Regulation	9 Months Ended
Sep. 30, 2016
Public Utilities, General Disclosures [Abstract]
Regulation	Regulation General The rates and services of the Company are regulated by incorporated municipalities in Texas, the PUCT, the NMPRC, and the Federal Energy Regulatory Commission ("FERC"). Municipal orders, ordinances and other agreements regarding rates and services adopted by Texas municipalities are subject to review and approval by the PUCT. The FERC has jurisdiction over the Company's wholesale (sales for resale) transactions, transmission service and compliance with federally-mandated reliability standards. The decisions of the PUCT, the NMPRC and the FERC are subject to judicial review. Texas Regulatory Matters 2015 Texas Retail Rate Case Filing. On August 10, 2015, the Company filed with the City of El Paso, other municipalities incorporated in its Texas service territory, and the PUCT in Docket No. 44941, a request for an annual increase in non-fuel base revenues of approximately $71.5 million. On January 15, 2016, the Company filed its rebuttal testimony modifying the requested increase to $63.3 million. On August 25, 2016, the PUCT issued its final order in Docket No. 44941 (the "PUCT Final Order"), as proposed, approving the Joint Motion to Implement Uncontested Amended and Restated Stipulation and Agreement (the "Unopposed Settlement") that was filed with the PUCT on July 21, 2016, which was unopposed by the parties to the rate case. The PUCT Final Order provides for the following: (i) an annual non-fuel rate increase of $37 million, lower annual depreciation expense of approximately $8.5 million, a return on equity of 9.7% for AFUDC purposes, and inclusion of substantially all new plant in service in rate base; (ii) an additional annual non-fuel base rate increase of $3.7 million related to Four Corners costs, which will be collected through a surcharge that terminates on July 12, 2017 and applies to consumption on and after January 12, 2016; (iii) removal of the separate rate treatment for residential customers with solar systems; (iv) recovery of $3.1 million in rate case expenses through a separate surcharge; and (v) recovery of revenues associated with the relate back of rates to consumption on and after January 12, 2016 through March 31, 2016 (aggregating $4.8 million) through a separate surcharge, all as specified in the Unopposed Settlement. The costs of serving residential customers with solar generation will be addressed in a future proceeding. Interim rates associated with the annual non-fuel rate increase of $37 million became effective on April 1, 2016. The additional surcharges associated with the incremental Four Corners costs, rate case expenses and the relate back of rates to consumption on and after January 12, 2016 through March 31, 2016 were implemented on October 1, 2016. Given the uncertainties regarding the ultimate resolution of the rate case, the Company did not recognize the impacts of the Unopposed Settlement in the Statements of Operations until it received the PUCT Final Order on August 25, 2016. Accordingly, operating revenues increased approximately $34.8 million, depreciation decreased approximately $7.4 million, and other expenses, net, increased approximately $1.9 million for an aggregate increase in income before income taxes of $40.3 million and an increase in net income of $23.3 million in the third quarter of 2016 to reflect the effects of the PUCT Final Order. Energy Efficiency Cost Recovery Factor. On May 1, 2015, the Company filed its annual application to establish its energy efficiency cost recovery factor for 2016. In addition to projected energy efficiency costs for 2016 and a true-up to prior year actual costs, the Company requested approval of a $1.0 million bonus for the 2014 energy efficiency program results in accordance with PUCT rules. This case was assigned PUCT Docket No. 44677. A stipulation and settlement agreement was filed September 24, 2015 and the PUCT approved the settlement on November 5, 2015. The settlement approved by the PUCT includes a performance bonus of $1.0 million. The Company recorded the performance bonus as operating revenue in the fourth quarter of 2015. On April 29, 2016, the Company filed its annual application to establish its energy efficiency cost recovery factor for 2017. In addition to projected energy efficiency costs for 2017 and true-up to prior year actual costs, the Company requested approval of a $668 thousand bonus for the 2015 energy efficiency program results in accordance with PUCT rules. This case was assigned PUCT Docket No. 45885. Parties in the proceeding, including PUCT staff and the City of El Paso, have filed a settlement in the case that approves the Company's filed proposal with a reduction to the 2015 program bonus of $155 thousand. The PUCT approved the settlement on October 28, 2016. The settlement approved by the PUCT includes a performance bonus of $0.5 million. The Company recorded the performance bonus as operating revenue in the third quarter of 2016. Fuel and Purchased Power Costs. The Company's actual fuel costs, including purchased power energy costs, are recovered from customers through a fixed fuel factor. The PUCT has adopted a fuel cost recovery rule (the "Texas Fuel Rule") that allows the Company to seek periodic adjustments to its fixed fuel factor. The Company can seek to revise its fixed fuel factor based upon the approved formula at least four months after its last revision except in the month of December. The Texas Fuel Rule requires the Company to request to refund fuel costs in any month when the over-recovery balance exceeds a threshold material amount and it expects fuel costs to continue to be materially over-recovered. The Texas Fuel Rule also permits the Company to seek to surcharge fuel under-recoveries in any month the balance exceeds a threshold material amount and it expects fuel cost recovery to continue to be materially under-recovered. Fuel over- and under-recoveries are considered material when they exceed 4% of the previous twelve months' fuel costs. All such fuel revenue and expense activities are subject to periodic final review by the PUCT in fuel reconciliation proceedings. On April 15, 2015, the Company filed a request, which was assigned PUCT Docket No. 44633, to reduce its fixed fuel factor by approximately 24% to reflect reduced fuel expenses primarily related to a reduction in the price of natural gas used to generate power. The over-recovered balance was below the PUCT's materiality threshold. The reduction in the fixed fuel factor was effective on an interim basis May 1, 2015 and approved by the PUCT on May 20, 2015. As of September 30, 2016, the Company had under-recovered fuel costs in the amount of $8.9 million for the Texas jurisdiction. Fuel Reconciliation Proceeding. On September 27, 2016, the Company filed an application with the PUCT, designated as PUCT Docket No. 46308, to reconcile $436.6 million of fuel and purchased power expenses incurred during the period of April 1, 2013 through March 31, 2016. Montana Power Station Approvals. The Company has received a Certificate of Convenience and Necessity ("CCN") from the PUCT to construct four natural gas fired generating units at Montana Power Station ("MPS") in El Paso County, Texas. The Company also obtained air permits from the Texas Commission on Environmental Quality (the "TCEQ") and the U.S. Environmental Protection Agency (the "EPA"). MPS Units 1 and 2 and associated transmission lines and common facilities were completed and placed into service in March 2015. MPS Units 3 and 4 were completed and placed into service on May 3, 2016 and September 15, 2016, respectively. Community Solar. On June 8, 2015, the Company filed a petition with the PUCT to initiate a community solar program to include construction and ownership of a 3 MW solar photovoltaic system located at MPS. Participation will be on a voluntary basis, and customers will contract for a set capacity (kW) amount and receive all energy produced. This case was assigned PUCT Docket No. 44800. The Company filed a settlement agreement among all parties on July 1, 2016 approving the program, and the PUCT approved the settlement agreement and program on September 1, 2016. Four Corners Generating Station. On February 17, 2015, the Company and APS entered the Purchase and Sale Agreement providing for purchase by APS of the Company's interests in Four Corners. The Four Corners transaction closed on July 6, 2016. See Note D for further details on the sale of Four Corners. On June 10, 2015, the Company filed an application in Texas requesting reasonableness and public interest findings and certain rate and accounting findings related to the Purchase and Sale Agreement. This case was assigned PUCT Docket No. 44805. Subsequent to the filing of the application, the case has been subject to numerous procedural matters, including a March 23, 2016 order in which the PUCT determined not to dismiss the reasonableness and public interest issues in this docket but to consider the requested rate and accounting findings, including mine reclamation costs, in the Company's next rate case, which is expected to be filed in the first half of 2017. The procedural schedule related to the public interest issues called for a hearing to be held on October 6-7, 2016. However, on September 1, 2016, a motion by parties in the proceeding to suspend the procedural schedule in order to pursue settlement was approved by the PUCT. At September 30, 2016, the regulatory asset associated with the Four Corners mine reclamation costs for our Texas jurisdiction approximated $7.5 million. The Company currently continues to recover its mine reclamation costs in Texas under previous orders and decisions of the PUCT. If any future determinations made by our regulators result in changes to how existing regulatory assets or previously incurred costs for Four Corners are recovered in rates, any such changes would be recognized only when it becomes probable future cash flows will change as a result of such regulatory actions. Other Required Approvals. The Company has obtained other required approvals for tariffs and approvals as required by the Public Utility Regulatory Act (the "PURA") and the PUCT. New Mexico Regulatory Matters 2015 New Mexico Rate Case Filing. On May 11, 2015, the Company filed with the NMPRC in Case No. 15-00127-UT, for an annual increase in non-fuel base rates of approximately $8.6 million or 7.1%. Subsequently, the Company reduced its requested increase in non-fuel base rates to approximately $6.4 million. On June 8, 2016, the NMPRC issued its final order approving an annual increase in non-fuel base rates of approximately $1.1 million and a decrease in the Company's allowed return on equity to 9.48%. The final order concludes that all of the Company's new plant in service was reasonable and necessary and therefore would be recoverable in rate base. The Company's rates were approved by the NMPRC effective July 1, 2016 and implemented at such time. Fuel and Purchased Power Costs. On January 8, 2014, the NMPRC approved the continuation of the Fuel and Purchased Power Cost Adjustment Clause (the "FPPCAC") without modification in NMPRC Case No. 13-00380-UT. Historically, fuel and purchased power costs were recovered through base rates and a FPPCAC that accounts for changes in the costs of fuel relative to the amount included in base rates. Effective July 1, 2016, with the implementation of the final order of Case No. 15-00127-UT, fuel and purchased power costs will no longer be recovered through base rates but will be completely recovered through the FPPCAC. Fuel and purchased power costs are reconciled to actual costs on a monthly basis and recovered or refunded to customers the second succeeding month. The Company recovers costs related to Palo Verde Unit 3 capacity and energy in New Mexico through the FPPCAC as purchased power using a proxy market price approved in Case No. 13-00380-UT. At September 30, 2016, the Company had a net fuel over-recovery balance of $1.3 million in New Mexico. Montana Power Station Approvals. The Company has received a CCN from the NMPRC to construct four units at MPS and the associated transmission lines. The Company also obtained all necessary air permits from the TCEQ and the EPA. A final order in NMPRC Case No. 13-00297-UT approving the CCN for MPS Units 3 and 4 was issued on June 11, 2014. MPS Units 1 and 2 were completed and placed into service in March 2015. MPS Units 3 and 4 were completed and placed into service on May 3, 2016 and September 15, 2016, respectively. Four Corners. On February 17, 2015, the Company and APS entered into the Purchase and Sale Agreement providing for the purchase by APS of the Company's interests in Four Corners. On April 27, 2015, the Company filed an application in NMPRC Case No. 15-00109-UT requesting all necessary regulatory approvals to sell its ownership interest in Four Corners. On February 2, 2016, the Company filed a joint stipulation with the NMPRC reflecting a settlement agreement among the NMPRC's Utility Division Staff, the Company and the New Mexico Attorney General proposing approval of abandonment and sale of its seven percent minority ownership interest in Four Corners Units 4 and 5 and common facilities to APS. A hearing in the case was held on February 16, 2016, and the Hearing Examiner issued a Certification of Stipulation on April 22, 2016 recommending approval of the joint stipulation without modification. On June 15, 2016, the NMPRC issued its final order approving the stipulation. See Note D for further details on the sale of Four Corners. 5 MW Holloman Air Force Base ("HAFB") Facility CCN. On June 15, 2015, the Company filed a petition with the NMPRC requesting CCN authorization to construct a 5 MW solar-powered generation facility to be located at HAFB in the Company's service territory in New Mexico. The new facility will be a dedicated Company-owned resource serving HAFB. This case was assigned NMPRC Case No. 15-00185-UT. On October 7, 2015, the NMPRC issued a final order accepting the Hearing Examiner’s Recommended Decision to approve the CCN, as modified. The Company and HAFB negotiated a special retail contract, which includes power sales agreement for the facility, to replace the existing load retention agreement and requested approval in NMPRC Case No. 16-00224-UT. On October 5, 2016 the new agreement was approved by the NMPRC. Construction of the solar generation facility will begin in the fourth quarter of 2016 and is expected to be completed in the second quarter of 2017. Issuance of Long-Term Debt and Guarantee of Debt. On October 7, 2015, the Company received approval in NMPRC Case No. 15-00280-UT to issue up to $310 million in new long-term debt; and to guarantee the issuance of up to $65 million of new debt by Rio Grande Resources Trust ("RGRT") to finance future purchases of nuclear fuel and to refinance existing nuclear fuel debt obligations. This approval supersedes prior approvals. Under this authorization, on March 24, 2016, the Company issued $150 million in aggregate principal amount of 5.00% Senior Notes due December 1, 2044. The net proceeds from the issuance of these senior notes, after deducting the underwriters' commission, were $158.1 million. These proceeds include accrued interest of $2.4 million and a $7.1 million premium before expenses. These senior notes constitute an additional issuance of the Company's 5.00% Senior Notes due 2044, of which $150 million was previously issued on December 1, 2014, for a total principal amount outstanding of $300 million. Other Required Approvals. The Company has obtained other required approvals for other tariffs, securities transactions, recovery of energy efficiency costs through a base rate rider and other approvals as required by the NMPRC. Federal Regulatory Matters Four Corners. On June 26, 2015, APS filed an application requesting authorization from FERC to purchase 100% of the Company’s ownership interest in Units 4 and 5 of Four Corners and the associated transmission interconnection facilities and rights. On December 22, 2015, FERC issued an order approving the proposed transaction. The Four Corners transaction closed on July 6, 2016. See Note D for further details on the sale of Four Corners. Public Service Company of New Mexico ("PNM") Transmission Rate Case. On December 31, 2012, PNM filed with FERC to change its method of transmission rate recovery for its transmission delivery services from stated rates to formula rates. The Company takes transmission service from PNM and is among the PNM transmission customers affected by PNM's shift to formula rates. On March 1, 2013, the FERC issued an order rejecting in part PNM's filing, and establishing settlement judge and hearing procedures. On March 20, 2015, PNM filed with FERC a settlement agreement and offer of settlement resolving all issues set for hearing in the proceeding. On March 25, 2015, the Chief Judge issued an order granting PNM's motion to implement the settled rates. On March 17, 2016, FERC issued an order approving the settlement. Revolving Credit Facility; Issuance of Long-Term Debt and Guarantee of Debt. On October 19, 2015, the FERC issued an order in Docket No. ES15-66-000 approving the Company’s filing to issue short-term debt under its existing revolving credit facility ("RCF") up to $400 million outstanding at any time, to issue up to $310 million in long-term debt, and to guarantee the issuance of up to $65 million of new long-term debt by RGRT to finance future nuclear fuel purchases. The authorization is effective from November 15, 2015 through November 15, 2017. This approval supersedes prior approvals. Under this authorization, on March 24, 2016, the Company issued $150 million in aggregate principal amount of 5.00% Senior Notes due December 1, 2044. The net proceeds from the issuance of these senior notes, after deducting the underwriters' commission, were $158.1 million. These proceeds include accrued interest of $2.4 million and a $7.1 million premium before expenses. These senior notes constitute an additional issuance of the Company's 5.00% Senior Notes due 2044, of which $150 million was previously issued on December 1, 2014, for a total principal amount outstanding of $300 million. Other Required Approvals. The Company has obtained required approvals for rates and tariffs, securities transactions and other approvals as required by the FERC.

