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Commitments and Contingencies (Details) (USD $)
 12 Months Ended 0 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Oct. 01, 2014
Dec. 20, 2013
MW
Dec. 21, 2011
mw
Jun. 26, 2014
Oct. 31, 2014
Oct. 31, 2012
Sep. 30, 2014
Nov. 25, 2014
opp
Jan. 31, 2010
opp
Apr. 12, 2012
Jun. 27, 2014
Mar. 11, 2014
May 23, 2013
Jan. 06, 2014
Allotment_Parcel
Sep. 01, 2012
Allotment_Parcel
Nov. 08, 2013
Jan. 07, 2015
MW
Jan. 15, 2015
MW
Jan. 22, 2015
Loss Contingencies [Line Items]                                            
Minimum Megawatt Capacity from Coal and Oil-Fired Electric Generating Units under Jurisdiction of the Merucy and Air Toxics Standards           25pnm_MinimumMegawattCapacityFromCoalAndOilFiredElectricGeneratingUnitsUnderJurisdictionOfMerucyAndAirToxicsStandards                                
Other current assets $ 58,471,000us-gaap_OtherAssetsCurrent $ 34,590,000us-gaap_OtherAssetsCurrent                                        
San Juan Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Mercury Removal Rate, Percentage           99.00%pnm_MercuryRemovalRatePercentage
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember		                                
Four Corners [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Jointly Owned Utility Plant, Sale of Ownership Percentage   48.00%pnm_PublicUtilitiesJointlyOwnedUtilityPlantSaleofOwnershipPercentage
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_FourCornersMember		                                        
Public Service Company of New Mexico [Member]                                            
Loss Contingencies [Line Items]                                            
Regulatory Assets 401,025,000us-gaap_RegulatoryAssets
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		 403,611,000us-gaap_RegulatoryAssets
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                        
Public Service Company of New Mexico [Member] | San Juan Generating Station Unit 4 [Member]                                            
Loss Contingencies [Line Items]                                            
Jointly Owned Utility Plan, Proposed Proportionate Ownership Share             64.50%pnm_JointlyOwnedUtilityPlanProposedProportionateOwnershipShare
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit4Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                              
Public Service Company of New Mexico [Member] | Palo Verde Nuclear Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Payments to Acquire Investments to be Held in Decommissioning Trust Fund 4,900,000us-gaap_PaymentsToInvestInDecommissioningFund
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		 4,900,000us-gaap_PaymentsToInvestInDecommissioningFund
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		 2,600,000us-gaap_PaymentsToInvestInDecommissioningFund
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                      
Decommissioning Fund Investments, Fair Value 244,600,000us-gaap_DecommissioningTrustAssetsAmount
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		 222,500,000us-gaap_DecommissioningTrustAssetsAmount
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                        
Jointly Owned Utility Plant, Proportionate Ownership Share 10.20%us-gaap_JointlyOwnedUtilityPlantProportionateOwnershipShare
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		 [1]                                          
Public Service Company of New Mexico [Member] | Palo Verde Nuclear Generating Station [Member] | Nuclear Spent Fuel And Waste Disposal [Member]                                            
Loss Contingencies [Line Items]                                            
Loss Contingency, Estimate of Possible Loss 58,000,000us-gaap_LossContingencyEstimateOfPossibleLoss
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= pnm_NuclearSpentFuelAndWasteDisposalMember		                                          
Annual Fee, Nuclear Waste Disposal 0pnm_AnnualFeeNuclearWasteDisposal
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= pnm_NuclearSpentFuelAndWasteDisposalMember		 3,000,000pnm_AnnualFeeNuclearWasteDisposal
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= pnm_NuclearSpentFuelAndWasteDisposalMember		                                        
Public Service Company of New Mexico [Member] | Palo Verde Nuclear Generating Station [Member] | Department of energy, spent nuclear fuel removal July 2011 - June 2014 [Member]                                            
Loss Contingencies [Line Items]                                            
Lawsuit settlement, Third party settlement claim               42,500,000pnm_LawsuitsettlementThirdpartysettlementclaim
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= pnm_DepartmentofenergyspentnuclearfuelremovalJuly2011June2014Member		                            
PNMs share of third party settlement claim               4,300,000pnm_PNMsshareofthirdpartysettlementclaim
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= pnm_DepartmentofenergyspentnuclearfuelremovalJuly2011June2014Member		                            
Public Service Company of New Mexico [Member] | San Juan Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Jointly Owned Utility Plant, Proportionate Ownership Share                 46.30%us-gaap_JointlyOwnedUtilityPlantProportionateOwnershipShare
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                          
Public Service Company of New Mexico [Member] | San Juan Generating Station Units 2 and 3 [Member]                                            
Loss Contingencies [Line Items]                                            
Net book value 282,000,000pnm_NetBookValue
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnits2And3Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                          
Public Service Company of New Mexico [Member] | Four Corners Units 4 and 5 (Coal) [Member]                                            
Loss Contingencies [Line Items]                                            
Jointly Owned Utility Plant, Proportionate Ownership Share 13.00%us-gaap_JointlyOwnedUtilityPlantProportionateOwnershipShare
