Debt Instrument, Convertible Notes, Conversion Premium Percent

No definition available.

Name:	pnm_DebtInstrumentConvertibleNotesConversionPremiumPercent
Namespace Prefix:	pnm_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Covenant, Debt To Capitalization Ratio

+ References

No definition available.

+ Details

Name:	pnm_DebtInstrumentCovenantDebtToCapitalizationRatio
Namespace Prefix:	pnm_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Interest Payments, Number Of Deferral Payments Allowed

+ References

No definition available.

+ Details

Name:	pnm_DebtInstrumentInterestPaymentsNumberOfDeferralPaymentsAllowed
Namespace Prefix:	pnm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Number Of Debt Issuances

+ References

No definition available.

+ Details

Name:	pnm_DebtInstrumentNumberOfDebtIssuances
Namespace Prefix:	pnm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Series Of Bond Issuance

+ References

No definition available.

+ Details

Name:	pnm_DebtInstrumentSeriesOfBondIssuance
Namespace Prefix:	pnm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Public Utilities, Maturity Term Over Which Financings Require Regulator Approval

+ References

No definition available.

+ Details

Name:	pnm_PublicUtilitiesMaturityTermOverWhichFinancingsRequireRegulatorApproval
Namespace Prefix:	pnm_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Sale Of Stock, Distribution Agreement, Aggregate Value

+ References

No definition available.

+ Details

Name:	pnm_SaleOfStockDistributionAgreementAggregateValue
Namespace Prefix:	pnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The price per share of the conversion feature embedded in the debt instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-5

+ Details

Name:	us-gaap_DebtInstrumentConvertibleConversionPrice1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22)(a)(5))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-3

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-7

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-6

+ Details

Name:	us-gaap_DebtInstrumentConvertibleConversionRatio1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instrument must exceed threshold percentage for specified number of trading days to trigger conversion feature.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum percentage of common stock price to conversion price of convertible debt instruments to determine eligibility of conversion.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Threshold number of specified trading days that common stock price to conversion price of convertible debt instruments must exceed threshold percentage within a specified consecutive trading period to trigger conversion feature.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentConvertibleThresholdTradingDays
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- 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

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482949/835-30-55-8

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(f))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-3

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69B

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69C
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69C

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69E
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69E

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69F
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69F

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 11: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1D
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1D
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1D
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1E

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1E

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1E

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1F

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1F

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1F

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1F

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1I

Reference 26: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482925/835-30-45-2

Reference 27: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482900/835-30-50-1

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 470
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477734/942-470-50-3

+ Details

Name:	us-gaap_DebtInstrumentRedemptionPricePercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The effective interest rate at the end of the reporting period.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-SubTopic 10
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482949/835-30-55-8

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69B

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69C
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69C

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1D
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16)(a)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-4

+ Details

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of cash outflow for short-term and long-term debt. Excludes payment of lease obligation.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 15
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-15

+ Details

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

- Definition

The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 15
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-15

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479886/946-10-S99-3

+ Details

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

- Definition

The cash outflow to repay long-term debt that is not secured by collateral. Excludes repayments of tax exempt unsecured debt.

+ References

+ Details

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

- Definition

The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

+ References

No definition available.

+ Details

Name:	us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

+ References

No definition available.