Regulation

General

The rates and services of the Company are regulated by incorporated municipalities in Texas, the PUCT, the NMPRC, and the Federal Energy Regulatory Commission ("FERC"). Municipal orders, ordinances and other agreements regarding rates and services adopted by Texas municipalities are subject to review and approval by the PUCT. The FERC has jurisdiction over the Company's wholesale (sales for resale) transactions, transmission service and compliance with federally-mandated reliability standards. The decisions of the PUCT, the NMPRC and the FERC are subject to judicial review.

Texas Regulatory Matters

2015 Texas Retail Rate Case Filing. On August 10, 2015, the Company filed with the City of El Paso, other municipalities incorporated in its Texas service territory, and the PUCT in Docket No. 44941, a request for an annual increase in non-fuel base revenues of approximately $71.5 million. On January 15, 2016, the Company filed its rebuttal testimony modifying the requested increase to $63.3 million.

On August 25, 2016, the PUCT issued its final order in Docket No. 44941 (the "PUCT Final Order"), as proposed, approving the Joint Motion to Implement Uncontested Amended and Restated Stipulation and Agreement (the "Unopposed Settlement") that was filed with the PUCT on July 21, 2016, which was unopposed by the parties to the rate case. The PUCT Final Order provides for the following: (i) an annual non-fuel rate increase of $37 million, lower annual depreciation expense of approximately $8.5 million, a return on equity of 9.7% for AFUDC purposes, and inclusion of substantially all new plant in service in rate base; (ii) an additional annual non-fuel base rate increase of $3.7 million related to Four Corners costs, which will be collected through a surcharge that terminates on July 12, 2017 and applies to consumption on and after January 12, 2016; (iii) removal of the separate rate treatment for residential customers with solar systems; (iv) recovery of $3.1 million in rate case expenses through a separate surcharge; and (v) recovery of revenues associated with the relate back of rates to consumption on and after January 12, 2016 through March 31, 2016 (aggregating $4.8 million) through a separate surcharge, all as specified in the Unopposed Settlement. The costs of serving residential customers with solar generation will be addressed in a future proceeding.

Interim rates associated with the annual non-fuel rate increase of $37 million became effective on April 1, 2016. The additional surcharges associated with the incremental Four Corners costs, rate case expenses and the relate back of rates to consumption on and after January 12, 2016 through March 31, 2016 were implemented on October 1, 2016.

Given the uncertainties regarding the ultimate resolution of the rate case, the Company did not recognize the impacts of the Unopposed Settlement in the Statements of Operations until it received the PUCT Final Order on August 25, 2016. Accordingly, operating revenues increased approximately $34.8 million, depreciation decreased approximately $7.4 million, and other expenses, net, increased approximately $1.9 million for an aggregate increase in income before income taxes of $40.3 million and an increase in net income of $23.3 million in the third quarter of 2016 to reflect the effects of the PUCT Final Order.

Energy Efficiency Cost Recovery Factor. On May 1, 2015, the Company filed its annual application to establish its energy efficiency cost recovery factor for 2016. In addition to projected energy efficiency costs for 2016 and a true-up to prior year actual costs, the Company requested approval of a $1.0 million bonus for the 2014 energy efficiency program results in accordance with PUCT rules. This case was assigned PUCT Docket No. 44677. A stipulation and settlement agreement was filed September 24, 2015 and the PUCT approved the settlement on November 5, 2015. The settlement approved by the PUCT includes a performance bonus of $1.0 million. The Company recorded the performance bonus as operating revenue in the fourth quarter of 2015.

On April 29, 2016, the Company filed its annual application to establish its energy efficiency cost recovery factor for 2017. In addition to projected energy efficiency costs for 2017 and true-up to prior year actual costs, the Company requested approval of a $668 thousand bonus for the 2015 energy efficiency program results in accordance with PUCT rules. This case was assigned PUCT Docket No. 45885. Parties in the proceeding, including PUCT staff and the City of El Paso, have filed a settlement in the case that approves the Company's filed proposal with a reduction to the 2015 program bonus of $155 thousand. The PUCT approved the settlement on October 28, 2016. The settlement approved by the PUCT includes a performance bonus of $0.5 million. The Company recorded the performance bonus as operating revenue in the third quarter of 2016.

Fuel and Purchased Power Costs. The Company's actual fuel costs, including purchased power energy costs, are recovered from customers through a fixed fuel factor. The PUCT has adopted a fuel cost recovery rule (the "Texas Fuel Rule") that allows the Company to seek periodic adjustments to its fixed fuel factor. The Company can seek to revise its fixed fuel factor based upon the approved formula at least four months after its last revision except in the month of December. The Texas Fuel Rule requires the Company to request to refund fuel costs in any month when the over-recovery balance exceeds a threshold material amount and it expects fuel costs to continue to be materially over-recovered. The Texas Fuel Rule also permits the Company to seek to surcharge fuel under-recoveries in any month the balance exceeds a threshold material amount and it expects fuel cost recovery to continue to be materially under-recovered. Fuel over- and under-recoveries are considered material when they exceed 4% of the previous twelve months' fuel costs. All such fuel revenue and expense activities are subject to periodic final review by the PUCT in fuel reconciliation proceedings.

On April 15, 2015, the Company filed a request, which was assigned PUCT Docket No. 44633, to reduce its fixed fuel factor by approximately 24% to reflect reduced fuel expenses primarily related to a reduction in the price of natural gas used to generate power. The over-recovered balance was below the PUCT's materiality threshold. The reduction in the fixed fuel factor was effective on an interim basis May 1, 2015 and approved by the PUCT on May 20, 2015. As of September 30, 2016, the Company had under-recovered fuel costs in the amount of $8.9 million for the Texas jurisdiction.

Fuel Reconciliation Proceeding. On September 27, 2016, the Company filed an application with the PUCT, designated as PUCT Docket No. 46308, to reconcile $436.6 million of fuel and purchased power expenses incurred during the period of April 1, 2013 through March 31, 2016.

Montana Power Station Approvals. The Company has received a Certificate of Convenience and Necessity ("CCN") from the PUCT to construct four natural gas fired generating units at Montana Power Station ("MPS") in El Paso County, Texas. The Company also obtained air permits from the Texas Commission on Environmental Quality (the "TCEQ") and the U.S. Environmental Protection Agency (the "EPA"). MPS Units 1 and 2 and associated transmission lines and common facilities were completed and placed into service in March 2015. MPS Units 3 and 4 were completed and placed into service on May 3, 2016 and September 15, 2016, respectively.

Community Solar. On June 8, 2015, the Company filed a petition with the PUCT to initiate a community solar program to include construction and ownership of a 3 MW solar photovoltaic system located at MPS. Participation will be on a voluntary basis, and customers will contract for a set capacity (kW) amount and receive all energy produced. This case was assigned PUCT Docket No. 44800. The Company filed a settlement agreement among all parties on July 1, 2016 approving the program, and the PUCT approved the settlement agreement and program on September 1, 2016.

Four Corners Generating Station. On February 17, 2015, the Company and APS entered the Purchase and Sale Agreement providing for purchase by APS of the Company's interests in Four Corners. The Four Corners transaction closed on July 6, 2016. See Note D for further details on the sale of Four Corners.

On June 10, 2015, the Company filed an application in Texas requesting reasonableness and public interest findings and certain rate and accounting findings related to the Purchase and Sale Agreement. This case was assigned PUCT Docket No. 44805. Subsequent to the filing of the application, the case has been subject to numerous procedural matters, including a March 23, 2016 order in which the PUCT determined not to dismiss the reasonableness and public interest issues in this docket but to consider the requested rate and accounting findings, including mine reclamation costs, in the Company's next rate case, which is expected to be filed in the first half of 2017. The procedural schedule related to the public interest issues called for a hearing to be held on October 6-7, 2016. However, on September 1, 2016, a motion by parties in the proceeding to suspend the procedural schedule in order to pursue settlement was approved by the PUCT.