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_FourCornersUnits4And5CoalMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                          
Public Service Company of New Mexico [Member] | Palo Verde Nuclear Generating Station Unit 3 [Member]                                            
Loss Contingencies [Line Items]                                            
Net book value                   144,000,000pnm_NetBookValue
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationUnit3Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                        
Public Service Company of New Mexico [Member] | San Juan Generating Station Units 1 and 4 [Member]                                            
Loss Contingencies [Line Items]                                            
Jointly Owned Utility Plan, Proposed Proportionate Ownership Share             58.70%pnm_JointlyOwnedUtilityPlanProposedProportionateOwnershipShare
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnits1And4Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                              
Public Service Company of New Mexico [Member] | Other Deferred Credits [Member] | Palo Verde Nuclear Generating Station [Member] | Nuclear Spent Fuel And Waste Disposal [Member]                                            
Loss Contingencies [Line Items]                                            
Mine Reclamation and Closing Liability, Noncurrent 12,300,000us-gaap_LossContingencyAccrualAtCarryingValue
/ pnm_FinancialStatementLocationAxis
= pnm_OtherDeferredCreditsMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= pnm_NuclearSpentFuelAndWasteDisposalMember		 11,900,000us-gaap_LossContingencyAccrualAtCarryingValue
/ pnm_FinancialStatementLocationAxis
= pnm_OtherDeferredCreditsMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= pnm_NuclearSpentFuelAndWasteDisposalMember		                                        
Public Service Company of New Mexico [Member] | Minimum [Member] | San Juan Generating Station And Four Corners [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Proposed Government Standard Emission Limit                     65pnm_PublicUtilitiesProposedGovernmentStandardEmissionLimit
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationAndFourCornersMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember		 60pnm_PublicUtilitiesProposedGovernmentStandardEmissionLimit
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationAndFourCornersMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember		                    
Public Service Company of New Mexico [Member] | Maximum [Member] | San Juan Generating Station And Four Corners [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Government Standard Emission Limit (pounds per MMBTU, parts per million) 75pnm_PublicUtilitiesGovernmentStandardEmissionLimit
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationAndFourCornersMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember		                                          
Public Utilities, Proposed Government Standard Emission Limit                     70pnm_PublicUtilitiesProposedGovernmentStandardEmissionLimit
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationAndFourCornersMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember		 70pnm_PublicUtilitiesProposedGovernmentStandardEmissionLimit
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationAndFourCornersMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember		                    
Public Service Company of New Mexico [Member] | Coal Supply [Member] | San Juan Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Other current assets 37,300,000us-gaap_OtherAssetsCurrent
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_PurchaseCommitmentExcludingLongtermCommitmentAxis
= pnm_CoalSupplyMember		 12,300,000us-gaap_OtherAssetsCurrent
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_PurchaseCommitmentExcludingLongtermCommitmentAxis
= pnm_CoalSupplyMember		                                        
Public Utilities, Estimated Increase in Coal Cost, Percentage 30.00%pnm_PublicUtilitiesEstimatedIncreaseinCoalCostPercentage
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_PurchaseCommitmentExcludingLongtermCommitmentAxis
= pnm_CoalSupplyMember		                                          
Public Service Company of New Mexico [Member] | Surface [Member]                                            
Loss Contingencies [Line Items]                                            
Regulatory Assets 100,000,000us-gaap_RegulatoryAssets
/ pnm_ClassificationOfMineAxis
= pnm_SurfaceMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                          
Public Service Company of New Mexico [Member] | Surface [Member] | Loss on Long-term Purchase Commitment [Member]                                            
Loss Contingencies [Line Items]                                            
Mine Reclamation and Closing Liability, Noncurrent 25,700,000us-gaap_LossContingencyAccrualAtCarryingValue
/ pnm_ClassificationOfMineAxis
= pnm_SurfaceMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= us-gaap_LossOnLongTermPurchaseCommitmentMember		 23,800,000us-gaap_LossContingencyAccrualAtCarryingValue
/ pnm_ClassificationOfMineAxis
= pnm_SurfaceMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= us-gaap_LossOnLongTermPurchaseCommitmentMember		                                        
Final Reclamation, capped amount to be collected 100,000,000pnm_FinalReclamationCappedAmountToBeCollected
/ pnm_ClassificationOfMineAxis
= pnm_SurfaceMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= us-gaap_LossOnLongTermPurchaseCommitmentMember		                                          
Public Service Company of New Mexico [Member] | Surface [Member] | San Juan Generating Station [Member] | Loss on Long-term Purchase Commitment [Member]                                            
Loss Contingencies [Line Items]                                            
Loss Contingency, Estimate of Possible Loss 57,300,000us-gaap_LossContingencyEstimateOfPossibleLoss
/ pnm_ClassificationOfMineAxis
