false FY 2019 0001126975 5.0 0.0515 0.05 0.0425 0.0425 0.042 0.042 0.042 0.0655 0.0640 0.032 0.11 0.04 700000 3200000 P7Y 2979000 6255000 228195000 228403000 0 172000000 P53Y P40Y P56Y P59Y P53Y P10Y P10Y P3Y P10Y P3Y P10Y P19Y P1Y P1Y P12M 1700000 1700000 1700000 1700000(1) Additions to property, plant and equipment$(572,744)$(562,296)$(980,575)Changes in accounts payable and other current liabilities related to capital expenditures 14,07510,03936,585Additions to property, plant and equipment, net $(558,669)$(552,257)$(943,990) 0001126975 2019-01-01 2019-12-31 0001126975 2020-05-04 2020-05-04 0001126975 exch:XNYS 2020-05-04 2020-05-04 0001126975 2018-01-01 2018-12-31 0001126975 2017-01-01 2017-12-31 0001126975 us-gaap:ServiceMember 2019-01-01 2019-12-31 0001126975 us-gaap:ProductAndServiceOtherMember 2018-01-01 2018-12-31 0001126975 us-gaap:ServiceMember 2017-01-01 2017-12-31 0001126975 us-gaap:ProductAndServiceOtherMember 2017-01-01 2017-12-31 0001126975 us-gaap:ProductMember 2017-01-01 2017-12-31 0001126975 us-gaap:ServiceMember 2018-01-01 2018-12-31 0001126975 us-gaap:ProductMember 2018-01-01 2018-12-31 0001126975 us-gaap:ProductMember 2019-01-01 2019-12-31 0001126975 us-gaap:ProductAndServiceOtherMember 2019-01-01 2019-12-31 0001126975 2019-12-31 0001126975 2018-12-31 0001126975 2016-12-31 0001126975 2017-12-31 0001126975 us-gaap:LimitedPartnerMember 2019-01-01 2019-12-31 0001126975 us-gaap:LimitedPartnerMember 2018-01-01 2018-12-31 0001126975 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2019-12-31 0001126975 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2018-01-01 2018-12-31 0001126975 us-gaap:LimitedPartnerMember 2017-01-01 2017-12-31 0001126975 us-gaap:LimitedPartnerMember 2019-12-31 0001126975 2018-01-01 0001126975 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2019-01-01 2019-12-31 0001126975 us-gaap:LimitedPartnerMember 2017-12-31 0001126975 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2017-01-01 2017-12-31 0001126975 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2016-12-31 0001126975 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2017-12-31 0001126975 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2018-12-31 0001126975 us-gaap:LimitedPartnerMember 2018-12-31 0001126975 us-gaap:LimitedPartnerMember 2018-01-01 0001126975 us-gaap:LimitedPartnerMember 2016-12-31 0001126975 mmp:RefinedProductsSegmentMember 2019-12-31 0001126975 mmp:CrudeOilPipelineandTerminalsSegmentMember 2019-12-31 0001126975 mmp:RefinedProductsSegmentMember 2019-01-01 2019-12-31 0001126975 mmp:RefinedProductsTransportationServicesMember mmp:RefinedProductsSegmentMember 2019-12-31 0001126975 us-gaap:AccountingStandardsUpdate201602Member us-gaap:AssetsTotalMember 2019-01-01 2019-01-01 0001126975 us-gaap:AccountingStandardsUpdate201602Member us-gaap:LiabilitiesTotalMember 2019-01-01 2019-01-01 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ServiceMember mmp:RefinedProductsSegmentMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:CrudeOilPipelineandTerminalsSegmentMember 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:RefinedProductsSegmentMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ProductAndServiceOtherMember mmp:CrudeOilPipelineandTerminalsSegmentMember 2019-01-01 2019-12-31 0001126975 us-gaap:IntersegmentEliminationMember 2019-01-01 2019-12-31 0001126975 us-gaap:IntersegmentEliminationMember us-gaap:ProductMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:CrudeOilPipelineandTerminalsSegmentMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ProductMember mmp:CrudeOilPipelineandTerminalsSegmentMember 2019-01-01 2019-12-31 0001126975 us-gaap:IntersegmentEliminationMember us-gaap:ServiceMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:RefinedProductsSegmentMember 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ProductMember mmp:RefinedProductsSegmentMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ServiceMember mmp:CrudeOilPipelineandTerminalsSegmentMember 2019-01-01 2019-12-31 0001126975 us-gaap:CorporateNonSegmentMember 2019-12-31 0001126975 us-gaap:IntersegmentEliminationMember us-gaap:ProductAndServiceOtherMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ProductAndServiceOtherMember mmp:RefinedProductsSegmentMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember 2017-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:RefinedProductsSegmentMember 2017-01-01 2017-12-31 0001126975 us-gaap:IntersegmentEliminationMember 2017-01-01 2017-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:CrudeOilPipelineandTerminalsSegmentMember 2017-01-01 2017-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:RefinedProductsSegmentMember 2017-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ProductMember mmp:CrudeOilPipelineandTerminalsSegmentMember 2017-01-01 2017-12-31 0001126975 us-gaap:OperatingSegmentsMember 2017-01-01 2017-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ProductAndServiceOtherMember mmp:CrudeOilPipelineandTerminalsSegmentMember 2017-01-01 2017-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ServiceMember mmp:RefinedProductsSegmentMember 2017-01-01 2017-12-31 0001126975 us-gaap:IntersegmentEliminationMember us-gaap:ProductAndServiceOtherMember 2017-01-01 2017-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ServiceMember mmp:CrudeOilPipelineandTerminalsSegmentMember 2017-01-01 2017-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ProductAndServiceOtherMember mmp:RefinedProductsSegmentMember 2017-01-01 2017-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ProductMember mmp:RefinedProductsSegmentMember 2017-01-01 2017-12-31 0001126975 us-gaap:IntersegmentEliminationMember us-gaap:ServiceMember 2017-01-01 2017-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:CrudeOilPipelineandTerminalsSegmentMember 2017-12-31 0001126975 us-gaap:IntersegmentEliminationMember us-gaap:ProductMember 2017-01-01 2017-12-31 0001126975 us-gaap:CorporateNonSegmentMember 2017-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:RefinedProductsSegmentMember 2018-01-01 2018-12-31 0001126975 us-gaap:IntersegmentEliminationMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ProductMember mmp:CrudeOilPipelineandTerminalsSegmentMember 2018-01-01 2018-12-31 0001126975 us-gaap:IntersegmentEliminationMember us-gaap:ProductAndServiceOtherMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:CrudeOilPipelineandTerminalsSegmentMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ServiceMember mmp:RefinedProductsSegmentMember 2018-01-01 2018-12-31 0001126975 us-gaap:IntersegmentEliminationMember us-gaap:ServiceMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:RefinedProductsSegmentMember 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ProductAndServiceOtherMember mmp:CrudeOilPipelineandTerminalsSegmentMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:CrudeOilPipelineandTerminalsSegmentMember 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ProductMember mmp:RefinedProductsSegmentMember 2018-01-01 2018-12-31 0001126975 us-gaap:IntersegmentEliminationMember us-gaap:ProductMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ProductAndServiceOtherMember mmp:RefinedProductsSegmentMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ServiceMember mmp:CrudeOilPipelineandTerminalsSegmentMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember 2018-01-01 2018-12-31 0001126975 us-gaap:CorporateNonSegmentMember 2018-12-31 0001126975 2019-12-31 mmp:RefinedProductsSegmentMember 2019-12-31 0001126975 2019-12-31 mmp:CrudeOilPipelineandTerminalsSegmentMember 2019-12-31 0001126975 2019-12-31 2019-12-31 0001126975 us-gaap:IntersegmentEliminationMember mmp:TransportationMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:AncillaryServicesMember mmp:CrudeOilPipelineandTerminalsSegmentMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 mmp:AncillaryServicesMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ProductMember mmp:RefinedProductsSegmentMember us-gaap:TransferredAtPointInTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:LeaseRevenueMember mmp:RefinedProductsSegmentMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:ProductMember us-gaap:TransferredAtPointInTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:TerminallingMember mmp:CrudeOilPipelineandTerminalsSegmentMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:TransportationMember mmp:RefinedProductsSegmentMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:LeaseRevenueMember mmp:CrudeOilPipelineandTerminalsSegmentMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:AncillaryServicesMember mmp:RefinedProductsSegmentMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 mmp:LeaseRevenueMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:IntersegmentEliminationMember mmp:StorageMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:IntersegmentEliminationMember us-gaap:ProductMember us-gaap:TransferredAtPointInTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:IntersegmentEliminationMember mmp:LeaseRevenueMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:IntersegmentEliminationMember us-gaap:ServiceMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 mmp:TransportationMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 mmp:StorageMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ServiceMember mmp:RefinedProductsSegmentMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:IntersegmentEliminationMember mmp:AncillaryServicesMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:StorageMember mmp:CrudeOilPipelineandTerminalsSegmentMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:StorageMember mmp:RefinedProductsSegmentMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:TerminallingMember mmp:RefinedProductsSegmentMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ProductMember mmp:CrudeOilPipelineandTerminalsSegmentMember us-gaap:TransferredAtPointInTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:TransportationMember mmp:CrudeOilPipelineandTerminalsSegmentMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 mmp:TerminallingMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:ServiceMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ServiceMember mmp:CrudeOilPipelineandTerminalsSegmentMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:IntersegmentEliminationMember mmp:TerminallingMember us-gaap:TransferredOverTimeMember 2018-01-01 2018-12-31 0001126975 us-gaap:IntersegmentEliminationMember mmp:TransportationMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:TerminallingMember mmp:CrudeOilPipelineandTerminalsSegmentMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:TransportationMember mmp:RefinedProductsSegmentMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:TerminallingMember mmp:RefinedProductsSegmentMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ServiceMember mmp:CrudeOilPipelineandTerminalsSegmentMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:TransportationMember mmp:CrudeOilPipelineandTerminalsSegmentMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:StorageMember mmp:CrudeOilPipelineandTerminalsSegmentMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:AncillaryServicesMember mmp:RefinedProductsSegmentMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:AncillaryServicesMember mmp:CrudeOilPipelineandTerminalsSegmentMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 mmp:LeaseRevenueMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 mmp:AncillaryServicesMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ProductMember mmp:RefinedProductsSegmentMember us-gaap:TransferredAtPointInTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:IntersegmentEliminationMember us-gaap:ServiceMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:ServiceMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:IntersegmentEliminationMember mmp:StorageMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 mmp:TransportationMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:IntersegmentEliminationMember us-gaap:ProductMember us-gaap:TransferredAtPointInTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:LeaseRevenueMember mmp:CrudeOilPipelineandTerminalsSegmentMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:IntersegmentEliminationMember mmp:TerminallingMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 mmp:StorageMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:LeaseRevenueMember mmp:RefinedProductsSegmentMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:ProductMember us-gaap:TransferredAtPointInTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ProductMember mmp:CrudeOilPipelineandTerminalsSegmentMember us-gaap:TransferredAtPointInTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember us-gaap:ServiceMember mmp:RefinedProductsSegmentMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:OperatingSegmentsMember mmp:StorageMember mmp:RefinedProductsSegmentMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:IntersegmentEliminationMember mmp:LeaseRevenueMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 us-gaap:IntersegmentEliminationMember mmp:AncillaryServicesMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 mmp:TerminallingMember us-gaap:TransferredOverTimeMember 2019-01-01 2019-12-31 0001126975 srt:MinimumMember 2019-12-31 mmp:RefinedProductsSegmentMember 2019-12-31 0001126975 srt:MaximumMember 2019-12-31 mmp:RefinedProductsSegmentMember 2019-12-31 0001126975 srt:MaximumMember 2019-12-31 mmp:CrudeOilPipelineandTerminalsSegmentMember 2019-12-31 0001126975 srt:MinimumMember 2019-12-31 mmp:CrudeOilPipelineandTerminalsSegmentMember 2019-12-31 0001126975 srt:MaximumMember 2019-01-01 2019-12-31 0001126975 mmp:CapitalizedInterestMember us-gaap:PropertyPlantAndEquipmentOtherTypesMember 2019-12-31 0001126975 mmp:CapitalizedInterestMember us-gaap:PropertyPlantAndEquipmentOtherTypesMember 2018-12-31 0001126975 us-gaap:OtherEnergyEquipmentMember 2019-12-31 0001126975 us-gaap:PipelinesMember 2019-12-31 0001126975 us-gaap:BuildingAndBuildingImprovementsMember 2019-12-31 0001126975 us-gaap:ContainersMember 2018-12-31 0001126975 us-gaap:ContainersMember 2019-12-31 0001126975 us-gaap:LandMember 2018-12-31 0001126975 us-gaap:OtherEnergyEquipmentMember 2018-12-31 0001126975 us-gaap:LandMember 2019-12-31 0001126975 us-gaap:PropertyPlantAndEquipmentOtherTypesMember 2018-12-31 0001126975 us-gaap:ConstructionInProgressMember 2019-12-31 0001126975 us-gaap:PropertyPlantAndEquipmentOtherTypesMember 2019-12-31 0001126975 us-gaap:ConstructionInProgressMember 2018-12-31 0001126975 us-gaap:PipelinesMember 2018-12-31 0001126975 us-gaap:BuildingAndBuildingImprovementsMember 2018-12-31 0001126975 srt:MinimumMember 2019-01-01 2019-12-31 0001126975 srt:MinimumMember us-gaap:PropertyPlantAndEquipmentOtherTypesMember 2019-01-01 2019-12-31 0001126975 srt:MaximumMember us-gaap:ContainersMember 2019-01-01 2019-12-31 0001126975 srt:MinimumMember us-gaap:ContainersMember 2019-01-01 2019-12-31 0001126975 srt:MinimumMember us-gaap:BuildingAndBuildingImprovementsMember 2019-01-01 2019-12-31 0001126975 srt:MinimumMember us-gaap:OtherEnergyEquipmentMember 2019-01-01 2019-12-31 0001126975 srt:MaximumMember us-gaap:BuildingAndBuildingImprovementsMember 2019-01-01 2019-12-31 0001126975 srt:MaximumMember us-gaap:OtherEnergyEquipmentMember 2019-01-01 2019-12-31 0001126975 srt:MaximumMember us-gaap:PipelinesMember 2019-01-01 2019-12-31 0001126975 srt:MinimumMember us-gaap:PipelinesMember 2019-01-01 2019-12-31 0001126975 srt:MaximumMember us-gaap:PropertyPlantAndEquipmentOtherTypesMember 2019-01-01 2019-12-31 0001126975 mmp:SeabrookLogisticsLLCMember us-gaap:EquityMethodInvesteeMember 2018-12-31 0001126975 mmp:SaddlehornPipelineCompanyMember us-gaap:EquityMethodInvesteeMember 2018-12-31 0001126975 mmp:BridgetexMember us-gaap:EquityMethodInvesteeMember 2018-12-31 0001126975 mmp:DoubleEaglePipelineLlcMember us-gaap:EquityMethodInvesteeMember 2018-12-31 0001126975 mmp:PowderSpringsLogisticsLLCMember us-gaap:EquityMethodInvesteeMember 2018-12-31 0001126975 mmp:MVPTerminallingLLCMember us-gaap:EquityMethodInvesteeMember 2018-12-31 0001126975 mmp:HoustonLinkPipelineCompanyLLCMember 2019-12-31 0001126975 mmp:DoubleEaglePipelineLlcMember 2019-12-31 0001126975 mmp:SeabrookLogisticsLLCMember 2019-12-31 0001126975 mmp:TexasFronteraLlcMember 2019-12-31 0001126975 mmp:PowderSpringsLogisticsLLCMember 2019-12-31 0001126975 mmp:BridgetexMember 2019-12-31 0001126975 mmp:MVPTerminallingLLCMember 2019-12-31 0001126975 mmp:SaddlehornPipelineCompanyMember 2019-12-31 0001126975 us-gaap:ServiceMember mmp:DoubleEaglePipelineLlcMember us-gaap:EquityMethodInvesteeMember 2019-01-01 2019-12-31 0001126975 mmp:BridgetexMember us-gaap:EquityMethodInvesteeMember 2017-01-01 2017-12-31 0001126975 mmp:MVPTerminallingLLCMember us-gaap:EquityMethodInvesteeMember 2018-01-01 2018-12-31 0001126975 us-gaap:ServiceMember mmp:SaddlehornPipelineCompanyMember us-gaap:EquityMethodInvesteeMember 2018-01-01 2018-12-31 0001126975 us-gaap:ProductMember mmp:SeabrookLogisticsLLCMember us-gaap:EquityMethodInvesteeMember 2019-01-01 2019-12-31 0001126975 us-gaap:ServiceMember