Regulatory and Rate Matters (Details) (USD $)	12 Months Ended				1 Months Ended		3 Months Ended																			12 Months Ended	3 Months Ended				0 Months Ended	3 Months Ended		12 Months Ended			12 Months Ended				3 Months Ended	12 Months Ended			0 Months Ended	3 Months Ended	12 Months Ended		1 Months Ended	0 Months Ended		12 Months Ended	0 Months Ended		12 Months Ended							1 Months Ended				0 Months Ended	1 Months Ended	12 Months Ended				12 Months Ended	1 Months Ended				0 Months Ended	12 Months Ended				1 Months Ended
	Dec. 31, 2013 Renewable Portfolio Standard [Member]	Aug. 11, 2011 2010 Rate Case [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Emergency FPPAC [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] La Luz Generating Station [Member] MW	Dec. 31, 2011 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member]	Aug. 31, 2010 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] mw	Dec. 31, 2013 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] MW	Mar. 31, 2013 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member]	Jan. 31, 2014 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] MW	Dec. 31, 2012 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] Minimum [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] Minimum [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] Maximum [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] Maximum [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] Wind Energy [Member] Minimum [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] Wind Energy [Member] Minimum [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] Solar Energy [Member] Minimum [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] Solar Energy [Member] Minimum [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] Renewable Technologies [Member] Minimum [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] Renewable Technologies [Member] Minimum [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] Distributed Generation [Member] Minimum [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] Distributed Generation [Member] Minimum [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] Required Percentage by 2011 [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] Required Percentage by 2015 [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Renewable Portfolio Standard [Member] Required Percentage by 2020 [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] 2014 Wind generated Renewable Energy Credits [Member] MWh	Dec. 31, 2013 Public Service Company of New Mexico [Member] Renewable Portfolio Standard Supplemental Procurement [Member] MW	Dec. 31, 2013 Public Service Company of New Mexico [Member] Renewable Portfolio Standard Supplemental Procurement Reduction [Member] MW	Dec. 31, 2013 Public Service Company of New Mexico [Member] Renewable Portfolio Standard Supplemental Procurement Reduction [Member] Maximum [Member] MW	Jun. 30, 2011 Public Service Company of New Mexico [Member] Energy Efficient and Load Management [Member] Program Costs [Member]	Oct. 05, 2012 Public Service Company of New Mexico [Member] Energy Efficient and Load Management [Member] Disincentives / Incentives Adder [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Energy Efficient and Load Management [Member] Disincentives / Incentives Adder [Member]	Aug. 11, 2011 Public Service Company of New Mexico [Member] Energy Efficient and Load Management [Member] Disincentives / Incentives Adder [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member] 2010 Electric Rate Case [Member]	Aug. 21, 2011 Public Service Company of New Mexico [Member] 2010 Electric Rate Case [Member]	May 31, 2010 Public Service Company of New Mexico [Member] 2010 Electric Rate Case [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member] 2010 Electric Rate Case [Member] Fuel [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] FPPAC Continuation Application [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Electric Rate Case [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Electric Rate Case [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Renewable Energy Rider [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Renewable Energy Rider [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Renewable Energy Rider [Member] Maximum [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Renewable Energy Rider [Member] Maximum [Member]	Aug. 20, 2011 Public Service Company of New Mexico [Member] Nmprc Rulemaking on Disincentives to Energy Efficiency Programs [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Nmprc Rulemaking on Disincentives to Energy Efficiency Programs [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Nmprc Rulemaking on Disincentives to Energy Efficiency Programs [Member]	Nov. 29, 2010 Public Service Company of New Mexico [Member] Nmprc Rulemaking on Disincentives to Energy Efficiency Programs [Member]	Jul. 31, 2011 Public Service Company of New Mexico [Member] 2011 Integrated Resource Plan [Member] Protests_Filed	Jul. 03, 2012 Public Service Company of New Mexico [Member] Transmission Rate Case [Member]	Oct. 27, 2010 Public Service Company of New Mexico [Member] Transmission Rate Case [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Formula Transmission Rate Case [Member]	Dec. 06, 2012 Public Service Company of New Mexico [Member] Firm Requirements Wholesale Power Rate Case [Member]	Sep. 15, 2011 Public Service Company of New Mexico [Member] Firm Requirements Wholesale Power Rate Case [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] City of Gallup, New Mexico Contract [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Renewable Portfolio Standard 2014 [Member] MW	Dec. 31, 2013 Public Service Company of New Mexico [Member] 2015 Wind generated Renewable Energy Credits [Member] MWh	Dec. 31, 2012 Texas-New Mexico Power Company [Member] Interest Rate Compliance Tariff [Member]	Jan. 31, 2008 Texas-New Mexico Power Company [Member] Interest Rate Compliance Tariff [Member]	Jan. 27, 2011 Texas-New Mexico Power Company [Member] 2010 Rate Case [Member]	Aug. 26, 2010 Texas-New Mexico Power Company [Member] 2010 Rate Case [Member]	Jun. 30, 2012 Texas-New Mexico Power Company [Member] Ercot Transmission Rates [Member]	Jun. 30, 2012 Texas-New Mexico Power Company [Member] Ercot Transmission Rates [Member] PUCT staff agreed to interim rate relief that will permit TNMP to add uncontested costs to its existing TCRF [Member]	Jun. 30, 2012 Texas-New Mexico Power Company [Member] Ercot Transmission Rates [Member] Permited to add costs in a subsequent TCRF if TNMP is successful in contested case [Member]	May 26, 2011 Texas-New Mexico Power Company [Member] 2010 Rate Case Expense Proceeding [Member]	Aug. 28, 2012 Texas-New Mexico Power Company [Member] Energy Efficiency [Member]	Sep. 30, 2011 Texas-New Mexico Power Company [Member] Energy Efficiency [Member]	Dec. 31, 2011 Texas-New Mexico Power Company [Member] Energy Efficiency [Member]	Dec. 31, 2013 Texas-New Mexico Power Company [Member] Energy Efficiency [Member]	Dec. 31, 2012 Texas-New Mexico Power Company [Member] Energy Efficiency [Member]	Sep. 30, 2012 Texas-New Mexico Power Company [Member] Energy Efficiency [Member]	Dec. 31, 2013 Texas-New Mexico Power Company [Member] August 2013 Transmission Rate Filings [Member]	Jul. 31, 2011 Texas-New Mexico Power Company [Member] Advanced Meter System Deployment and Surcharge Request [Member]	Dec. 31, 2013 Texas-New Mexico Power Company [Member] Advanced Meter System Deployment and Surcharge Request [Member]	Dec. 31, 2013 Texas-New Mexico Power Company [Member] Advanced Meter System Deployment and Surcharge Request [Member] Minimum [Member]	Dec. 31, 2013 Texas-New Mexico Power Company [Member] Advanced Meter System Deployment and Surcharge Request [Member] Maximum [Member]	Aug. 23, 2012 Texas-New Mexico Power Company [Member] Transmission Cost of Service Rates [Member]	Dec. 31, 2013 Texas-New Mexico Power Company [Member] January 2014 Transmission Rate Filings [Member]	Dec. 31, 2013 Delta [Member] Public Service Company of New Mexico [Member] Applications for Approvals to Purchase Delta [Member] MW	Dec. 31, 2013 San Juan Generating Station Unit 4 [Member] Public Service Company of New Mexico [Member] Clean Air Act, SNCR [Member] MW	Jan. 02, 2013 Subsequent Event [Member] Public Service Company of New Mexico [Member] Formula Transmission Rate Case [Member]	Jan. 31, 2013 Subsequent Event [Member] Texas-New Mexico Power Company [Member] Transmission Rate Filings [Member]	Jan. 06, 2014 Navajo Nation Allottee Matters [Member] Public Service Company of New Mexico [Member]
Rate Matters [Line Items]
Public Utilities, Expected Rate Increase Over Previously Approved Rates																																																				$ 1,300,000
Number of allotment parcels' appraisal requested for review																																																																																			58
Public Utilities, Required Percentage of Renewable Energy in Portfolio to Electric Sales																							10.00%	15.00%	20.00%
Public Utilities, Required Percentage of Diversification															30.00%	20.00%	20.00%	20.00%	5.00%	10.00%	1.50%	1.50%
Public Utilities, Reasonable Cost Threshold											3.00%	2.00%	3.00%	3.00%
Public Utilities, Annual Incremental Increase in Reasonable Cost Threshold										0.25%
Public Utilities, Procurement of Energy, Nonmonetary						22
Public Utilities, Actual Regulatory Costs for Solar PV Facilities and Demonstration Project	95,000,000
Public Utilites, Additional Renewable Procurements Spending Required by NMPRC					900,000
Public Utilities, Number of Mega Watts of Solar Photovoltaic Capacity							20																				2	1.5	2																											23
Public Utilities, Estimated Cost of Mega Watts of Solar Photovoltaic Capacity							45,500,000																				4,500,000																													46,700,000
Public Utilities, Number of Mega Watts of Geothermal Capacity							10
Public Utilities, Final Cost of Solar Photovoltaic Capacity								48,900,000
Public Utilities, Number of Mega Watts of Solar Photovoltaic Capacity, Current Output									4
Public Utilities, Number of Mega Watts of Solar Photovoltaic Capacity, Expected Output									10
Public Utilities, Number of Mega Watt Hours of Wind Generation																										50,000																															120,000
Public Utilities, Wind Capacity Planned Purchase Agreement Term																																																								20 years
Public Utilities, Number of Mega Watts of Wind Energy Capacity																																																								102
Public Utilities, First Year Cost of Wind Capacity Planned Purchase Agreement																																																								5,800,000.0
Public Utilities, Approved Rider Rate For 2012																																									0.0022335
Public Utilities, Approved Rider Rate For 2013																																									0.0028371
Public Utilities, Order Disapproved Recovery of Costs As Regulatory Agency Had Not Acted on Specific Procurements Proposed																																									900,000
Public Utilities, Additional Revenue To be Collected in 2012																																												18,000,000
Public Utilities, Additional Revenue To be Collected in 2013																																											24,600,000
Public Utilities, Rider Condition of Earned Return on Jurisdictional Equity in 2013																																											10.50%
Public Utilities, Rate Rider to be Implemented																														17,100,000											0.0030468	0.0030468
Public Utilities, Requested Rider Rate For 2014																																										0.0044391
Public Utilities, Rate Rider Recovered																																													2,600,000	2,600,000
Public Utilities, Program Costs Related To Energy Efficiency																															22,500,000
Public Utilities, Proposed Profit Incentive Adder Revenues Related To Energy Efficiency Program																															4,200,000	2,900,000
Public Utilities, Approved Profit Incentive Adder Revenues Related To Energy Efficiency Program																																1,700,000
Public Utilities, Regulatory Costs Approved																																																4,200,000												10,250,000					2,800,000																2,900,000
Public Utilities, Lease ownership percentage in EIP																																																				60.00%
Public Utilities, Eliminated Recovery of Adder Revenue		1,600,000																															1,300,000
Public Utilities, Rate Rider Net Over-Recovery																																															200,000
Public Utilities, Rate Rider Program Costs Over-Recovery																																															1,000,000
Public Utilities, Rate Rider Incentives Under-Recovery																																															800,000
Public Utilities, Rate Rider Estimated Incentives Under-Recovery																																														500,000	500,000
Amount of Regulatory Costs Not yet Approved			8,000,000																																	165,200,000															11,100,000	3,200,000		8,700,000							20,100,000
Public Utilities, Regulatory Rate Recommended For Recovery																																			72,100,000
Public Utilities, Regulatory Costs to be Collected																																							36,200,000	38,800,000
Public Utilities, Regulatory Costs Incurred and Eligible For Recovery, Amount Deferred for Collection in Future Period																																							48,600,000
Public Utilities, Pre-Tax Loss Not to be Recovered																																		7,500,000			10,000,000
Public Utilities, Retention Percentage of Sales Margins																																						10.00%
Public Utilities, Under-collected balance write-off																																						10,500,000
Public Utilities, Planning Period Covered of IRP																																																	20 years
Public Utilities, Number of protests that were filed to IRP requesting rejection of the plan																																																	2
Public Utilites, Number of Mega Watts Natural Gas Peaking Units to be Purchased																																																																															132
Public Utilities, Number of Mega Watts of Gas-fired Generation				40
Estimated Installation Capital Costs				63,200,000
Public Utilities, Rate Base Value				56,000,000
Public Utilities, Additional Ownership To Be Obtained, in Megawatts																																																																																78
Public Utilities, Return on Equity																																																			12.25%	10.81%								10.125%
Public Utilities, Increase Annual Transmission Service Revenue																																																		2,900,000																											2,500,000
Public Utilities, Regulatory Rate Increase																																																						39.80%
Public Utilities, Total Revenue Requirement Increase																																																					5,300,000																			2,800,000						2,900,000				2,900,000
Public Utilities, Contract Extension																																																					10 years
Public Utilities, Estimated Increase in Revenue over amendment term																																																							3,100,000
Public Utilities, Revenue For Power Sold Under Specific Contract																																																							11,700,000
Public Utilities, Proposed Rate																																																											0.0831
Public Utilities, Regulatory Disallowance Before Income Taxes																																																										3,900,000
Public Utitlities, Debt to Equity Capital Structure, Debt																																																												0.55
Public Utilities, Debt to Equity Capital Structure, Equity																																																												0.45
Public Utilities, Approved Deployment Costs																																																																									113,300,000
Public Utilities, Collection of Deployment Costs Through Surcharge Period																																																																									12 years
Public Utilities, Completion Period of Advanced Meter Deployment																																																																									5 years
Public Utilities, Non-standard metering service cost total to be borne by opt-out customers																																																																										0
Public Utilities, Non-standard metering service cost initial fee range																																																																											142.84	247.48
Public Utilities, Non-standard metering ongoing expenses total to be borne by opt-out customers																																																																										500,000
Public Utilities, Non-standard metering ongoing expenses monthly charge																																																																										38.99
Gain Contingency, Additional Transmission Costs Requested																																																														3,200,000	1,600,000	1,600,000
Public Utilities, Approved Program Implementation Costs																																																																		4,800,000		2,600,000		2,700,000	3,400,000
Public Utilities, Recovery Period of Program Costs																																																																				11 months
Public Utilities, Approved Program Implementation Costs, Bonus																																																																		400,000	300,000
Public Utilities, Unapproved 2014 Program Implementation Costs																																																																					5,600,000
Public Utilities, Unapproved 2014 Program Implementation Costs, Expense																																																																					4,700,000
Public Utilities, Unapproved 2014 Program Implementation Costs, Bonus																																																																					700,000
Public Utilities, Unapproved 2014 Program Implementation Costs, Overcollection refund																																																																					100,000
Public Utilities, Requested Increase in Total Base to Reflect Changes in Invested Capital																																																																													26,400,000
Public Utilities, Additional Revenue from Proposed Rates																																																																								$ 18,100,000						$ 18,200,000				$ 21,900,000