= pnm_SurfaceMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= us-gaap_LossOnLongTermPurchaseCommitmentMember		                                          
Public Service Company of New Mexico [Member] | Underground [Member] | Loss on Long-term Purchase Commitment [Member]                                            
Loss Contingencies [Line Items]                                            
Mine Reclamation and Closing Liability, Noncurrent 8,600,000us-gaap_LossContingencyAccrualAtCarryingValue
/ pnm_ClassificationOfMineAxis
= pnm_UndergroundMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= us-gaap_LossOnLongTermPurchaseCommitmentMember		 7,800,000us-gaap_LossContingencyAccrualAtCarryingValue
/ pnm_ClassificationOfMineAxis
= pnm_UndergroundMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= us-gaap_LossOnLongTermPurchaseCommitmentMember		                                        
Public Service Company of New Mexico [Member] | Underground [Member] | San Juan Generating Station [Member] | Loss on Long-term Purchase Commitment [Member]                                            
Loss Contingencies [Line Items]                                            
Loss Contingency, Estimate of Possible Loss 93,300,000us-gaap_LossContingencyEstimateOfPossibleLoss
/ pnm_ClassificationOfMineAxis
= pnm_UndergroundMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= us-gaap_LossOnLongTermPurchaseCommitmentMember		                                          
Public Service Company of New Mexico [Member] | Nuclear Plant [Member] | Palo Verde Nuclear Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Ownership Percentage in Nuclear Reactor 10.20%pnm_PublicUtilitiesOwnershipPercentageInNuclearReactor
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_PublicUtilityAxis
= us-gaap_NuclearPlantMember		                                          
Public Utilities, Maximum Potential Assessment Per Incident 38,900,000pnm_PublicUtilitiesMaximumPotentialAssessmentPerIncident
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_PublicUtilityAxis
= us-gaap_NuclearPlantMember		                                          
Public Utilities, Annual Payment Limitation Related to Incident 5,700,000pnm_PublicUtilitiesAnnualPaymentLimitationRelatedToIncident
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_PublicUtilityAxis
= us-gaap_NuclearPlantMember		                                          
Public Utilities, Aggregate Amount of All Risk Insurance 2,750,000,000pnm_PublicUtilitiesAggregateAmountOfAllRiskInsurance
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_PublicUtilityAxis
= us-gaap_NuclearPlantMember		                                          
Public Utilities, Sublimit Amount under Nuclear Electric Insurance Limited 2,250,000,000pnm_PublicUtilitiesSublimitAmountUnderNuclearElectricInsuranceLimited
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_PublicUtilityAxis
= us-gaap_NuclearPlantMember		                                          
Public Utilities, Maximum Amount under Nuclear Electic Insurance Limited 4,800,000pnm_PublicUtilitiesMaximumAmountUnderNuclearElecticInsuranceLimited
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_PublicUtilityAxis
= us-gaap_NuclearPlantMember		                                          
Public Service Company of New Mexico [Member] | Nuclear Plant [Member] | Maximum [Member] | Palo Verde Nuclear Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Liability Insurance Coverage 13,600,000,000pnm_PublicUtilitiesLiabilityInsuranceCoverage
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_PublicUtilityAxis
= us-gaap_NuclearPlantMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember		                                          
Public Service Company of New Mexico [Member] | Commercial Providers [Member] | Nuclear Plant [Member] | Palo Verde Nuclear Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Liability Insurance Coverage 375,000,000pnm_PublicUtilitiesLiabilityInsuranceCoverage
/ pnm_InsuranceCarrierAxis
= pnm_CommercialProvidersMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_PublicUtilityAxis
= us-gaap_NuclearPlantMember		                                          
Public Service Company of New Mexico [Member] | Industry Wide Retrospective Assessment Program [Member] | Nuclear Plant [Member] | Palo Verde Nuclear Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Liability Insurance Coverage 13,200,000,000pnm_PublicUtilitiesLiabilityInsuranceCoverage
/ pnm_InsuranceCarrierAxis
= pnm_IndustryWideRetrospectiveAssessmentProgramMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_PublicUtilityAxis
= us-gaap_NuclearPlantMember		                                          
Pnm Electric [Member] | San Juan Generating Station Units 2 and 3 [Member]                                            
Loss Contingencies [Line Items]                                            
Estimated cost of replacing gas fired peaking capacity due to retirement of SJGS units 268,400,000pnm_EstimatedCostOfReplacingGasFiredPeakingCapacityDueToRetirementOfSjgsUnits
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnits2And3Member
/ dei_LegalEntityAxis
= pnm_PnmElectricMember		                                          
PNMR and PNM [Member] | Palo Verde Nuclear Generating Station Unit 3 [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Number of Megawatts Nuclear Generation 134pnm_PublicUtilitiesNumberofMegawattsNuclearGeneration
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationUnit3Member
/ dei_LegalEntityAxis
= pnm_PnmrAndPnmMember		                                          
Fuel and purchased power adjustment clause [Member] | Public Service Company of New Mexico [Member] | Minimum [Member] | San Juan Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Preliminary estimate increased deferral related to mine fire incident 17,400,000pnm_PreliminaryEstimateIncreasedDeferralRelatedToMineFireIncident
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
/ us-gaap_RegulatoryAssetAxis
= pnm_FuelAndPurchasedPowerAdjustmentClauseMember		                                          
