Income Taxes Interest Expense (Income) Related to Income Taxes (Details) (USD $)	1 Months Ended	12 Months Ended
	May 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Taxes [Line Items]
New Mexico Corporate tax rate, current		7.60%
Interest income related to income taxes		$ 242,000	$ 243,000	$ 467,000
New Mexico Corporate tax rate, 2014		5.90%
Increase in regulatory liabilities due to change in state corporate tax rate		23,900,000
Increase in income tax expense due to change in state corporate tax rate		1,200,000
Additional Income Tax Expense, Impairment of NM Wind Credits		2,400,000	700,000
Federal Tax Refund	96,200,000
Public Service Company of New Mexico [Member]
Income Taxes [Line Items]
Interest income related to income taxes		251,000	244,000	401,000
Federal Tax Refund	77,400,000
Texas-New Mexico Power Company [Member]
Income Taxes [Line Items]
Interest income related to income taxes		$ (2,000)	$ (3,000)	$ 2,000