Rate Matters	6 Months Ended
Jun. 30, 2017
Public Utilities, General Disclosures [Abstract]
Rate Matters	Rate Matters Except to the extent noted below, the circumstances set forth in Note 10 to the financial statements included in SPS’ Annual Report on Form 10-K for the year ended Dec. 31, 2016 and in Note 5 to the financial statements included in to SPS’ Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2017, appropriately represent, in all material respects, the current status of other rate matters, and are incorporated herein by reference. Pending and Recently Concluded Regulatory Proceedings — Public Utility Commission of Texas (PUCT) Appeal of the Texas 2015 Electric Rate Case Decision — In 2014, SPS had requested an overall retail electric revenue rate increase of $42.1 million. In 2015, the PUCT approved an overall rate decrease of approximately $4.0 million, net of rate case expenses. In April 2016, SPS filed an appeal, with the Texas State District Court, of the PUCT’s order that had denied SPS’ request for rehearing on certain items in SPS’ Texas 2015 electric rate case related to capital structure, incentive compensation and wholesale load reductions. In March 2017, the Travis County District Court denied SPS’ appeal. In April 2017, SPS appealed the District Court’s decision to the Court of Appeals. Texas 2016 Transmission Cost Recovery Factor (TCRF) Application — In February 2017, SPS filed with the PUCT to recover additional annual revenue of approximately $16.1 million through its TCRF, or 1.8 percent. The filing was based upon capital transmission additions made during 2016. In June 2017, the PUCT approved TCRF rider recovery of approximately $14.4 million effective immediately. Pending Regulatory Proceeding — New Mexico Public Regulation Commission (NMPRC) New Mexico 2016 Electric Rate Case — In November 2016, SPS filed an electric rate case with the NMPRC seeking an increase in base rates of approximately $41.4 million, representing a total revenue increase of approximately 10.9 percent. The rate filing is based on a requested ROE of 10.1 percent, an equity ratio of 53.97 percent, an electric rate base of approximately $832 million and a future test year ending June 30, 2018. On April 10, 2017, the hearing examiner determined that SPS’ rate filing was deficient and recommended the NMPRC extend the procedural schedule by approximately one month and restart the suspension period once it is determined that the deficiencies are resolved. On April 19, 2017, the NMPRC dismissed SPS’ rate case. On May 15, 2017, SPS filed a notice of appeal to the New Mexico Supreme Court. A decision from the New Mexico Supreme Court is not expected until the second or third quarter of 2018.

Rate Matters

Except to the extent noted below, the circumstances set forth in Note 10 to the financial statements included in SPS’ Annual Report on Form 10-K for the year ended Dec. 31, 2016 and in Note 5 to the financial statements included in to SPS’ Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2017, appropriately represent, in all material respects, the current status of other rate matters, and are incorporated herein by reference.

Pending and Recently Concluded Regulatory Proceedings — Public Utility Commission of Texas (PUCT)

Appeal of the Texas 2015 Electric Rate Case Decision — In 2014, SPS had requested an overall retail electric revenue rate increase of $42.1 million. In 2015, the PUCT approved an overall rate decrease of approximately $4.0 million, net of rate case expenses. In April 2016, SPS filed an appeal, with the Texas State District Court, of the PUCT’s order that had denied SPS’ request for rehearing on certain items in SPS’ Texas 2015 electric rate case related to capital structure, incentive compensation and wholesale load reductions. In March 2017, the Travis County District Court denied SPS’ appeal. In April 2017, SPS appealed the District Court’s decision to the Court of Appeals.

Texas 2016 Transmission Cost Recovery Factor (TCRF) Application — In February 2017, SPS filed with the PUCT to recover additional annual revenue of approximately $16.1 million through its TCRF, or 1.8 percent. The filing was based upon capital transmission additions made during 2016. In June 2017, the PUCT approved TCRF rider recovery of approximately $14.4 million effective immediately.

Pending Regulatory Proceeding — New Mexico Public Regulation Commission (NMPRC)

New Mexico 2016 Electric Rate Case — In November 2016, SPS filed an electric rate case with the NMPRC seeking an increase in base rates of approximately $41.4 million, representing a total revenue increase of approximately 10.9 percent. The rate filing is based on a requested ROE of 10.1 percent, an equity ratio of 53.97 percent, an electric rate base of approximately $832 million and a future test year ending June 30, 2018.

On April 10, 2017, the hearing examiner determined that SPS’ rate filing was deficient and recommended the NMPRC extend the procedural schedule by approximately one month and restart the suspension period once it is determined that the deficiencies are resolved. On April 19, 2017, the NMPRC dismissed SPS’ rate case. On May 15, 2017, SPS filed a notice of appeal to the New Mexico Supreme Court. A decision from the New Mexico Supreme Court is not expected until the second or third quarter of 2018.