3.25.3 html 853 566 1 false 219 0 false 22 false false R1.htm 0000001 - Document - Cover Page Sheet http://www.pnmresources.com/role/CoverPage Cover Page Cover 1 false false R2.htm 9952151 - Statement - Condensed Consolidated Statements of Earnings - TXNM Sheet http://www.pnmresources.com/role/CondensedConsolidatedStatementsofEarningsTXNM Condensed Consolidated Statements of Earnings - TXNM Statements 2 false false R3.htm 9952152 - Statement - Condensed Consolidated Statements of Comprehensive Income - TXNM Sheet http://www.pnmresources.com/role/CondensedConsolidatedStatementsofComprehensiveIncomeTXNM Condensed Consolidated Statements of Comprehensive Income - TXNM Statements 3 false false R4.htm 9952153 - Statement - Condensed Consolidated Statements of Comprehensive Income - TXNM (Parenthetical) Sheet http://www.pnmresources.com/role/CondensedConsolidatedStatementsofComprehensiveIncomeTXNMParenthetical Condensed Consolidated Statements of Comprehensive Income - TXNM (Parenthetical) Statements 4 false false R5.htm 9952154 - Statement - Condensed Consolidated Statements of Cash Flows - TXNM Sheet http://www.pnmresources.com/role/CondensedConsolidatedStatementsofCashFlowsTXNM Condensed Consolidated Statements of Cash Flows - TXNM Statements 5 false false R6.htm 9952155 - Statement - Condensed Consolidated Balance Sheets - TXNM Sheet http://www.pnmresources.com/role/CondensedConsolidatedBalanceSheetsTXNM Condensed Consolidated Balance Sheets - TXNM Statements 6 false false R7.htm 9952156 - Statement - Condensed Consolidated Balance Sheets - TXNM (Parenthetical) Sheet http://www.pnmresources.com/role/CondensedConsolidatedBalanceSheetsTXNMParenthetical Condensed Consolidated Balance Sheets - TXNM (Parenthetical) Statements 7 false false R8.htm 9952157 - Statement - Condensed Consolidated Statements of Changes in Equity - TXNM Sheet http://www.pnmresources.com/role/CondensedConsolidatedStatementsofChangesinEquityTXNM Condensed Consolidated Statements of Changes in Equity - TXNM Statements 8 false false R9.htm 9952158 - Statement - Condensed Consolidated Statements of Earnings - PNM Sheet http://www.pnmresources.com/role/CondensedConsolidatedStatementsofEarningsPNM Condensed Consolidated Statements of Earnings - PNM Statements 9 false false R10.htm 9952159 - Statement - Condensed Consolidated Statements of Comprehensive Income - PNM Sheet http://www.pnmresources.com/role/CondensedConsolidatedStatementsofComprehensiveIncomePNM Condensed Consolidated Statements of Comprehensive Income - PNM Statements 10 false false R11.htm 9952160 - Statement - Condensed Consolidated Statements of Comprehensive Income - PNM (Parenthetical) Sheet http://www.pnmresources.com/role/CondensedConsolidatedStatementsofComprehensiveIncomePNMParenthetical Condensed Consolidated Statements of Comprehensive Income - PNM (Parenthetical) Statements 11 false false R12.htm 9952161 - Statement - Condensed Consolidated Statements of Cash Flows - PNM Sheet http://www.pnmresources.com/role/CondensedConsolidatedStatementsofCashFlowsPNM Condensed Consolidated Statements of Cash Flows - PNM Statements 12 false false R13.htm 9952162 - Statement - Condensed Consolidated Balance Sheets - PNM Sheet http://www.pnmresources.com/role/CondensedConsolidatedBalanceSheetsPNM Condensed Consolidated Balance Sheets - PNM Statements 13 false false R14.htm 9952163 - Statement - Condensed Consolidated Balance Sheets - PNM (Parenthetical) Sheet http://www.pnmresources.com/role/CondensedConsolidatedBalanceSheetsPNMParenthetical Condensed Consolidated Balance Sheets - PNM (Parenthetical) Statements 14 false false R15.htm 9952164 - Statement - Condensed Consolidated Statements of Changes in Equity - PNM Sheet http://www.pnmresources.com/role/CondensedConsolidatedStatementsofChangesinEquityPNM Condensed Consolidated Statements of Changes in Equity - PNM Statements 15 false false R16.htm 9952165 - Statement - Condensed Consolidated Statements of Earnings - TNMP Sheet http://www.pnmresources.com/role/CondensedConsolidatedStatementsofEarningsTNMP Condensed Consolidated Statements of Earnings - TNMP Statements 16 false false R17.htm 9952166 - Statement - Condensed Consolidated Statements of Cash Flows - TNMP Sheet http://www.pnmresources.com/role/CondensedConsolidatedStatementsofCashFlowsTNMP Condensed Consolidated Statements of Cash Flows - TNMP Statements 17 false false R18.htm 9952167 - Statement - Condensed Consolidated Balance Sheets - TNMP Sheet http://www.pnmresources.com/role/CondensedConsolidatedBalanceSheetsTNMP Condensed Consolidated Balance Sheets - TNMP Statements 18 false false R19.htm 9952168 - Statement - Condensed Consolidated Balance Sheets - TNMP (Parenthetical) Sheet http://www.pnmresources.com/role/CondensedConsolidatedBalanceSheetsTNMPParenthetical Condensed Consolidated Balance Sheets - TNMP (Parenthetical) Statements 19 false false R20.htm 9952169 - Statement - Condensed Consolidated Statements of Changes in Common Stockholder's Equity - TNMP Sheet http://www.pnmresources.com/role/CondensedConsolidatedStatementsofChangesinCommonStockholdersEquityTNMP Condensed Consolidated Statements of Changes in Common Stockholder's Equity - TNMP Statements 20 false false R21.htm 9952170 - Disclosure - Significant Accounting Policies and Responsibility for Financial Statements Sheet http://www.pnmresources.com/role/SignificantAccountingPoliciesandResponsibilityforFinancialStatements Significant Accounting Policies and Responsibility for Financial Statements Notes 21 false false R22.htm 9952171 - Disclosure - Segment Information Sheet http://www.pnmresources.com/role/SegmentInformation Segment Information Notes 22 false false R23.htm 9952172 - Disclosure - Accumulated Other Comprehensive Income (Loss) Sheet http://www.pnmresources.com/role/AccumulatedOtherComprehensiveIncomeLoss Accumulated Other Comprehensive Income (Loss) Notes 23 false false R24.htm 9952173 - Disclosure - Earnings Per Share Sheet http://www.pnmresources.com/role/EarningsPerShare Earnings Per Share Notes 24 false false R25.htm 9952174 - Disclosure - Electric Operating Revenues Sheet http://www.pnmresources.com/role/ElectricOperatingRevenues Electric Operating Revenues Notes 25 false false R26.htm 9952175 - Disclosure - Variable Interest Entities Sheet http://www.pnmresources.com/role/VariableInterestEntities Variable Interest Entities Notes 26 false false R27.htm 9952176 - Disclosure - Fair Value of Derivative and Other Financial Instruments Sheet http://www.pnmresources.com/role/FairValueofDerivativeandOtherFinancialInstruments Fair Value of Derivative and Other Financial Instruments Notes 27 false false R28.htm 9952177 - Disclosure - Stock-Based Compensation Sheet http://www.pnmresources.com/role/StockBasedCompensation Stock-Based Compensation Notes 28 false false R29.htm 9952178 - Disclosure - Financing Sheet http://www.pnmresources.com/role/Financing Financing Notes 29 false false R30.htm 9952179 - Disclosure - Pension and Other Postretirement Benefit Plans Sheet http://www.pnmresources.com/role/PensionandOtherPostretirementBenefitPlans Pension and Other Postretirement Benefit Plans Notes 30 false