Significant Accounting Policies and Responsibility for Financial Statements (Policies)	6 Months Ended
	Jun. 30, 2015
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 began consolidating Rio Bravo, formerly known as Delta, upon its acquisition on July 17, 2014. PNM also consolidates the PVNGS Capital Trust and Valencia. 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 shared services’ administrative and general expenses, which represent costs that are primarily driven by corporate level activities, are charged to the business segments at cost. Other significant intercompany transactions between PNMR, PNM, and TNMP include interest and income tax sharing payments, as well as equity transactions. All intercompany transactions and balances have been eliminated. See Note 14.
Dividends on Common Stock	Dividends on Common Stock Dividends on PNMR’s common stock are declared by its Board. The timing of the declaration of dividends is dependent on the timing of meetings and other actions of the Board. This has historically resulted in dividends considered to be attributable to the second quarter of each year being declared through actions of the Board during the third quarter of the year.
New Accounting Pronouncements	New Accounting Pronouncements Information concerning recently issued accounting pronouncements that have not been adopted by the Company is presented below. Accounting Standards Update 2014-09 – Revenue from Contracts with Customers (Topic 606) On May 28, 2014, the FASB issued ASU No. 2014-09. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The ASU will replace most existing revenue recognition guidance in GAAP when it becomes effective. The new standard was to be effective for the Company beginning on January 1, 2017. Early adoption is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. On July 9, 2015, the FASB approved a one-year deferral in the effective date of ASU 2014-09, with early adoption as of the original effective date permitted. The Company is analyzing the impacts this new standard will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting. Accounting Standards Update 2014-15 – Presentation of Financial Statements – Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern On August 27, 2014, the FASB issued ASU No. 2014-15, which requires management to evaluate whether there is substantial doubt about a company’s ability to continue as a going concern in connection with the preparation of financial statements for each annual and interim reporting period. Disclosure requirements associated with management’s evaluation are also outlined in the new guidance. The new standard is effective for the Company for reporting periods ending after December 15, 2016, with early adoption permitted. The Company is analyzing the impacts of this new standard. Accounting Standards Update 2015-03 - Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs On April 7, 2015, the FASB issued ASU No. 2015-03, which requires that issuance costs related to a recognized debt liability be presented in the balance sheet as a direct reduction of the carrying amount of that debt and not as an asset. The ASU is effective for the Company for reporting periods beginning after December 15, 2015, with early adoption permitted. The Company is evaluating the impacts of the ASU. Currently, unamortized debt issuance costs that would be reclassified are included in other deferred charges on the Condensed Consolidated Balance Sheets and, at June 30, 2015, amounted to $11.8 million for PNMR, $7.5 million for PNM, and $4.2 million for TNMP. Accounting Standards Update 2015-07 - Fair Value Measurement (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent) On May 1, 2015, the FASB issued ASU No. 2015-07, which removes the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share practical expedient. The new standard is effective for reporting periods beginning after December 31, 2016, with early adoption permitted. Once adopted, the update is required to be applied on a retrospective basis for all periods presented. The Company is in the process of analyzing this new standard; however, it is not expected to have a material impact on the financial statements other than the disclosure and presentation of certain investments of the Company’s employee benefit plans that are measured using the net asset value practical expedient.
Consolidation, Variable Interest Entity	GAAP determines how an enterprise evaluates and accounts for its involvement with variable interest entities, focusing primarily on whether the enterprise has the power to direct the activities that most significantly impact the economic performance of a variable interest entity. GAAP also requires continual reassessment of the primary beneficiary of a variable interest entity.

Disclosure of accounting policy for consolidation to describe the significant judgments and assumptions made in determining whether a variable interest held by the entity requires the variable interest entity to be consolidated and (or) disclose information about its involvement with the variable interest entity; the methodology used by the entity for determining whether or not it is the primary beneficiary of the variable interest entity; and the significant factors considered and judgments made in determining that the power to direct the activities that significantly impact the economic performance of the variable interest entity are shared (as defined).