Convertible Debt Exchanged in Private Placement, Principal Amount

No definition available.

Name:	pnm_ConvertibleDebtExchangedInPrivatePlacementPrincipalAmount
Namespace Prefix:	pnm_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- 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/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482662/260-10-50-1

+ Details

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

- Definition

Maximum number of shares that could be issued to settle forward contract indexed to equity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480237/815-40-50-5

+ Details

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

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=pnm_TXNM2025ATMProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=pnm_TXNM2024ATMProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Earnings Per Share - Narrative (Details) - shares		3 Months Ended		9 Months Ended
Earnings Per Share - Narrative (Details) - shares	May 27, 2025	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Initial forward price (in shares)			2,196,926	3,542,377
Common stock in private placement (in shares)		11,600,000		11,600,000
TXNM 2025 ATM Program
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Initial forward price (in shares)		3,500,000		3,500,000
TXNM 2024 ATM Program
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Initial forward price (in shares)	1,104,641	1,100,000		1,100,000