Schedule I - Condensed Financial Information of Parent Company (Statements of Earnings) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]
Operating Expenses									$ 1,101,081	$ 1,068,682	$ 1,443,320
Operating income	40,532	117,739	77,867	50,704	36,736	118,150	65,106	53,729	286,842	273,721	257,299
Other Income and Deductions:
Other income									10,572	12,746	5,309
Other (deductions)									(21,552)	(17,636)	(24,715)
Net other income and deductions									9,675	22,159	180,019
Earnings before Income Taxes									175,069	175,035	312,469
Income Tax Expense (Benefit)									59,513	54,910	121,535
Net Earnings (Loss) Attributable to Company	7,648	54,555	27,678	10,626	9,091	57,864	21,512	17,080	100,507	105,547	176,359
PNM Resources [Member]
Condensed Financial Statements, Captions [Line Items]
Non-affiliates									0	0	0
Operating Expenses									941	3,287	20,547
Operating income									(941)	(3,287)	(20,547)
Other Income and Deductions:
Equity in earnings of subsidiaries									116,634	117,900	205,215
Other income									769	670	59
Other (deductions)									(22,825)	(20,904)	(34,124)
Net other income and deductions									94,578	97,666	171,150
Earnings before Income Taxes									93,637	94,379	150,603
Income Tax Expense (Benefit)									(6,870)	(11,168)	(25,756)
Net Earnings (Loss) Attributable to Company									$ 100,507	$ 105,547	$ 176,359