false R31.htm 9952180 - Disclosure - Commitments and Contingencies Sheet http://www.pnmresources.com/role/CommitmentsandContingencies Commitments and Contingencies Notes 31 false false R32.htm 9952181 - Disclosure - Regulatory and Rate Matters Sheet http://www.pnmresources.com/role/RegulatoryandRateMatters Regulatory and Rate Matters Notes 32 false false R33.htm 9952182 - Disclosure - Lease Commitments Sheet http://www.pnmresources.com/role/LeaseCommitments Lease Commitments Notes 33 false false R34.htm 9952183 - Disclosure - Income Taxes Sheet http://www.pnmresources.com/role/IncomeTaxes Income Taxes Notes 34 false false R35.htm 9952184 - Disclosure - Related Party Transactions Sheet http://www.pnmresources.com/role/RelatedPartyTransactions Related Party Transactions Notes 35 false false R36.htm 9952185 - Disclosure - Goodwill Sheet http://www.pnmresources.com/role/Goodwill Goodwill Notes 36 false false R37.htm 9952186 - Disclosure - Merger Sheet http://www.pnmresources.com/role/Merger Merger Notes 37 false false R38.htm 995445 - Disclosure - Insider Trading Arrangements Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements Insider Trading Arrangements Notes 38 false false R39.htm 9955511 - Disclosure - Significant Accounting Policies and Responsibility for Financial Statements (Policies) Sheet http://www.pnmresources.com/role/SignificantAccountingPoliciesandResponsibilityforFinancialStatementsPolicies Significant Accounting Policies and Responsibility for Financial Statements (Policies) Policies http://www.pnmresources.com/role/SignificantAccountingPoliciesandResponsibilityforFinancialStatements 39 false false R40.htm 9955512 - Disclosure - Segment Information (Tables) Sheet http://www.pnmresources.com/role/SegmentInformationTables Segment Information (Tables) Tables http://www.pnmresources.com/role/SegmentInformation 40 false false R41.htm 9955513 - Disclosure - Accumulated Other Comprehensive Income (Loss) (Tables) Sheet http://www.pnmresources.com/role/AccumulatedOtherComprehensiveIncomeLossTables Accumulated Other Comprehensive Income (Loss) (Tables) Tables http://www.pnmresources.com/role/AccumulatedOtherComprehensiveIncomeLoss 41 false false R42.htm 9955514 - Disclosure - Earnings Per Share (Tables) Sheet http://www.pnmresources.com/role/EarningsPerShareTables Earnings Per Share (Tables) Tables http://www.pnmresources.com/role/EarningsPerShare 42 false false R43.htm 9955515 - Disclosure - Electric Operating Revenues (Tables) Sheet http://www.pnmresources.com/role/ElectricOperatingRevenuesTables Electric Operating Revenues (Tables) Tables http://www.pnmresources.com/role/ElectricOperatingRevenues 43 false false R44.htm 9955516 - Disclosure - Variable Interest Entities (Tables) Sheet http://www.pnmresources.com/role/VariableInterestEntitiesTables Variable Interest Entities (Tables) Tables http://www.pnmresources.com/role/VariableInterestEntities 44 false false R45.htm 9955517 - Disclosure - Fair Value of Derivative and Other Financial Instruments (Tables) Sheet http://www.pnmresources.com/role/FairValueofDerivativeandOtherFinancialInstrumentsTables Fair Value of Derivative and Other Financial Instruments (Tables) Tables http://www.pnmresources.com/role/FairValueofDerivativeandOtherFinancialInstruments 45 false false R46.htm 9955518 - Disclosure - Stock-Based Compensation (Tables) Sheet http://www.pnmresources.com/role/StockBasedCompensationTables Stock-Based Compensation (Tables) Tables http://www.pnmresources.com/role/StockBasedCompensation 46 false false R47.htm 9955519 - Disclosure - Financing (Tables) Sheet http://www.pnmresources.com/role/FinancingTables Financing (Tables) Tables http://www.pnmresources.com/role/Financing 47 false false R48.htm 9955520 - Disclosure - Pension and Other Postretirement Benefit Plans (Tables) Sheet http://www.pnmresources.com/role/PensionandOtherPostretirementBenefitPlansTables Pension and Other Postretirement Benefit Plans (Tables) Tables http://www.pnmresources.com/role/PensionandOtherPostretirementBenefitPlans 48 false false R49.htm 9955521 - Disclosure - Regulatory and Rate Matters (Tables) Sheet http://www.pnmresources.com/role/RegulatoryandRateMattersTables Regulatory and Rate Matters (Tables) Tables http://www.pnmresources.com/role/RegulatoryandRateMatters 49 false false R50.htm 9955522 - Disclosure - Lease Commitments (Tables) Sheet http://www.pnmresources.com/role/LeaseCommitmentsTables Lease Commitments (Tables) Tables http://www.pnmresources.com/role/LeaseCommitments 50 false false R51.htm 9955523 - Disclosure - Related Party Transactions (Tables) Sheet http://www.pnmresources.com/role/RelatedPartyTransactionsTables Related Party Transactions (Tables) Tables http://www.pnmresources.com/role/RelatedPartyTransactions 51 false false R52.htm 9955524 - Disclosure - Significant Accounting Policies and Responsibility for Financial Statements (Details) Sheet http://www.pnmresources.com/role/SignificantAccountingPoliciesandResponsibilityforFinancialStatementsDetails Significant Accounting Policies and Responsibility for Financial Statements (Details) Details http://www.pnmresources.com/role/SignificantAccountingPoliciesandResponsibilityforFinancialStatementsPolicies 52 false false R53.htm 9955525 - Disclosure - Segment Information - Narrative (Details) Sheet http://www.pnmresources.com/role/SegmentInformationNarrativeDetails Segment Information - Narrative (Details) Details 53 false false R54.htm 9955526 - Disclosure - Segment Information - Schedule of Financial Information by Segment (Details) Sheet http://www.pnmresources.com/role/SegmentInformationScheduleofFinancialInformationbySegmentDetails Segment Information - Schedule of Financial Information by Segment (Details) Details 54 false false R55.htm 9955527 - Disclosure - Accumulated Other Comprehensive Income (Loss) (Details) Sheet http://www.pnmresources.com/role/AccumulatedOtherComprehensiveIncomeLossDetails Accumulated Other Comprehensive Income (Loss) (Details) Details http://www.pnmresources.com/role/AccumulatedOtherComprehensiveIncomeLossTables 55 false false R56.htm 9955528 - Disclosure - Earnings Per Share - Narrative (Details) Sheet http://www.pnmresources.com/role/EarningsPerShareNarrativeDetails Earnings Per Share - Narrative (Details) Details 56 false false R57.htm 9955529 - Disclosure - Earnings Per Share - Schedule of Computation of Earnings Per Share (Details) Sheet http://www.pnmresources.com/role/EarningsPerShareScheduleofComputationofEarningsPerShareDetails Earnings Per Share - Schedule of Computation of Earnings Per Share (Details) Details 57 false false R58.htm 9955530 - Disclosure - Electric Operating Revenues - Narrative (Details) Sheet http://www.pnmresources.com/role/ElectricOperatingRevenuesNarrativeDetails Electric Operating Revenues - Narrative (Details) Details 58 false false R59.htm 9955531 - Disclosure - Electric Operating Revenues - Schedule of Disaggregation of revenues (Details) Sheet http://www.pnmresources.com/role/ElectricOperatingRevenuesScheduleofDisaggregationofrevenuesDetails Electric Operating Revenues - Schedule of Disaggregation of revenues (Details) Details 