Fuel and purchased power adjustment clause [Member] | Public Service Company of New Mexico [Member] | Maximum [Member] | San Juan Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Preliminary estimate increased deferral related to mine fire incident 21,600,000pnm_PreliminaryEstimateIncreasedDeferralRelatedToMineFireIncident
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_RegulatoryAssetAxis
= pnm_FuelAndPurchasedPowerAdjustmentClauseMember		                                          
Clean Air Act related to Regional Haze [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Number of States To Address Regional Haze 50pnm_PublicUtilitiesNumberOfStatesToAddressRegionalHaze
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActRelatedToRegionalHazeMember		                                          
Public Utilities, Potential to emit tons per year of visibility impairing pollution, maximum 250pnm_PublicUtilitiesPotentialToEmitTonsPerYearOfVisibilityImpairingPollutionMaximum
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActRelatedToRegionalHazeMember		                                          
Clean Air Act, SNCR [Member] | San Juan Generating Station Unit 4 [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Estimated rate base value at 1/1/2018       26,000,000pnm_PublicUtilitiesEstimatedratebasevalueat112018
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit4Member		                                    
Clean Air Act, SNCR [Member] | Public Service Company of New Mexico [Member] | San Juan Generating Station Unit 4 [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Additional Ownership To Be Obtained, in Megawatts       132pnm_PublicUtilitiesAdditionalOwnershipToBeObtainedinMegawatts
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit4Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		 78pnm_PublicUtilitiesAdditionalOwnershipToBeObtainedinMegawatts
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit4Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		   132pnm_PublicUtilitiesAdditionalOwnershipToBeObtainedinMegawatts
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit4Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                              
Percentage of ownership held by exiting owners 38.80%pnm_Percentageofownershipheldbyexitingowners
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit4Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                          
Public Utilities, Ownership Percentage 38.50%pnm_PublicUtilitiesOwnershipPercentage
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit4Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                          
Public Utilities, Costs to obtain additional ownership             0pnm_PublicUtilitiesCoststoobtainadditionalownership
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit4Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                              
Clean Air Act, SNCR [Member] | Public Service Company of New Mexico [Member] | San Juan Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Overall Reduction Of Ownership, in Megawatts         340pnm_PublicUtilitiesOverallReductionOfOwnershipinMegawatts
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                  
Clean Air Act, SNCR [Member] | Public Service Company of New Mexico [Member] | San Juan Generating Station Units 2 and 3 [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Requested Time Period to Recover Retired Units NBV       20 years 20 years                                  
Public Utilities, Number of Mega Watts of Gas-fired Generation         177pnm_PublicUtilitiesNewlyIdentifiedReplacementGasfiredGenerationinMegawattsDecember2013
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnits2And3Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                  
Public Utilities, Newly Identified Replacement Solar Generation, in Megawatts, December2013         40pnm_PublicUtilitiesNewlyIdentifiedReplacementSolarGenerationinMegawattsDecember2013
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnits2And3Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                  
Public Utilities, Recovery Percentage of Estimated undepreciated value at 12/31/17       50.00%pnm_PublicUtilitiesRecoveryPercentageofEstimatedundepreciatedvalueat123117
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnits2And3Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                    
Public Utilities, Estimated undepreciated value at 12/31/17       231,000,000pnm_PublicUtilitiesEstimatedundepreciatedvalueat123117
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnits2And3Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                    
Public Utilities, Write-off Percentage of Estimated undepreciated value at 12/31/17       50.00%pnm_PublicUtilitiesWriteoffPercentageofEstimatedundepreciatedvalueat123117
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnits2And3Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                    
Clean Air Act, SNCR [Member] | Public Service Company of New Mexico [Member] | Palo Verde Nuclear Generating Station Unit 3 [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Proposed value per Kilowatt effective January 1, 2018       1,650pnm_PublicUtilitiesProposedvalueperKilowatteffectiveJanuary12018
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationUnit3Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                    
Public Utilities, Estimated rate base value at 1/1/2018       221,100,000pnm_PublicUtilitiesEstimatedratebasevalueat112018
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationUnit3Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                    
Clean Air Act, SNCR [Member] | Public Service Company of New Mexico [Member] | San Juan Generating Station Unit 3 [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Ownership To Be Exchanged, in Megawatts         78pnm_PublicUtilitiesOwnershipToBeExchangedinMegawatts
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit3Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                  
Public Utilities, Proposed reduction in carrying value       26,000,000pnm_PublicUtilitiesProposedreductionincarryingvalue
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit3Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                    