mmp:DoubleEaglePipelineLlcMember us-gaap:EquityMethodInvesteeMember 2017-01-01 2017-12-31 0001126975 mmp:SeabrookLogisticsLLCMember us-gaap:EquityMethodInvesteeMember 2018-01-01 2018-12-31 0001126975 us-gaap:ServiceMember mmp:DoubleEaglePipelineLlcMember us-gaap:EquityMethodInvesteeMember 2018-01-01 2018-12-31 0001126975 mmp:PowderSpringsLogisticsLLCMember us-gaap:EquityMethodInvesteeMember 2018-01-01 2018-12-31 0001126975 us-gaap:ServiceMember mmp:SaddlehornPipelineCompanyMember us-gaap:EquityMethodInvesteeMember 2017-01-01 2017-12-31 0001126975 us-gaap:ServiceMember mmp:SaddlehornPipelineCompanyMember us-gaap:EquityMethodInvesteeMember 2019-01-01 2019-12-31 0001126975 us-gaap:ServiceMember mmp:BridgetexMember us-gaap:EquityMethodInvesteeMember 2017-01-01 2017-12-31 0001126975 mmp:MVPTerminallingLLCMember us-gaap:EquityMethodInvesteeMember 2019-01-01 2019-12-31 0001126975 us-gaap:ProductMember mmp:PowderSpringsLogisticsLLCMember us-gaap:EquityMethodInvesteeMember 2018-01-01 2018-12-31 0001126975 mmp:SeabrookLogisticsLLCMember us-gaap:EquityMethodInvesteeMember 2019-01-01 2019-12-31 0001126975 us-gaap:ServiceMember mmp:BridgetexMember us-gaap:EquityMethodInvesteeMember 2018-01-01 2018-12-31 0001126975 us-gaap:ServiceMember mmp:BridgetexMember us-gaap:EquityMethodInvesteeMember 2019-01-01 2019-12-31 0001126975 mmp:SaddlehornPipelineCompanyMember us-gaap:EquityMethodInvesteeMember 2019-12-31 0001126975 mmp:PowderSpringsLogisticsLLCMember us-gaap:EquityMethodInvesteeMember 2019-12-31 0001126975 mmp:DoubleEaglePipelineLlcMember us-gaap:EquityMethodInvesteeMember 2019-12-31 0001126975 mmp:MVPTerminallingLLCMember us-gaap:EquityMethodInvesteeMember 2019-12-31 0001126975 mmp:HoustonLinkPipelineCompanyLLCMember us-gaap:EquityMethodInvesteeMember 2019-12-31 0001126975 mmp:BridgetexMember us-gaap:EquityMethodInvesteeMember 2019-12-31 0001126975 mmp:SeabrookLogisticsLLCMember us-gaap:EquityMethodInvesteeMember 2019-12-31 0001126975 us-gaap:EquityMethodInvesteeMember 2018-01-01 2018-12-31 0001126975 us-gaap:EquityMethodInvesteeMember 2019-01-01 2019-12-31 0001126975 us-gaap:EquityMethodInvesteeMember 2017-01-01 2017-12-31 0001126975 us-gaap:RevolvingCreditFacilityMember 2019-12-31 0001126975 mmp:FourPointEightFivePercentageNotesDueTwoThousandFortyNineMember 2019-12-31 0001126975 srt:MinimumMember us-gaap:RevolvingCreditFacilityMember 2019-01-01 2019-12-31 0001126975 us-gaap:CommercialPaperMember 2018-01-01 2018-12-31 0001126975 mmp:SixPointFiveFivePercentageNotesDueTwoThousandNinteenMember 2019-02-11 0001126975 mmp:ThreePointNineFivePercentageNotesDueTwoThousandFiftyMember 2019-12-31 0001126975 srt:MaximumMember us-gaap:RevolvingCreditFacilityMember 2019-01-01 2019-12-31 0001126975 us-gaap:CommercialPaperMember 2019-12-31 0001126975 us-gaap:RevolvingCreditFacilityMember 2018-12-31 0001126975 srt:MaximumMember us-gaap:CommercialPaperMember 2019-01-01 2019-12-31 0001126975 us-gaap:RevolvingCreditFacilityMember us-gaap:LineOfCreditMember 2019-12-31 0001126975 us-gaap:RevolvingCreditFacilityMember 2019-01-01 2019-12-31 0001126975 mmp:FourPointEightFivePercentageNotesDueTwoThousandFortyNineMember 2019-01-01 2019-12-31 0001126975 mmp:ThreePointNineFivePercentageNotesDueTwoThousandFiftyMember 2019-01-01 2019-12-31 0001126975 us-gaap:CommercialPaperMember 2019-01-01 2019-12-31 0001126975 mmp:SixPointFiveFivePercentageNotesDueTwoThousandNinteenMember 2018-12-31 0001126975 mmp:FourPointTwoZeroPercentageNotesDueTwoThousandFortySevenMember 2018-12-31 0001126975 mmp:FourPointTwoPercentageNotesDueTwoThousandFortyFiveMember 2019-12-31 0001126975 mmp:FourPointTwoFivePercentageNotesDueTwoThousandFortySixMember 2018-12-31 0001126975 mmp:FivePointZeroPercentageNotesDueTwoThousandTwentySixMember 2019-12-31 0001126975 mmp:FivePointOneFivePercentageNotesDueTwoThousandFourtyThreeMember 2019-12-31 0001126975 mmp:FourPointTwoZeroPercentageNotesDueTwoThousandFourtyTwoMember 2019-12-31 0001126975 mmp:FourPointTwoFivePercentageNotesDueTwoThousandTwentyOneMember 2018-12-31 0001126975 mmp:FourPointTwoZeroPercentageNotesDueTwoThousandFourtyTwoMember 2018-12-31 0001126975 mmp:FourPointEightFivePercentageNotesDueTwoThousandFortyNineMember 2018-12-31 0001126975 mmp:SixPointFiveFivePercentageNotesDueTwoThousandNinteenMember 2019-12-31 0001126975 mmp:FourPointTwoZeroPercentageNotesDueTwoThousandFortySevenMember 2019-12-31 0001126975 mmp:FivePointOneFivePercentageNotesDueTwoThousandFourtyThreeMember 2018-12-31 0001126975 mmp:FourPointTwoFivePercentageNotesDueTwoThousandFortySixMember 2019-12-31 0001126975 mmp:FivePointZeroPercentageNotesDueTwoThousandTwentySixMember 2018-12-31 0001126975 mmp:FourPointTwoFivePercentageNotesDueTwoThousandTwentyOneMember 2019-12-31 0001126975 mmp:ThreePointTwoPercentageNotesDueTwoThousandTwentyFiveMember 2018-12-31 0001126975 mmp:FourPointTwoPercentageNotesDueTwoThousandFortyFiveMember 2018-12-31 0001126975 mmp:SixPointFourZeroPercentageNotesDueTwoThousandThirtySevenMember 2018-12-31 0001126975 mmp:SixPointFourZeroPercentageNotesDueTwoThousandThirtySevenMember 2019-12-31 0001126975 mmp:ThreePointNineFivePercentageNotesDueTwoThousandFiftyMember 2018-12-31 0001126975 mmp:ThreePointTwoPercentageNotesDueTwoThousandTwentyFiveMember 2019-12-31 0001126975 us-gaap:RevolvingCreditFacilityMember us-gaap:LineOfCreditMember 2018-12-31 0001126975 mmp:ThirdPartyMember 2019-12-31 0001126975 mmp:SeabrookLogisticsLLCMember mmp:RelatedPartyMember us-gaap:EquityMethodInvesteeMember 2019-12-31 0001126975 mmp:SeabrookLogisticsLLCMember mmp:RelatedPartyMember us-gaap:EquityMethodInvesteeMember 2019-01-01 2019-12-31 0001126975 mmp:ThirdPartyMember 2019-01-01 2019-12-31 0001126975 us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-12-31 0001126975 us-gaap:DefinedBenefitPlanEquitySecuritiesUsLargeCapMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 mmp:LongTermInvestmentGradeBondFundMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 mmp:IntermediateTermBondFundsMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 mmp:IntermediateTermBondFundsMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 mmp:LongTermInvestmentGradeBondFundMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMidCapMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 mmp:ShortTermBondFundMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 mmp:GroupAnnuityContractMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 mmp:ShortTermBondFundMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 us-gaap:DefinedBenefitPlanEquitySecuritiesUsSmallCapMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 mmp:GroupAnnuityContractMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMidCapMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 us-gaap:DefinedBenefitPlanEquitySecuritiesUsSmallCapMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 mmp:ShortTermInvestmentFundMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 us-gaap:DefinedBenefitPlanEquitySecuritiesUsLargeCapMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 mmp:ShortTermInvestmentFundMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0001126975 us-gaap:EquitySecuritiesMember 2018-12-31 0001126975 us-gaap:EquitySecuritiesMember 2019-12-31 0001126975 us-gaap:CashAndCashEquivalentsMember 2019-12-31 0001126975 us-gaap:FixedIncomeSecuritiesMember 2018-12-31 0001126975 us-gaap:CashAndCashEquivalentsMember 2018-12-31 0001126975 us-gaap:FixedIncomeSecuritiesMember 2019-12-31 0001126975 mmp:GroupAnnuityContractMember 2019-01-01 2019-12-31 0001126975 mmp:SmallCapFundMember 2019-01-01 2019-12-31 0001126975 mmp:IntermediateTermBondFundsMember 2019-01-01 2019-12-31 0001126975 mmp:ShortTermBondFundMember 2019-01-01 2019-12-31 0001126975 mmp:LargeCapFundMember 2019-01-01 2019-12-31 0001126975 mmp:LongTermInvestmentGradeBondFundMember 2019-01-01 2019-12-31 0001126975 mmp:InternationalEquityFundMember 2019-01-01 2019-12-31 0001126975 mmp:MidCapFundMember 2019-01-01 2019-12-31 0001126975 mmp:ShortTermInvestmentFundMember 2019-01-01 2019-12-31 0001126975 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2019-01-01 2019-12-31 0001126975 us-gaap:PensionPlansDefinedBenefitMember 2019-01-01 2019-12-31 0001126975 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0001126975 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-01-01 2018-12-31 0001126975 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0001126975 us-gaap:PensionPlansDefinedBenefitMember 2018-01-01 2018-12-31 0001126975 us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0001126975 us-gaap:DefinedBenefitPlanEquitySecuritiesUsLargeCapMember us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 mmp:ShortTermInvestmentFundMember us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 mmp:IntermediateTermBondFundsMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 us-gaap:DefinedBenefitPlanEquitySecuritiesUsLargeCapMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 us-gaap:DefinedBenefitPlanEquitySecuritiesUsSmallCapMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMidCapMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 mmp:ShortTermBondFundMember us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 mmp:ShortTermInvestmentFundMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 mmp:LongTermInvestmentGradeBondFundMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 mmp:GroupAnnuityContractMember us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 mmp:LongTermInvestmentGradeBondFundMember us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 mmp:GroupAnnuityContractMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 us-gaap:DefinedBenefitPlanEquitySecuritiesUsMidCapMember us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 mmp:IntermediateTermBondFundsMember us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 us-gaap:DefinedBenefitPlanEquitySecuritiesUsSmallCapMember us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 mmp:ShortTermBondFundMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 us-gaap:DefinedBenefitPlanEquitySecuritiesNonUsMember us-gaap:PensionPlansDefinedBenefitMember 2019-12-31 0001126975 mmp:ErrorinActuarialAssumptionsMember 2018-12-31 0001126975 us-gaap:ScenarioPlanMember us-gaap:EquitySecuritiesMember 2019-12-31 0001126975 us-gaap:ScenarioPlanMember us-gaap:FixedIncomeSecuritiesMember 2019-12-31 0001126975 mmp:ErrorinActuarialAssumptionsMember 2018-01-01 2018-12-31 0001126975 mmp:USWPlanMember 2018-12-31 0001126975 mmp:IUOEPlanMember 2019-12-31 0001126975 mmp:SalariedPlanMember 2018-12-31 0001126975 mmp:SalariedPlanMember 2019-12-31 0001126975 mmp:IUOEPlanMember 2018-12-31 0001126975 mmp:USWPlanMember 2019-12-31 0001126975 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-01-01 2017-12-31 0001126975 us-gaap:PensionPlansDefinedBenefitMember 2017-01-01 2017-12-31 0001126975 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2016-12-31 0001126975 us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0001126975 mmp:USWPlanMember 2019-01-01 2019-12-31 0001126975 mmp:IUOEPlanMember 2017-01-01 2017-12-31 0001126975 mmp:SalariedPlanMember 2017-01-01 2017-12-31 0001126975 mmp:USWPlanMember 2017-01-01 2017-12-31 0001126975 mmp:OtherRetirementPlanMember 2018-01-01 2018-12-31 0001126975 mmp:OtherRetirementPlanMember 2017-01-01 2017-12-31 0001126975 mmp:USWPlanMember 2018-01-01 2018-12-31 0001126975 mmp:IUOEPlanMember 2019-01-01 2019-12-31 0001126975 mmp:SalariedPlanMember 2018-01-01 2018-12-31 0001126975 mmp:IUOEPlanMember 