59 false false R60.htm 9955532 - Disclosure - Variable Interest Entities - Narrative (Details) Sheet http://www.pnmresources.com/role/VariableInterestEntitiesNarrativeDetails Variable Interest Entities - Narrative (Details) Details 60 false false R61.htm 9955533 - Disclosure - Variable Interest Entities - Schedule of Operations for Valencia (Details) Sheet http://www.pnmresources.com/role/VariableInterestEntitiesScheduleofOperationsforValenciaDetails Variable Interest Entities - Schedule of Operations for Valencia (Details) Details 61 false false R62.htm 9955534 - Disclosure - Variable Interest Entities - Schedule of Impact on Results of Operation (Details) Sheet http://www.pnmresources.com/role/VariableInterestEntitiesScheduleofImpactonResultsofOperationDetails Variable Interest Entities - Schedule of Impact on Results of Operation (Details) Details 62 false false R63.htm 9955535 - Disclosure - Variable Interest Entities - Schedule of Impact on Balance Sheet (Details) Sheet http://www.pnmresources.com/role/VariableInterestEntitiesScheduleofImpactonBalanceSheetDetails Variable Interest Entities - Schedule of Impact on Balance Sheet (Details) Details 63 false false R64.htm 9955536 - Disclosure - Fair Value of Derivative and Other Financial Instruments - Narrative (Details) Sheet http://www.pnmresources.com/role/FairValueofDerivativeandOtherFinancialInstrumentsNarrativeDetails Fair Value of Derivative and Other Financial Instruments - Narrative (Details) Details http://www.pnmresources.com/role/FairValueofDerivativeandOtherFinancialInstrumentsTables 64 false false R65.htm 9955537 - Disclosure - Fair Value of Derivative and Other Financial Instruments - Schedule of Derivatives (Details) Sheet http://www.pnmresources.com/role/FairValueofDerivativeandOtherFinancialInstrumentsScheduleofDerivativesDetails Fair Value of Derivative and Other Financial Instruments - Schedule of Derivatives (Details) Details 65 false false R66.htm 9955538 - Disclosure - Fair Value of Derivative and Other Financial Instruments - Schedule of Commodity Contract Volume Positions (Details) Sheet http://www.pnmresources.com/role/FairValueofDerivativeandOtherFinancialInstrumentsScheduleofCommodityContractVolumePositionsDetails Fair Value of Derivative and Other Financial Instruments - Schedule of Commodity Contract Volume Positions (Details) Details 66 false false R67.htm 9955539 - Disclosure - Fair Value of Derivative and Other Financial Instruments - Investments in NDT and Gross Realized Losses (Details) Sheet http://www.pnmresources.com/role/FairValueofDerivativeandOtherFinancialInstrumentsInvestmentsinNDTandGrossRealizedLossesDetails Fair Value of Derivative and Other Financial Instruments - Investments in NDT and Gross Realized Losses (Details) Details 67 false false R68.htm 9955540 - Disclosure - Fair Value of Derivative and Other Financial Instruments - Schedule of Gross Realized Gains and Losses (Details) Sheet http://www.pnmresources.com/role/FairValueofDerivativeandOtherFinancialInstrumentsScheduleofGrossRealizedGainsandLossesDetails Fair Value of Derivative and Other Financial Instruments - Schedule of Gross Realized Gains and Losses (Details) Details 68 false false R69.htm 9955541 - Disclosure - Fair Value of Derivative and Other Financial Instruments - Schedule of Maturities of Debt Securities (Details) Sheet http://www.pnmresources.com/role/FairValueofDerivativeandOtherFinancialInstrumentsScheduleofMaturitiesofDebtSecuritiesDetails Fair Value of Derivative and Other Financial Instruments - Schedule of Maturities of Debt