[Line Items] for Leases, Operating [Table]

No definition available.

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

- Definition

Lessee, Operating Lease, Lease Not Yet Commenced, Fixed Consideration

+ References

No definition available.

+ Details

Name:	pnm_LesseeOperatingLeaseLeaseNotYetCommencedFixedConsideration
Namespace Prefix:	pnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Lessee, Operating Lease, Unguaranteed Residual Value

+ References

No definition available.

+ Details

Name:	pnm_LesseeOperatingLeaseUnguaranteedResidualValue
Namespace Prefix:	pnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Annual lease payments

+ References

No definition available.

+ Details

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

- Definition

Right-Of-Way Lease Payments

+ References

No definition available.

+ Details

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

- Definition

Non-Lease Component, Percent Of Lease Liability

+ References

No definition available.

+ Details

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

- Definition

Operating Lease, Right-Of-Use Asset And Operating Lease Liability Retirement

+ References

No definition available.

+ Details

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

- Definition

Unamortized Cost Of Prepaid Right-Of-Way Agreements

+ References

No definition available.

+ Details

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

- Definition

Term of lessee's operating lease not yet commenced, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-3

+ Details

Name:	us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of residual asset covered by residual value guarantee under operating lease. Excludes guarantee considered to be lease payments for lessor.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479773/842-30-50-3

+ Details

Name:	us-gaap_OperatingLeaseResidualValueOfLeasedAsset
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of periodic reduction over lease term of carrying amount of right-of-use asset from operating lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

+ Details

Name:	us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_EquipmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=pnm_EnergyStorageFacilitiesMember
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_PublicUtilityAxis=pnm_NavajoNationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Lease Commitments - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended			9 Months Ended
	Apr. 30, 2026	Sep. 30, 2026	Mar. 31, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025	Dec. 31, 2025
Leases, Operating [Line Items]
Unamortized cost, right-of-way lease payments		$ 82.1			$ 82.1		$ 69.2
Operating lease, right-of-use asset, amortization expense		$ 1.3		$ 1.1	$ 3.6	$ 3.3
Non-lease component, percent of lease liability		25.50%			25.50%
Lessee, operating lease, unguaranteed residual value		$ 36.9			$ 36.9
Lease to be executed, fixed consideration		$ 94.3			$ 94.3
Lease to be executed, term of contract		20 years			20 years
Equipment
Leases, Operating [Line Items]
Operating lease, residual value of leased asset		$ 0.9			$ 0.9
Energy Storage Facilities
Leases, Operating [Line Items]
Right-of-use asset and operating lease lability, retirement			$ 57.2
Public Service Company of New Mexico
Leases, Operating [Line Items]
Lessee, operating lease, unguaranteed residual value		15.4			15.4
Public Service Company of New Mexico \| Equipment
Leases, Operating [Line Items]
Operating lease, residual value of leased asset		0.5			0.5
Texas-New Mexico Power Company
Leases, Operating [Line Items]
Lessee, operating lease, unguaranteed residual value		21.3			21.3
Texas-New Mexico Power Company \| Equipment
Leases, Operating [Line Items]
Operating lease, residual value of leased asset		$ 0.4			0.4
Navajo Nation \| Public Service Company of New Mexico
Leases, Operating [Line Items]
Annual lease payments					$ 6.0
Right-of-way lease payments	$ 9.1