2018-01-01 2018-12-31 0001126975 mmp:OtherRetirementPlanMember 2019-01-01 2019-12-31 0001126975 mmp:SalariedPlanMember 2019-01-01 2019-12-31 0001126975 srt:MaximumMember mmp:SalariedPlanMember 2017-01-01 2017-12-31 0001126975 srt:MinimumMember mmp:SalariedPlanMember 2017-01-01 2017-12-31 0001126975 us-gaap:PerformanceSharesMember 2019-01-01 2019-12-31 0001126975 us-gaap:PhantomShareUnitsPSUsMember 2018-01-01 2018-12-31 0001126975 us-gaap:PhantomShareUnitsPSUsMember 2019-01-01 2019-12-31 0001126975 us-gaap:PerformanceSharesMember 2018-01-01 2018-12-31 0001126975 us-gaap:PerformanceSharesMember 2017-01-01 2017-12-31 0001126975 us-gaap:PhantomShareUnitsPSUsMember 2017-01-01 2017-12-31 0001126975 us-gaap:PerformanceSharesMember mmp:TwoThousandEighteenAwardsMember 2019-12-31 0001126975 us-gaap:PhantomShareUnitsPSUsMember mmp:RetentionAwardsVesting2021Member 2019-12-31 0001126975 us-gaap:PhantomShareUnitsPSUsMember mmp:RetentionAwardsVesting2020Member 2019-12-31 0001126975 us-gaap:PhantomShareUnitsPSUsMember mmp:RetentionAwardsVesting2022Member 2019-12-31 0001126975 us-gaap:PerformanceSharesMember mmp:TwoThousandNineteenAwardsMember 2019-12-31 0001126975 us-gaap:PerformanceSharesMember 2018-12-31 0001126975 us-gaap:PhantomShareUnitsPSUsMember 2018-12-31 0001126975 us-gaap:PerformanceSharesMember 2019-12-31 0001126975 us-gaap:PhantomShareUnitsPSUsMember 2019-12-31 0001126975 us-gaap:ExchangeTradedMember 2019-12-31 0001126975 us-gaap:ExchangeTradedMember 2018-12-31 0001126975 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember us-gaap:DesignatedAsHedgingInstrumentMember us-gaap:InterestExpenseMember 2017-01-01 2017-12-31 0001126975 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember us-gaap:DesignatedAsHedgingInstrumentMember 2017-01-01 2017-12-31 0001126975 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember us-gaap:DesignatedAsHedgingInstrumentMember 2018-01-01 2018-12-31 0001126975 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember us-gaap:DesignatedAsHedgingInstrumentMember us-gaap:InterestExpenseMember 2018-01-01 2018-12-31 0001126975 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember us-gaap:DesignatedAsHedgingInstrumentMember 2019-01-01 2019-12-31 0001126975 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember us-gaap:DesignatedAsHedgingInstrumentMember us-gaap:InterestExpenseMember 2019-01-01 2019-12-31 0001126975 us-gaap:OtherNoncurrentLiabilitiesMember us-gaap:InterestRateContractMember us-gaap:DesignatedAsHedgingInstrumentMember 2018-12-31 0001126975 us-gaap:OtherCurrentAssetsMember us-gaap:CommodityContractMember us-gaap:DesignatedAsHedgingInstrumentMember 2018-12-31 0001126975 us-gaap:OtherNoncurrentAssetsMember us-gaap:InterestRateContractMember us-gaap:DesignatedAsHedgingInstrumentMember 2018-12-31 0001126975 us-gaap:DesignatedAsHedgingInstrumentMember 2018-12-31 0001126975 us-gaap:OtherCurrentLiabilitiesMember us-gaap:CommodityContractMember us-gaap:DesignatedAsHedgingInstrumentMember 2018-12-31 0001126975 us-gaap:InterestExpenseMember 2019-01-01 2019-12-31 0001126975 us-gaap:EnergyRelatedDerivativeMember 2019-12-31 0001126975 mmp:FutureDebtIssuance2018Member us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember 2018-01-01 2018-12-31 0001126975 mmp:FutureDebtIssuance2018Member us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember 2018-12-31 0001126975 us-gaap:NondesignatedMember 2019-01-01 2019-12-31 0001126975 us-gaap:NondesignatedMember 2018-01-01 2018-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:NondesignatedMember us-gaap:SalesMember 2019-01-01 2019-12-31 0001126975 us-gaap:EnergyRelatedDerivativeMember us-gaap:NondesignatedMember us-gaap:OtherOperatingIncomeExpenseMember 2017-01-01 2017-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:NondesignatedMember us-gaap:CostOfSalesMember 2018-01-01 2018-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:NondesignatedMember us-gaap:CostOfSalesMember 2017-01-01 2017-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:NondesignatedMember us-gaap:OperatingExpenseMember 2018-01-01 2018-12-31 0001126975 us-gaap:NondesignatedMember 2017-01-01 2017-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:NondesignatedMember us-gaap:OperatingExpenseMember 2019-01-01 2019-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:NondesignatedMember us-gaap:SalesMember 2018-01-01 2018-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:NondesignatedMember us-gaap:SalesMember 2017-01-01 2017-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:NondesignatedMember us-gaap:OperatingExpenseMember 2017-01-01 2017-12-31 0001126975 us-gaap:EnergyRelatedDerivativeMember us-gaap:NondesignatedMember us-gaap:OtherOperatingIncomeExpenseMember 2018-01-01 2018-12-31 0001126975 us-gaap:EnergyRelatedDerivativeMember us-gaap:NondesignatedMember us-gaap:OtherOperatingIncomeExpenseMember 2019-01-01 2019-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:NondesignatedMember us-gaap:CostOfSalesMember 2019-01-01 2019-12-31 0001126975 us-gaap:OtherNoncurrentAssetsMember us-gaap:EnergyRelatedDerivativeMember us-gaap:NondesignatedMember 2019-12-31 0001126975 us-gaap:NondesignatedMember 2019-12-31 0001126975 us-gaap:OtherCurrentAssetsMember us-gaap:CommodityContractMember us-gaap:NondesignatedMember 2018-12-31 0001126975 us-gaap:OtherCurrentAssetsMember us-gaap:EnergyRelatedDerivativeMember us-gaap:NondesignatedMember 2019-12-31 0001126975 us-gaap:OtherCurrentLiabilitiesMember us-gaap:CommodityContractMember us-gaap:NondesignatedMember 2019-12-31 0001126975 us-gaap:OtherNoncurrentLiabilitiesMember us-gaap:EnergyRelatedDerivativeMember us-gaap:NondesignatedMember 2019-12-31 0001126975 us-gaap:OtherCurrentLiabilitiesMember