Public Utilities,Estimated unrecoverable increase in operations and maintenance       20,000,000pnm_PublicUtilitiesEstimatedunrecoverableincreaseinoperationsandmaintenance
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit3Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                    
Percentage of ownership held by exiting owners 50.00%pnm_Percentageofownershipheldbyexitingowners
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit3Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                          
Public Utilities, Ownership Percentage 50.00%pnm_PublicUtilitiesOwnershipPercentage
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit3Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                          
Clean Air Act, SNCR [Member] | Public Service Company of New Mexico [Member] | Minimum [Member] | San Juan Generating Station Unit 3 [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities,Estimated pre-tax regulatory disallowance       60,000,000pnm_PublicUtilitiesEstimatedpretaxregulatorydisallowance
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit3Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember		                                    
Clean Air Act, SNCR [Member] | Public Service Company of New Mexico [Member] | Maximum [Member] | San Juan Generating Station Unit 3 [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities,Estimated pre-tax regulatory disallowance       70,000,000pnm_PublicUtilitiesEstimatedpretaxregulatorydisallowance
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit3Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember		                                    
Clean Air Act, SNCR [Member] | PNMR and PNM [Member] | Palo Verde Nuclear Generating Station Unit 3 [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Number of Megawatts Nuclear Generation       134pnm_PublicUtilitiesNumberofMegawattsNuclearGeneration
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationUnit3Member
/ dei_LegalEntityAxis
= pnm_PnmrAndPnmMember		 134pnm_PublicUtilitiesNumberofMegawattsNuclearGeneration
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationUnit3Member
/ dei_LegalEntityAxis
= pnm_PnmrAndPnmMember		                                  
Public Utilities, Proposed value per Kilowatt effective January 1, 2018         2,500pnm_PublicUtilitiesProposedvalueperKilowatteffectiveJanuary12018
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationUnit3Member
/ dei_LegalEntityAxis
= pnm_PnmrAndPnmMember		                                  
Public Utilities, Percentage capacity factor 7-year performance threshold       75.00%pnm_PublicUtilitiesPercentagecapacityfactor7yearperformancethreshold
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationUnit3Member
/ dei_LegalEntityAxis
= pnm_PnmrAndPnmMember		                                    
Public Utilities, Period over which to measure capacity performance       7 years                                    
Clean Air Act related to Post-Combustion Controls [Member] | Public Service Company of New Mexico [Member] | Four Corners [Member]                                            
Loss Contingencies [Line Items]                                            
Loss Contingency, Estimate of Possible Loss 80,000,000us-gaap_LossContingencyEstimateOfPossibleLoss
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActRelatedToPostCombustionControlsMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_FourCornersMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                          
Public Utilities, Number of Compliance alternatives 2pnm_PublicUtilitiesNumberOfComplianceAlternatives
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActRelatedToPostCombustionControlsMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_FourCornersMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                          
Public Utilities, Government Standard Emission Limit (pounds per MMBTU, parts per million) 0.015pnm_PublicUtilitiesGovernmentStandardEmissionLimit
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActRelatedToPostCombustionControlsMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_FourCornersMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                          
Public Utilitites, Plant Requirment to Meet Opacity Limit, Percentage 20.00%pnm_PublicUtilititesPlantRequirmentToMeetOpacityLimitPercentage
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActRelatedToPostCombustionControlsMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_FourCornersMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                          
Public Utilities, Rule Imposes Opacity Limitation on Certain Fugitive Dust Emissions From Coal and Material Handling Operations 20.00%pnm_PublicUtilitiesRuleImposesOpacityLimitationOnCertainFugitiveDustEmissionsFromCoalAndMaterialHandlingOperations
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActRelatedToPostCombustionControlsMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_FourCornersMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                          
Clean Air Act related to Post-Combustion Controls [Member] | Public Service Company of New Mexico [Member] | Four Corners Units 4 and 5 (Coal) [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Ownership Percentage 13.00%pnm_PublicUtilitiesOwnershipPercentage
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActRelatedToPostCombustionControlsMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_FourCornersUnits4And5CoalMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                          
Mercury Control [Member] | Public Service Company of New Mexico [Member] | San Juan Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Current Annual Mercury Control Costs 700,000pnm_CurrentAnnualMercuryControlCosts
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_MercuryControlMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                          
Mercury Control [Member] | Public Service Company of New Mexico [Member] | Maximum [Member] | San Juan Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Contingent Estimated Annual Mercury Control Cost 6,600,000pnm_ContingentEstimatedAnnualMercuryControlCost
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_MercuryControlMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember		                                          
Sierra Club Allegations [Member] | San Juan Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Estimated Total Litigation Settlement Cost                         10,200,000pnm_EstimatedTotalLitigationSettlementCost
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_SierraClubAllegationsMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember		                  
Sierra Club Allegations [Member] | Public Service Company of New Mexico [Member] | San Juan Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Estimated Company Share Litigation Settlement Cost                         4,500,000pnm_EstimatedCompanyShareLitigationSettlementCost
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_SierraClubAllegationsMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                  
Loss on Long-term Purchase Commitment [Member] | Public Service Company of New Mexico [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Annual Funding 1,000,000pnm_PublicUtilitiesAnnualFunding
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= us-gaap_LossOnLongTermPurchaseCommitmentMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		 300,000pnm_PublicUtilitiesAnnualFunding
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= us-gaap_LossOnLongTermPurchaseCommitmentMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		 3,500,000pnm_PublicUtilitiesAnnualFunding
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= us-gaap_LossOnLongTermPurchaseCommitmentMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                      
Public Utilities, Expected Funding Annual Requirements 600,000pnm_PublicUtilitiesExpectedFundingAnnualRequirements
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= us-gaap_LossOnLongTermPurchaseCommitmentMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		                                          
Installation Costs Including Construction Management, Gross Receipts Taxes, AFUDC, and Other PNM Costs [Member] | Clean Air Act, SCR [Member] | Public Service Company of New Mexico [Member] | Minimum [Member] | San Juan Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Estimated Total Capital Cost If Requirement Occurred                 824,000,000pnm_EstimatedTotalCapitalCostIfRequirementOccurred
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSCRMemberMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ pnm_PublicUtilitiesCommitmentsAndContingenciesByNatureOfExpenseAxis
= pnm_InstallationCostsIncludingConstructionManagementGrossReceiptsTaxesAfudcAndOtherPnmCostsMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember		                          
Installation Costs Including Construction Management, Gross Receipts Taxes, AFUDC, and Other PNM Costs [Member] | Clean Air Act, SCR [Member] | Public Service Company of New Mexico [Member] | Maximum [Member] | San Juan Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Estimated Total Capital Cost If Requirement Occurred                 910,000,000pnm_EstimatedTotalCapitalCostIfRequirementOccurred
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSCRMemberMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ pnm_PublicUtilitiesCommitmentsAndContingenciesByNatureOfExpenseAxis
= pnm_InstallationCostsIncludingConstructionManagementGrossReceiptsTaxesAfudcAndOtherPnmCostsMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember		                          
Installation Costs Including Construction Management, Gross Receipts Taxes, AFUDC, and Other PNM Costs [Member] | Clean Air Act, SNCR [Member] | Public Service Company of New Mexico [Member] | San Juan Generating Station Unit 4 [Member]                                            
Loss Contingencies [Line Items]                                            
Requested Expenditure, Installation Capital Costs                             1,900,000pnm_RequestedExpenditureInstallationCapitalCosts
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit4Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ pnm_PublicUtilitiesCommitmentsAndContingenciesByNatureOfExpenseAxis
= pnm_InstallationCostsIncludingConstructionManagementGrossReceiptsTaxesAfudcAndOtherPnmCostsMember		              
Requested Additional Expenditure, Installation Capital Costs                           6,400,000pnm_RequestedAdditionalExpenditureInstallationCapitalCosts
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit4Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ pnm_PublicUtilitiesCommitmentsAndContingenciesByNatureOfExpenseAxis
= pnm_InstallationCostsIncludingConstructionManagementGrossReceiptsTaxesAfudcAndOtherPnmCostsMember		                
Installation Costs Including Construction Management, Gross Receipts Taxes, AFUDC, and Other PNM Costs [Member] | Clean Air Act, SNCR [Member] | Public Service Company of New Mexico [Member] | Minimum [Member] | San Juan Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Estimated Installation Capital Costs                 85,000,000pnm_EstimatedInstallationCapitalCosts
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ pnm_PublicUtilitiesCommitmentsAndContingenciesByNatureOfExpenseAxis
= pnm_InstallationCostsIncludingConstructionManagementGrossReceiptsTaxesAfudcAndOtherPnmCostsMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember		                          
Estimated Portion of Total Capital Costs if Requirement Occured                 105,000,000pnm_EstimatedPortionOfTotalCapitalCostsIfRequirementOccured
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ pnm_PublicUtilitiesCommitmentsAndContingenciesByNatureOfExpenseAxis
= pnm_InstallationCostsIncludingConstructionManagementGrossReceiptsTaxesAfudcAndOtherPnmCostsMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember		                          
