Lease Commitments Schedule of Future Minimum Rental Payments for Operating Leases (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
PNMR [Member]
Lease commitments
2012	$ 49,923
2013	51,547
2014	59,511
2015	39,827
2016	18,461
Later years	103,669
Operating Leases, Future Minimum Payments Due	322,938
Future payments under non-cancelable subleases	1,523
Net minimum lease payments	321,415
Public Service Company of New Mexico [Member]
Lease commitments
2012	43,562
2013	45,315
2014	54,057
2015	36,663
2016	17,457
Later years	103,302
Operating Leases, Future Minimum Payments Due	300,356
Future payments under non-cancelable subleases	0
Net minimum lease payments	300,356
Texas-New Mexico Power Company [Member]
Lease commitments
2012	3,045
2013	2,875
2014	2,457
2015	1,549
2016	1,000
Later years	367
Operating Leases, Future Minimum Payments Due	11,293
Future payments under non-cancelable subleases	0
Net minimum lease payments	$ 11,293

Net minimum lease payments

No definition available.

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- Definition

The total of future contractually required payments on leases defined as operating.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 122

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

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-Name Accounting Standards Codification

-Topic 840

-SubTopic 10

-Section 55

-Paragraph 40

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- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within one year of the balance sheet date relating to leases defined as operating.

+ References

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- Definition

Contractually required future rental payments receivable on noncancelable subleasing arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 16

-Subparagraph b(ii)

-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 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

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- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the fifth year of the balance sheet date relating to leases defined as operating.

+ References

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For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the fourth year of the balance sheet date relating to leases defined as operating.

+ References

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For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the third year of the balance sheet date relating to leases defined as operating.

+ References

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For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the second year of the balance sheet date relating to leases defined as operating.

+ References

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- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due after the fifth year from the balance sheet date on leases defined as operating.

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