us-gaap:EnergyRelatedDerivativeMember us-gaap:NondesignatedMember 2019-12-31 0001126975 us-gaap:OtherCurrentLiabilitiesMember us-gaap:CommodityContractMember us-gaap:NondesignatedMember 2018-12-31 0001126975 us-gaap:OtherCurrentAssetsMember us-gaap:CommodityContractMember us-gaap:NondesignatedMember 2019-12-31 0001126975 mmp:EconomicHedgesFuturesMember 2019-12-31 0001126975 mmp:EconomicHedgesMember 2019-12-31 0001126975 us-gaap:EnergyRelatedDerivativeMember us-gaap:FairValueInputsLevel1Member 2019-12-31 0001126975 us-gaap:EnergyRelatedDerivativeMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2019-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member 2019-12-31 0001126975 us-gaap:FairValueInputsLevel3Member 2019-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member 2019-12-31 0001126975 us-gaap:FairValueInputsLevel1Member 2019-12-31 0001126975 us-gaap:EnergyRelatedDerivativeMember us-gaap:FairValueInputsLevel3Member 2019-12-31 0001126975 us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member 2019-12-31 0001126975 us-gaap:FairValueInputsLevel2Member 2019-12-31 0001126975 us-gaap:CarryingReportedAmountFairValueDisclosureMember 2019-12-31 0001126975 us-gaap:EnergyRelatedDerivativeMember us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-12-31 0001126975 us-gaap:EnergyRelatedDerivativeMember us-gaap:FairValueInputsLevel2Member 2019-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2019-12-31 0001126975 mmp:BridgetexMember 2019-03-31 0001126975 mmp:BridgetexMember 2019-01-01 2019-03-31 0001126975 us-gaap:InterestRateContractMember us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0001126975 us-gaap:FairValueInputsLevel3Member 2018-12-31 0001126975 us-gaap:FairValueInputsLevel2Member 2018-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2018-12-31 0001126975 us-gaap:InterestRateContractMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0001126975 us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0001126975 us-gaap:InterestRateContractMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2018-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0001126975 us-gaap:FairValueInputsLevel1Member 2018-12-31 0001126975 us-gaap:InterestRateContractMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0001126975 us-gaap:CarryingReportedAmountFairValueDisclosureMember 2018-12-31 0001126975 us-gaap:InterestRateContractMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0001126975 us-gaap:CommodityContractMember us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0001126975 mmp:PowderSpringsLogisticsLLCMember us-gaap:GuaranteeOfIndebtednessOfOthersMember us-gaap:EquityMethodInvesteeMember 2019-12-31 0001126975 us-gaap:AccountsReceivableMember 2018-12-31 0001126975 us-gaap:AccountsReceivableMember 2019-12-31 0001126975 us-gaap:OtherNoncurrentAssetsMember 2018-12-31 0001126975 us-gaap:PendingLitigationMember us-gaap:UnfavorableRegulatoryActionMember 2017-10-04 0001126975 us-gaap:OtherNoncurrentAssetsMember 2019-12-31 0001126975 us-gaap:UnionizedEmployeesConcentrationRiskMember mmp:IUOEPlanMember mmp:RefinedProductsSegmentMember 2019-01-01 2019-12-31 0001126975 us-gaap:CustomerConcentrationRiskMember 2019-01-01 2019-12-31 0001126975 us-gaap:UnionizedEmployeesConcentrationRiskMember mmp:USWPlanMember mmp:RefinedProductsSegmentMember 2019-01-01 2019-12-31 0001126975 us-gaap:UnionizedEmployeesConcentrationRiskMember mmp:CrudeOilPipelineandTerminalsSegmentMember 2019-01-01 2019-12-31 0001126975 mmp:MethvinCompanyMember srt:DirectorMember 2019-12-31 0001126975 mmp:MethvinCompanyMember srt:DirectorMember 2019-01-01 2019-12-31 0001126975 mmp:MethvinCompanyMember srt:DirectorMember 2018-12-31 0001126975 mmp:MethvinCompanyMember srt:DirectorMember 2017-01-01 2017-12-31 0001126975 mmp:MethvinCompanyMember srt:DirectorMember 2018-01-01 2018-12-31 0001126975 2019-02-14 2019-02-14 0001126975 2019-11-14 2019-11-14 0001126975 2017-08-14 2017-08-14 0001126975 2018-11-14 0001126975 2017-05-15 0001126975 2018-02-14 0001126975 2017-02-14 2017-02-14 0001126975 2019-08-14 2019-08-14 0001126975 2019-11-14 0001126975 2019-02-14 0001126975 2017-11-14 2017-11-14 0001126975 2018-02-14 2018-02-14 0001126975 2017-08-14 0001126975 2019-08-14 0001126975 2019-05-15 2019-05-15 0001126975 2018-08-14 2018-08-14 0001126975 2018-08-14 0001126975 2017-02-14 0001126975 2018-05-15 2018-05-15 0001126975 2018-11-14 2018-11-14 0001126975 2019-05-15 0001126975 2018-05-15 0001126975 2017-11-14 0001126975 2017-05-15 2017-05-15 0001126975 srt:ManagementMember 2018-01-01 2018-12-31 0001126975 srt:DirectorMember 2019-01-01 2019-12-31 0001126975 srt:DirectorMember 2017-01-01 2017-12-31 0001126975 srt:ManagementMember 2017-01-01 2017-12-31 0001126975 srt:ManagementMember 2019-01-01 2019-12-31 0001126975 srt:DirectorMember 2018-01-01 2018-12-31 0001126975 mmp:BuckeyePartnersL.P.Member us-gaap:SubsequentEventMember 2020-01-01 2020-03-31 0001126975 us-gaap:SubsequentEventMember 2020-01-01 2020-03-31 0001126975 srt:ScenarioForecastMember 2020-05-15 0001126975 mmp:SaddlehornPipelineCompanyMember us-gaap:SubsequentEventMember 2020-01-01 2020-03-31 0001126975 mmp:SaddlehornPipelineCompanyMember us-gaap:SubsequentEventMember 2020-03-31 0001126975 us-gaap:SubsequentEventMember 2020-03-31 0001126975 us-gaap:SubsequentEventMember 2020-02-14 xbrli:shares mmp:Terminal iso4217:USD utreg:mi xbrli:pure utreg:bbl iso4217:USD xbrli:shares mmp:pension_plan mmp:facility mmp:Employee
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 8-K
CURRENT REPORT PURSUANT TO
SECTION 13 OR 15(d) OF THE
SECURITIES EXCHANGE ACT OF 1934
Date of Report (Date of earliest event reported): May 4, 2020
Magellan Midstream Partners, L.P.
(Exact Name of Registrant as Specified in Charter)

Delaware |  | 1-16335 |  | 73-1599053
(State or Other Jurisdiction of Incorporation) |  | (Commission File Number) |  | (IRS Employer Identification No.)

One Williams Center
Tulsa, Oklahoma 74172
(Address of Principal Executive Offices) (Zip Code)
Registrant's telephone number, including area code (918) 574-7000
(Former Name or Former Address, if Changed Since Last Report)
Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:
☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))
Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).
Emerging growth company ☐
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐
Securities registered pursuant to Section 12(b) of the Act:

Title of Each Class | Trading Symbol(s) | Name of Each Exchange on Which Registered
Common Units | MMP | New York Stock Exchange

Item 8.01. Other Events.
The terms “we”, “us”, “our” and similar language included in this Current Report on Form 8-K refers to Magellan Midstream Partners, L.P., together with its subsidiaries. During first quarter 2020, we completed a reorganization of our reporting segments. This reorganization was effected to reflect changes in the management of our business in conjunction with the sale of three of our marine terminals.
Accordingly, effective March 1, 2020, we redesigned our internal management reports to correspond to this new organizational structure, resulting in changes to our reporting segments. Our new reporting segments are as follows:

• | Refined products; and

• | Crude oil.

A summary of each of our current reporting segments follows:

• | Our refined products segment is comprised of our approximately 9,800-mile refined products pipeline system with 53 connected terminals, as well as 25 independent terminals not connected to our pipeline system and five marine terminals (one of which is owned through a joint venture).

• | Our crude oil segment is comprised of approximately 2,200 miles of crude oil pipelines, a condensate splitter and 37 million barrels of aggregate storage capacity, of which approximately 25 million barrels are used for contract storage. Approximately 1,000 miles of these pipelines, the condensate splitter and 30 million barrels of this storage capacity (including 22 million barrels used for contract storage) are wholly-owned, with the remainder owned through joint ventures.

Exhibit 99.1 hereto updates the following information contained in our Annual Report on Form 10-K for the year ended December 31, 2019 filed with the Securities and Exchange Commission on February 18, 2020 ("2019 10-K") to reflect these changes in reportable segments: (i) Item 1. Business; (ii) Item 6. Selected Financial Data; (iii) Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations ("MD&A"); and (iv) Item 8. Financial Statements and Supplementary Data.
The recast items of the Form 10-K described above continue to speak as of the date of the filing of our 2019 10-K report with the SEC and have not been updated for events or developments that occurred subsequent to such filing, other than the change in our segment reporting and certain other events disclosed in Note 19 - Subsequent Events within Item 8 of Exhibit 99.1. More current information about us and our business is contained in our Quarterly Report on Form 10-Q for the period ended March 31, 2020, and the information in this Current Report, including the exhibits, should be read in conjunction with such Quarterly Report and other filings we make with the SEC.
Item 9.01. Financial Statements and Exhibits.

Exhibit 23.1 | Consent of Independent Registered Public Accounting Firm.

Exhibit 99.1 | Item 1—Business, Item 6—Selected Financial Data, Item 7—Management's Discussion and Analysis of Financial Condition and Results of Operations and

Item 8—Financial Statements and Supplementary Data from our 2019 10-K, updated to reflect revised operating segment information.

Exhibit 101.INS | XBRL Instance Document - the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document.

Exhibit 101.SCH | XBRL Taxonomy Extension Schema Document.

Exhibit 101.CAL | XBRL Taxonomy Extension Calculation Linkbase Document.

Exhibit 101.DEF | XBRL Taxonomy Extension Definition Linkbase Document.

Exhibit 101.LAB | XBRL Taxonomy Extension Label Linkbase Document.

Exhibit 101.PRE | XBRL Taxonomy Extension Presentation Linkbase Document.

Exhibit 104 | Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

| Magellan Midstream Partners, L.P.
| By: | Magellan GP, LLC,
|  | its general partner
Date: May 4, 2020 | By: | /s/ Jeff Holman
| Name: | Jeff Holman
| Title: | Senior Vice President, Chief Financial Officer and Treasurer