Installation Costs Including Construction Management, Gross Receipts Taxes, AFUDC, and Other PNM Costs [Member] | Clean Air Act, SNCR [Member] | Public Service Company of New Mexico [Member] | Maximum [Member] | San Juan Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Estimated Installation Capital Costs                 90,000,000pnm_EstimatedInstallationCapitalCosts
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ pnm_PublicUtilitiesCommitmentsAndContingenciesByNatureOfExpenseAxis
= pnm_InstallationCostsIncludingConstructionManagementGrossReceiptsTaxesAfudcAndOtherPnmCostsMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember		                          
Estimated Portion of Total Capital Costs if Requirement Occured                 110,000,000pnm_EstimatedPortionOfTotalCapitalCostsIfRequirementOccured
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ pnm_PublicUtilitiesCommitmentsAndContingenciesByNatureOfExpenseAxis
= pnm_InstallationCostsIncludingConstructionManagementGrossReceiptsTaxesAfudcAndOtherPnmCostsMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember		                          
Installation Costs Including Construction Management, Gross Receipts Taxes, AFUDC, and Other PNM Costs [Member] | Clean Air Act, SNCR [Member] | Public Service Company of New Mexico [Member] | Maximum [Member] | San Juan Generating Station Units 1 and 4 [Member]                                            
Loss Contingencies [Line Items]                                            
Estimated Installation Capital Costs       90,600,000pnm_EstimatedInstallationCapitalCosts
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnits1And4Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ pnm_PublicUtilitiesCommitmentsAndContingenciesByNatureOfExpenseAxis
= pnm_InstallationCostsIncludingConstructionManagementGrossReceiptsTaxesAfudcAndOtherPnmCostsMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember		 82,000,000pnm_EstimatedInstallationCapitalCosts
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnits1And4Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ pnm_PublicUtilitiesCommitmentsAndContingenciesByNatureOfExpenseAxis
= pnm_InstallationCostsIncludingConstructionManagementGrossReceiptsTaxesAfudcAndOtherPnmCostsMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember		                                  
San Juan Underground Mine Fire [Member] | Fuel and purchased power adjustment clause [Member] | Public Service Company of New Mexico [Member] | San Juan Generating Station [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Insurance Recovery 18,700,000pnm_PublicUtilitiesInsuranceRecovery
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_OtherCommitmentsAxis
= pnm_SanJuanUndergroundMineFireMember
/ us-gaap_RegulatoryAssetAxis
= pnm_FuelAndPurchasedPowerAdjustmentClauseMember		                                          
NMTRD Coal Severance Tax [Member] | Four Corners [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Assessed Coal Severance Surtax Penalty and Interest                               30,000,000pnm_PublicUtilitiesAssessedCoalSeveranceSurtaxPenaltyandInterest
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_FourCornersMember
/ us-gaap_OtherCommitmentsAxis
= pnm_NMTRDCoalSeveranceTaxMember		            
NMTRD Coal Severance Tax [Member] | Public Service Company of New Mexico [Member] | Four Corners [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, PNM Share Assessed Coal Severance Surtax Penalty and Interest to pass through FFPAC                               9.40%pnm_PublicUtilitiesPNMShareAssessedCoalSeveranceSurtaxPenaltyandInteresttopassthroughFFPAC
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_FourCornersMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_OtherCommitmentsAxis
= pnm_NMTRDCoalSeveranceTaxMember		            
Navajo Nation Allottee Matters [Member] | Public Service Company of New Mexico [Member]                                            
Loss Contingencies [Line Items]                                            
Number of landowners claiming to be Navajo allottees                                   43pnm_NumberoflandownersclaimingtobeNavajoallottees
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_OtherCommitmentsAxis
= pnm_NavajoNationAllotteeMattersMember		        
Number of allotment parcels' appraisal requested for review                                 58pnm_Numberofallotmentparcelsappraisalrequestedforreview
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_OtherCommitmentsAxis
= pnm_NavajoNationAllotteeMattersMember		          
San Juan Generating Station [Member] | National Ambient Air Quality Standards [Member] | Public Service Company of New Mexico [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Revised SO2 Emissions Agreed Upon                                     0.10pnm_PublicUtilitiesRevisedSO2EmissionsAgreedUpon
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_NationalAmbientAirQualityStandardsMember
/ pnm_JointlyOwnedGeneratingFacilitiesAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember		      
San Juan Generating Station [Member] | Continuous Highwall Mining [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Proposed Retroactive Surface Mining Royalty Rate 12.50%pnm_PublicUtilitiesProposedRetroactiveSurfaceMiningRoyaltyRate
/ pnm_JointlyOwnedGeneratingFacilitiesAxis
= pnm_SanJuanGeneratingStationMember
/ us-gaap_OtherCommitmentsAxis
= pnm_ContinuousHighwallMiningMember		                                          
Public Utilities, Current Surface Mining Royalty Rate applied between 2000 and 2003 8.00%pnm_PublicUtilitiesCurrentSurfaceMiningRoyaltyRateappliedbetween2000and2003
/ pnm_JointlyOwnedGeneratingFacilitiesAxis
= pnm_SanJuanGeneratingStationMember
/ us-gaap_OtherCommitmentsAxis
= pnm_ContinuousHighwallMiningMember		                                          
Public Utilities, Estimated Underpaid Surface Mining Royalties under proposed rate change 5,000,000pnm_PublicUtilitiesEstimatedUnderpaidSurfaceMiningRoyaltiesunderproposedratechange
/ pnm_JointlyOwnedGeneratingFacilitiesAxis
= pnm_SanJuanGeneratingStationMember
/ us-gaap_OtherCommitmentsAxis
= pnm_ContinuousHighwallMiningMember		                                          
Public Utilities, PNM Share Estimated Underpaid Surface Mining Royalties under proposed rate change 46.30%pnm_PublicUtilitiesPNMShareEstimatedUnderpaidSurfaceMiningRoyaltiesunderproposedratechange