+ Details

Name:	us-gaap_SaleOfStockPricePerShare
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=pnm_AtTheMarketMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=pnm_A2024ForwardSaleAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_FMBNotesDueJulyTwentyTwentyFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShortTermDebtTypeAxis=pnm_SeniorUnsecuredNotedPollutionControlRevenueBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_TXNM2021DelayedDrawTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_TXNM2023TermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_PNM2024TermLoanDueNovemberTwentyTwentyFiveMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_PNMSeniorUnsecuredNotesExpiresMayTwentyTwentySixMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_PNMThreePointOneFiveSeniorUnsecuredNotesDueMayTwentyTwentyThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_PNM2023NotePurchaseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_PNM2023SUNsAtFivePointFiveOnePercentDueApril282035Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_PNM2023SUNsAtFivePointNinetyTwoPercentDueApril282053Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_TNMP2024BondPurchaseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_TNMP2024BondAtFivePointTwoSixPercentDueMarch282029Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_TNMP2024BondAtFivePointFiveFivePercentDueMarch282036Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_TNMP2024BondAtFivePointSixFivePercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_TNMP2024BondAtFivePointSevenNinePercentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_ConvertibleDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_FivePointSevenFivePercentConvertibleNotesDueJuneTwentyFiftyFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	pnm_DebtInstrumentConvertibleTermsOfConversionAxis=pnm_DebtConversionTermsOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	pnm_DebtInstrumentConvertibleTermsOfConversionAxis=pnm_DebtConversionTermsTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_FivePointSevenFivePercentConvertibleNotesDueJuneTwentyFiftyFourOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_NotesPayableOtherPayablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_PollutionControlRevenueBondsOnePointOnePercentDueTwentyFortyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_PollutionControlRevenueBondsThreePointNineZeroPercentDueTwentyTwentyEightMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_TXNM2023DelayedDrawTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_ThreePointZeroZeroPercentPollutionControlRevenueBondsDueJuneTwentyThirtyEightMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_OnePointOneFivePercentPollutionControlRevenueBondsDueJuneTwentyThirtyEightMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_PollutionControlRevenueBondsDueJuneTwentyTwentyFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_PollutionControlRevenueBondsDueJuneTwentyTwentyNIneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_TNMP2023BondPurchaseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_TNMP2023BondPurchaseAgreementAtFivePointZeroOnePercentDueApril282033Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=pnm_TNMP2023BondPurchaseAgreementAtFivePointFortySevenPercentDueJuly282053Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Financing - Financing Activities (Details)								1 Months Ended	3 Months Ended		9 Months Ended
Financing - Financing Activities (Details)	Aug. 05, 2024 USD ($)	Jun. 21, 2024 USD ($)	Jun. 10, 2024 USD ($) d deferralPayment $ / shares	Jun. 04, 2024	May 06, 2024 USD ($)	May 15, 2023 USD ($)	Nov. 10, 2022 USD ($)	Jul. 31, 2024 USD ($)	Sep. 30, 2024 USD ($) $ / shares shares	Jun. 30, 2024 $ / shares shares	Sep. 30, 2024 USD ($) $ / shares	Sep. 30, 2023 USD ($)	Jul. 01, 2024 USD ($)	Jun. 03, 2024 USD ($)	May 10, 2024 USD ($)	Mar. 28, 2024 USD ($) debtInstrument	Dec. 31, 2023 USD ($)	Jun. 30, 2023 USD ($)	Jun. 01, 2023 USD ($)	May 16, 2023 USD ($)	Apr. 28, 2023 USD ($) bond debtInstrument	Dec. 31, 2022 USD ($)
Debt Instrument [Line Items]
Repayments of long-term debt											$ 819,529,000	$ 685,000,000
At-The-Market
Debt Instrument [Line Items]
Distribution agreement	$ 300,000,000				$ 100,000,000		$ 200,000,000
2024 Forward Sale Agreements
Debt Instrument [Line Items]
Number of shares issued in transaction (in shares) \| shares									2,196,926	262,025
Sale of stock, price per share (in dollars per share) \| $ / shares									$ 40.58	$ 37.77	$ 40.58
PNM
Debt Instrument [Line Items]
Maturity term over which financings require regulator approval (more than)											18 months
Repayments of long-term debt											$ 200,529,000	185,000,000
Texas-New Mexico Power Company
Debt Instrument [Line Items]
Repayments of long-term debt											$ 80,000,000	$ 0
Texas-New Mexico Power Company \| FMB Notes Due July 2024 \| Senior Unsecured Noted, Pollution Control Revenue Bonds
Debt Instrument [Line Items]
Stated interest rate								4.03%
Repayments of unsecured debt								$ 80,000,000
Line of credit
Debt Instrument [Line Items]
Ratio of debt to capital (less than or equal to)											70.00%
Line of credit \| TXNM 2021 Delayed Draw Term Loan \| Revolving credit facility
Debt Instrument [Line Items]
Repayments of debt		$ 449,000,000
Line of credit \| TXNM 2023 Term Loan \| Revolving credit facility
Debt Instrument [Line Items]
Repayments of debt		90,000,000
Line of credit \| PNM and TNMP
Debt Instrument [Line Items]
Ratio of debt to capital (less than or equal to)											65.00%
Line of credit \| PNM \| PNM 2024 Term Loan, Due November 2025 \| Secured Debt
