XML 140 R110.htm IDEA: XBRL DOCUMENT
v3.20.4

Regulatory and Rate Matters - Renewable Portfolio Standard (Details) |  |  |  |  | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Jan. 01, 2021 USD ($) | Nov. 18, 2020 | Jun. 01, 2020 USD ($) | Jun. 03, 2019 MW | Dec. 31, 2020 USD ($) MW | Mar. 27, 2020 MW | Aug. 10, 2018 kv | Jun. 01, 2017 GWh MW
KV Transmission Line |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |
Transmission line and associated facilities | kv |  |  |  |  |  |  | 345 |
Public Service Company of New Mexico |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |
Solar distributed generation (in mw) |  |  |  |  |  | 300 |  |
Public Service Company of New Mexico | Renewable Portfolio Standard |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |
Solar photovoltaic capacity (in mw) |  |  |  |  | 158 |  |  |
Solar distributed generation (in mw) |  |  |  |  | 161.0 |  |  |
Public Service Company of New Mexico | Renewable Portfolio Standard | Maximum |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |
Reasonable cost threshold in megawatts per hour | $ |  |  |  |  | $ 60 |  |  |
NMPRC | Public Service Company of New Mexico |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |
Additional megawatt hours in first year (in mw) | GWh |  |  |  |  |  |  |  | 80
Requested solar production (in mw) |  |  |  |  |  |  |  | 50
NMPRC | Public Service Company of New Mexico | Renewable Energy Rider |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |
Proposed revision to rider that will allow for recovery | $ |  |  | $ 67,800,000 |  |  |  |  |
NMPRC | Public Service Company of New Mexico | Renewable Energy Rider | Subsequent Event |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |
Proposed revision to rider that will allow for recovery | $ | $ 67,800,000 |  |  |  |  |  |  |
NMPRC | Public Service Company of New Mexico | Renewable Energy Rider, Sky Blue Energy Program |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |
Proposed revision to rider that will allow for recovery | $ |  |  | $ 2,300,000 |  |  |  |  |
Renewable energy procurement plan, carrying charges, percent |  | 4.00% | 8.64% |  |  |  |  |
Renewable energy procurement plan, carrying charges | $ |  |  | $ 700,000 |  |  |  |  |
NMPRC | Public Service Company of New Mexico | Renewable Energy Rider, Sky Blue Energy Program | Subsequent Event |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |
Proposed revision to rider that will allow for recovery | $ | $ 2,300,000 |  |  |  |  |  |  |
New Mexico Wind | Public Service Company of New Mexico | Renewable Portfolio Standard 2014 |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |
Wind energy capacity (in mw) |  |  |  |  | 200 |  |  |
New Mexico Wind | NMPRC | Public Service Company of New Mexico |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |
Additional megawatt hours in second year (in mw) | GWh |  |  |  |  |  |  |  | 105
Red Mesa Wind | Public Service Company of New Mexico | Renewable Portfolio Standard 2014 |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |
Wind energy capacity (in mw) |  |  |  |  | 102 |  |  |
La Joya Wind | Public Service Company of New Mexico | Renewable Portfolio Standard |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |
Wind energy capacity (in mw) |  |  |  |  | 140 |  |  |
Solar distributed generation (in mw) |  |  |  | 140 |  |  |  |
PPA term |  |  |  | 20 years |  |  |  |
Lightning Dock Geothermal | Public Service Company of New Mexico | Renewable Portfolio Standard |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |
Geothermal energy capacity (in mw) |  |  |  |  | 11 |  |  |
Lightning Dock Geothermal | NMPRC | Public Service Company of New Mexico |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |
Additional megawatt hours in first year (in mw) | GWh |  |  |  |  |  |  |  | 55
Additional megawatt hours in second year (in mw) | GWh |  |  |  |  |  |  |  | 77

X
- Definition Power Purchase Agreement Term + References No definition available. + Details
Name: | pnm_PowerPurchaseAgreementTerm
Namespace Prefix: | pnm_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Public Utilities, Number Of Mega Watts Of Geothermal Energy Capacity + References No definition available. + Details
Name: | pnm_PublicUtilitiesNumberOfMegaWattsOfGeothermalEnergyCapacity
Namespace Prefix: | pnm_
Data Type: | num:powerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Public Utilities, Number of Mega Watts of Solar Photovoltaic Capacity + References No definition available. + Details
Name: | pnm_PublicUtilitiesNumberOfMegaWattsOfSolarPhotovoltaicCapacity
Namespace Prefix: | pnm_
Data Type: | num:powerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Public Utilities, Number of Mega Watts of Wind Energy Capacity + References No definition available. + Details
Name: | pnm_PublicUtilitiesNumberofMegaWattsofWindEnergyCapacity
Namespace Prefix: | pnm_
Data Type: | num:powerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Public Utilities, Reasonable Cost Threshold In Megawatts Per Hour + References No definition available. + Details
Name: | pnm_PublicUtilitiesReasonableCostThresholdInMegawattsPerHour
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Public Utilities, Renewable Energy Procurement Plan, Carrying Charges, Amount + References No definition available. + Details
Name: | pnm_PublicUtilitiesRenewableEnergyProcurementPlanCarryingChargesAmount
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Public Utilities, Renewable Energy Procurement Plan, Carrying Charges, Percent + References No definition available. + Details
Name: | pnm_PublicUtilitiesRenewableEnergyProcurementPlanCarryingChargesPercent
Namespace Prefix: | pnm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Public Utilities, Renewable Energy Procurement Plan, Proposed Recovery, Amount + References No definition available. + Details
Name: | pnm_PublicUtilitiesRenewableEnergyProcurementPlanProposedRecoveryAmount
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Public Utilities, Renewable Energy Procurement Plan, Requested Additional Megawatt Hours, Year 1 + References No definition available. + Details
Name: | pnm_PublicUtilitiesRenewableEnergyProcurementPlanRequestedAdditionalMegawattHoursYear1
Namespace Prefix: | pnm_
Data Type: | num:energyItemType
Balance Type: | na
Period Type: | instant

X
- Definition Public Utilities, Renewable Energy Procurement Plan, Requested Additional Megawatt Hours, Year 2 + References No definition available. + Details
Name: | pnm_PublicUtilitiesRenewableEnergyProcurementPlanRequestedAdditionalMegawattHoursYear2
Namespace Prefix: | pnm_
Data Type: | num:energyItemType
Balance Type: | na
Period Type: | instant

X
- Definition Public Utilities, Renewable Energy Procurement Plan, Requested Solar Facility Construction, Megawatts + References No definition available. + Details
Name: | pnm_PublicUtilitiesRenewableEnergyProcurementPlanRequestedSolarFacilityConstructionMegawatts
Namespace Prefix: | pnm_
Data Type: | num:powerItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition Public Utilities, Transmission Line And Associated Facilities + References No definition available. + Details
Name: | pnm_PublicUtilitiesTransmissionLineAndAssociatedFacilities
Namespace Prefix: | pnm_
Data Type: | xbrli:integerItemType
Balance Type: | na
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
- Details
Name: | pnm_ScheduleOfRegulatoryRateMattersAxis=pnm_KVTransmissionLineMember
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_RenewablePortfolioStandardMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAgencyAxis=pnm_NMPRCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_PublicUtilityAxis=pnm_NewMexicoWindMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | pnm_ScheduleOfRegulatoryRateMattersAxis=pnm_RenewablePortfolioStandard2014Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilityAxis=pnm_RedMesaWindMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilityAxis=pnm_LaJoyaWindMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilityAxis=pnm_LightningDockGeothermalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |