.01.01.11.01.31.31.31.21.41.41.40.81.11.11.11.41.61.61.51.51.71.81.71.10.80.80.80.7

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent us-gaap:RetirementPlanType

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Pension
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value1514111212
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent9.79.69.210.917.3
Percentage of Assets0.20.20.10.20.2
Percentage of Assets us-gaap:OtherPostretirementBenefitPlansDefinedBenefit0.00.00.00.00.0

us-gaap:PensionPlansDefinedBenefit


Pension
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value1471311119959
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent90.390.490.889.182.7
Percentage of Assets1.81.61.41.30.9
Percentage of Assets us-gaap:PensionPlansDefinedBenefit0.00.00.00.00.0

Other Liabilities Noncurrent

us-gaap:OtherLiabilitiesNoncurrent

us-gaap:OtherLiabilitiesNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value6860545558615955484082646934302927272529262324242323292928192120171516211523191222231712
Percentage of OtherLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.80.70.70.70.70.70.70.70.60.51.10.80.90.50.40.40.40.40.40.40.40.40.40.40.40.40.50.60.50.40.50.40.40.30.40.50.40.60.50.30.60.60.50.4

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
Value1641681371211341391441351461480.0
Percentage of OperatingLeaseLiabilityNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets2.02.01.71.51.71.71.71.61.81.90.0

us-gaap:OperatingLeaseLiabilityNoncurrent mmp:LeaseType

mmp:ThirdParty


Operating
Period End2020-12-312019-12-31
Value8481
Percentage of OperatingLeaseLiabilityNoncurrent61.856.6
Percentage of Assets1.01.0
Percentage of Assets mmp:ThirdParty0.00.0

us-gaap:OperatingLeaseLiabilityNoncurrent mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:RelatedParty, mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Operating
Period End2020-12-312019-12-31
Value5262
Percentage of OperatingLeaseLiabilityNoncurrent38.243.4
Percentage of Assets0.60.7
Percentage of Assets mmp:RelatedParty mmp:SeabrookLogisticsLLC us-gaap:EquityMethodInvestee0.00.0

us-gaap:OperatingLeaseLiabilityNoncurrent us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

mmp:NA


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value1161188467777981
Percentage of OperatingLeaseLiabilityNoncurrent70.570.161.855.357.657.056.6
Percentage of Assets1.41.41.00.81.01.01.0
Percentage of Assets mmp:NA0.00.00.00.00.00.00.0

us-gaap:OperatingLeaseLiabilityNoncurrent us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value48505254565962
Percentage of OperatingLeaseLiabilityNoncurrent29.529.938.244.742.443.043.4
Percentage of Assets0.60.60.60.70.70.70.7
Percentage of Assets mmp:SeabrookLogisticsLLC us-gaap:EquityMethodInvestee0.00.00.00.00.00.00.0

Lessee Operating Lease Liability Payments Due Year Two

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value3031292829
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo100.0100.0100.0100.0100.0
Percentage of Assets0.40.40.30.40.4

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo mmp:LeaseType

mmp:ThirdParty


Lessee
Period End2020-12-31
Value20
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo67.5
Percentage of Assets0.3
Percentage of Assets mmp:ThirdParty0.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:RelatedParty, mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Lessee
Period End2020-12-31
Value9.919
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo32.5
Percentage of Assets0.1
Percentage of Assets mmp:RelatedParty mmp:SeabrookLogisticsLLC us-gaap:EquityMethodInvestee0.0

Lessee Operating Lease Liability Payments Due Year Three

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value3028272728
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearThree100.0100.0100.0100.0100.0
Percentage of Assets0.40.30.30.30.4

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree mmp:LeaseType

mmp:ThirdParty


Lessee
Period End2020-12-31
Value20
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearThree67.8
Percentage of Assets0.3
Percentage of Assets mmp:ThirdParty0.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:RelatedParty, mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Lessee
Period End2020-12-31
Value9.919
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearThree32.2
Percentage of Assets0.1
Percentage of Assets mmp:RelatedParty mmp:SeabrookLogisticsLLC us-gaap:EquityMethodInvestee0.0

Lessee Operating Lease Liability Payments Due Year Four

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value2628252525
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFour100.0100.0100.0100.0100.0
Percentage of Assets0.30.30.30.30.3

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour mmp:LeaseType

mmp:ThirdParty


Lessee
Period End2020-12-31
Value16
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFour63.7
Percentage of Assets0.2
Percentage of Assets mmp:ThirdParty0.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:RelatedParty, mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Lessee
Period End2020-12-31
Value9.643
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFour36.3
Percentage of Assets0.1
Percentage of Assets mmp:RelatedParty mmp:SeabrookLogisticsLLC us-gaap:EquityMethodInvestee0.0

Lessee Operating Lease Liability Payments Due Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value2223242425
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFive100.0100.0100.0100.0100.0
Percentage of Assets0.30.30.30.30.3

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive mmp:LeaseType

mmp:ThirdParty


Lessee
Period End2020-12-31
Value16
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFive71.1
Percentage of Assets0.2
Percentage of Assets mmp:ThirdParty0.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:RelatedParty, mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Lessee
Period End2020-12-31
Value6.612
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFive28.9
Percentage of Assets0.1
Percentage of Assets mmp:RelatedParty mmp:SeabrookLogisticsLLC us-gaap:EquityMethodInvestee0.0

Lessee Operating Lease Liability Payments Due After Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value4250717167
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive100.0100.0100.0100.0100.0
Percentage of Assets0.50.60.90.90.9

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive mmp:LeaseType

mmp:ThirdParty


Lessee
Period End2020-12-31
Value18
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive43.3
Percentage of Assets0.2
Percentage of Assets mmp:ThirdParty0.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:RelatedParty, mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Lessee
Period End2020-12-31
Value24
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive56.7
Percentage of Assets0.3
Percentage of Assets mmp:RelatedParty mmp:SeabrookLogisticsLLC us-gaap:EquityMethodInvestee0.0

Operating Lease Liability

us-gaap:OperatingLeaseLiability

us-gaap:OperatingLeaseLiability


Operating
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value165170158169171
Percentage of OperatingLeaseLiability100.0100.0100.0100.0100.0
Percentage of Assets2.02.01.92.12.2

us-gaap:OperatingLeaseLiability mmp:LeaseType

mmp:ThirdParty


Operating
Period End2020-12-31
Value102
Percentage of OperatingLeaseLiability61.9
Percentage of Assets1.2
Percentage of Assets mmp:ThirdParty0.0

us-gaap:OperatingLeaseLiability mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:RelatedParty, mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Operating
Period End2020-12-31
Value62
Percentage of OperatingLeaseLiability38.1
Percentage of Assets0.8
Percentage of Assets mmp:RelatedParty mmp:SeabrookLogisticsLLC us-gaap:EquityMethodInvestee0.0

Lessee Operating Lease Liability Payments Due

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value186195184196200
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue100.0100.0100.0100.0100.0
Percentage of Assets2.32.32.22.52.6

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue mmp:LeaseType

mmp:ThirdParty


Lessee
Period End2020-12-31
Value113
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue60.9
Percentage of Assets1.4
Percentage of Assets mmp:ThirdParty0.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:RelatedParty, mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Lessee
Period End2020-12-31
Value73
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue39.1
Percentage of Assets0.9
Percentage of Assets mmp:RelatedParty mmp:SeabrookLogisticsLLC us-gaap:EquityMethodInvestee0.0

Lessee Operating Lease Liability Undiscounted Excess Amount

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount


Lessee
Period End2020-12-312019-12-31
Value2125
Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount100.0100.0
Percentage of Assets0.30.3

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount mmp:LeaseType

mmp:ThirdParty


Lessee
Period End2020-12-31
Value11
Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount53.4
Percentage of Assets0.1
Percentage of Assets mmp:ThirdParty0.0

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:RelatedParty, mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Lessee
Period End2020-12-31
Value10
Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount46.6
Percentage of Assets0.1
Percentage of Assets mmp:RelatedParty mmp:SeabrookLogisticsLLC us-gaap:EquityMethodInvestee0.0

Accumulated Other Comprehensive Income Loss Net Of Tax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-31
Value-166.15-180.657-183.19-163.304-165.627-169.771-162.077-147.945-136.268-122.937-120.491-118.2-127.553-132.299-137.578-94.099-96.423-96.658-101.241-117.913-115.937-108.012-96.35-94.894-92.742-96.161-81.54-23.158-21.534-23.214-19.504-34.263-34.31-34.772-35.058-29.149-42.903-46.39-47.201-10.958-6.41-11.059-11.096-8.001-17.118
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-2.0-2.2-2.2-2.0-2.0-2.1-1.9-1.8-1.7-1.6-1.6-1.6-1.7-1.8-1.9-1.3-1.4-1.4-1.5-1.7-1.8-1.7-1.6-1.6-1.6-1.7-1.5-0.4-0.4-0.5-0.4-0.8-0.8-0.8-0.8-0.7-1.1-1.2-1.2-0.3-0.2-0.3-0.3-0.30.0

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:RetirementPlanType

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Accumulated
Period End2020-12-312020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-312014-12-31
Value-10.409-8.259-8.378-6.045-6.105-5.338-5.409-5.889-6.036-6.437-6.597-7.319-7.481-7.681-7.881-6.07-5.433-3.945-1.696
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax5.74.95.24.14.54.34.55.04.74.94.87.87.87.97.85.14.74.12.1
Percentage of Assets-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.0
Percentage of Assets us-gaap:OtherPostretirementBenefitPlansDefinedBenefit0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PensionPlansDefinedBenefit


Accumulated
Period End2020-12-312020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-312014-12-31
Value-117.782-101.447-104.739-92.131-93.876-87.37-88.602-94.738-96.352-98.261-97.226-52.488-54.138-56.236-58.584-58.727-60.045-62.279-63.257
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax64.359.864.662.368.971.173.580.275.574.370.755.856.158.257.949.851.864.677.6
Percentage of Assets-1.4-1.2-1.2-1.1-1.2-1.1-1.1-1.2-1.3-1.3-1.3-0.7-0.8-0.8-0.9-0.8-0.9-1.0-1.1
Percentage of Assets us-gaap:PensionPlansDefinedBenefit0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue


Adjustments
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
Value5.3814.6796.4051.1694.2560.1551.4356.773104.9147.4417.933106.632
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue us-gaap:PartnerCapitalComponents

us-gaap:LimitedPartner


Adjustments
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
Value5.3814.6796.4051.1694.2560.1551.4356.773104.9147.4417.933106.632
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:LimitedPartner0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value35224026727617838439835236420648929928627731422230726532523119720934530922319139323520727025117917216923273248891512087014710810213973
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax52.934.945.648.038.961.453.957.953.831.671.747.243.742.046.738.849.641.352.942.038.140.360.353.645.936.659.145.241.843.743.540.438.839.346.322.655.318.231.047.818.433.327.325.333.122.2

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value228-31.161-88.982-91.462-150.596131-272.504-232.574-280.28-221.894-220.693423-162.256-160.233-154.476-95.408-139.636-181.103-175.254-268.744-214.337-199.031-203.977-242.976-229.25-134.566-221.183-171.478-234.84-202.483-304.75-269.475-159.204-148.617-147.251-107.857-71.11-41.863-52.691-49.164-58.965-97.921-118.363-353.63-78.113-40.054
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax34.4-4.5-15.2-15.9-32.821.0-36.8-38.3-41.5-33.9-32.366.8-24.8-24.2-22.9-16.7-22.5-28.2-28.5-48.7-41.3-38.3-35.6-42.1-47.0-25.8-33.2-32.9-47.3-32.7-52.8-60.7-35.9-34.4-29.3-33.1-15.8-8.5-10.8-11.3-15.4-22.1-29.7-87.1-18.5-12.1

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-328.286-218.574-176.177-174.213-168.437-451.456-232.97140-103.007-243.394-219.445-567.468-94.048-219.5415-130.843-169.031-91.871-426.187293-158.892170-121.887-86.332-18.269-20.767-170.593-50.359-168.34110364-15.022-114.537-128.436142-99.124-95.561-105.856-86.93526-27.245-28.415-59.938292-33.674-30.535
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-49.3-31.8-30.1-30.2-36.7-72.1-31.56.7-15.2-37.2-32.2-89.4-14.4-33.22.2-22.8-27.3-14.3-69.353.2-30.632.8-21.3-15.0-3.7-4.0-25.6-9.7-33.916.811.1-3.4-25.8-29.728.3-30.4-21.3-21.5-17.96.0-7.1-6.4-15.072.1-8.0-9.3

Depreciation Depletion And Amortization

us-gaap:DepreciationDepletionAndAmortization

us-gaap:DepreciationDepletionAndAmortization


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value525864715863655662611035653515049484744474343424240413938463736353436333131313030302929272526
Percentage of DepreciationDepletionAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DepreciationDepletionAndAmortization us-gaap:ConsolidationItems

us-gaap:IntersegmentElimination


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-30
Value1.6681.6391.7881.6231.6341.5641.3811.3461.3441.4351.4881.6141.4521.3931.3611.2821.3111.321.3091.2911.1631.1921.0120.8950.9371.0070.9850.8850.8390.8040.8980.7590.7620.760.8530.698
Percentage of DepreciationDepletionAndAmortization3.22.82.82.32.82.52.12.42.12.31.42.92.72.72.72.62.72.83.02.72.72.72.42.12.32.42.52.31.82.12.52.22.22.12.62.2

us-gaap:DepreciationDepletionAndAmortization us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mmp:CrudeOilPipelineandTerminalsSegment


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
Value1616162815151714151513151212121212109.8179.3339.0629.8699.6869.5028.2648.2297.6946.9186.7256.4636.0085.5385.1047.469
Percentage of DepreciationDepletionAndAmortization31.629.125.039.827.125.026.926.225.224.713.226.923.824.625.425.225.623.022.319.820.922.622.722.620.419.719.618.214.317.216.515.714.920.6

us-gaap:OperatingSegments, mmp:RefinedProductsSegment


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
Value34394641414634313435793030282727272624282425242423232323322322212121
Percentage of DepreciationDepletionAndAmortization65.368.172.257.970.172.553.556.155.657.476.554.156.955.755.455.055.257.056.560.457.757.457.557.959.356.259.460.668.461.861.762.062.158.8

Increase Decrease In Accounts Payable

us-gaap:IncreaseDecreaseInAccountsPayable

us-gaap:IncreaseDecreaseInAccountsPayable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1910-4.815-3.2724.3867.926-30.2516.904192.909-6.3528.655-0.61419-6.6222.4445.8577.275-10.273-3.2758.0731.052-8.1193.8212-4.351-17.4015.997-2.4742.961.0461.278-11.632113.665-4.9586.981-16.863-7.067204.4052.596-7.4399.852-14.46919
Percentage of IncreaseDecreaseInAccountsPayable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Increase Decrease In Inventories

us-gaap:IncreaseDecreaseInInventories

us-gaap:IncreaseDecreaseInInventories


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1345381245-112.007-21.55333-22.1419.3136.369-4.212-12.409131349-26.9771211-33.419241.22-4.313-24.739-1.0293.187-44.71313-21.29323-21.2610.5812.752-16.7361.1725.049-24.5-18.6931.74-28.876618.15113-5.525-33.84349
Percentage of IncreaseDecreaseInInventories100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Increase Decrease In Other Operating Capital Net

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-45.0768.003-12.508-0.845242.536-8.062168.09-21.583-1.7812.63431-25.406-10.8041.97817-7.618-12.4672419-9.896-23.067-2.90626-9.83-28.6671122-25.5881111-1.166-5.9155.731-5.2513-4.7264.017-9.44717-8.5372.173-9.1626.709-8.718
Percentage of IncreaseDecreaseInOtherOperatingCapitalNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value35224026727617838439835236420648929928627731422230726532523119720934530922319139323520727025117917216923273248891512087014710810213973
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax52.934.945.648.038.961.453.957.953.831.671.747.243.742.046.738.849.641.352.942.038.140.360.353.645.936.659.145.241.843.743.540.438.839.346.322.655.318.231.047.818.433.327.325.333.122.2

Profit Loss

us-gaap:ProfitLoss

us-gaap:ProfitLoss


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2802211832111332872862732532073145942142102371982102222131941872079311011010290875610264
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax42.132.231.436.729.145.938.744.937.531.746.093.732.831.935.334.734.034.734.735.336.239.819.022.625.326.920.322.113.924.219.6

us-gaap:ProfitLoss us-gaap:PartnerCapitalComponents

us-gaap:LimitedPartner


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value280221183211133287286273253207314594214210
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax42.132.231.436.729.145.938.744.937.531.746.093.732.831.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:LimitedPartner0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Share Based Compensation

us-gaap:ShareBasedCompensation

us-gaap:ShareBasedCompensation


Share
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value5.3814.6796.4051.1694.2560.1551.4356.773104.9147.4417.933106.6326.4583.4666.574.1474.6214.6783.4096.659.0194.6875.7884.7519.5534.9787.6655.0889.5844.2175.4264.8568.4815.5474.1652.8435.9592.7345.2673.757.4174.5731.954.959
Percentage of ShareBasedCompensation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value228-31.161-88.982-91.462-150.596131-272.504-232.574-280.28-221.894-220.693423-162.256-160.233-154.476-95.408-139.636-181.103-175.254-268.744-214.337-199.031-203.977-242.976-229.25-134.566-221.183-171.478-234.84-202.483-304.75-269.475-159.204-148.617-147.251-107.857-71.11-41.863-52.691-49.164-58.965-97.921-118.363-353.63-78.113-40.054
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax34.4-4.5-15.2-15.9-32.821.0-36.8-38.3-41.5-33.9-32.366.8-24.8-24.2-22.9-16.7-22.5-28.2-28.5-48.7-41.3-38.3-35.6-42.1-47.0-25.8-33.2-32.9-47.3-32.7-52.8-60.7-35.9-34.4-29.3-33.1-15.8-8.5-10.8-11.3-15.4-22.1-29.7-87.1-18.5-12.1

Payments To Acquire Property Plant And Equipment

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value372968781191722252302812061771541199914013613914115620717013918915514712812988787094108918912412170375647455060625641
Percentage of PaymentsToAcquirePropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-328.286-218.574-176.177-174.213-168.437-451.456-232.97140-103.007-243.394-219.445-567.468-94.048-219.5415-130.843-169.031-91.871-426.187293-158.892170-121.887-86.332-18.269-20.767-170.593-50.359-168.34110364-15.022-114.537-128.436142-99.124-95.561-105.856-86.93526-27.245-28.415-59.938292-33.674-30.535
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-49.3-31.8-30.1-30.2-36.7-72.1-31.56.7-15.2-37.2-32.2-89.4-14.4-33.22.2-22.8-27.3-14.3-69.353.2-30.632.8-21.3-15.0-3.7-4.0-25.6-9.7-33.916.811.1-3.4-25.8-29.728.3-30.4-21.3-21.5-17.96.0-7.1-6.4-15.072.1-8.0-9.3

Payments For Repurchase Of Common Stock

us-gaap:PaymentsForRepurchaseOfCommonStock

us-gaap:PaymentsForRepurchaseOfCommonStock


Payments
Period End2020-12-312020-09-302020-06-302020-03-312019-06-302019-03-31
Value24490.02010.00.0
Percentage of PaymentsForRepurchaseOfCommonStock100.0100.00.0100.00.00.0

mmp:AdditionalInvestmentinNonControlledEntities

mmp:AdditionalInvestmentinNonControlledEntities


Additional
Period End2021-06-302021-03-312020-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value3.7511.8652164486119962227
Percentage of AdditionalInvestmentinNonControlledEntities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mmp:AmortizationofExcessInvestmentandCapitalizedInterest

mmp:AmortizationofExcessInvestmentandCapitalizedInterest


Amortizationof
Period End2021-06-302021-03-312020-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value430000.0453000.0449000.0546000.0530000.0627000.0697000.0697000.0697000.0698000.0717000.0188000.0187000.0188000.0
Percentage of AmortizationofExcessInvestmentandCapitalizedInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mmp:DisposalGroupIncludingDiscontinuedOperationCostsAndExpenses

mmp:DisposalGroupIncludingDiscontinuedOperationCostsAndExpenses


Disposal
Period End2021-06-302020-06-30
Value2517
Percentage of DisposalGroupIncludingDiscontinuedOperationCostsAndExpenses100.0100.0

mmp:OperatingMarginLoss

mmp:OperatingMarginLoss


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value375384361376301427450428415352511399373370385316353359339316304300329369286297373299264347296222251208248138224178199188184170172133170
Percentage of OperatingMarginLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mmp:OperatingMarginLoss us-gaap:ConsolidationItems

us-gaap:IntersegmentElimination


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-30
Value1.6681.6391.7881.6231.6341.5641.3811.3461.3441.4351.4881.6141.4521.3931.3611.2821.3111.321.3091.2911.1631.1921.0120.8950.9371.0070.9850.8850.8390.8040.8980.7590.7620.760.8530.698
Percentage of OperatingMarginLoss0.40.40.50.40.50.40.30.30.30.40.30.40.40.40.40.40.40.40.40.40.40.40.30.20.30.30.30.30.30.20.30.30.30.40.30.5

mmp:OperatingMarginLoss us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mmp:CrudeOilPipelineandTerminalsSegment


Operating
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
Value10610810913512811915115416014012915315112714111510510111198961009594106848870736362504022
Percentage of OperatingMarginLoss28.328.430.436.142.628.133.636.138.639.825.438.540.734.536.836.629.928.432.931.231.933.528.925.637.328.523.823.527.818.221.122.716.110.8

us-gaap:OperatingSegments, mmp:RefinedProductsSegment


Operating
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
Value267273249239171305264240224171349214191211216173214221191183177170203241148183251200162255209146177160
Percentage of OperatingMarginLoss71.271.269.163.556.971.658.856.153.948.868.353.851.357.156.154.960.661.656.357.958.356.861.965.451.861.867.567.061.573.470.665.970.676.7

mmp:ProportionateShareOfEquityEarnings

mmp:ProportionateShareOfEquityEarnings


Proportionate
Period End2021-06-302021-03-312020-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value41393719151817162510161.8332.1420.6541.2792.5410.9022.217
Percentage of ProportionateShareOfEquityEarnings100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationOtherLongtermIncentivePlansRequisiteServicePeriodRecognition

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationOtherLongtermIncentivePlansRequisiteServicePeriodRecognition


Adjustments
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
Value0-6151000.0000-14700000.0000-9764000.0000-9285000.0
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationOtherLongtermIncentivePlansRequisiteServicePeriodRecognition0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.0

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationOtherLongtermIncentivePlansRequisiteServicePeriodRecognition us-gaap:PartnerCapitalComponents

us-gaap:LimitedPartner


Adjustments
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
Value0-6151000.0000-14700000.0000-9764000.0000-9285000.0
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationOtherLongtermIncentivePlansRequisiteServicePeriodRecognition0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.0

us-gaap:AmortizationOfDebtDiscountPremium us-gaap:DebtInstrument

us-gaap:AmortizationOfDebtDiscountPremium

mmp:FourPointTwoFivePercentageNotesDueTwoThousandTwentyOne


Amortization
Period End2020-12-31
Value1400000.0
Percentage of AmortizationOfDebtDiscountPremium100.0

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value253-9.4962.11411-140.40164-106.893160-19.283-258.7324915629-101.871174-4.09
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ContractWithCustomerLiabilityChangeInTimeframePerformanceObligationSatisfiedRevenueRecognized

us-gaap:ContractWithCustomerLiabilityChangeInTimeframePerformanceObligationSatisfiedRevenueRecognized


Contract
Period End2021-06-302021-03-312020-12-312020-09-302020-06-30
Value7.4664.19.310
Percentage of ContractWithCustomerLiabilityChangeInTimeframePerformanceObligationSatisfiedRevenueRecognized100.0100.0100.0100.0100.0

us-gaap:CostDirectMaterial

us-gaap:CostDirectMaterial


Cost
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value1711841179650249188108152169
Percentage of CostDirectMaterial100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CostDirectMaterial us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mmp:CrudeOilPipelineandTerminalsSegment


Cost
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value4630119.7634.893158.3368.3414.716.664
Percentage of CostDirectMaterial27.216.310.110.29.76.44.47.73.13.9

us-gaap:OperatingSegments, mmp:RefinedProductsSegment


Cost
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value1251541058645233180100148162
Percentage of CostDirectMaterial72.883.789.989.890.393.695.692.396.996.1

us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value-171000.0-147000.0-127000.0-127000.0-136000.0-119000.0-83000.0-60000.0-117000.0-71000.0-148000.0-147000.0-134000.0-160000.0-187000.0-162000.0-200000.0-200000.0-220000.0-291000.0
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value-1241000.0-1544000.0-1345000.0-1346000.0-1322000.0-1412000.0-1352000.0-1352000.0-1508000.0-1277000.0-1581000.0-1659000.0-1569000.0-4954000.0-1405000.0-1406000.0-1783000.0-1028000.0-1160000.0-1161000.0
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses725.71050.31059.11059.8972.11186.61628.92253.31288.91798.61068.21128.61170.93096.2751.3867.9891.5514.0527.3399.0

us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value-45000.0-45000.0-45000.0-46000.0-45000.0-45000.0-45000.0-46000.0-45000.0-45000.0-45000.0-45000.0-46000.0-45000.0-45000.0-45000.0-46000.0-45000.0-46000.0-45000.0
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value2.9213.0462.832.8292.8092.8862.3562.3542.3172.3743.0333.0553.0242.9782.5672.5662.6462.4872.2192.235
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanInterestCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanInterestCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value0.1120.0950.1190.1210.1270.1120.1270.1260.1350.1190.1040.1040.1020.1060.1190.1110.1230.1220.1210.148
Percentage of DefinedBenefitPlanInterestCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value2.2832.42.7382.7382.7112.8023.0273.0263.113.02.8532.8162.7956.4432.4672.4662.5822.351.981.992
Percentage of DefinedBenefitPlanInterestCost2038.42526.32300.82262.82134.62501.82383.52401.62303.72521.02743.32707.72740.26078.32073.12221.62099.21926.21636.41345.9

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value0.3570.3180.3110.3120.330.2930.2580.2340.2950.2440.3210.3090.2870.3310.3670.3240.3890.387-0.15-0.436
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value8.9728.2068.1088.1077.9148.1138.3468.677108.385137.7997.563246.8296.6757.2647.2295.4065.63
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost2513.22580.52607.12598.42398.22768.93234.93708.13618.33436.54079.12523.92635.27273.11860.82060.21867.41868.0-3604.0-1291.3

us-gaap:DefinedBenefitPlanOtherCosts us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanOtherCosts

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312020-09-302020-06-302020-03-312019-06-302019-03-31
Value000-1342000.000
Percentage of DefinedBenefitPlanOtherCosts0.00.00.0100.00.00.0

us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1 us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value-1451000.0000-969000.0-107000.0-439000.0-2060000.00-1964000.0000-445000.0-289000.0-361000.0-1365000.00-202000.0
Percentage of DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1100.00.00.00.0100.0100.0100.0100.00.0100.00.00.00.0100.0100.0100.0100.00.0100.0

us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1

us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1


Defined
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value1451000.0000969000.0107000.0439000.02060000.00
Percentage of DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1100.00.00.00.0100.0100.0100.0100.00.0

us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1 us-gaap:RetirementPlanType

