XML 145 R124.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Regulatory and Rate Matters - SJGS Abandonment Application (Details) $ in Millions |  | 12 Months Ended |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Jul. 01, 2019 USD ($) | Dec. 31, 2021 USD ($) MW | Apr. 02, 2021 MW | Dec. 31, 2020 USD ($) | Nov. 13, 2020 MW | Sep. 28, 2020 USD ($) | Jul. 29, 2020 MW | Mar. 31, 2020 USD ($) | Feb. 21, 2020 USD ($) | May 31, 2019 MW
PNM Solar Direct |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Solar distributed generation (in mw) | MW |  |  |  |  |  |  |  |  |  | 50
Public Service Company of New Mexico |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Solar distributed generation (in mw) | MW |  |  |  |  |  |  | 650 |  |  |
Number of megawatts in battery storage facilities (in megawatts) | MW |  |  |  |  |  |  | 300 |  |  |
Public Service Company of New Mexico | Replacement Resource Portfolio One |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Solar distributed generation (in mw) | MW |  |  | 150 |  | 200 |  |  |  |  |
Number of megawatts in battery storage facilities (in megawatts) | MW |  |  | 40 |  | 100 |  |  |  |  |
Public Service Company of New Mexico | Replacement Resource Portfolio Two |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Solar distributed generation (in mw) | MW |  |  |  |  | 100 |  |  |  |  |
Number of megawatts in battery storage facilities (in megawatts) | MW |  |  | 100 |  | 30 |  |  |  |  |
Public Service Company of New Mexico | Portfolio One |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Number of megawatts available in purchase power agreement (in megawatts) | MW |  | 85 |  |  |  |  |  |  |  |
Public Service Company of New Mexico | Portfolio Two |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Number of megawatts available in purchase power agreement (in megawatts) | MW |  | 150 |  |  |  |  |  |  |  |
Public Service Company of New Mexico | Portfolio Three |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Number of megawatts available in purchase power agreement (in megawatts) | MW |  | 40 |  |  |  |  |  |  |  |
San Juan Generating Station |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Estimated costs of replacement resources |  |  |  |  |  | $ 8.1 |  |  |  |
San Juan Generating Station | Other deferred credits |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Restructuring reserve |  | $ 36.9 |  | $ 38.1 |  |  |  |  |  |
San Juan Generating Station | Employee Severance |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Restructuring reserve |  |  |  |  |  |  |  | $ 9.4 |  |
San Juan Generating Station | Public Service Company of New Mexico |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Request issuance of energy transition bonds | $ 361.0 |  |  |  |  |  |  |  |  |
Forecasted undepreciated investment |  | 283.0 |  |  |  |  |  |  | $ 361.0 |
Plant decommissioning and coal mine reclamation costs |  | 28.6 |  |  |  |  |  |  |  |
Upfront financing costs |  | 9.6 |  |  |  |  |  |  |  |
Severance costs |  | 20.0 |  |  |  |  |  |  |  |
Proceeds from securitization bonds | $ 19.8 |  |  |  |  |  |  |  |  |
San Juan Generating Station | Public Service Company of New Mexico | Other deferred credits |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Restructuring reserve |  | $ 36.0 |  | $ 36.8 |  |  |  |  |  |
San Juan Generating Station | Public Service Company of New Mexico | Employee Severance |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Restructuring reserve |  |  |  |  |  |  |  | 8.1 |  |
San Juan Generating Station | Public Service Company of New Mexico | Other Restructuring |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Restructuring reserve |  |  |  |  |  |  |  | 8.9 |  |
San Juan Generating Station | Public Service Company of New Mexico | Economic Development and Workforce Training Costs |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Restructuring reserve |  |  |  |  |  |  |  | $ 19.8 |  |

X
- Definition Proceeds From Securitization Bonds + References No definition available. + Details
Name: | pnm_ProceedsFromSecuritizationBonds
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Public Utilities, Estimated Costs Of Replacement Resources + References No definition available. + Details
Name: | pnm_PublicUtilitiesEstimatedCostsOfReplacementResources
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Public Utilities, forecasted undepreciated investment + References No definition available. + Details
Name: | pnm_PublicUtilitiesForecastedUndepreciatedInvestment
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Public Utilities, Number Of Megawatts Available In Purchase Power Agreement + References No definition available. + Details
Name: | pnm_PublicUtilitiesNumberOfMegawattsAvailableInPurchasePowerAgreement
Namespace Prefix: | pnm_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Public Utilities, Number Of Megawatts In Battery Storage Facilities + References No definition available. + Details
Name: | pnm_PublicUtilitiesNumberOfMegawattsInBatteryStorageFacilities
Namespace Prefix: | pnm_
Data Type: | dtr-types:powerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Public Utilities, Plant Decommissioning And Coal Mine Reclamation Costs + References No definition available. + Details
Name: | pnm_PublicUtilitiesPlantDecommissioningAndCoalMineReclamationCosts
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Public Utilities, Request Issuance Of Energy Transition Bonds + References No definition available. + Details
Name: | pnm_PublicUtilitiesRequestIssuanceOfEnergyTransitionBonds
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Public Utilities, Solar generation capacity in Megawatts + References No definition available. + Details
Name: | pnm_PublicUtilitiesSolarGenerationCapacityInMegawatts
Namespace Prefix: | pnm_
Data Type: | dtr-types:powerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Public Utilities, Upfront Financing Costs + References No definition available. + Details
Name: | pnm_PublicUtilitiesUpfrontFinancingCosts
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesGeneralDisclosuresLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB TOPIC 5.P.4(b)(2)) -URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747 + Details
Name: | us-gaap_RestructuringReserve
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585 + Details
Name: | us-gaap_SeveranceCosts1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | pnm_ScheduleOfRegulatoryRateMattersAxis=pnm_PNMSolarDirectMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=pnm_PublicServiceCompanyOfNewMexicoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | pnm_ScheduleOfRegulatoryRateMattersAxis=pnm_ReplacementResourcePortfolioOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | pnm_ScheduleOfRegulatoryRateMattersAxis=pnm_ReplacementResourcePortfolioTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | pnm_ScheduleOfRegulatoryRateMattersAxis=pnm_PortfolioOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | pnm_ScheduleOfRegulatoryRateMattersAxis=pnm_PortfolioTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | pnm_ScheduleOfRegulatoryRateMattersAxis=pnm_PortfolioThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_JointlyOwnedUtilityPlantAxis=pnm_SanJuanGeneratingStationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=pnm_OtherDeferredCreditsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringCostAndReserveAxis=us-gaap_EmployeeSeveranceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringCostAndReserveAxis=us-gaap_OtherRestructuringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringCostAndReserveAxis=pnm_EconomicDevelopmentAndWorkforceTrainingCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |