Asset Retirement Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Asset Retirement Obligations [Line Items]
ARO liabilities related to nuclear decommissioning (as a percent)	75.70%
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance	$ 245,531	$ 223,377	$ 234,146
Liabilities incurred	0	0	0
Liabilities settled	(12,451)	(3,482)	0
Accretion expense	11,538	10,218	10,767
Revisions to estimated cash flows	0	15,418	(21,536)
Ending balance	244,618	245,531	223,377
San Juan Generating Station
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Revisions to estimated cash flows			(21,500)
PVNGS (Nuclear)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Revisions to estimated cash flows		15,400
PNM
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance	244,633	222,549	233,383
Liabilities incurred	0	0	0
Liabilities settled	(12,432)	(3,482)	0
Accretion expense	11,462	10,148	10,702
Revisions to estimated cash flows	0	15,418	(21,536)
Ending balance	243,663	244,633	222,549
TNMP
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance	898	828	763
Liabilities incurred	0	0	0
Liabilities settled	(19)	0	0
Accretion expense	76	70	65
Revisions to estimated cash flows	0	0	0
Ending balance	$ 955	$ 898	$ 828

Asset Retirement Obligation, Liabilities Related To Nuclear Decommissioning

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- Definition

Asset Retirement Obligations [Line Items]

+ References

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- Definition

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 410
-SubTopic 20
-Name Accounting Standards Codification
-Section 25
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481999/410-20-25-4

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 410
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481850/410-20-50-1

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- Definition

Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 410
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481879/410-20-45-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 410
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481850/410-20-50-1

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- Definition

Amount of asset retirement obligations incurred during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 410
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481850/410-20-50-1

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- Definition

Amount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 410
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481850/410-20-50-1

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- Definition

Amount of increase (decrease) in the asset retirement obligation from changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 410
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481850/410-20-50-1

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

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