At September 30, 2016, the regulatory asset associated with the Four Corners mine reclamation costs for our Texas jurisdiction approximated $7.5 million. The Company currently continues to recover its mine reclamation costs in Texas under previous orders and decisions of the PUCT. If any future determinations made by our regulators result in changes to how existing regulatory assets or previously incurred costs for Four Corners are recovered in rates, any such changes would be recognized only when it becomes probable future cash flows will change as a result of such regulatory actions.

Other Required Approvals. The Company has obtained other required approvals for tariffs and approvals as required by the Public Utility Regulatory Act (the "PURA") and the PUCT.

New Mexico Regulatory Matters

2015 New Mexico Rate Case Filing. On May 11, 2015, the Company filed with the NMPRC in Case No. 15-00127-UT, for an annual increase in non-fuel base rates of approximately $8.6 million or 7.1%. Subsequently, the Company reduced its requested increase in non-fuel base rates to approximately $6.4 million. On June 8, 2016, the NMPRC issued its final order approving an annual increase in non-fuel base rates of approximately $1.1 million and a decrease in the Company's allowed return on equity to 9.48%. The final order concludes that all of the Company's new plant in service was reasonable and necessary and therefore would be recoverable in rate base. The Company's rates were approved by the NMPRC effective July 1, 2016 and implemented at such time.

Fuel and Purchased Power Costs. On January 8, 2014, the NMPRC approved the continuation of the Fuel and Purchased Power Cost Adjustment Clause (the "FPPCAC") without modification in NMPRC Case No. 13-00380-UT. Historically, fuel and purchased power costs were recovered through base rates and a FPPCAC that accounts for changes in the costs of fuel relative to the amount included in base rates. Effective July 1, 2016, with the implementation of the final order of Case No. 15-00127-UT, fuel and purchased power costs will no longer be recovered through base rates but will be completely recovered through the FPPCAC. Fuel and purchased power costs are reconciled to actual costs on a monthly basis and recovered or refunded to customers the second succeeding month. The Company recovers costs related to Palo Verde Unit 3 capacity and energy in New Mexico through the FPPCAC as purchased power using a proxy market price approved in Case No. 13-00380-UT. At September 30, 2016, the Company had a net fuel over-recovery balance of $1.3 million in New Mexico.

Montana Power Station Approvals. The Company has received a CCN from the NMPRC to construct four units at MPS and the associated transmission lines. The Company also obtained all necessary air permits from the TCEQ and the EPA. A final order in NMPRC Case No. 13-00297-UT approving the CCN for MPS Units 3 and 4 was issued on June 11, 2014. MPS Units 1 and 2 were completed and placed into service in March 2015. MPS Units 3 and 4 were completed and placed into service on May 3, 2016 and September 15, 2016, respectively.

Four Corners. On February 17, 2015, the Company and APS entered into the Purchase and Sale Agreement providing for the purchase by APS of the Company's interests in Four Corners. On April 27, 2015, the Company filed an application in NMPRC Case No. 15-00109-UT requesting all necessary regulatory approvals to sell its ownership interest in Four Corners. On February 2, 2016, the Company filed a joint stipulation with the NMPRC reflecting a settlement agreement among the NMPRC's Utility Division Staff, the Company and the New Mexico Attorney General proposing approval of abandonment and sale of its seven percent minority ownership interest in Four Corners Units 4 and 5 and common facilities to APS. A hearing in the case was held on February 16, 2016, and the Hearing Examiner issued a Certification of Stipulation on April 22, 2016 recommending approval of the joint stipulation without modification. On June 15, 2016, the NMPRC issued its final order approving the stipulation. See Note D for further details on the sale of Four Corners.