Securities (Details) Details 69 false false R70.htm 9955542 - Disclosure - Fair Value of Derivative and Other Financial Instruments - Schedule of Items Recorded and Presented by Level of Hierarchy (Details) Sheet http://www.pnmresources.com/role/FairValueofDerivativeandOtherFinancialInstrumentsScheduleofItemsRecordedandPresentedbyLevelofHierarchyDetails Fair Value of Derivative and Other Financial Instruments - Schedule of Items Recorded and Presented by Level of Hierarchy (Details) Details 70 false false R71.htm 9955543 - Disclosure - Stock-Based Compensation - Narrative (Details) Sheet http://www.pnmresources.com/role/StockBasedCompensationNarrativeDetails Stock-Based Compensation - Narrative (Details) Details 71 false false R72.htm 9955544 - Disclosure - Stock-Based Compensation - Weighted Average Assumptions (Details) Sheet http://www.pnmresources.com/role/StockBasedCompensationWeightedAverageAssumptionsDetails Stock-Based Compensation - Weighted Average Assumptions (Details) Details 72 false false R73.htm 9955545 - Disclosure - Stock-Based Compensation - Restricted Stock Awards (Details) Sheet http://www.pnmresources.com/role/StockBasedCompensationRestrictedStockAwardsDetails Stock-Based Compensation - Restricted Stock Awards (Details) Details 73 false false R74.htm 9955546 - Disclosure - Stock-Based Compensation - Additional Information Concerning Restricted Stock Activity (Details) Sheet http://www.pnmresources.com/role/StockBasedCompensationAdditionalInformationConcerningRestrictedStockActivityDetails Stock-Based Compensation - Additional Information Concerning Restricted Stock Activity (Details) Details 74 false false R75.htm 9955547 - Disclosure - Financing - Financing Activities (Details) Sheet http://www.pnmresources.com/role/FinancingFinancingActivitiesDetails Financing - Financing Activities (Details) Details 75 false false R76.htm 9955548 - Disclosure - Financing - Schedule of Forward Contracts (Details) Sheet http://www.pnmresources.com/role/FinancingScheduleofForwardContractsDetails Financing - Schedule of Forward Contracts (Details) Details 76 false false R77.htm 9955549 - Disclosure - Financing - Schedule of Long-Term Debt (Details) Sheet http://www.pnmresources.com/role/FinancingScheduleofLongTermDebtDetails Financing - Schedule of Long-Term Debt (Details) Details 77 false false R78.htm 9955550 - Disclosure - Financing - Short-term Debt and Liquidity (Details) Sheet http://www.pnmresources.com/role/FinancingShorttermDebtandLiquidityDetails Financing - Short-term Debt and Liquidity (Details) Details 78 false false R79.htm 9955551 - Disclosure - Financing - Schedule of Short-Term Debt (Details) Sheet http://www.pnmresources.com/role/FinancingScheduleofShortTermDebtDetails Financing - Schedule of Short-Term Debt (Details) Details 79 false false R80.htm 9955552 - Disclosure - Pension and Other Postretirement Benefit Plans - Schedule of Net Periodic Benefit Costs (Details) Sheet http://www.pnmresources.com/role/PensionandOtherPostretirementBenefitPlansScheduleofNetPeriodicBenefitCostsDetails Pension and Other Postretirement Benefit Plans - Schedule of Net Periodic Benefit Costs (Details) Details 80 false false R81.htm 9955553 - Disclosure - Pension and Other Postretirement Benefit Plans - Narrative (Details) Sheet http://www.pnmresources.com/role/PensionandOtherPostretirementBenefitPlansNarrativeDetails Pension and Other Postretirement Benefit Plans - Narrative (Details) Details 81 false false R82.htm 9955554 - Disclosure - Commitments and Contingencies - Nuclear Spent Fuel and Waste Disposal (Details) Sheet http://www.pnmresources.com/role/CommitmentsandContingenciesNuclearSpentFuelandWasteDisposalDetails Commitments and Contingencies - Nuclear Spent Fuel and Waste Disposal (Details) Details 82 false false R83.htm 9955555 - Disclosure - Commitments and Contingencies - Santa Fe Generating Station (Details) Sheet http://www.pnmresources.com/role/CommitmentsandContingenciesSantaFeGeneratingStationDetails Commitments and Contingencies - Santa Fe Generating Station (Details) Details 83 false false R84.htm 9955556 - Disclosure - Commitments and Contingencies - Coal Supply (Details) Sheet http://www.pnmresources.com/role/CommitmentsandContingenciesCoalSupplyDetails Commitments and Contingencies - Coal Supply (Details) Details 84 false false R85.htm 9955557 - Disclosure - Commitments and Contingencies - SJGS Decommissioning (Details) Sheet http://www.pnmresources.com/role/CommitmentsandContingenciesSJGSDecommissioningDetails Commitments and Contingencies - SJGS Decommissioning (Details) Details 85 false false R86.htm 9955558 - Disclosure - Commitments and Contingencies - PVNGS Liability and Insurance Matters (Details) Sheet http://www.pnmresources.com/role/CommitmentsandContingenciesPVNGSLiabilityandInsuranceMattersDetails Commitments and Contingencies - PVNGS Liability and Insurance Matters (Details) Details 86 false false R87.htm 9955559 - Disclosure - Regulatory and Rate Matters - TXNM (Details) Sheet http://www.pnmresources.com/role/RegulatoryandRateMattersTXNMDetails Regulatory and Rate Matters - TXNM (Details) Details 87 false false R88.htm 9955560 - Disclosure - Regulatory and Rate Matters - PNM (Details) Sheet http://www.pnmresources.com/role/RegulatoryandRateMattersPNMDetails Regulatory and Rate Matters - PNM (Details) Details http://www.pnmresources.com/role/RegulatoryandRateMattersTables 88 false false R89.htm 9955561 - Disclosure - Regulatory and Rate Matters - 2023 IRP, 2028 Resource Application, Grid Modernization Application (Details) Sheet http://www.pnmresources.com/role/RegulatoryandRateMatters2023IRP2028ResourceApplicationGridModernizationApplicationDetails Regulatory and Rate Matters - 2023 IRP, 2028 Resource Application, Grid Modernization Application (Details) Details 89 false false R90.htm 9955562 - Disclosure - Regulatory and Rate Matters - Transportation and Electrification Program (TEP) (Details) Sheet http://www.pnmresources.com/role/RegulatoryandRateMattersTransportationandElectrificationProgramTEPDetails Regulatory and Rate Matters - Transportation and Electrification Program (TEP) (Details) Details 90 false false R91.htm 9955563 - Disclosure - Regulatory and Rate Matters - Meta Platforms Inc. Data Center - Phase IV, BESS Project (Details) Sheet http://www.pnmresources.com/role/RegulatoryandRateMattersMetaPlatformsIncDataCenterPhaseIVBESSProjectDetails Regulatory and Rate Matters - Meta Platforms Inc. Data Center - Phase IV, BESS Project (Details) Details 91 false false R92.htm 9955564 - Disclosure - Regulatory and Rate Matters - TNMP Narrative (Details) Sheet http://www.pnmresources.com/role/RegulatoryandRateMattersTNMPNarrativeDetails Regulatory and Rate Matters - TNMP Narrative (Details) Details 92 false false R93.htm 9955565 - Disclosure - Regulatory and Rate Matters - Schedule of Transmission Cost of Service Rates (Details) Sheet http://www.pnmresources.com/role/RegulatoryandRateMattersScheduleofTransmissionCostofServiceRatesDetails Regulatory and Rate Matters - Schedule of Transmission Cost of Service Rates (Details) Details 93 false false R94.htm 9955566 - Disclosure - Regulatory and Rate Matters - Schedule of Interim Distribution Rate Increases (Details) Sheet http://www.pnmresources.com/role/RegulatoryandRateMattersScheduleofInterimDistributionRateIncreasesDetails Regulatory and Rate Matters - Schedule of Interim Distribution Rate Increases (Details) Details 94 false false R95.htm 9955567 - Disclosure - Lease Commitments - Narrative (Details) Sheet http://www.pnmresources.com/role/LeaseCommitmentsNarrativeDetails Lease Commitments - Narrative (Details) Details 95 false false R96.htm 9955568 - Disclosure - Lease Commitments - Schedule of Operating Lease Balance Sheet Information (Details) Sheet http://www.pnmresources.com/role/LeaseCommitmentsScheduleofOperatingLeaseBalanceSheetInformationDetails Lease Commitments - Schedule of Operating Lease Balance Sheet Information (Details) Details 96 false false R97.htm 9955569 - Disclosure - Lease Commitments - Schedule of Finance Lease Balance Sheet Information (Details) Sheet http://www.pnmresources.com/role/LeaseCommitmentsScheduleofFinanceLeaseBalanceSheetInformationDetails Lease Commitments - Schedule of Finance Lease Balance Sheet Information (Details) Details 97 false false R98.htm 9955570 - Disclosure - Lease Commitments - Schedule of Weighted Average Remaining Lease Terms and Discount Rates (Details) Sheet http://www.pnmresources.com/role/LeaseCommitmentsScheduleofWeightedAverageRemainingLeaseTermsandDiscountRatesDetails Lease Commitments - Schedule of Weighted Average Remaining Lease Terms and Discount Rates (Details) Details 98 false false R99.htm 9955571 - Disclosure - Lease Commitments - Schedule of Components of Lease Expense (Details) Sheet http://www.pnmresources.com/role/LeaseCommitmentsScheduleofComponentsofLeaseExpenseDetails Lease Commitments - Schedule of Components of Lease Expense (Details) Details 99 false false R100.htm 9955572 - Disclosure - Lease Commitments - Schedule of Supplemental Cash Flows Related to Leases (Details) Sheet http://www.pnmresources.com/role/LeaseCommitmentsScheduleofSupplementalCashFlowsRelatedtoLeasesDetails Lease Commitments - Schedule of Supplemental Cash Flows Related to Leases (Details) Details 100 false false R101.htm 9955573 - Disclosure - Lease Commitments - Schedule of Future Expected Lease Payments (Details) Sheet http://www.pnmresources.com/role/LeaseCommitmentsScheduleofFutureExpectedLeasePaymentsDetails Lease Commitments - Schedule of Future Expected Lease Payments (Details) Details 101 false false R102.htm 9955574 - Disclosure - Income Taxes (Details) Sheet http://www.pnmresources.com/role/IncomeTaxesDetails Income Taxes (Details) Details http://www.pnmresources.com/role/IncomeTaxes 102 false false R103.htm 9955575 - Disclosure - Related Party Transactions (Details) Sheet http://www.pnmresources.com/role/RelatedPartyTransactionsDetails Related Party Transactions (Details) Details http://www.pnmresources.com/role/RelatedPartyTransactionsTables 103 false false R104.htm 9955576 - Disclosure - Goodwill (Details) Sheet http://www.pnmresources.com/role/GoodwillDetails Goodwill (Details) Details http://www.pnmresources.com/role/Goodwill 104 false false R105.htm 9955577 - Disclosure - Merger (Details) Sheet http://www.pnmresources.com/role/MergerDetails Merger (Details) Details http://www.pnmresources.com/role/Merger 105 false false All Reports Book All Reports pnm-20250930.htm pnm-20250930.xsd pnm-20250930_cal.xml pnm-20250930_def.xml pnm-20250930_lab.xml pnm-20250930_pre.xml http://fasb.org/us-gaap/2025 http://xbrl.sec.gov/dei/2025 http://xbrl.sec.gov/ecd/2025 true true