Energy Efficiency Cost Recovery Factor, Approved Performance Bonus

No definition available.

Name:	pnm_EnergyEfficiencyCostRecoveryFactorApprovedPerformanceBonus
Namespace Prefix:	pnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Energy Efficiency Cost Recovery Factor, Recovery

No definition available.

Name:	pnm_EnergyEfficiencyCostRecoveryFactorRecovery
Namespace Prefix:	pnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Energy Efficiency Cost Recovery Factor, Requested Change Amount

No definition available.

Name:	pnm_EnergyEfficiencyCostRecoveryFactorRequestedChangeAmount
Namespace Prefix:	pnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Energy Efficiency Cost Recovery Factor, Requested Performance Bonus

No definition available.

Name:	pnm_EnergyEfficiencyCostRecoveryFactorRequestedPerformanceBonus
Namespace Prefix:	pnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Public Utilities, Commitments And Contingencies [Line Items]

No definition available.

Name:	pnm_PublicUtilitiesCommitmentsAndContingenciesLineItems
Namespace Prefix:	pnm_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Public Utilities, Recovery Of Base Rate

No definition available.

Name:	pnm_PublicUtilitiesRecoveryOfBaseRate
Namespace Prefix:	pnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Amount of public utility's requested rate increase (decrease) with regulatory agency.

No definition available.

Name:	us-gaap_PublicUtilitiesRequestedRateIncreaseDecreaseAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Name:	dei_LegalEntityAxis=pnm_TexasNewMexicoPowerCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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Regulatory and Rate Matters - TNMP Narrative (Details) - TNMP - USD ($) $ in Millions	Apr. 01, 2024	Sep. 28, 2023	Mar. 01, 2022
Public Utilities, Commitments And Contingencies [Line Items]
Energy efficiency cost recovery, requested change amount			$ 7.3
Energy efficiency cost recovery, requested bonus			$ 1.9
Energy efficiency cost recovery factor, recovery		$ 6.6
Energy efficiency cost recovery factor, approved performance bonus		$ 1.2
Subsequent event
Public Utilities, Commitments And Contingencies [Line Items]
Requested rate increase (decrease)	$ 15.9
Recovery of base rate	$ 207.4