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value1451000.0000969000.0107000.0439000.02060000.00
Percentage of DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1100.00.00.00.0100.0100.0100.0100.00.0

us-gaap:DefinedBenefitPlanServiceCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanServiceCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value0.0740.0760.0650.0640.0670.0620.0480.0480.0430.0540.0690.0580.0510.0650.0610.0510.0660.0650.0590.053
Percentage of DefinedBenefitPlanServiceCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value6.9637.3536.96.8986.7357.2036.2616.266.3586.5279.7746.4246.269155.1245.1255.235.0184.5314.555
Percentage of DefinedBenefitPlanServiceCost9409.59675.010615.410778.110052.211617.713043.813041.714786.012087.014165.211075.912292.224153.88400.010049.07924.27720.07679.78594.3

us-gaap:DefinedContributionPlanCostRecognized

us-gaap:DefinedContributionPlanCostRecognized


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value2.33.12.52.82.44.52.12.82.44.12.22.72.33.82.52.02.13.31.82.42.43.02.11.82.22.82.01.72.02.6
Percentage of DefinedContributionPlanCostRecognized100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DepreciationAndAmortizationDiscontinuedOperations

us-gaap:DepreciationAndAmortizationDiscontinuedOperations


Depreciation
Period End2021-06-302020-06-30
Value3519000.03556000.0
Percentage of DepreciationAndAmortizationDiscontinuedOperations100.0100.0

us-gaap:DerivativeGainLossOnDerivativeNet us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation, us-gaap:IncomeStatementLocation

us-gaap:DerivativeGainLossOnDerivativeNet

us-gaap:CommodityContract, us-gaap:Nondesignated, us-gaap:CostOfSales


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-30
Value6.2571.674.7121.815-0.417-3.9277.525-5.581-6.1482.273-32.005118.337-3.9445.85319-1.1841.2377.3550.8313.24-0.428-3.15-3.767-0.856-1.224-14.004-3.9130.632
Percentage of DerivativeGainLossOnDerivativeNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CommodityContract, us-gaap:Nondesignated, us-gaap:Sales


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-30
Value-40.427-53.793-30.587-7.734-26.755123-31.05817-4.619-54.511155-24.354-38.411-7.375-51.896-47.3361428-30.146-12.65-11.77151571-23.353.8811147-16.6532.823-14.735-2.03512-1.7612.573-44.706
Percentage of DerivativeGainLossOnDerivativeNet-646.1-3221.1-649.1-426.16416.1-3151.7-412.7-315.875.1-2398.2-484.8-208.8-460.7187.0-886.7-240.8-1200.52318.5-409.9-1522.3-363.3-3734.1-507.7-1908.72727.8-317.0-797.0-1215.1-2635.00.00.00.00.00.00.00.0

us-gaap:EnergyRelatedDerivative, us-gaap:Nondesignated, us-gaap:OtherOperatingIncomeExpense


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-1.277-0.65-1.599-3.1553.4-2.899-1.383-3.91-6.4870.00.00.00.0
Percentage of DerivativeGainLossOnDerivativeNet-20.4-38.9-33.9-173.8-815.373.8-18.470.1105.50.0-0.00.00.0

us-gaap:DerivativeGainLossOnDerivativeNet us-gaap:HedgingDesignation

us-gaap:Nondesignated


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-30
Value-35.447-52.773-27.474-9.074-23.772116-24.9168.135-17.254-52.238123-12.689-30.074-11.319-43.704-27.0131329-26.599-7.607-16.533181782-33.0893.95911447-20.2893.332-16.295-2.26415-4.4286.557-49.432
Percentage of DerivativeGainLossOnDerivativeNet-566.5-3160.1-583.1-499.95700.7-2977.9-331.1-145.8280.6-2298.2-384.8-108.8-360.7287.0-746.7-137.4-1100.52418.5-361.6-915.4-510.3-4241.4-555.0-2200.63865.5-323.4-821.0-1226.2-3210.30.00.00.00.00.00.00.0

us-gaap:DirectOperatingCosts

us-gaap:DirectOperatingCosts


Direct
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value149130143161146149149169168146174172159143135165145131137135134123158137131981131321247310010377657410382687389816262877062
Percentage of DirectOperatingCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DirectOperatingCosts us-gaap:ConsolidationItems

us-gaap:IntersegmentElimination


Direct
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-30
Value-2.857-3.451-3.257-3.553-3.215-3.146-2.963-2.902-2.685-2.373-2.426-2.537-2.367-2.308-2.276-2.183-2.204-2.014-1.915-1.492-1.163-1.192-1.012-0.895-0.937-1.007-0.985-0.885-0.839-0.804-0.898-0.759-0.762-0.76-0.853-0.698
Percentage of DirectOperatingCosts-1.9-2.6-2.3-2.2-2.2-2.1-2.0-1.7-1.6-1.6-1.4-1.5-1.5-1.6-1.7-1.3-1.5-1.5-1.4-1.1-0.9-1.0-0.6-0.6-0.7-1.0-0.9-0.7-0.7-1.1-0.9-0.7-1.0-1.2-1.1-0.7

us-gaap:DirectOperatingCosts us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mmp:CrudeOilPipelineandTerminalsSegment


Direct
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
Value43394946454640423743564531333031312722242021401916131614119.0585.9634.0344.0275.107
Percentage of DirectOperatingCosts29.430.034.429.031.431.327.225.122.030.032.326.319.523.422.818.821.620.816.318.215.317.225.414.112.214.114.210.99.512.36.03.95.27.8

us-gaap:OperatingSegments, mmp:RefinedProductsSegment


Direct
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
Value108949711810310594111115891051121139487118100931009598851021041007081101975175826646
Percentage of DirectOperatingCosts72.572.667.973.270.870.863.166.068.661.460.465.270.965.664.571.869.371.173.570.873.469.864.875.976.471.471.876.477.969.675.679.685.871.0

us-gaap:DirectOperatingCosts us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Direct
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-09-30
Value5.5495.317.5637.1757.4796.8996.4346.2676.2416.9096.64.00.00.00.0
Percentage of DirectOperatingCosts3.74.15.34.45.14.64.33.73.74.73.82.30.00.00.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold

us-gaap:DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold


Disposal
Period End2021-06-302020-06-30
Value176.535
Percentage of DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense

us-gaap:DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense


Disposal
Period End2021-06-302020-06-30
Value627000.0521000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationOperatingExpense

us-gaap:DisposalGroupIncludingDiscontinuedOperationOperatingExpense


Disposal
Period End2021-06-302020-06-30
Value3887000.06420000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationOperatingExpense100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue

us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue


Disposal
Period End2021-06-302020-06-30
Value4120
Percentage of DisposalGroupIncludingDiscontinuedOperationRevenue100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue us-gaap:ProductOrService

us-gaap:Product


Disposal
Period End2021-06-302020-06-30
Value278.907
Percentage of DisposalGroupIncludingDiscontinuedOperationRevenue66.842.5

us-gaap:Service


Disposal
Period End2021-06-302020-06-30
Value1312
Percentage of DisposalGroupIncludingDiscontinuedOperationRevenue33.257.5

us-gaap:EnvironmentalRemediationExpense

us-gaap:EnvironmentalRemediationExpense


Environmental
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value0.91.12.50.10.80.40.20.81.42.04.25.52.82.51.53.00.24.31.30.30.83.52.81.32.91.40.93.70.10.30.62.9-9.40.7-0.710.00.12.57.03.68.63.91.65.12.7
Percentage of EnvironmentalRemediationExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EquityMethodInvestmentDividendsOrDistributions

us-gaap:EquityMethodInvestmentDividendsOrDistributions


Equity
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value435154494754655540434853425145312620281813171915229.2290.6880.6851.3290.3840.5870.6050.6260.676-1.9141.7491.4781.6481.2331.6551.3431.3671.6131.370.851.02
Percentage of EquityMethodInvestmentDividendsOrDistributions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EquityMethodInvestmentSoldCarryingAmount

us-gaap:EquityMethodInvestmentSoldCarryingAmount


Equity
Period End2020-12-31
Value0.0
Percentage of EquityMethodInvestmentSoldCarryingAmount0.0

us-gaap:GainLossOnDispositionOfAssets1

us-gaap:GainLossOnDispositionOfAssets1


Gain
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value-0.4430.1430.18513-0.2612.794.67821-19.486352-2.589-1.997-13.3718-1.87-3.461-11.190.0
Percentage of GainLossOnDispositionOfAssets1100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

us-gaap:GainLossOnSaleOfOtherAssets

us-gaap:GainLossOnSaleOfOtherAssets


Gain
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value690.00.00.0120.02.5324.646210.03530.00.00.018
Percentage of GainLossOnSaleOfOtherAssets100.00.00.00.0100.00.0100.0100.0100.00.0100.00.00.00.0100.0

us-gaap:GainLossOnSaleOfOtherAssets us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

mmp:MVPTerminallingLLC


Gain
Period End2021-06-30
Value-69.3
Percentage of GainLossOnSaleOfOtherAssets-99.4

us-gaap:GainLossOnSaleOfOtherAssets us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:FairValueByAssetClass

mmp:SaddlehornPipelineCompany, mmp:InvestmentinSaddlehornJV


Gain
Period End2020-09-302020-06-302020-03-31
Value0.00.0-12.9
Percentage of GainLossOnSaleOfOtherAssets0.00.0-100.1

us-gaap:IncomeLossFromContinuingOperationsPerOutstandingLimitedPartnershipAndGeneralPartnershipUnitBasicAndDiluted

us-gaap:IncomeLossFromContinuingOperationsPerOutstandingLimitedPartnershipAndGeneralPartnershipUnitBasicAndDiluted


Income
Period End2021-06-302020-06-30
Value1.190.57
Percentage of IncomeLossFromContinuingOperationsPerOutstandingLimitedPartnershipAndGeneralPartnershipUnitBasicAndDiluted100.0100.0

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTax

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTax


Income
Period End2021-06-302020-06-30
Value153.924
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTax100.0100.0

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerOutstandingLimitedPartnershipAndGeneralPartnershipUnitBasicAndDiluted

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerOutstandingLimitedPartnershipAndGeneralPartnershipUnitBasicAndDiluted


Income
Period End2021-06-302020-06-30
Value0.070.02
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxPerOutstandingLimitedPartnershipAndGeneralPartnershipUnitBasicAndDiluted100.0100.0

us-gaap:IncomeLossFromEquityMethodInvestments

us-gaap:IncomeLossFromEquityMethodInvestments


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value403936393343465040315053423442312521271815171615249.59151.6451.9550.4661.1132.3750.7362.051-1.9141.7491.4781.6481.9981.9551.4431.3671.4091.6541.481.189
Percentage of IncomeLossFromEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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

us-gaap:OperatingSegments, mmp:CrudeOilPipelineandTerminalsSegment


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
Value322930322929384643323949413143312420271814161614238.924140.9590.888-0.180.5261.770.111.375
Percentage of IncomeLossFromEquityMethodInvestments79.876.582.181.886.467.483.091.7107.2103.378.391.998.491.5102.3100.395.896.399.897.995.996.396.296.097.493.195.558.345.4-38.647.374.514.967.0

us-gaap:OperatingSegments, mmp:RefinedProductsSegment


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
Value8.1979.1716.6097.1344.592146.4153.373-4.218-1.43103.393-0.0972.318-1.465-0.70.4220.111-0.616-0.272-0.038-0.042-0.047-0.048-0.043-0.0550.00.00.00.00.00.00.00.0
Percentage of IncomeLossFromEquityMethodInvestments20.223.517.918.213.632.613.76.7-10.3-4.620.76.3-0.26.7-3.4-2.21.60.5-2.3-1.5-0.2-0.2-0.3-0.3-0.2-0.60.00.00.00.00.00.00.00.0

us-gaap:IncreaseDecreaseInAccountsAndOtherReceivables

us-gaap:IncreaseDecreaseInAccountsAndOtherReceivables


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value0.402329.42525-3.406-29.988-4.798-10.803-1.12936-32.47233-1.368-23.371111731-33.988-17.907383.7996.904-28.26527-15.2912-38.28614-10.464-15.0228.2219-25.016-11.69421-21.78922-3.6747.713-18.4888.6586.62190.694-10.014
Percentage of IncreaseDecreaseInAccountsAndOtherReceivables100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInDeferredRevenue

us-gaap:IncreaseDecreaseInDeferredRevenue


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value3.054-0.1876.67-13.443-7.643.6561.802-4.044-6.794-2.395-0.1621.1132.7771.4631.0981.6747.5425.593.0730.2562.948136.3444.105-4.7424.7780.4941.314.7261.448-4.71813-2.832101.3064.03-0.9582.01
Percentage of IncreaseDecreaseInDeferredRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInEmployeeRelatedLiabilities

us-gaap:IncreaseDecreaseInEmployeeRelatedLiabilities


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value18-12.45511-0.2899.025-43.962189.28116-39.065168.09415-26.54416-0.09912-17.7666.6512.2121.926-16.8633.014151.857-16.5796.724103.118-14.5524.027106.284-10.7132.5298.2095.496-13.9846.141-1.136.168-13.3884.0795.9125.615-13.513
Percentage of IncreaseDecreaseInEmployeeRelatedLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInInterestPayableNet

us-gaap:IncreaseDecreaseInInterestPayableNet


Increase
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-9.0069.497-6.0448.061-16.79216-9.60711-16.4713-21.28617-17.95628-23.20223-23.39116-13.39114-3.3656.164-6.9056.237-0.1731.612-1.612-4.1565.1947.761-4.2524.02-4.6538.795-7.2837.288-7.2887.297-3.64.657-4.2854.6390.2991.449-3.465
Percentage of IncreaseDecreaseInInterestPayableNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInOtherAccountsPayable

us-gaap:IncreaseDecreaseInOtherAccountsPayable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1.879-9.229-27.3193.14-36.251-20.379-19.91929-27.148548.760.893-5.5275.913-11.125176.9461.12-17.026-14.557100.114-6.32315-6.191-0.8080.7186.5891.107-5.219-7.910.276-18.181-11.8639.9363511-1.9794.67-3.076-2.0512.583-7.320.05.426-1.538
Percentage of IncreaseDecreaseInOtherAccountsPayable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0

