The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3255-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 18
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 19
-Subparagraph b
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

Name:	us-gaap_ProceedsFromIssuanceOfLongTermDebt
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Capitalization, Financing Activities (Details) (USD $)	6 Months Ended		0 Months Ended
Capitalization, Financing Activities (Details) (USD $)	Jun. 30, 2011	Jun. 30, 2010	Mar. 31, 2009 Texas-New Mexico Power Company [Member] Secured Debt [Member] Term Loan Agreement 2009 [Member]	Jun. 30, 2011 Texas-New Mexico Power Company [Member] Secured Debt [Member] Term Loan Agreement 2009 [Member] Year One to Year Three [Member]	Jun. 30, 2011 Texas-New Mexico Power Company [Member] Secured Debt [Member] Term Loan Agreement 2009 [Member] After Three Years [Member]	Jun. 30, 2011 Texas-New Mexico Power Company [Member] Secured Debt [Member] Term Loan Agreement 2009 [Member] January 2010 to March 2012 [Member]	Jun. 30, 2011 Texas-New Mexico Power Company [Member] Secured Debt [Member] After March 2012 [Member]	Jun. 30, 2011 Texas-New Mexico Power Company [Member] Current Liabilities [Member]	Dec. 31, 2010 Texas-New Mexico Power Company [Member] Current Liabilities [Member]	Jun. 30, 2011 Texas-New Mexico Power Company [Member] Deferred Credits and Accumulated Other Comprehensive Income [Member]	Dec. 31, 2010 Texas-New Mexico Power Company [Member] Deferred Credits and Accumulated Other Comprehensive Income [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Long-term Debt	$ 0	$ 403,845,000	$ 50,000,000
Debt Instrument, Interest Rate, Stated Percentage				6.05%	6.30%	4.80%	5.05%
Cash Flow Hedge Derivative Instrument Liabilities at Fair Value								$ 2,100,000	$ 1,900,000	$ 1,000,000	$ 800,000