Lease Commitments Narratives (Details) (USD $)	12 Months Ended																			12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 Public Service Company of New Mexico [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Palo Verde Nuclear Generating Station [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Palo Verde Nuclear Generating Station, Unit 1 Leases [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Palo Verde Nuclear Generating Station, Unit 2 Leases [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Navajo Nation [Member]	Dec. 31, 2013 Public Service Company of New Mexico [Member] Delta [Member]	Dec. 31, 2013 Texas-New Mexico Power Company [Member]	Dec. 31, 2012 Texas-New Mexico Power Company [Member]	Dec. 31, 2011 Texas-New Mexico Power Company [Member]	Dec. 31, 2013 Corporate Headquarters [Member]	Dec. 31, 2013 Administrative and General Expense [Member]	Dec. 31, 2013 Administrative and General Expense [Member] Public Service Company of New Mexico [Member]	Dec. 31, 2013 Administrative and General Expense [Member] Texas-New Mexico Power Company [Member]	Dec. 31, 2013 Approximate Annual Total for Operating Lease Payments [Member]	Dec. 31, 2013 Approximate Annual Total for Operating Lease Payments [Member]	Dec. 31, 2013 Approximate Annual Total for Operating Lease Payments [Member]	Dec. 31, 2013 TGP Granada, LLC and its affiliate Complaint [Member] Public Service Company of New Mexico [Member]	Dec. 31, 2013 TGP Granada, LLC and its affiliate Complaint [Member] Tortoise Capital Resources Corporation [Member]	Jan. 15, 2016 Subsequent Event [Member] Public Service Company of New Mexico [Member] Palo Verde Nuclear Generating Station, Unit 2 Leases [Member] MW
Lease commitments
Annual lease payments						$ 33,000,000	$ 23,700,000	$ 6,000,000	$ 6,000,000
Operating Lease, Extended Term	2 years
Operating Leases, Renewal Options After Original Lease Term	6 years	2
Rental Payments, Fixed renewal option period during original terms of leases					50.00%
Operating Lease, Extended Term, Notice Period to Retain Leased Assets					3 years
Operating Lease, Extended Term, Notice Period to Purchase or Renewal Options					2 years
Annual Lease Payments During Renewal Period						16,500,000	1,600,000
Estimated Purchase Price of Leased Asset																						78,100,000
Leased Capacity to be Purchased																						0
Lease Covenant, Restriction on Conveying, Transferring, Leasing, & Dividends					5.00%
Loss Contingency, Range of Possible Loss, Portion Not Accrued					154,100,000
Public Utilities, Lease ownership percentage in EIP																				60.00%	40.00%
Operating Lease, Notice Period to Purchase Leased Assets																				24 months
Public Utilities, Option to Purchase Leased Capacity At Fair Value		7,700,000
Operating Leases, Rent Expense, Net		78,306,000	78,483,000	78,422,000						2,663,000	2,871,000	3,606,000	1,900,000
Abandonment expense														(7,400,000)	(6,200,000)	(1,200,000)
Operating Leases Rent Expense Return on Lessor notes Rental Payments to be Received																	$ 9,000,000	$ 24,000,000	$ 25,400,000