Jointly-Owned Electric Generating Plants	6 Months Ended
Jun. 30, 2011
Regulated Operations [Abstract]
Jointly Owned Electric Generating Plants	Jointly-Owned Electric Generating Plants Information concerning Jointly-Owned Electric Generating Plants is discussed in Note 14 of Notes to Consolidated Financial Statements in the 2010 Annual Reports on Form 10-K. As discussed in that note, operation of each of the three PVNGS units requires an operating license from the NRC and a portion of PNM’s interests in PVNGS Units 1 and 2 are held under leases that expire in 2015 and 2016. The NRC issued 40 year operating licenses for Unit 1 in June 1985, Unit 2 in April 1986 and Unit 3 in November 1987. In December 2008, APS, on behalf of the PVNGS participants, applied for renewed operating licenses for the PVNGS units for a period of 20 years beyond the expirations of the current licenses. On April 21, 2011, the NRC approved extensions in the operating licenses for the plants for 20 years through 2045 for Unit 1, 2046 for Unit 2, and 2047 for Unit 3. PNM is currently evaluating the impacts of the license extensions. Information concerning the Company's AROs is contained in Note 15 of Notes to Consolidated Financial Statements in the 2010 Annual Reports on Form 10-K. PNM has an ARO for PVNGS that includes the obligation for nuclear decommissioning of that facility. In the second quarter of 2011, PNM adopted a new decommissioning study for PVNGS that reflects updated cash flow estimates and the 20-year license extension, which extends the commencement of decommissioning to 2045. The new study resulted in a $4.2 million decrease to the ARO liability for asset retirements and electric plant in service. The Four Corners plant site is leased from the Navajo Nation and is also subject to a rights-of-way grant from the federal government. APS, on behalf of the Four Corners participants, negotiated amendments to the facility lease with the Navajo Nation, which would extend the Four Corners leasehold interest to 2041. The amendments have been approved by the Navajo Nation Council and signed by the Nation’s President. The effectiveness of the amendments also requires the approval of the DOI, as does the related federal rights-of-way grant, which the Four Corners participants will pursue. A federal environmental review will be conducted as part of the DOI review process. PNM’s share of the annual lease payments will be $0.9 million beginning in 2016.

Jointly-Owned Electric Generating Plants

Information concerning Jointly-Owned Electric Generating Plants is discussed in Note 14 of Notes to Consolidated Financial Statements in the 2010 Annual Reports on Form 10-K. As discussed in that note, operation of each of the three PVNGS units requires an operating license from the NRC and a portion of PNM’s interests in PVNGS Units 1 and 2 are held under leases that expire in 2015 and 2016. The NRC issued 40 year operating licenses for Unit 1 in June 1985, Unit 2 in April 1986 and Unit 3 in November 1987. In December 2008, APS, on behalf of the PVNGS participants, applied for renewed operating licenses for the PVNGS units for a period of 20 years beyond the expirations of the current licenses. On April 21, 2011, the NRC approved extensions in the operating licenses for the plants for 20 years through 2045 for Unit 1, 2046 for Unit 2, and 2047 for Unit 3. PNM is currently evaluating the impacts of the license extensions.

Information concerning the Company's AROs is contained in Note 15 of Notes to Consolidated Financial Statements in the 2010 Annual Reports on Form 10-K. PNM has an ARO for PVNGS that includes the obligation for nuclear decommissioning of that facility. In the second quarter of 2011, PNM adopted a new decommissioning study for PVNGS that reflects updated cash flow estimates and the 20-year license extension, which extends the commencement of decommissioning to 2045. The new study resulted in a $4.2 million decrease to the ARO liability for asset retirements and electric plant in service.

The Four Corners plant site is leased from the Navajo Nation and is also subject to a rights-of-way grant from the federal government. APS, on behalf of the Four Corners participants, negotiated amendments to the facility lease with the Navajo Nation, which would extend the Four Corners leasehold interest to 2041. The amendments have been approved by the Navajo Nation Council and signed by the Nation’s President. The effectiveness of the amendments also requires the approval of the DOI, as does the related federal rights-of-way grant, which the Four Corners participants will pursue. A federal environmental review will be conducted as part of the DOI review process. PNM’s share of the annual lease payments will be $0.9 million beginning in 2016.