Regulatory Matters	3 Months Ended
Mar. 31, 2016
Regulated Operations [Abstract]
Regulatory Matters	5. REGULATORY MATTERS GMO Missouri 2016 Rate Case Proceedings In February 2016, GMO filed an application with the Public Service Commission of the State of Missouri (MPSC) to request an increase to its retail revenues of $59.3 million, with a return on equity of 9.9% and a rate-making equity ratio of 54.83%. The request included recovery of increased transmission and property tax expenses as well as costs for infrastructure and system improvements made to be able to provide reliable electric service. Testimony from MPSC staff and other parties regarding the case is expected in July 2016, with an evidentiary hearing to occur in September 2016. New rates are expected to be effective in December 2016. KCP&L Kansas 2015 Rate Case Proceedings In September 2015, the State Corporation Commission of the State of Kansas (KCC) issued an order for KCP&L authorizing an increase in annual revenues of $48.7 million, a return on equity of 9.3% and a rate-making equity ratio of 50.48%. KCP&L filed a Petition for Judicial Review with the Court of Appeals of Kansas in November 2015 regarding various issues, which was denied in March 2016. The rates established by the order took effect on October 1, 2015. KCP&L Missouri 2015 Rate Case Proceedings In September 2015, the MPSC issued an order for KCP&L authorizing an increase in annual revenues of $89.7 million, a return on equity of 9.5% and a rate-making equity ratio of approximately 50.09%. The MPSC also approved KCP&L’s request to implement a Fuel Adjustment Clause (FAC). The rates established by the order took effect on September 29, 2015, and are effective unless and until modified by the MPSC or stayed by a court. Notices of Appeal of the September 2015 MPSC order were filed with the Missouri Court of Appeals, Western District, by KCP&L in October 2015 and by Midwest Energy Consumers' Group in November 2015 regarding various issues.

5. REGULATORY MATTERS

GMO Missouri 2016 Rate Case Proceedings

In February 2016, GMO filed an application with the Public Service Commission of the State of Missouri (MPSC) to request an increase to its retail revenues of $59.3 million, with a return on equity of 9.9% and a rate-making equity ratio of 54.83%. The request included recovery of increased transmission and property tax expenses as well as costs for infrastructure and system improvements made to be able to provide reliable electric service. Testimony from MPSC staff and other parties regarding the case is expected in July 2016, with an evidentiary hearing to occur in September 2016. New rates are expected to be effective in December 2016.

KCP&L Kansas 2015 Rate Case Proceedings

In September 2015, the State Corporation Commission of the State of Kansas (KCC) issued an order for KCP&L authorizing an increase in annual revenues of $48.7 million, a return on equity of 9.3% and a rate-making equity ratio of 50.48%. KCP&L filed a Petition for Judicial Review with the Court of Appeals of Kansas in November 2015 regarding various issues, which was denied in March 2016. The rates established by the order took effect on October 1, 2015.

KCP&L Missouri 2015 Rate Case Proceedings

In September 2015, the MPSC issued an order for KCP&L authorizing an increase in annual revenues of $89.7 million, a return on equity of 9.5% and a rate-making equity ratio of approximately 50.09%. The MPSC also approved KCP&L’s request to implement a Fuel Adjustment Clause (FAC). The rates established by the order took effect on September 29, 2015, and are effective unless and until modified by the MPSC or stayed by a court. Notices of Appeal of the September 2015 MPSC order were filed with the Missouri Court of Appeals, Western District, by KCP&L in October 2015 and by Midwest Energy Consumers' Group in November 2015 regarding various issues.