us-gaap:IncreaseDecreaseInOtherAccruedLiabilities

us-gaap:IncreaseDecreaseInOtherAccruedLiabilities


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-5.48358-0.222260.542-38.44-18.09632-17.97218-4.71316-21.249-10.893-23.413729.01-13.807262.6750.816-9.67410-1.221-16.324-6.402-10.09416-5.3-19.978-6.66920-29.1586.2731.52315-12.3637.7051.6311-38.3743718-10.544-4.4547.253
Percentage of IncreaseDecreaseInOtherAccruedLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInPropertyAndOtherTaxesPayable

us-gaap:IncreaseDecreaseInPropertyAndOtherTaxesPayable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value4.482-19.8323.03135.151-17.6732.632157.075-12.020.786116.522-16.7211.4996.4353.419-10.176-3.5368.5784.638-11.101-2.6357.3574.778-5.8012.498103.8-7.4790.1798.0433.061-5.7981.1567.0772.993-5.707-0.4714.52.751-6.1631.0665.660.75-2.098
Percentage of IncreaseDecreaseInPropertyAndOtherTaxesPayable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestCostsCapitalizedAdjustment

us-gaap:InterestCostsCapitalizedAdjustment


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value0.4170.5080.8191.2724.2284.9514.8655.8315.1343.4544.1013.0995.6084.6474.7613.4243.1834.1976.2327.8777.136.1365.4053.9842.9462.1071.4459.2056.8435.313.8653.783.2433.4512.8641.4391.028
Percentage of InterestCostsCapitalizedAdjustment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InvestmentIncomeInterestAndDividend

us-gaap:InvestmentIncomeInterestAndDividend


Investment
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value148000.0153000.0134000.0260000.0223000.0420000.0639000.0648000.0338000.01660000.01550000.0501000.0380000.0579000.0627000.0240000.0256000.0292000.0335000.0302000.0404000.0361000.0283000.0310000.0334000.0349000.0369000.0374000.0406000.0391000.092000.0215000.013000.022000.027000.016000.029000.035000.039000.011000.01000.010000.055000.074000.07000.04000.0
Percentage of InvestmentIncomeInterestAndDividend100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LeaseCost

us-gaap:LeaseCost


Lease
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value121214131312248.8148.3648.404
Percentage of LeaseCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LeaseCost us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

mmp:NA


Lease
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value6.9247.0216.4745.7095.996.2065.7765.649
Percentage of LeaseCost55.556.947.443.346.570.469.167.2

us-gaap:LeaseCost us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Lease
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value5.5495.317.1757.4796.8996.2676.2416.909
Percentage of LeaseCost44.543.152.656.753.571.174.682.2

us-gaap:LimitedPartnersCapitalAccountDistributionAmount

us-gaap:LimitedPartnersCapitalAccountDistributionAmount


Limited
Period End2021-05-142021-02-122020-11-132020-12-312020-08-142020-09-302020-05-152020-02-142019-11-142019-12-312019-08-142019-09-302019-05-152019-02-142018-11-142018-12-312018-08-142018-09-302018-05-152018-02-142017-11-142017-12-312017-08-142017-09-302017-05-152017-02-142016-11-142016-12-312016-08-122016-09-302016-05-132016-02-122015-11-132015-12-312015-08-142015-09-302015-05-152015-02-132014-11-142014-12-312014-08-142014-09-302014-05-152014-02-142013-11-142013-12-312013-08-142013-09-302013-05-152013-02-142012-11-142012-12-312012-08-142012-09-302012-05-152012-02-142011-11-142011-12-312011-10-312011-08-122011-09-302011-07-312011-05-132011-02-142010-11-122010-12-312010-08-132010-09-302010-05-142010-02-122009-11-132009-08-142009-05-152009-02-13
Value228229229229231231231234232232231231229227223223218218213209206206202202198194190190186186182178173173168168163158151151145145139132126126120120115113109-106.5971061069592900.090888888868583838282767575474747
Percentage of LimitedPartnersCapitalAccountDistributionAmount100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LimitedPartnersCapitalAccountDistributionAmount us-gaap:StatementScenario

srt:ScenarioForecast


Limited
Period End2021-08-132021-09-302021-05-142020-11-132020-12-312020-08-142020-09-302020-05-152019-11-142019-12-312019-08-14
Value227227229229229231231231232232231
Percentage of LimitedPartnersCapitalAccountDistributionAmount0.00.0100.2100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LongTermDebtWeightedAverageInterestRateOverTime us-gaap:CreditFacility

us-gaap:LongTermDebtWeightedAverageInterestRateOverTime

us-gaap:CommercialPaper


Long
Period End2021-06-302021-03-312020-12-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value00.2-0.2-0.0010-0.0010.02800.0020.0020.0190
Percentage of LongTermDebtWeightedAverageInterestRateOverTime0.0100.0100.0100.00.0100.0100.00.0100.0100.0100.00.0

us-gaap:MaturitiesOfSeniorDebt

us-gaap:MaturitiesOfSeniorDebt


Maturities
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312015-12-312015-09-302014-12-312014-09-302013-12-312013-09-30
Value0.00.05500.00.00.00.05500.02500.00.00.00.00.00.00.00.00.0
Percentage of MaturitiesOfSeniorDebt0.00.0100.00.00.00.00.0100.00.0100.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLossNetOfTaxPerOutstandingLimitedPartnershipUnitDiluted

us-gaap:NetIncomeLossNetOfTaxPerOutstandingLimitedPartnershipUnitDiluted


Net
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value0.990.820.940.591.261.251.191.110.911.382.60.940.921.040.870.920.980.930.850.820.910.911.10.780.811.10.870.641.070.830.550.680.5
Percentage of NetIncomeLossNetOfTaxPerOutstandingLimitedPartnershipUnitDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NetIncomeLossPerOutstandingLimitedPartnershipAndGeneralPartnershipUnitBasicAndDiluted

us-gaap:NetIncomeLossPerOutstandingLimitedPartnershipAndGeneralPartnershipUnitBasicAndDiluted


Net
Period End2021-06-302020-06-302015-06-302015-03-312014-06-302014-03-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value1.260.590.780.810.641.070.550.680.50.680.221.220.830.490.490.910.8
Percentage of NetIncomeLossPerOutstandingLimitedPartnershipAndGeneralPartnershipUnitBasicAndDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax

us-gaap:NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax


Net
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value0.990.820.940.591.261.251.191.110.911.372.60.940.921.040.870.920.980.940.850.820.910.911.10.780.811.110.870.641.070.840.550.680.5
Percentage of NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingLeaseLeaseIncome

us-gaap:OperatingLeaseLeaseIncome


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value22212524222726252424
Percentage of OperatingLeaseLeaseIncome100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingLeaseLeaseIncome us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mmp:CrudeOilPipelineandTerminalsSegment


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value18171919181919191716
Percentage of OperatingLeaseLeaseIncome82.181.175.278.383.370.372.975.471.469.6

us-gaap:OperatingSegments, mmp:RefinedProductsSegment


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value3.9954.1476.435.3153.778.1622.9262.1032.8893.245
Percentage of OperatingLeaseLeaseIncome17.918.924.821.716.729.711.18.211.613.4

us-gaap:OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax

us-gaap:OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax


Other
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312014-12-312014-09-302013-12-312013-09-30
Value10-23.1660.00.414-0.747-16.4380.0-10.9130.02.9680.00.653-5.944-46.0080.00.00.0-33.9370.014-0.367
Percentage of OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax100.0100.00.0100.0100.0100.00.0100.00.0100.00.0100.0100.0100.00.00.00.0100.00.0100.0100.0

us-gaap:OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax us-gaap:RetirementPlanType

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Other
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-1.565-1.3940.0-1.1460.0-2.4160.0-0.8840.00.3320.00.2670.00.5350.00.00.0
Percentage of OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax-14.56.00.0-276.8-0.014.70.08.10.011.20.040.9-0.0-1.20.00.00.0

us-gaap:PensionPlansDefinedBenefit


Other
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value12-21.7720.01.56-0.747-14.0220.0-10.0290.02.6360.00.386-5.944-46.5430.00.00.0
Percentage of OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax114.594.00.0376.8100.085.30.091.90.088.80.059.1100.0101.20.00.00.0

us-gaap:OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax

us-gaap:OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax


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
Value-45000.0-45000.0-45000.0-46000.0-45000.0-45000.0-45000.0-46000.0-45000.0-45000.0-45000.0-45000.0-46000.0-45000.0-45000.0-45000.0-46000.0-45000.0-596000.0-973000.0-974000.0-973000.0-929000.0-928000.0-928000.0-928000.0-929000.0-928000.0-928000.0-895000.0-851000.0-852000.0-851000.0-851000.0
Percentage of OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax us-gaap:RetirementPlanType

us-gaap:PensionPlansDefinedBenefit


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value-45000.0-45000.0-45000.0-46000.0-45000.0-45000.0-45000.0-46000.0-45000.0-45000.0-45000.0-45000.0-46000.0-45000.0-45000.0-45000.0-46000.0-45000.0-46000.0-45000.0
Percentage of OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.07.74.6

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax


Other
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value960000.001470000.0-11914000.00-14181000.0-6659000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax100.00.0100.0100.00.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:HedgingDesignation

us-gaap:InterestRateContract, us-gaap:CashFlowHedging, us-gaap:DesignatedAsHedgingInstrument


Other
Period End2020-09-302020-06-302020-03-312019-09-302019-06-30
Value01470000.0-11914000.0-14181000.0-6659000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax0.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value-888000.0-887000.0-893000.0-896000.0-847000.0-809000.0-809000.0-699000.0-601000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship, us-gaap:HedgingDesignation, us-gaap:IncomeStatementLocation

us-gaap:InterestRateContract, us-gaap:CashFlowHedging, us-gaap:DesignatedAsHedgingInstrument, us-gaap:InterestExpense


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-30
Value-888000.0-887000.0-896000.0-847000.0-809000.0-699000.0-601000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationNetOfTax

us-gaap:OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationNetOfTax


Other
Period End2020-12-312020-09-302020-06-302020-03-312019-06-302019-03-312012-09-302011-09-30
Value0001703000.000-4081000.00
Percentage of OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationNetOfTax0.00.00.0100.00.00.0100.00.0

us-gaap:OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationNetOfTax us-gaap:RetirementPlanType

us-gaap:PensionPlansDefinedBenefit


Other
Period End2020-12-312020-09-302020-06-302020-03-312019-06-302019-03-31
Value0001703000.000
Percentage of OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationNetOfTax0.00.00.0100.00.00.0

us-gaap:OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent

us-gaap:OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
Value142.533-19.8862.3234.144-7.694-14.132-11.677-13.331-2.446-2.2919.3534.7465.279-43.4792.3240.2354.58316-1.976-7.925-11.662-1.456-2.1523.419-14.621-58.382-1.6241.68-3.71140.0470.462
Percentage of OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent us-gaap:PartnerCapitalComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value142.533-19.8862.3234.144-7.694-14.132-11.677-13.331-2.446-2.2919.3534.7465.279
Percentage of OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax


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
Value-1412000.0-1691000.0-1472000.0-1473000.0-1458000.0-1531000.0-1435000.0-1412000.0-1625000.0-1348000.0-1729000.0-1806000.0-1703000.0-5114000.0-1592000.0-1568000.0-1983000.0-1228000.0-1380000.0-1452000.0-1292000.0-1401000.0-1798000.0-1798000.0-2023000.0-1572000.0-985000.0-985000.0-1192000.0-824000.0-1342000.0-1343000.0-1354000.0-1330000.0
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax us-gaap:RetirementPlanType

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value-171000.0-147000.0-127000.0-127000.0-136000.0-119000.0-83000.0-60000.0-117000.0-71000.0-148000.0-147000.0-134000.0-160000.0-187000.0-162000.0-200000.0-200000.0-220000.0-291000.0
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax12.18.78.68.69.37.85.84.27.25.38.68.17.93.111.710.310.116.315.920.0

us-gaap:PensionPlansDefinedBenefit


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value-1241000.0-1544000.0-1345000.0-1346000.0-1322000.0-1412000.0-1352000.0-1352000.0-1508000.0-1277000.0-1581000.0-1659000.0-1569000.0-4954000.0-1405000.0-1406000.0-1783000.0-1028000.0-1160000.0-1161000.0
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax87.991.391.491.490.792.294.295.892.894.791.491.992.196.988.389.789.983.784.180.0

us-gaap:OtherOperatingIncomeExpenseNet

us-gaap:OtherOperatingIncomeExpenseNet


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1904000.0-462000.0-438000.0-2863000.03913000.0-511000.01437000.0-379000.0-5024000.06941000.00000
Percentage of OtherOperatingIncomeExpenseNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.0

us-gaap:OtherOperatingIncomeExpenseNet us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mmp:CrudeOilPipelineandTerminalsSegment


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-1263000.0-701000.0-1462000.0-3056000.03775000.0-2403000.0899000.0-3629000.0-6056000.01573000.0
Percentage of OtherOperatingIncomeExpenseNet-66.3151.7333.8106.796.5470.362.6957.5120.522.7

us-gaap:OperatingSegments, mmp:RefinedProductsSegment


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value3167000.0239000.01024000.0193000.0138000.01892000.0157000.01046000.0738000.0614000.0
Percentage of OtherOperatingIncomeExpenseNet166.3-51.7-233.8-6.73.5-370.310.9-276.0-14.78.8

us-gaap:OtherOperatingIncomeExpenseNet us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Other
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-06-302019-03-31
Value434000.00001410000.000
Percentage of OtherOperatingIncomeExpenseNet22.8-0.0-0.00.0-275.9-0.00.0

us-gaap:PartnersCapitalAccountDistributions

us-gaap:PartnersCapitalAccountDistributions


Partners
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-31
Value228229229231231234232231229227223218213209697-106.597-95.004-92.177611-88.498-86.807-85.398-83.798
Percentage of PartnersCapitalAccountDistributions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PartnersCapitalAccountDistributions us-gaap:PartnerCapitalComponents

us-gaap:LimitedPartner


Partners
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
Value228229229231231234232231229227223218213209
Percentage of PartnersCapitalAccountDistributions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PartnersCapitalAccountUnitBasedCompensation

us-gaap:PartnersCapitalAccountUnitBasedCompensation


Partners
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312011-12-312011-09-30
Value0520000.0000600000.0000480000.0000120000.000
Percentage of PartnersCapitalAccountUnitBasedCompensation0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.0

us-gaap:PartnersCapitalAccountUnitBasedCompensation us-gaap:PartnerCapitalComponents

us-gaap:LimitedPartner


Partners
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
Value0520000.0000600000.0000480000.0000120000.0
Percentage of PartnersCapitalAccountUnitBasedCompensation0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.0

us-gaap:PartnersCapitalOther

us-gaap:PartnersCapitalOther


Partners
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-262000.0-250000.0-234000.0-211000.0-237000.0-220000.0-205000.0-199000.0-193000.0-194000.0-147000.0-195000.0-164000.0-157000.0
Percentage of PartnersCapitalOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PartnersCapitalOther us-gaap:PartnerCapitalComponents

us-gaap:LimitedPartner


Partners
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-262000.0-250000.0-234000.0-211000.0-237000.0-220000.0-205000.0-199000.0-193000.0-194000.0-147000.0-195000.0-164000.0-157000.0
Percentage of PartnersCapitalOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsForProceedsFromHedgeFinancingActivities

us-gaap:PaymentsForProceedsFromHedgeFinancingActivities


Payments
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-312010-12-31
Value-0.960.0100.00.0250.08.028-3.694-20.9250.00.00.00.0190.00.00.00.00.0420.00.00.03.6130.1840.00.00.0-10.9770.032
Percentage of PaymentsForProceedsFromHedgeFinancingActivities100.00.0100.00.00.0100.00.0100.0100.0100.00.00.00.00.0100.00.00.00.00.00.0100.00.00.00.0100.0100.00.00.00.0100.00.0100.0

us-gaap:PaymentsOfDebtExtinguishmentCosts

us-gaap:PaymentsOfDebtExtinguishmentCosts


Payments
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
Value0.00.0120.00.00.00.08.270.00.00.00.0
Percentage of PaymentsOfDebtExtinguishmentCosts0.00.0100.00.00.00.00.0100.00.00.00.00.0

us-gaap:PaymentsOfDebtIssuanceCosts

us-gaap:PaymentsOfDebtIssuanceCosts


Payments
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-312010-12-31
Value3.3280.04.2550.00.05.1951.4625.3550.0780.00.0110.3156.3160.00.00.00.4065.0920.095.3181.4690.020.0734.6610.00.0250.2392.6484.8490.00.00.02.5522.3830.006
Percentage of PaymentsOfDebtIssuanceCosts100.00.0100.00.00.0100.0100.0100.0100.00.0100.0100.0100.00.00.00.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.00.00.00.0100.0100.0100.0

us-gaap:PaymentsOfOrdinaryDividends

us-gaap:PaymentsOfOrdinaryDividends


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-06-302011-03-312010-06-302010-03-31
Value228229229231231234232231229227223218213209206202198194190186182178173168163158151145139132126120115113109106959286857675
Percentage of PaymentsOfOrdinaryDividends100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsRelatedToTaxWithholdingForShareBasedCompensation

us-gaap:PaymentsRelatedToTaxWithholdingForShareBasedCompensation


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value0.06.1510.00.00.0140.00.00.09.7640.00.00.09.2850.00.00.0130.00.00.0140.00.00.0170.00.00.0140.00.00.0120.0
Percentage of PaymentsRelatedToTaxWithholdingForShareBasedCompensation0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.0

us-gaap:PaymentsToAcquireInterestInJointVenture

us-gaap:PaymentsToAcquireInterestInJointVenture


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value3.7511.8652114312854453576692.18983602058104425644861199622132992158127
Percentage of PaymentsToAcquireInterestInJointVenture100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionAndOtherPostretirementBenefitExpense

us-gaap:PensionAndOtherPostretirementBenefitExpense


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2.8181.6462.7691.4271.4131.1131.4971.8053.641.3033.6481.7611.6575.0691.9921.8122.2982.5480.7840.6810.3180.4280.8690.871.0950.6440.2660.0871.833-0.0710.4910.4910.5030.479-0.0121.2690.8530.8520.2610.7010.0770.0780.0260.101-0.0360.015
Percentage of PensionAndOtherPostretirementBenefitExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromIssuanceOfSeniorLongTermDebt

us-gaap:ProceedsFromIssuanceOfSeniorLongTermDebt


Proceeds
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-312010-12-31
Value3290.04990.00.04990.04960.00.00.00.04960.00.00.00.04930.06490.00.00.04990.00.00.02572980.00.00.02480.00.0
Percentage of ProceedsFromIssuanceOfSeniorLongTermDebt100.00.0100.00.00.0100.00.0100.00.00.00.00.0100.00.00.00.00.0100.00.0100.00.00.00.0100.00.00.00.0100.0100.00.00.00.0100.00.00.0

us-gaap:ProceedsFromRepaymentsOfCommercialPaper

us-gaap:ProceedsFromRepaymentsOfCommercialPaper


Proceeds
Period End2021-03-312020-09-302020-06-302020-03-312019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value171071410.0128690.0-119.8961190.0-268.977229116141123-279.9615281144-296.942-19.025942200.00.00.0
Percentage of ProceedsFromRepaymentsOfCommercialPaper100.0100.0100.00.0100.0100.00.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:ProceedsFromSaleOfProductiveAssets

us-gaap:ProceedsFromSaleOfProductiveAssets


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2710.6560.3111.7110.083332-0.2081.6871053-2.885790.0270.2140.089391.5183.3681.4541.3424.7390.0170.1930.0250.0643.089100.1570.0650.0421.1960.1092.280.0250.8010.0180.1970.041.7443.8020.7260.0273.0030.1692.0913.037
Percentage of ProceedsFromSaleOfProductiveAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromSaleOfProductiveAssets us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DiscontinuedOperationsHeldforsale, mmp:IndependentTerminalsNetwork


Proceeds
Period End2021-06-10
Value435
Percentage of ProceedsFromSaleOfProductiveAssets0.0

us-gaap:ProceedsFromSaleOfProductiveAssets us-gaap:FairValueByAssetClass

mmp:MarineTerminals


Proceeds
Period End2020-09-302020-06-302020-03-31
Value0.0-0.8252
Percentage of ProceedsFromSaleOfProductiveAssets0.0-963.975.9

us-gaap:ProceedsFromSaleOfProductiveAssets us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

mmp:MVPTerminallingLLC


Proceeds
Period End2021-04-30
Value271
Percentage of ProceedsFromSaleOfProductiveAssets0.0

us-gaap:ProceedsFromSaleOfProductiveAssets us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:FairValueByAssetClass

mmp:SaddlehornPipelineCompany, mmp:InvestmentinSaddlehornJV


Proceeds
Period End2020-09-302020-06-302020-03-31
Value0.00.079
Percentage of ProceedsFromSaleOfProductiveAssets0.00.024.0

us-gaap:ProceedsFromSaleOfProductiveAssets us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:SubsequentEventType

mmp:MVPTerminallingLLC, us-gaap:SubsequentEvent


Proceeds
Period End2021-04-30
Value271
Percentage of ProceedsFromSaleOfProductiveAssets0.0

us-gaap:PropertyPlantAndEquipmentAdditions

us-gaap:PropertyPlantAndEquipmentAdditions


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value3920418283152205260254260186155114105129153146142139193181139183170141127129887870
Percentage of PropertyPlantAndEquipmentAdditions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty

mmp:MethvinCompany, srt:Director


Related
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value1711138.67.38.48.27.17.07.37.36.04.6
Percentage of RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mmp:MethvinCompany2, srt:Director


Related
Period End2020-12-312020-09-302020-06-30
Value0.20.10.2
Percentage of RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty1.51.22.7

us-gaap:RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:EquityMethodInvestee


Related
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value0.70.50.70.71.01.21.51.21.11.51.30.91.20.50.50.71.41.01.51.21.00.5
Percentage of RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty4.04.45.38.113.714.318.316.915.720.517.815.026.10.00.00.00.00.00.00.00.00.0

us-gaap:RevenueFromRelatedParties

us-gaap:RevenueFromRelatedParties


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value5.2945.3025.3345.2885.3165.2915.385.3575.3055.1485.2274.8425.0465.254.7974.9034.1973.7833.5494.9932.9683.1793.3933.5573.5583.3636.7655.2195.2214.9063.9853.6573.5283.4391.3520.1990.1980.1990.1920.1930.1920.1930.1890.190.1890.19
Percentage of RevenueFromRelatedParties100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromRelatedParties us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mmp:CrudeOilPipelineandTerminalsSegment


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value3.6853.7523.743.7093.8033.7073.7473.5923.6463.4863.5043.4633.8494.0163.6393.7033.4743.1342.8474.4162.4862.7843.0463.2113.2113.0276.3914.9024.9024.5953.5943.3693.2393.159
Percentage of RevenueFromRelatedParties69.670.870.170.171.570.169.667.168.767.767.071.576.376.575.975.582.882.880.288.483.887.689.890.390.290.094.593.993.993.790.292.191.891.9

us-gaap:OperatingSegments, mmp:RefinedProductsSegment


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value1.6091.551.5941.5791.5131.5840.4330.4320.470.4120.5120.3510.3520.2970.3530.3530.3530.3290.3430.2180.1240.080.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromRelatedParties30.429.229.929.928.529.98.08.18.98.09.87.27.05.77.47.28.48.79.74.44.22.50.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StockRepurchasedDuringPeriodValue

us-gaap:StockRepurchasedDuringPeriodValue


Stock
Period End2021-06-302020-12-312020-09-302020-06-302020-03-31
Value8224490.0201
Percentage of StockRepurchasedDuringPeriodValue100.0100.0100.00.0100.0

us-gaap:StockRepurchasedDuringPeriodValue us-gaap:PartnerCapitalComponents

us-gaap:LimitedPartner


Stock
Period End2021-06-302020-12-312020-09-302020-06-302020-03-31
Value8224490.0201
Percentage of StockRepurchasedDuringPeriodValue100.0100.0100.00.0100.0

us-gaap:UnrealizedGainLossOnDerivatives

us-gaap:UnrealizedGainLossOnDerivatives


Unrealized
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-40.427-53.793-30.587-7.734-26.755123-31.05817-4.618-54.511155-24.355-38.41-7.375
Percentage of UnrealizedGainLossOnDerivatives100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UnrealizedGainLossOnDerivatives us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, mmp:CrudeOilPipelineandTerminalsSegment


Unrealized
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-6.175-5.356-3.141-0.884-2.3212.722-1.2810.5640.095-2.4024.95-0.102-3.57-1.91
Percentage of UnrealizedGainLossOnDerivatives15.310.010.311.48.72.24.13.2-2.14.43.20.49.325.9

us-gaap:OperatingSegments, mmp:RefinedProductsSegment


Unrealized
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-34.252-48.437-27.446-6.85-24.434121-29.77717-4.713-52.109150-24.253-34.84-5.465
Percentage of UnrealizedGainLossOnDerivatives84.790.089.788.691.397.895.996.8102.195.696.899.690.774.1

us-gaap:WeightedAverageLimitedPartnershipUnitsOutstanding

us-gaap:WeightedAverageLimitedPartnershipUnitsOutstanding


Weighted
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312013-09-30
Value222223-0.5422252252270.0162282282280.0092282282280.0092282282280.0132272272270.012272272270.0182270.017226
Percentage of WeightedAverageLimitedPartnershipUnitsOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:WeightedAverageLimitedPartnershipUnitsOutstandingDiluted

us-gaap:WeightedAverageLimitedPartnershipUnitsOutstandingDiluted


Weighted
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312013-09-30
Value222223-0.5142252252270.1752282282280.1612282282280.1162282282280.112272272270.1862272272270.2042270.282226
Percentage of WeightedAverageLimitedPartnershipUnitsOutstandingDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:EntityCommonStockSharesOutstanding

dei:EntityCommonStockSharesOutstanding


Entity
Period End2021-02-17
Value223
Percentage of EntityCommonStockSharesOutstanding100.0

mmp:AmountAfterOffset us-gaap:TransactionType

mmp:AmountAfterOffset

us-gaap:ExchangeTraded


Amount
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value2318121214141726181017158.2429.98810188.6231019183518182819231710
Percentage of AmountAfterOffset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mmp:AmountofLiabilitiesandAccumulatedOtherComprehensiveLossRecognizedinConsolidatedBalanceSheet us-gaap:RetirementPlanType

mmp:AmountofLiabilitiesandAccumulatedOtherComprehensiveLossRecognizedinConsolidatedBalanceSheet