5 MW Holloman Air Force Base ("HAFB") Facility CCN. On June 15, 2015, the Company filed a petition with the NMPRC requesting CCN authorization to construct a 5 MW solar-powered generation facility to be located at HAFB in the Company's service territory in New Mexico. The new facility will be a dedicated Company-owned resource serving HAFB. This case was assigned NMPRC Case No. 15-00185-UT. On October 7, 2015, the NMPRC issued a final order accepting the Hearing Examiner’s Recommended Decision to approve the CCN, as modified. The Company and HAFB negotiated a special retail contract, which includes power sales agreement for the facility, to replace the existing load retention agreement and requested approval in NMPRC Case No. 16-00224-UT. On October 5, 2016 the new agreement was approved by the NMPRC. Construction of the solar generation facility will begin in the fourth quarter of 2016 and is expected to be completed in the second quarter of 2017.

Issuance of Long-Term Debt and Guarantee of Debt. On October 7, 2015, the Company received approval in NMPRC Case No. 15-00280-UT to issue up to $310 million in new long-term debt; and to guarantee the issuance of up to $65 million of new debt by Rio Grande Resources Trust ("RGRT") to finance future purchases of nuclear fuel and to refinance existing nuclear fuel debt obligations. This approval supersedes prior approvals. Under this authorization, on March 24, 2016, the Company issued $150 million in aggregate principal amount of 5.00% Senior Notes due December 1, 2044. The net proceeds from the issuance of these senior notes, after deducting the underwriters' commission, were $158.1 million. These proceeds include accrued interest of $2.4 million and a $7.1 million premium before expenses. These senior notes constitute an additional issuance of the Company's 5.00% Senior Notes due 2044, of which $150 million was previously issued on December 1, 2014, for a total principal amount outstanding of $300 million.

Other Required Approvals. The Company has obtained other required approvals for other tariffs, securities transactions, recovery of energy efficiency costs through a base rate rider and other approvals as required by the NMPRC.

Federal Regulatory Matters

Four Corners. On June 26, 2015, APS filed an application requesting authorization from FERC to purchase 100% of the Company’s ownership interest in Units 4 and 5 of Four Corners and the associated transmission interconnection facilities and rights. On December 22, 2015, FERC issued an order approving the proposed transaction. The Four Corners transaction closed on July 6, 2016. See Note D for further details on the sale of Four Corners.

Public Service Company of New Mexico ("PNM") Transmission Rate Case. On December 31, 2012, PNM filed with FERC to change its method of transmission rate recovery for its transmission delivery services from stated rates to formula rates. The Company takes transmission service from PNM and is among the PNM transmission customers affected by PNM's shift to formula rates. On March 1, 2013, the FERC issued an order rejecting in part PNM's filing, and establishing settlement judge and hearing procedures. On March 20, 2015, PNM filed with FERC a settlement agreement and offer of settlement resolving all issues set for hearing in the proceeding. On March 25, 2015, the Chief Judge issued an order granting PNM's motion to implement the settled rates. On March 17, 2016, FERC issued an order approving the settlement.

Revolving Credit Facility; Issuance of Long-Term Debt and Guarantee of Debt. On October 19, 2015, the FERC issued an order in Docket No. ES15-66-000 approving the Company’s filing to issue short-term debt under its existing revolving credit facility ("RCF") up to $400 million outstanding at any time, to issue up to $310 million in long-term debt, and to guarantee the issuance of up to $65 million of new long-term debt by RGRT to finance future nuclear fuel purchases. The authorization is effective from November 15, 2015 through November 15, 2017. This approval supersedes prior approvals. Under this authorization, on March 24, 2016, the Company issued $150 million in aggregate principal amount of 5.00% Senior Notes due December 1, 2044. The net proceeds from the issuance of these senior notes, after deducting the underwriters' commission, were $158.1 million. These proceeds include accrued interest of $2.4 million and a $7.1 million premium before expenses. These senior notes constitute an additional issuance of the Company's 5.00% Senior Notes due 2044, of which $150 million was previously issued on December 1, 2014, for a total principal amount outstanding of $300 million.

Other Required Approvals. The Company has obtained required approvals for rates and tariffs, securities transactions and other approvals as required by the FERC.