XML 166 R136.htm IDEA: XBRL DOCUMENT
v3.20.4

Merger (Details) - Forecast - USD ($) $ / shares in Units, $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2022 | Dec. 31, 2021
Avangrid | Iberdrola, S.A. |  |
Business Acquisition [Line Items] |  |
Noncontrolling interest, ownership percentage by parent |  | 81.50%
Merger Agreement |  |
Business Acquisition [Line Items] |  |
Business combination, cash right per common share (in dollars per share) |  | $ 50.30
Out-of-pocket fees and expenses reimbursement | $ 10.0 |
Merger Agreement | PNMR |  |
Business Acquisition [Line Items] |  |
Termination fees | 130.0 |
Merger Agreement | Avangrid |  |
Business Acquisition [Line Items] |  |
Termination fees | $ 184.0 |

X
- Definition Business Combination, Cash Right Per Common Share + References No definition available. + Details
Name: | pnm_BusinessCombinationCashRightPerCommonShare
Namespace Prefix: | pnm_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Out-of-pocket Fees And Expenses Reimbursement + References No definition available. + Details
Name: | pnm_OutOfPocketFeesAndExpensesReimbursement
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Termination Fees + References No definition available. + Details
Name: | pnm_TerminationFees
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The parent entity's interest in net assets of the subsidiary, expressed as a percentage. + References No definition available. + Details
Name: | us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_OwnershipAxis=pnm_AvangridMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=pnm_MergerAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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