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Amountof
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value6.8846.8296.6716.1635.13
Percentage of AmountofLiabilitiesandAccumulatedOtherComprehensiveLossRecognizedinConsolidatedBalanceSheet100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Amountof
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value3027221.9440.48
Percentage of AmountofLiabilitiesandAccumulatedOtherComprehensiveLossRecognizedinConsolidatedBalanceSheet437.4398.4341.131.59.4

mmp:ContractedStorage us-gaap:StatementBusinessSegments

mmp:ContractedStorage

mmp:CrudeOilPipelineandTerminalsSegment


Contracted
Period End2021-06-302021-03-312020-12-312020-09-30
Value27272725
Percentage of ContractedStorage100.0100.0100.0100.0

mmp:ContractedStorageWhollyOwned us-gaap:StatementBusinessSegments

mmp:ContractedStorageWhollyOwned

mmp:CrudeOilPipelineandTerminalsSegment


Contracted
Period End2021-06-302021-03-312020-12-312020-09-30
Value24242422
Percentage of ContractedStorageWhollyOwned100.0100.0100.0100.0

mmp:DebtInstrumentNotesAtPricePercentageOfPar us-gaap:DebtInstrument

mmp:DebtInstrumentNotesAtPricePercentageOfPar

mmp:ThreePointTwoFivePercentageNotesDueTwoThousandThirty


Debt
Period End2020-09-30
Value99.88
Percentage of DebtInstrumentNotesAtPricePercentageOfPar100.0

mmp:EnergyRelatedInventoryTransmix

mmp:EnergyRelatedInventoryTransmix


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-31
Value53442320151339323235284337383345353528332322212847333677807972574963635060
Percentage of EnergyRelatedInventoryTransmix100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mmp:EquityMethodInvestmentsUnamortizedExcessInvestmentNet

mmp:EquityMethodInvestmentsUnamortizedExcessInvestmentNet


Equity
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value3333345961767915151617
Percentage of EquityMethodInvestmentsUnamortizedExcessInvestmentNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mmp:OperatingLeaseRightOfUseAssetGross us-gaap:PropertyPlantAndEquipmentByType

mmp:OperatingLeaseRightOfUseAssetGross

us-gaap:Containers


Operating
Period End2020-12-312019-12-31
Value5877
Percentage of OperatingLeaseRightOfUseAssetGross100.0100.0

us-gaap:OtherEnergyEquipment


Operating
Period End2020-12-312019-12-31
Value226231
Percentage of OperatingLeaseRightOfUseAssetGross388.3298.7

us-gaap:Pipelines


Operating
Period End2020-12-312019-12-31
Value4849
Percentage of OperatingLeaseRightOfUseAssetGross83.564.3

us-gaap:PropertyPlantAndEquipmentOtherTypes


Operating
Period End2020-12-312019-12-31
Value3032
Percentage of OperatingLeaseRightOfUseAssetGross52.341.5

mmp:PipelineLength us-gaap:StatementBusinessSegments

mmp:PipelineLength

mmp:CrudeOilPipelineandTerminalsSegment


Pipeline
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value2200.02200.02200.02200.02200.02200.02200.02200.02200.02200.02200.02200.02200.02200.02200.02200.02200.02200.02200.02100.01600.01600.01700.01600.01600.01600.01600.01600.01100.01100.0
Percentage of PipelineLength100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

mmp:RevenueMarketsRegulatedByStateOrFERCPercentage us-gaap:StatementBusinessSegments

mmp:RevenueMarketsRegulatedByStateOrFERCPercentage

mmp:RefinedProductsSegment


Revenue
Period End2020-12-31
Value60.0
Percentage of RevenueMarketsRegulatedByStateOrFERCPercentage100.0

mmp:RevenueShipmentsRegulatedByFERCPercentage us-gaap:StatementBusinessSegments

mmp:RevenueShipmentsRegulatedByFERCPercentage

mmp:RefinedProductsSegment


Revenue
Period End2020-12-31
Value40.0
Percentage of RevenueShipmentsRegulatedByFERCPercentage100.0

mmp:StorageCapacity us-gaap:StatementBusinessSegments

mmp:StorageCapacity

mmp:CrudeOilPipelineandTerminalsSegment


Storage
Period End2021-06-302021-03-312020-12-312020-09-302019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-12-31
Value37373737353333333333282828272726262322220.021212120181818
Percentage of StorageCapacity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0

mmp:StorageCapacityWhollyOwned us-gaap:StatementBusinessSegments

mmp:StorageCapacityWhollyOwned

mmp:CrudeOilPipelineandTerminalsSegment


Storage
Period End2021-06-302021-03-312020-12-312020-09-302019-12-312019-09-302019-06-302019-03-312018-12-31
Value303030302828282828
Percentage of StorageCapacityWhollyOwned100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccountsAndOtherReceivablesNetCurrent

us-gaap:AccountsAndOtherReceivablesNetCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value393537271820232225312524212414131213252412
Percentage of AccountsAndOtherReceivablesNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccountsAndOtherReceivablesNetCurrent us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:Bridgetex, us-gaap:EquityMethodInvestee


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value0.0160.0120.0270.4412.0540.0170.0260.0310.0310.7791.50.1
Percentage of AccountsAndOtherReceivablesNetCurrent0.00.00.11.610.90.10.10.10.12.46.00.4

mmp:MVPTerminallingLLC, us-gaap:EquityMethodInvestee


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value1.2710.6330.4670.460.4220.690.4180.3640.3870.3610.41.20.4
Percentage of AccountsAndOtherReceivablesNetCurrent3.31.81.31.72.23.41.71.61.51.11.65.02.7

mmp:PowderSpringsLogisticsLLC, us-gaap:EquityMethodInvestee


Accounts
Period End2021-03-312020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302017-12-31
Value0.0960.00.310.010.0050.2692.10.9
Percentage of AccountsAndOtherReceivablesNetCurrent0.30.01.50.00.00.88.76.2

mmp:SaddlehornPipelineCompany, us-gaap:EquityMethodInvestee


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value5.0110.1750.1210.1420.2360.1260.1260.120.1230.1090.20.20.1
Percentage of AccountsAndOtherReceivablesNetCurrent12.80.50.30.51.30.60.50.50.50.30.80.80.7

mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Accounts
Period End2021-06-302021-03-312020-06-302020-03-312019-09-302019-06-302017-12-31
Value0.0140.1050.00.00.3320.2520.2
Percentage of AccountsAndOtherReceivablesNetCurrent0.00.30.00.01.51.01.4

us-gaap:AccountsPayableOtherCurrent us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:AccountsPayableOtherCurrent

mmp:Bridgetex, us-gaap:EquityMethodInvestee


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value4391000.01308000.0970000.0225000.000530000.0530000.0179000.0
Percentage of AccountsPayableOtherCurrent100.0100.0100.0100.00.00.0100.0100.0100.0

mmp:HoustonLinkPipelineCompanyLLC, us-gaap:EquityMethodInvestee


Accounts
Period End2021-06-302021-03-312020-12-312017-12-31
Value170000.0149000.0144000.0100000.0
Percentage of AccountsPayableOtherCurrent3.911.414.80.0

mmp:MVPTerminallingLLC, us-gaap:EquityMethodInvestee


Accounts
Period End2021-03-312020-12-31
Value862000.02297000.0
Percentage of AccountsPayableOtherCurrent65.9236.8

mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value1857000.02528000.07274000.04267000.03976000.01695000.01349000.01223000.01195000.01646000.01140000.02100000.0
Percentage of AccountsPayableOtherCurrent42.3193.3749.91896.40.00.00.0230.8225.5919.60.00.0

us-gaap:AccountsPayableOtherCurrentAndNoncurrent us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:AccountsPayableOtherCurrentAndNoncurrent

mmp:Bridgetex, us-gaap:EquityMethodInvestee


Accounts
Period End2020-12-31
Value970000.0
Percentage of AccountsPayableOtherCurrentAndNoncurrent100.0

mmp:HoustonLinkPipelineCompanyLLC, us-gaap:EquityMethodInvestee


Accounts
Period End2020-12-312017-12-31
Value144000.0100000.0
Percentage of AccountsPayableOtherCurrentAndNoncurrent14.80.0

mmp:MVPTerminallingLLC, us-gaap:EquityMethodInvestee


Accounts
Period End2020-12-31
Value2297000.0
Percentage of AccountsPayableOtherCurrentAndNoncurrent236.8

mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Accounts
Period End2020-12-312019-12-312018-12-31
Value7274000.01349000.01100000.0
Percentage of AccountsPayableOtherCurrentAndNoncurrent749.90.00.0

us-gaap:AccountsReceivableRelatedPartiesCurrent us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:AccountsReceivableRelatedPartiesCurrent

mmp:MethvinCompany, srt:Director


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302018-12-31
Value5200000.04000000.03900000.03700000.02300000.02900000.03800000.02700000.02000000.01900000.0
Percentage of AccountsReceivableRelatedPartiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccrualForEnvironmentalLossContingencies

us-gaap:AccrualForEnvironmentalLossContingencies


Accrual
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302012-12-31
Value111214111212141617182023171819201824242528323131363636373437383748
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us-gaap:AccrualForTaxesOtherThanIncomeTaxesCurrent

us-gaap:AccrualForTaxesOtherThanIncomeTaxesCurrent


Accrual
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value5248686551466663484153524134514943395053454051544642474534313838302733312421272823202621
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us-gaap:AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax


Accumulated
Period End2020-12-312020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
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Percentage of AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperation

us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperation


Assets
Period End2021-06-302020-12-31
Value290292
Percentage of AssetsOfDisposalGroupIncludingDiscontinuedOperation100.0100.0

us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent

us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent


Assets
Period End2021-06-302020-12-31
Value29015
Percentage of AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent100.0100.0

us-gaap:BilledContractReceivables

us-gaap:BilledContractReceivables


Billed
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value1321411081079294124129134130102135102101133
Percentage of BilledContractReceivables100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ContractWithCustomerAssetNet

us-gaap:ContractWithCustomerAssetNet


Contract
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value1411121315158.0717.6858.2268.6188.4878.0538.9169.2858.615
Percentage of ContractWithCustomerAssetNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ContractWithCustomerLiability

us-gaap:ContractWithCustomerLiability


Contract
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Value10410010294112112111110115124122119106
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us-gaap:DebtInstrumentFaceAmount

us-gaap:CommercialPaper


Debt
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us-gaap:DebtInstrumentUnamortizedDiscountPremiumNet

us-gaap:DebtInstrumentUnamortizedDiscountPremiumNet


Debt
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Percentage of DebtInstrumentUnamortizedDiscountPremiumNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredCompensationArrangementWithIndividualSharesAuthorizedForIssuance

us-gaap:DeferredCompensationArrangementWithIndividualSharesAuthorizedForIssuance


Deferred
Period End2021-04-302021-03-312020-12-312020-09-302016-03-312012-03-312011-12-31
Value131111119.44.74.7
Percentage of DeferredCompensationArrangementWithIndividualSharesAuthorizedForIssuance100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredFinanceCostsNet

us-gaap:DeferredFinanceCostsNet


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value393940373734353531312727282829252526262718
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us-gaap:DeferredRevenueCurrent

us-gaap:DeferredRevenueCurrent


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value10198989210511310910711111812112112011911711611510710198989581757175717069646367545746454141393630353427
Percentage of DeferredRevenueCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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us-gaap:DefinedBenefitPlanAccumulatedBenefitObligation

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value324274208206160
Percentage of DefinedBenefitPlanAccumulatedBenefitObligation100.0100.0100.0100.0100.0

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us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value-10409000.0-8378000.0-5409000.0-6597000.0-7881000.0
Percentage of DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value-120490000.0-107620000.0-91669000.0-100470000.0-62013000.0
Percentage of DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax1157.51284.61694.71523.0786.9

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us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditAfterTax

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value-2705000.0-2886000.0-3067000.0-3248000.0-3429000.0
Percentage of DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditAfterTax100.0100.0100.0100.0100.0

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us-gaap:DefinedBenefitPlanAmountsRecognizedInBalanceSheet

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value-17293000.0-15207000.0-12080000.0-12760000.0-13011000.0
Percentage of DefinedBenefitPlanAmountsRecognizedInBalanceSheet100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value-147890000.0-131950000.0-111360000.0-99170000.0-59064000.0
Percentage of DefinedBenefitPlanAmountsRecognizedInBalanceSheet855.2867.7921.8777.2454.0

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us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-31
Value2.33.06
Percentage of DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-31
Value2.233.01
Percentage of DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate97.098.4

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us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-31
Value4.534.58
Percentage of DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease100.0100.0

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us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationWeightedAverageInterestCreditingRate

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-31
Value1.72.16
Percentage of DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationWeightedAverageInterestCreditingRate100.0100.0

us-gaap:DefinedBenefitPlanBenefitObligation us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanBenefitObligation

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value171512121311
Percentage of DefinedBenefitPlanBenefitObligation100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value443381308297225209
Percentage of DefinedBenefitPlanBenefitObligation2565.52507.02557.52334.31736.81852.5

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us-gaap:DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value-600000.0-500000.0-200000.0-600000.0
Percentage of DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value-6200000.0-5700000.0-5100000.0-7000000.0
Percentage of DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear1033.31140.02550.01166.7

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us-gaap:DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-31
Value-200000.0
Percentage of DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear100.0

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value3.9294.0693.7874.021
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value14513614795
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter3713.03365.23882.32376.1

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value1.411.1630.8590.625
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value21151414
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths1518.01370.91715.32272.0

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value0.9750.9380.8780.844
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value23232418
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive2423.52518.22776.92194.1

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value1.0161.080.9130.785
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value22212216
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour2251.81985.62476.02109.0

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value1.1681.1410.9150.715
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value21181916
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree1833.31663.52139.52266.6

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value1.2751.1870.9010.678
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value17161713
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo1400.41387.81917.62043.4

us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value0.80.21.40.90.70.71.20.80.60.20.90.60.50.20.50.4
Percentage of DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value27282929293131313132323131312826
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us-gaap:DefinedBenefitPlanFairValueOfPlanAssets

mmp:GroupAnnuityContract, us-gaap:FairValueInputsLevel3, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value0.1620.1760.1890.20.22
Percentage of DefinedBenefitPlanFairValueOfPlanAssets100.0100.0100.0100.0100.0

mmp:IntermediateTermBondFunds, us-gaap:FairValueInputsLevel1, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value3429232523
Percentage of DefinedBenefitPlanFairValueOfPlanAssets21539.516752.812188.412937.510740.5

mmp:LongTermInvestmentGradeBondFund, us-gaap:FairValueInputsLevel1, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value161132998883
Percentage of DefinedBenefitPlanFairValueOfPlanAssets99387.075054.552443.444281.537836.4

mmp:ShortTermBondFund, us-gaap:FairValueInputsLevel1, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value4.2093.599.2425.114.414
Percentage of DefinedBenefitPlanFairValueOfPlanAssets2598.12039.84889.92555.02006.4

mmp:ShortTermInvestmentFund, us-gaap:FairValueInputsLevel1, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value6.3547.38.3125.7225.346
Percentage of DefinedBenefitPlanFairValueOfPlanAssets3922.24147.74397.92861.02430.0

us-gaap:DefinedBenefitPlanEquitySecuritiesNonUs, us-gaap:FairValueInputsLevel1, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value292519
Percentage of DefinedBenefitPlanFairValueOfPlanAssets18442.014534.110302.1

us-gaap:DefinedBenefitPlanEquitySecuritiesUsLargeCap, us-gaap:FairValueInputsLevel1, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value474030
Percentage of DefinedBenefitPlanFairValueOfPlanAssets29381.523229.516187.8

us-gaap:DefinedBenefitPlanEquitySecuritiesUsMidCap, us-gaap:FairValueInputsLevel1, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value5.8535.0953.811
Percentage of DefinedBenefitPlanFairValueOfPlanAssets3613.02894.92016.4

us-gaap:DefinedBenefitPlanEquitySecuritiesUsSmallCap, us-gaap:FairValueInputsLevel1, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value5.7985.0873.816
Percentage of DefinedBenefitPlanFairValueOfPlanAssets3579.02890.32019.0

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType

mmp:GroupAnnuityContract, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value0.1620.1760.1890.20.22
Percentage of DefinedBenefitPlanFairValueOfPlanAssets100.0100.0100.0100.0100.0

mmp:IntermediateTermBondFunds, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value3429232523
Percentage of DefinedBenefitPlanFairValueOfPlanAssets21539.516752.812188.412937.510740.5

mmp:LongTermInvestmentGradeBondFund, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value161132998883
Percentage of DefinedBenefitPlanFairValueOfPlanAssets99387.075054.552443.444281.537836.4

mmp:ShortTermBondFund, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value4.2093.599.2425.114.414
Percentage of DefinedBenefitPlanFairValueOfPlanAssets2598.12039.84889.92555.02006.4

mmp:ShortTermInvestmentFund, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value6.3547.38.3125.7225.346
Percentage of DefinedBenefitPlanFairValueOfPlanAssets3922.24147.74397.92861.02430.0

us-gaap:DefinedBenefitPlanEquitySecuritiesNonUs, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value292519
Percentage of DefinedBenefitPlanFairValueOfPlanAssets18442.014534.110302.1

us-gaap:DefinedBenefitPlanEquitySecuritiesUsLargeCap, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value474030
Percentage of DefinedBenefitPlanFairValueOfPlanAssets29381.523229.516187.8

us-gaap:DefinedBenefitPlanEquitySecuritiesUsMidCap, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value5.8535.0953.811
Percentage of DefinedBenefitPlanFairValueOfPlanAssets3613.02894.92016.4

us-gaap:DefinedBenefitPlanEquitySecuritiesUsSmallCap, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value5.7985.0873.816
Percentage of DefinedBenefitPlanFairValueOfPlanAssets3579.02890.32019.0

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:RetirementPlanType

us-gaap:FairValueInputsLevel1, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value295249197198166
Percentage of DefinedBenefitPlanFairValueOfPlanAssets182462.3141543.8104445.099243.075766.4

us-gaap:FairValueInputsLevel3, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value0.1620.1760.1890.20.22
Percentage of DefinedBenefitPlanFairValueOfPlanAssets100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets us-gaap:RetirementPlanType

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value295249197198166142
Percentage of DefinedBenefitPlanFairValueOfPlanAssets182562.3141643.8104545.099343.075866.40.0

us-gaap:DefinedBenefitPlanFundedStatusOfPlan us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanFundedStatusOfPlan

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value-17293000.0-15207000.0-12080000.0-12760000.0-13011000.0
Percentage of DefinedBenefitPlanFundedStatusOfPlan100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value-147890000.0-131950000.0-111360000.0-99170000.0-59064000.0
Percentage of DefinedBenefitPlanFundedStatusOfPlan855.2867.7921.8777.2454.0

us-gaap:DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear

us-gaap:DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear


Defined
Period End2020-12-31
Value6.0
Percentage of DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear100.0

us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage us-gaap:DefinedBenefitPlanByPlanAssetCategories

us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage

us-gaap:CashAndCashEquivalents


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value3.00.030.030.030.03
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage100.0100.0100.0100.0100.0

us-gaap:EquitySecurities


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value30.00.30.30.30.3
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage1000.01000.01000.01000.01000.0

us-gaap:FixedIncomeSecurities


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value67.00.670.670.670.67
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage2233.32233.32233.32233.32233.3

us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage us-gaap:StatementScenario, us-gaap:DefinedBenefitPlanByPlanAssetCategories

us-gaap:ScenarioPlan, us-gaap:EquitySecurities


Defined
Period End2020-12-312019-12-31
Value30.00.3
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage1000.01000.0

us-gaap:ScenarioPlan, us-gaap:FixedIncomeSecurities


Defined
Period End2020-12-312019-12-31
Value70.00.7
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage2333.32333.3

us-gaap:DefinedBenefitPlanUltimateHealthCareCostTrendRate1

us-gaap:DefinedBenefitPlanUltimateHealthCareCostTrendRate1


Defined
Period End2020-12-31
Value5.08
Percentage of DefinedBenefitPlanUltimateHealthCareCostTrendRate1100.0

us-gaap:DefinedBenefitPlanWeightedAverageAssetAllocations us-gaap:DefinedBenefitPlanByPlanAssetCategories

us-gaap:DefinedBenefitPlanWeightedAverageAssetAllocations

us-gaap:CashAndCashEquivalents


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value2.00.030.040.030.030.030.040.030.03
Percentage of DefinedBenefitPlanWeightedAverageAssetAllocations100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EquitySecurities


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value30.00.30.290.370.30.350.340.350.28
Percentage of DefinedBenefitPlanWeightedAverageAssetAllocations1500.01000.0725.01233.31000.01166.7850.01166.7933.3

us-gaap:FixedIncomeSecurities


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value68.00.670.670.60.670.62
Percentage of DefinedBenefitPlanWeightedAverageAssetAllocations3400.02233.31675.02000.02233.32066.7

us-gaap:DerivativeCollateralRightToReclaimCash us-gaap:TransactionType

us-gaap:DerivativeCollateralRightToReclaimCash

us-gaap:ExchangeTraded


Derivative
Period End2020-12-312019-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value342747352636314.3739.92149
Percentage of DerivativeCollateralRightToReclaimCash100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeFairValueOfDerivativeAsset us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation

us-gaap:DerivativeFairValueOfDerivativeAsset

us-gaap:OtherCurrentAssets, us-gaap:CommodityContract, us-gaap:Nondesignated


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302012-12-31
Value6.1072.6260.6161.0951.024620.811162.5580.5976122100.87212184.322.6726.063.1469.6151944589.463792311.1840.00.0485.6830.227
Percentage of DerivativeFairValueOfDerivativeAsset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0

us-gaap:OtherNoncurrentAssets, us-gaap:CommodityContract, us-gaap:Nondesignated


Derivative
Period End2020-12-312020-09-302020-06-302020-03-312018-03-312017-12-312015-09-302015-06-30
Value1.0741.6452.1943.1620.00.2465.0410.397
Percentage of DerivativeFairValueOfDerivativeAsset174.4150.2214.35.00.02.08.64.2

us-gaap:DerivativeFairValueOfDerivativeAsset us-gaap:HedgingDesignation

us-gaap:Nondesignated


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302018-03-312017-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value6.1072.6261.692.743.218660.811162.5580.87212639.8573792311.8860.0180.438.3935.4580.0171.5770.907213.4146.431285.191
Percentage of DerivativeFairValueOfDerivativeAsset100.0100.0274.4250.2314.3105.0100.0100.0100.0100.0102.0108.6104.2100.0100.0100.0159.30.0895.8147.70.00.0694.70.00.00.00.00.00.0

us-gaap:DerivativeFairValueOfDerivativeAsset us-gaap:TransactionType

us-gaap:ExchangeTraded


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302012-12-31
Value6.1072.6261.692.743.218660.811162.5580.5976222100.87212188.0583.046.063.2479.6152448892655106311.921.5342.6659.5732.05
Percentage of DerivativeFairValueOfDerivativeAsset100.0100.0274.4250.2314.3105.0100.0100.0100.0100.0100.7100.0100.0100.0102.0100.1186.5113.8100.0103.2100.0125.7107.9151.9277.6150.5116.0100.1162.20.05552.1168.4903.1

us-gaap:DerivativeFairValueOfDerivativeLiability us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation

us-gaap:DerivativeFairValueOfDerivativeLiability

us-gaap:OtherCurrentLiabilities, us-gaap:CommodityContract, us-gaap:Nondesignated


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302012-12-31
Value2423223.983141.046111211137.15554361638323.8082.51333152.2561.4895.64610120.0130.00.897123.2177.0210.1668.954
Percentage of DerivativeFairValueOfDerivativeLiability100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherCurrentLiabilities, us-gaap:EnergyRelatedDerivative, us-gaap:Nondesignated


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value5.0287.3418.7749.288.8399.7918.4578.9574.979
Percentage of DerivativeFairValueOfDerivativeLiability20.931.338.2233.060.7936.076.773.842.7

us-gaap:OtherNoncurrentLiabilities, us-gaap:CommodityContract, us-gaap:Nondesignated


Derivative
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312018-03-312017-12-312015-09-302015-06-30
Value3.3970.6810.4030.0150.0080.3160.6370.2690.0
Percentage of DerivativeFairValueOfDerivativeLiability14.12.910.10.10.81.91.72.60.0

us-gaap:OtherNoncurrentLiabilities, us-gaap:EnergyRelatedDerivative, us-gaap:Nondesignated


Derivative
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value1.4682.9943.918.6858.8478.7987.62
Percentage of DerivativeFairValueOfDerivativeLiability6.475.226.9830.380.272.565.4

us-gaap:DerivativeFairValueOfDerivativeLiability us-gaap:HedgingDesignation

us-gaap:Nondesignated


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302018-03-312017-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value323133162719282924173810121.691104.152133.2697.0210.1660.613.2989.181139.8248.2371.5480.98115
Percentage of DerivativeFairValueOfDerivativeLiability135.1134.3144.6418.3187.71867.1256.8246.3208.1101.9101.7102.6100.013007.70.0462.9100.7101.6100.0100.00.00.0102.50.00.00.00.00.00.0

us-gaap:DerivativeFairValueOfDerivativeLiability us-gaap:TransactionType

us-gaap:ExchangeTraded


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302012-12-31
Value2724224.386141.054111211137.15555371738323.8082.51336152.5431.4895.64610121.691104.222163.4397.1670.1669.388
Percentage of DerivativeFairValueOfDerivativeLiability114.1102.9100.0110.1100.1100.8100.0100.0100.0100.0100.0100.3102.0104.0102.1100.0100.0100.0109.1100.0112.7100.0100.0102.6100.013007.70.0470.7127.8106.9102.1100.0104.8

us-gaap:DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral us-gaap:TransactionType

us-gaap:DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral

us-gaap:ExchangeTraded


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-312016-09-302014-06-302014-03-312013-12-312012-12-31
Value2121211.646111032271626133012141.9054.5027.338
Percentage of DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeLiabilities us-gaap:DerivativeInstrumentRisk

us-gaap:DerivativeLiabilities

us-gaap:EnergyRelatedDerivative


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value5.07.310121218171712
Percentage of DerivativeLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeLiabilities us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:CommodityContract, us-gaap:FairValueInputsLevel1


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-03-312019-12-312019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-312012-12-31
Value2121211.64611109.097133227162613307.338
Percentage of DerivativeLiabilities426.4294.2208.813.461.459.172.20.00.00.00.00.00.00.00.0

us-gaap:EnergyRelatedDerivative, us-gaap:FairValueInputsLevel2


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value5.0287.34110121218171712
Percentage of DerivativeLiabilities100.6100.6100.499.8100.499.9100.099.7100.0

us-gaap:DerivativeLiabilities us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementBasis

us-gaap:CommodityContract, us-gaap:CarryingReportedAmountFairValueDisclosure


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-03-312019-12-312019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-312016-09-302014-06-302014-03-312013-12-312012-12-31
Value2121211.64611109.0971332271626133012141.9054.5027.338
Percentage of DerivativeLiabilities426.4294.2208.813.461.459.172.20.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommodityContract, us-gaap:EstimateOfFairValueFairValueDisclosure


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-03-312019-12-312019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-312016-09-302014-06-302014-03-312013-12-312012-12-31
Value2121211.64611109.0971332271626133012141.9054.5027.338
Percentage of DerivativeLiabilities426.4294.2208.813.461.459.172.20.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:EnergyRelatedDerivative, us-gaap:CarryingReportedAmountFairValueDisclosure


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value5.0287.34110121218171712
Percentage of DerivativeLiabilities100.6100.6100.499.8100.499.9100.099.7100.0

us-gaap:EnergyRelatedDerivative, us-gaap:EstimateOfFairValueFairValueDisclosure


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value5.0287.34110121218171712
Percentage of DerivativeLiabilities100.6100.6100.499.8100.499.9100.099.7100.0

us-gaap:DerivativeNonmonetaryNotionalAmount us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship

us-gaap:DerivativeNonmonetaryNotionalAmount

mmp:EconomicHedges


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value4300000.03000000.03400000.03100000.02300000.02300000.03200000.04500000.0
Percentage of DerivativeNonmonetaryNotionalAmount100.0100.0100.0100.0100.0100.0100.0100.0

mmp:EconomicHedgesFutures


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value700000.0200000.0100000.0600000.0200000.0100000.0700000.01500000.0
Percentage of DerivativeNonmonetaryNotionalAmount16.36.72.919.48.74.321.933.3

us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsNotesAndLoansReceivableNet

us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsNotesAndLoansReceivableNet


Disposal
Period End2021-06-302020-12-31
Value6311000.05568000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationAccountsNotesAndLoansReceivableNet100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsPayableCurrent

us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsPayableCurrent


Disposal
Period End2021-06-302020-12-31
Value2342000.02034000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationAccountsPayableCurrent100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationAccruedLiabilitiesCurrent

us-gaap:DisposalGroupIncludingDiscontinuedOperationAccruedLiabilitiesCurrent


Disposal
Period End2021-06-302020-12-31
Value5672000.03986000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationAccruedLiabilitiesCurrent100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent

us-gaap:DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent


Disposal
Period End2020-12-31
Value277
Percentage of DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationInventoryCurrent

us-gaap:DisposalGroupIncludingDiscontinuedOperationInventoryCurrent


Disposal
Period End2021-06-302020-12-31
Value109.185
Percentage of DisposalGroupIncludingDiscontinuedOperationInventoryCurrent100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets

us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets


Disposal
Period End2021-06-302020-12-31
Value2146000.0306000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities

us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities


Disposal
Period End2021-06-302020-12-31
Value1953000.03911000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent

us-gaap:DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent


Disposal
Period End2021-06-302020-12-31
Value268274
Percentage of DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent100.0100.0

us-gaap:EmployeeRelatedLiabilitiesCurrent

us-gaap:EmployeeRelatedLiabilitiesCurrent


Employee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value5740524040317556473170534529564040274539363451483331484130274238282132292116302425193230
Percentage of EmployeeRelatedLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized


Employee
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value1921241716
Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized100.0100.0100.0100.0100.0

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized us-gaap:AwardType, us-gaap:PlanName

us-gaap:PerformanceShares, mmp:TwoThousandNineteenAwards


Employee
Period End2020-12-312019-12-31
Value1.77.3
Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized8.633.5

us-gaap:PerformanceShares, mmp:TwoThousandTwentyAwards


Employee
Period End2020-12-31
Value7.0
Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized35.5

us-gaap:PhantomShareUnitsPSUs, mmp:RetentionAwardsVesting2021


Employee
Period End2020-12-312019-12-31
Value3.47.5
Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized17.334.4

us-gaap:PhantomShareUnitsPSUs, mmp:RetentionAwardsVesting2022


Employee
Period End2020-12-312019-12-31
Value7.60.2
Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized38.60.9

us-gaap:EnergyMarketingContractLiabilitiesCurrent

us-gaap:EnergyMarketingContractLiabilitiesCurrent


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-31
Value1720222.888130.0109.097130.032271625140.00.16730120.00.02.860.8145.4130.0113.4216.7370.00.05.0897.338120.0
Percentage of EnergyMarketingContractLiabilitiesCurrent100.0100.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.0100.0100.00.0100.0100.0100.00.00.0100.0100.0100.00.0100.0100.0100.00.00.0100.0100.0100.00.0

us-gaap:EnergyRelatedInventory

us-gaap:EnergyRelatedInventory


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-31
Value21621216712911671184205172195185179183195182168119146134123156132130135159160157202188210187208207205221220258
Percentage of EnergyRelatedInventory100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EnergyRelatedInventoryChemicals

us-gaap:EnergyRelatedInventoryChemicals


Energy
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
Value5354000.04816000.05354000.04670000.04670000.04670000.06029000.06380000.06452000.06382000.06655000.06179000.06341000.05594000.05865000.06511000.06579000.06769000.06067000.05716000.05813000.05877000.05777000.06099000.06102000.06109000.06183000.05607000.05587000.05629000.07260000.06451000.06857000.06690000.07132000.0
Percentage of EnergyRelatedInventoryChemicals100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EnergyRelatedInventoryNaturalGasLiquids

us-gaap:EnergyRelatedInventoryNaturalGasLiquids


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-31
Value39202630191029474652465357474551433224403815174239383775573323936848456555
Percentage of EnergyRelatedInventoryNaturalGasLiquids100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EnergyRelatedInventoryPetroleum

us-gaap:EnergyRelatedInventoryPetroleum


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-31
Value9394796063339610672809260607673512048542344555727336867323576774463718883127
Percentage of EnergyRelatedInventoryPetroleum100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EquityMethodInvestmentOwnershipPercentage us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:EquityMethodInvestmentOwnershipPercentage

mmp:MVPTerminallingLLC


Equity
Period End2021-05-012020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value25.00.50.50.50.50.50.50.50.50.50.50.50.5
Percentage of EquityMethodInvestmentOwnershipPercentage100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EquityMethodInvestmentOwnershipPercentage us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:SubsequentEventType

mmp:MVPTerminallingLLC, us-gaap:SubsequentEvent


Equity
Period End2021-04-19
Value25.0
Percentage of EquityMethodInvestmentOwnershipPercentage0.0

us-gaap:FiniteLivedIntangibleAssetsAccumulatedAmortization

us-gaap:FiniteLivedIntangibleAssetsAccumulatedAmortization


Finite
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value109.8819.2288.5756.9236.9236.2555.5884.924.2532.9792.4932.0351.591.3891.3081.2281.1472.1362.015.67614131312121110109.4898.8098.137.439101616151514141312119.974
Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:GoodFaithAndMarginDepositsWithBrokerDealers

us-gaap:GoodFaithAndMarginDepositsWithBrokerDealers


Good
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value44403414250.0272127230.047352636314.4929.9214930282.9120.00.05.6961.16.1840.13329121410111418378.239412622
Percentage of GoodFaithAndMarginDepositsWithBrokerDealers100.0100.0100.0100.0100.00.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:GoodFaithAndMarginDepositsWithBrokerDealers us-gaap:TransactionType

us-gaap:ExchangeTraded


Good
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-12-312019-09-302019-06-302019-03-312015-06-30
Value4440341425272127235.696
Percentage of GoodFaithAndMarginDepositsWithBrokerDealers100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:GuaranteesFairValueDisclosure us-gaap:BalanceSheetLocation, us-gaap:GuaranteeObligationsByNature

us-gaap:GuaranteesFairValueDisclosure

us-gaap:OtherCurrentLiabilities, us-gaap:PerformanceGuarantee


Guarantees
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value0.60.60.60.60.70.7
Percentage of GuaranteesFairValueDisclosure100.0100.0100.0100.0100.0100.0

us-gaap:GuaranteesFairValueDisclosure us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:FairValueInputsLevel3


Guarantees
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value1111111111110.4080.4080.4080.40816
Percentage of GuaranteesFairValueDisclosure1857.01862.01867.81873.21612.31617.10.00.00.00.00.0

us-gaap:GuaranteesFairValueDisclosure us-gaap:FairValueByMeasurementBasis

us-gaap:CarryingReportedAmountFairValueDisclosure


Guarantees
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value1111111111110.4080.4080.4080.40816
Percentage of GuaranteesFairValueDisclosure1857.01862.01867.81873.21612.31617.10.00.00.00.00.0

us-gaap:EstimateOfFairValueFairValueDisclosure


Guarantees
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value1111111111110.4080.4080.4080.40816
Percentage of GuaranteesFairValueDisclosure1857.01862.01867.81873.21612.31617.10.00.00.00.00.0

us-gaap:InterestPayableCurrentAndNoncurrent

us-gaap:InterestPayableCurrentAndNoncurrent


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value5849584955476448574663497052704265426548624751455245454445504437413742334033403336313532
Percentage of InterestPayableCurrentAndNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet

us-gaap:InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet


Interest
Period End2021-06-302021-03-312020-09-30
Value-3500000.0-3500000.0-3300000.0
Percentage of InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet100.0100.0100.0

us-gaap:InventoryCrudeOilProductsAndMerchandise

us-gaap:InventoryCrudeOilProductsAndMerchandise


Inventory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-31
Value24473212129.0111213151911162127231313232020433228293214101110157.1887.124191517148.065
Percentage of InventoryCrudeOilProductsAndMerchandise100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths


Lessee
Period End2020-12-312019-12-31
Value3332
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths100.0100.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths mmp:LeaseType

mmp:ThirdParty


Lessee
Period End2020-12-31
Value20
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths61.7

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths mmp:LeaseType, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

mmp:RelatedParty, mmp:SeabrookLogisticsLLC, us-gaap:EquityMethodInvestee


Lessee
Period End2020-12-31
Value12
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths38.3

us-gaap:LessorOperatingLeasePaymentsToBeReceived

us-gaap:LessorOperatingLeasePaymentsToBeReceived


Lessor
Period End2020-12-31
Value143
Percentage of LessorOperatingLeasePaymentsToBeReceived100.0

us-gaap:LessorOperatingLeasePaymentsToBeReceivedFiveYears

us-gaap:LessorOperatingLeasePaymentsToBeReceivedFiveYears


Lessor
Period End2020-12-31
Value13
Percentage of LessorOperatingLeasePaymentsToBeReceivedFiveYears100.0

us-gaap:LessorOperatingLeasePaymentsToBeReceivedFourYears

us-gaap:LessorOperatingLeasePaymentsToBeReceivedFourYears


Lessor
Period End2020-12-31
Value18
Percentage of LessorOperatingLeasePaymentsToBeReceivedFourYears100.0

us-gaap:LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths

us-gaap:LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths


Lessor
Period End2020-12-31
Value30
Percentage of LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths100.0

us-gaap:LessorOperatingLeasePaymentsToBeReceivedThereafter

us-gaap:LessorOperatingLeasePaymentsToBeReceivedThereafter


Lessor
Period End2020-12-31
Value40
Percentage of LessorOperatingLeasePaymentsToBeReceivedThereafter100.0

us-gaap:LessorOperatingLeasePaymentsToBeReceivedThreeYears

us-gaap:LessorOperatingLeasePaymentsToBeReceivedThreeYears


Lessor
Period End2020-12-31
Value18
Percentage of LessorOperatingLeasePaymentsToBeReceivedThreeYears100.0

us-gaap:LessorOperatingLeasePaymentsToBeReceivedTwoYears

us-gaap:LessorOperatingLeasePaymentsToBeReceivedTwoYears


Lessor
Period End2020-12-31
Value21
Percentage of LessorOperatingLeasePaymentsToBeReceivedTwoYears100.0

us-gaap:LettersOfCreditOutstandingAmount us-gaap:CreditFacility

us-gaap:LettersOfCreditOutstandingAmount

us-gaap:RevolvingCreditFacility


Letters
Period End2020-12-312019-12-312019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value3500000.03500000.03500000.06800000.06300000.06300000.06300000.06300000.06300000.0
Percentage of LettersOfCreditOutstandingAmount100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LettersOfCreditOutstandingAmount us-gaap:CreditFacility, us-gaap:LongtermDebtType

us-gaap:RevolvingCreditFacility, us-gaap:SeniorNotes


Letters
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302018-12-312016-09-302016-06-302015-12-31
Value3500000.03500000.03500000.03500000.03500000.03500000.03500000.03500000.03500000.06800000.06300000.06300000.06300000.0
Percentage of LettersOfCreditOutstandingAmount0.00.0100.00.00.00.0100.00.00.0100.00.00.00.0

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation


Liabilities
Period End2021-06-302020-12-31
Value9967000.09931000.0
Percentage of LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation100.0100.0

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent


Liabilities
Period End2021-06-302020-12-31
Value9967000.08423000.0
Percentage of LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent100.0100.0

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent


Liabilities
Period End2020-12-31
Value1508000.0
Percentage of LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent100.0

us-gaap:LimitedPartnersCapitalAccount

us-gaap:LimitedPartnersCapitalAccount


Limited
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302010-12-31
Value24512477248625512620271328772822277427392763266522812271226722292230221221932166215421452118207619891970194918411784177216661597158915471550150015531508151014871466
Percentage of LimitedPartnersCapitalAccount100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LimitedPartnersCapitalAccountUnitsOutstanding

us-gaap:LimitedPartnersCapitalAccountUnitsOutstanding


Limited
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-31
Value2212232232232252252282282282282282282282282282282282282272272272272272272272272272272272272262262262262262261131131121121121120.1124810.10658866
Percentage of LimitedPartnersCapitalAccountUnitsOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LongTermDebtFairValue us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:LongTermDebtFairValue

us-gaap:FairValueInputsLevel2


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-31
Value56885341588048724688436551925185474044494224431447064696482645624483439142623284267625610.00.00.00.0
Percentage of LongTermDebtFairValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.0

us-gaap:LongTermDebtFairValue us-gaap:FairValueByMeasurementBasis

us-gaap:CarryingReportedAmountFairValueDisclosure


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302012-12-31
Value497949964978490047924706470647054407427942704271464245234524430242314203408743233824380234393407332631832982300329102941268524862393
Percentage of LongTermDebtFairValue87.593.584.7100.6102.2107.890.690.793.096.2101.199.098.696.393.794.394.495.795.90.00.00.0104.70.00.00.00.00.00.00.00.092.90.0

us-gaap:EstimateOfFairValueFairValueDisclosure


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302012-12-31
Value568853415880487246884365519251854740444942244314470646964826456244834391426246784161388432843420342634813212326131753186281526762721
Percentage of LongTermDebtFairValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0100.00.00.00.00.00.00.00.00.0100.00.0

us-gaap:LongTermInvestmentsAndReceivablesNet us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:LongTermInvestmentsAndReceivablesNet

mmp:PowderSpringsLogisticsLLC, us-gaap:EquityMethodInvestee


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value1010108.978.2197.336.0064.8923.8242.7252.221
Percentage of LongTermInvestmentsAndReceivablesNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NetInvestmentInLease

us-gaap:NetInvestmentInLease


Net
Period End2020-12-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value111213131314
Percentage of NetInvestmentInLease100.0100.0100.0100.0100.0100.0

us-gaap:NetInvestmentInLeaseCurrent

us-gaap:NetInvestmentInLeaseCurrent


Net
Period End2020-12-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value1245000.01190000.01177000.01164000.01151000.01138000.0
Percentage of NetInvestmentInLeaseCurrent100.0100.0100.0100.0100.0100.0

us-gaap:NetInvestmentInLeaseNoncurrent

us-gaap:NetInvestmentInLeaseNoncurrent


Net
Period End2020-12-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value101112121212
Percentage of NetInvestmentInLeaseNoncurrent100.0100.0100.0100.0100.0100.0

us-gaap:NotesAndLoansReceivableNetNoncurrent

us-gaap:NotesAndLoansReceivableNetNoncurrent


Notes
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value20212221212120
Percentage of NotesAndLoansReceivableNetNoncurrent100.