Debt Instrument [Line Items]
Aggregate principal amount															$ 200,000,000
Variable interest rate									6.11%		6.11%
Unsecured Debt \| PNM, Due May 2026
Debt Instrument [Line Items]
Aggregate principal amount																				$ 650,000,000
Unsecured Debt \| PNM 3.15% Senior Unsecured Notes, Due May 2023
Debt Instrument [Line Items]
Stated interest rate																						3.15%
Repayments of long-term debt						$ 55,000,000
Unsecured Debt \| PNM \| PNM 3.15% Senior Unsecured Notes, Due May 2023
Debt Instrument [Line Items]
Aggregate principal amount																						$ 55,000,000
Unsecured Debt \| PNM \| PNM 2023 Note Purchase Agreement
Debt Instrument [Line Items]
Aggregate principal amount																					$ 200,000,000
Number of debt issuances \| debtInstrument																					2
Unsecured Debt \| PNM \| PNM 2023 SUNs At 5.1%, Due April 28, 2035
Debt Instrument [Line Items]
Aggregate principal amount																					$ 150,000,000.0
Stated interest rate																					5.51%
Unsecured Debt \| PNM \| PNM 2023 SUNs At 5.92%, Due April 28, 2053
Debt Instrument [Line Items]
Aggregate principal amount																					$ 50,000,000
Stated interest rate																					5.92%
Unsecured Debt \| Texas-New Mexico Power Company \| TNMP 2024 Bond Purchase Agreement
Debt Instrument [Line Items]
Aggregate principal amount																$ 285,000,000
Number of debt issuances \| debtInstrument																4
Unsecured Debt \| Texas-New Mexico Power Company \| TNMP 2024 Bond, 5.26%, Due March 28, 2029
Debt Instrument [Line Items]
Aggregate principal amount																$ 32,000,000
Stated interest rate																5.26%
Unsecured Debt \| Texas-New Mexico Power Company \| TNMP 2024 Bond, 5.55%, Due March 28, 2036
Debt Instrument [Line Items]
Aggregate principal amount																$ 85,000,000
Stated interest rate																5.55%
Unsecured Debt \| Texas-New Mexico Power Company \| TNMP 2024 Bond, 5.65%
Debt Instrument [Line Items]
Aggregate principal amount													$ 40,000,000
Stated interest rate													5.65%
Unsecured Debt \| Texas-New Mexico Power Company \| TNMP 2024 Bond, 5.79%
Debt Instrument [Line Items]
Aggregate principal amount													$ 128,000,000
Stated interest rate													5.79%
Convertible Debt \| Convertible Notes
Debt Instrument [Line Items]
Aggregate principal amount			$ 500,000,000
Stated interest rate			5.75%
Conversion ratio				0.0224911
Debt instrument, convertible, conversion price (in dollars per share) \| $ / shares			$ 44.46
Conversion premium percent				17.50%
Number of deferral payments allowed \| deferralPayment			20
Convertible Debt \| Convertible Notes \| Debt Conversion Terms One
Debt Instrument [Line Items]
Debt instrument, redemption price, percentage			100.00%
Convertible Debt \| Convertible Notes \| Debt Conversion Terms Two
Debt Instrument [Line Items]
Debt instrument, redemption price, percentage			100.00%
Threshold percentage of stock price trigger			130.00%
Threshold trading days \| d			20
Threshold consecutive trading days \| d			30
Convertible Debt \| Convertible Notes - Option
Debt Instrument [Line Items]
Aggregate principal amount		$ 50,000,000
Bonds \| PNM 2024 Term Loan, Due November 2025
Debt Instrument [Line Items]
Variable interest rate									6.11%		6.11%
Bonds \| TXNM 2021 Delayed Draw Term Loan
Debt Instrument [Line Items]
Long-term debt									$ 51,000,000		$ 51,000,000
Variable interest rate									5.90%		5.90%
Bonds \| PCRB 1.10%, Due June 2040
Debt Instrument [Line Items]
Aggregate principal amount																						$ 130,000,000
Stated interest rate																						1.10%
Bonds \| PCRB 3.90%, Due June 2028
Debt Instrument [Line Items]
Aggregate principal amount																			$ 130,000,000
Stated interest rate																			3.90%
Bonds \| TXNM 2023 Delayed-Draw Term Loan
Debt Instrument [Line Items]
Variable interest rate									6.30%		6.30%
Bonds \| PNM \| 3.00% Pollution Control Revenue Bonds Due June 2038
Debt Instrument [Line Items]
Aggregate principal amount																	$ 37,000,000
Stated interest rate																	3.00%
Bonds \| PNM \| 1.15% Pollution Control Revenue Bonds Due June 2038
Debt Instrument [Line Items]
Aggregate principal amount																	$ 125,000,000
Stated interest rate																	1.15%
Bonds \| PNM \| Pollution Control Revenue Bonds Due June 2024
Debt Instrument [Line Items]
Aggregate principal amount																	$ 36,000,000
Stated interest rate																	3.00%
Bonds \| PNM \| Pollution Control Revenue Bonds Due June 2029
Debt Instrument [Line Items]
Aggregate principal amount														$ 198,000,000
Stated interest rate														3.875%
Secured Debt \| TXNM 2023 Term Loan
Debt Instrument [Line Items]
Aggregate principal amount																		$ 500,000,000
Long-term debt									$ 410,000,000		$ 410,000,000
Variable rate											6.30%
Secured Debt \| Texas-New Mexico Power Company \| TNMP 2023 Bond Purchase Agreement
Debt Instrument [Line Items]
Aggregate principal amount																					$ 185,000,000
Debt instrument, series of bond issuance \| bond																					2
Secured Debt \| Texas-New Mexico Power Company \| TNMP 2023 Bond Purchase Agreement At 5.01%, Due April 28, 2033
Debt Instrument [Line Items]
Aggregate principal amount																					$ 130,000,000.0
Stated interest rate																					5.01%
Secured Debt \| Texas-New Mexico Power Company \| TNMP 2023 Bond Purchase Agreement At 5.47%, Due July 28, 2053
Debt Instrument [Line Items]
Aggregate principal amount																					$ 55,000,000.0
Stated interest rate																					5.47%