/ pnm_JointlyOwnedGeneratingFacilitiesAxis
= pnm_SanJuanGeneratingStationMember
/ us-gaap_OtherCommitmentsAxis
= pnm_ContinuousHighwallMiningMember		                                          
San Juan Generating Station [Member] | SJCC Arbitration [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Potential Unbilled Mining Costs Owed to SJCC 5,200,000.0pnm_PublicUtilitiesPotentialUnbilledMiningCostsOwedtoSJCC
/ pnm_JointlyOwnedGeneratingFacilitiesAxis
= pnm_SanJuanGeneratingStationMember
/ us-gaap_OtherCommitmentsAxis
= pnm_SJCCArbitrationMember		                                          
Public Utilities, Potential Overbilled Mining Costs SJCC Owes to SJGS Owners 1,100,000.0pnm_PublicUtilitiesPotentialOverbilledMiningCostsSJCCOwestoSJGSOwners
/ pnm_JointlyOwnedGeneratingFacilitiesAxis
= pnm_SanJuanGeneratingStationMember
/ us-gaap_OtherCommitmentsAxis
= pnm_SJCCArbitrationMember		                                          
Public Utilities, Potential Capital Improvements billed as Mining Costs to SJGS Owners 13,900,000.0pnm_PublicUtilitiesPotentialCapitalImprovementsbilledasMiningCoststoSJGSOwners
/ pnm_JointlyOwnedGeneratingFacilitiesAxis
= pnm_SanJuanGeneratingStationMember
/ us-gaap_OtherCommitmentsAxis
= pnm_SJCCArbitrationMember		                                          
San Juan Generating Station [Member] | SJCC Arbitration [Member] | Public Service Company of New Mexico [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, PNM Share of arbitration ruling 46.30%pnm_PublicUtilitiesPNMShareofarbitrationruling
/ pnm_JointlyOwnedGeneratingFacilitiesAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_OtherCommitmentsAxis
= pnm_SJCCArbitrationMember		                                          
Public Utilities, FFPAC Percentage of mining costs overbilled or unbilled ruled by arbitration 33.00%pnm_PublicUtilitiesFFPACPercentageofminingcostsoverbilledorunbilledruledbyarbitration
/ pnm_JointlyOwnedGeneratingFacilitiesAxis
= pnm_SanJuanGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_OtherCommitmentsAxis
= pnm_SJCCArbitrationMember		                                          
Settled Litigation [Member] | Public Service Company of New Mexico [Member] | Palo Verde Nuclear Generating Station [Member] | Department of energy, spent nuclear fuel removal January 2007 - June 2011 [Member]                                            
Loss Contingencies [Line Items]                                            
Lawsuit settlement, third party receipt 57,400,000pnm_Lawsuitsettlementthirdpartyreceipt
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_LitigationStatusAxis
= us-gaap_SettledLitigationMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= pnm_DepartmentofenergyspentnuclearfuelremovalJanuary2007June2011Member		                                          
Settled Litigation [Member] | Public Service Company of New Mexico [Member] | Palo Verde Nuclear Generating Station [Member] | Nuclear Spent Fuel And Waste Disposal [Member]                                            
Loss Contingencies [Line Items]                                            
PNMs share of lawsuit settlement, third party receipt 5,900,000pnm_PNMsshareoflawsuitsettlementthirdpartyreceipt
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_PaloVerdeNuclearGeneratingStationMember
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_LitigationStatusAxis
= us-gaap_SettledLitigationMember
/ us-gaap_LossContingenciesByNatureOfContingencyAxis
= pnm_NuclearSpentFuelAndWasteDisposalMember		                                          
Subsequent Event [Member] | Clean Air Act, SNCR [Member] | San Juan Generating Station Unit 4 [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Unsubscribed Ownership in Megawatts                                       65pnm_PublicUtilitiesUnsubscribedOwnershipinMegawatts
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit4Member
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember		    
Subsequent Event [Member] | Clean Air Act, SNCR [Member] | Public Service Company of New Mexico [Member] | San Juan Generating Station Unit 4 [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Ownership in Megawatts PNM has agreed not to obtain                                         65pnm_PublicUtilitiesOwnershipinMegawattsPNMhasagreednottoobtain
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit4Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember		  
Subsequent Event [Member] | Clean Air Act, SNCR [Member] | PNMR [Member] | San Juan Generating Station Unit 4 [Member]                                            
Loss Contingencies [Line Items]                                            
Public Utilities, Potential Acquisition of Ownership in Megawatts                                       65pnm_PublicUtilitiesPotentialAcquisitionofOwnershipinMegawatts
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit4Member
/ dei_LegalEntityAxis
= pnm_PnmrMember
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember		    
Subsequent Event [Member] | Installation Costs Including Construction Management, Gross Receipts Taxes, AFUDC, and Other PNM Costs [Member] | Clean Air Act, SNCR [Member] | Public Service Company of New Mexico [Member] | San Juan Generating Station Unit 4 [Member]                                            
Loss Contingencies [Line Items]                                            
Requested Expenditure, Installation Capital Costs                                           $ 76,600,000pnm_RequestedExpenditureInstallationCapitalCosts
/ pnm_CommitmentsAndContingenciesRelatedToEnvironmentAndOtherNatureAxis
= pnm_CleanAirActSncrMember
/ us-gaap_JointlyOwnedUtilityPlantAxis
= pnm_SanJuanGeneratingStationUnit4Member
/ dei_LegalEntityAxis
= pnm_PublicServiceCompanyOfNewMexicoMember
/ pnm_PublicUtilitiesCommitmentsAndContingenciesByNatureOfExpenseAxis
= pnm_InstallationCostsIncludingConstructionManagementGrossReceiptsTaxesAfudcAndOtherPnmCostsMember
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
[1] Includes interest in PVNGS Unit 3, interest in common facilities for all PVNGS units, and owned interests in PVNGS Units 1 and 2.