Significant Accounting Policies and Responsibility for Financial Statements (Policies)	6 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The Condensed Consolidated Financial Statements of each of PNMR, PNM, and TNMP include their accounts and those of subsidiaries in which that entity owns a majority voting interest. PNM also consolidates Valencia and ETBC I. See Note 6. PNM owns undivided interests in several jointly-owned power plants and records its pro-rata share of the assets, liabilities, and expenses for those plants. The agreements for the jointly-owned plants provide that if an owner were to default on its payment obligations, the non-defaulting owners would be responsible for their proportionate share of the obligations of the defaulting owner. In exchange, the non-defaulting owners would be entitled to their proportionate share of the generating capacity of the defaulting owner. There have been no such payment defaults under any of the agreements for the jointly-owned plants. PNMR Services Company expenses, which represent costs that are primarily driven by corporate level activities, are charged to the business segments. These services are billed at cost and are reflected as general and administrative expenses in the business segments. Other significant intercompany transactions between PNMR, PNM, and TNMP include interest and income tax sharing payments, as well as equity transactions, and interconnection billings. See Note 15. All intercompany transactions and balances have been eliminated.
New Accounting Pronouncements	New Accounting Pronouncements Information concerning recently issued accounting pronouncements that have not yet been adopted by the Company is presented below. The Company does not expect difficulty in adopting these standards by their required effective dates. Accounting Standards Update 2023-07 - Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures In November 2023, the FASB issued ASU 2023-07 enhancing disclosures about significant segment expenses. Disclosure requirements of this update include disclosure, on an annual and interim basis, of significant segment expenses that are regularly provided to the Chief Operating Decision Maker (“CODM”) and included within each reported measure of segment profit or loss (collectively referred to as the “significant expense principle”); an amount for other segment items by reportable segment and a description of its composition; the title and position of the CODM and an explanation of how the CODM uses the reported measures in assessing segment performance and deciding how to allocate resources; and that a single reportable segment provides all the disclosures required by the amendments in this ASU and all existing segment disclosures in Topic 280. The amendment also clarifies that in addition to the measure most consistent with the measurement principles under GAAP, reporting of additional measures of a segment’s profit or loss used by the CODM in assessing segment performance and determining allocation of resources is allowed. ASU 2023-07 is effective for the Company for annual periods beginning January 1, 2024 and interim periods beginning January 1, 2025 with early adoption being permitted. ASU 2023-07 is to be applied retrospectively to all prior periods presented in the financial statements. Accounting Standards Update 2023-09 - Income Taxes (Topic 740): Improvements to Income Tax Disclosures In December 2023, the FASB issued ASU 2023-09 enhancing the transparency and decision usefulness of income tax disclosures. Disclosure requirements of this update include (on an annual basis) the disclosure of specific categories in the rate reconciliation and the inclusion of additional information for reconciling items that meet a quantitative threshold (if the effect of the reconciling item is equal to or greater than 5 percent of the amount computed by multiplying pre-tax income by the applicable statutory rate). The amendment also requires the disclosure (on an annual basis) of information about income taxes paid (net of refunds) including the disaggregation by federal, state, and foreign taxes as well as by individual jurisdiction. Additional requirements include the disclosure of income (loss) from continuing operations before income tax expense (benefit) disaggregated between foreign and domestic as well as income tax expense (benefit) from continuing operations disaggregated by federal, state, and foreign. ASU 2023-09 is effective for the Company beginning January 1, 2025 with early adoption being permitted. ASU 2023-09 is to be applied on a prospective basis with retrospective application permitted.