Financing Schedule of Long-term Debt (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Oct. 24, 2011	Oct. 24, 2011 Unsecured Debt [Member]	Dec. 31, 2012 Unsecured Debt [Member] Senior unsecured notes, 9.25% due 2015 [Member]	Dec. 31, 2011 Unsecured Debt [Member] Senior unsecured notes, 9.25% due 2015 [Member]	Dec. 31, 2012 Other [Member]	Dec. 31, 2011 Other [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 4.875% due 2033 [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 4.875% due 2033 [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 5.15% due 2037 [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 5.15% due 2037 [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 6.25% due 2038 [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 6.25% due 2038 [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 4.75% due 2040, mandatory tender at June 1, 2017 [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 4.75% due 2040, mandatory tender at June 1, 2017 [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 5.20% due 2040, mandatory tender at June 1, 2020 [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 5.20% due 2040, mandatory tender at June 1, 2020 [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 5.90% due 2040 [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 5.90% due 2040 [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 6.25% due 2040 [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 6.25% due 2040 [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 2.54% due 2042, mandatory tender at June 1, 2017 [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 2.54% due 2042, mandatory tender at June 1, 2017 [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 4.00% due 2043, mandatory tender at June 1, 2015 [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 4.00% due 2043, mandatory tender at June 1, 2015 [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 5.20% due 2043, mandatory tender at June 1, 2020 [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member] Senior Unsecured Notes, Pollution Control Revenue Bonds [Member] 5.20% due 2043, mandatory tender at June 1, 2020 [Member]	Oct. 06, 2011 Public Service Company of New Mexico [Member] Unsecured Debt [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Unsecured Debt [Member] 7.95% due 2018 [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member] Unsecured Debt [Member] 7.95% due 2018 [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Unsecured Debt [Member] 7.50% due 2018 [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member] Unsecured Debt [Member] 7.50% due 2018 [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Unsecured Debt [Member] 5.35% due 2021 [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member] Unsecured Debt [Member] 5.35% due 2021 [Member]	Dec. 31, 2012 Public Service Company of New Mexico [Member] Other [Member]	Dec. 31, 2011 Public Service Company of New Mexico [Member] Other [Member]	Dec. 31, 2012 Texas-New Mexico Power Company [Member]	Dec. 31, 2011 Texas-New Mexico Power Company [Member]	Mar. 23, 2009 Texas-New Mexico Power Company [Member] First Mortgage Bonds [Member]	Dec. 31, 2012 Texas-New Mexico Power Company [Member] First Mortgage Bonds [Member] 2011 Term Loan Agreement, due 2014 [Member]	Dec. 31, 2011 Texas-New Mexico Power Company [Member] First Mortgage Bonds [Member] 2011 Term Loan Agreement, due 2014 [Member]	Dec. 31, 2012 Texas-New Mexico Power Company [Member] First Mortgage Bonds [Member] 9.50% due 2019, Series 2009A [Member]	Dec. 31, 2011 Texas-New Mexico Power Company [Member] First Mortgage Bonds [Member] 9.50% due 2019, Series 2009A [Member]	Dec. 31, 2012 Texas-New Mexico Power Company [Member] Other [Member]	Dec. 31, 2011 Texas-New Mexico Power Company [Member] Other [Member]	Dec. 31, 2012 PNMR [Member]	Dec. 31, 2011 PNMR [Member]	Dec. 31, 2012 PNMR [Member] Unsecured Debt [Member] Senior unsecured notes, 9.25% due 2015 [Member]	Dec. 31, 2011 PNMR [Member] Unsecured Debt [Member] Senior unsecured notes, 9.25% due 2015 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage				9.25%							4.875%	4.875%	5.15%	5.15%	6.25%	6.25%	4.75%	4.75%	5.20%	5.20%	5.90%	5.90%	6.25%	6.25%	2.54%	2.54%	4.00%	4.00%	5.20%	5.20%	5.35%	7.95%	7.95%	7.50%	7.50%	5.35%	5.35%					9.50%			9.50%	9.50%					9.25%	9.25%
Unsecured Long-term Debt, Noncurrent			$ 50,000		$ 142,592	$ 142,592	$ 2,530	$ 4,918			$ 146,000	$ 146,000	$ 0	$ 20,000	$ 36,000	$ 36,000	$ 37,000	$ 37,000	$ 40,045	$ 40,045	$ 255,000	$ 255,000	$ 11,500	$ 11,500	$ 20,000	$ 0	$ 39,300	$ 39,300	$ 21,000	$ 21,000		$ 350,000	$ 350,000	$ 100,025	$ 100,025	$ 160,000	$ 160,000						$ 50,000	$ 50,000	$ 265,500	$ 265,500
Other, including unamortized discounts																																						(291)	(330)								(3,911)	(4,537)
Long-term Debt	1,672,290	1,674,013							1,215,579	1,215,540																														311,589	310,963								145,122	147,510
Less current maturities	2,530	2,387							0	0																														0	0								2,530	2,387
Long-term Debt, Excluding Current Maturities	$ 1,669,760	$ 1,671,626							$ 1,215,579	$ 1,215,540																														$ 311,589	$ 310,963								$ 142,592	$ 145,123

The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

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- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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