XML 84 R68.htm IDEA: XBRL DOCUMENT v3.21.2

Regulatory and Rate Matters - Transmission Cost of Service Rates (Details) - PUCT - TNMP - USD ($) $ in Millions	Jul. 23, 2021	Mar. 12, 2021	Oct. 07, 2020	Mar. 27, 2020
Public Utilities, General Disclosures [Line Items]
Approved Increase in Rate Base		$ 112.6	$ 10.8	$ 59.2
Annual Increase in Revenue		$ 14.1	$ 2.0	$ 7.8
Subsequent event
Public Utilities, General Disclosures [Line Items]
Approved Increase in Rate Base	$ 41.2
Annual Increase in Revenue	$ 6.3

X

- Definition

Public Utilities, Increase Annual Transmission Service Revenue

+ References

No definition available.

+ Details

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

X

- Definition

Amount of public utility's approved rate increase (decrease) by regulatory agency.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesApprovedRateIncreaseDecreaseAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_PublicUtilitiesGeneralDisclosuresLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_RegulatoryAgencyAxis=pnm_PUCTMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: