Regulatory Matters	9 Months Ended
Sep. 30, 2014
Regulated Operations [Abstract]
Regulatory Matters	5. REGULATORY MATTERS KCP&L Kansas Abbreviated Rate Case Proceedings In December 2013, KCP&L filed an abbreviated application with KCC to request an increase to its retail revenues of $12.1 million, which was subsequently updated to $11.5 million, including the recovery of costs to reflect the completion of certain components of environmental upgrades at the La Cygne Station, construction work in progress for those components of the upgrades still under construction and updates to certain regulatory asset amortizations. The previously approved return on equity and rate-making equity ratio for KCP&L were not addressed in this case. In July 2014, KCC issued an order authorizing an increase to retail revenues of $11.5 million effective July 25, 2014. KCP&L Kansas La Cygne Rate Case Treatment Request Proceedings In July 2014, KCP&L filed a request with KCC to use budget amounts for its Kansas jurisdictional portion of costs for a project to install environmental upgrades at the La Cygne Station in determining its request for new retail rates in its next general rate case. KCP&L also requested to defer to a regulatory asset the Kansas jurisdictional portion of depreciation for the La Cygne project from the time the project is placed into service until the date new retail rates become effective in KCP&L's next general rate case in Kansas. In September 2014, KCC issued an order approving these requests. The La Cygne project is expected to be in-service by June 2015. KCP&L Missouri La Cygne Construction Accounting Request Proceedings In June 2014, KCP&L filed a request with the MPSC to use construction accounting for a project to install environmental upgrades at the La Cygne Station. Construction accounting would defer to a regulatory asset KCP&L's Missouri jurisdictional portion of carrying costs (interest) and depreciation expense on the project from the time the project is placed into service until the date new retail rates become effective in KCP&L's next general rate case in Missouri. A hearing in this case is scheduled for mid-December 2014 with an order expected in 2015. The La Cygne project is expected to be in-service by June 2015. KCP&L Missouri Energy Efficiency Investment Act Proceedings In June 2014, the MPSC issued an order approving KCP&L's request to recover costs for new and enhanced demand side management programs under the Missouri Energy Efficiency Investment Act (MEEIA). The costs are recovered through a rider mechanism which began in August 2014. KCP&L Missouri Rate Case Proceedings In October 2014, KCP&L filed an application with the MPSC to request an increase to its retail revenues of $120.9 million, with a return on equity of 10.3% and a rate-making equity ratio of 50.36%. The request includes recovery of increased transmission and property tax expenses, costs to install environmental upgrades at the La Cygne Station, upgrades at Wolf Creek and other infrastructure and system improvements made to be able to provide reliable electric service. KCP&L also requested authorization to implement a fuel adjustment clause. If approved, new rates are anticipated to be effective on or around September 30, 2015. KCP&L and GMO Missouri Transmission Cost Accounting Authority Order Proceeding In September 2013, KCP&L and GMO filed an application with the MPSC requesting an accounting authority order to defer transmission costs above or below the amount included in current base rates, including carrying costs, as a regulatory asset or liability with the recovery from or refund to Missouri retail customers to be determined in the next general rate case for each company. In July 2014, the MPSC issued its order denying KCP&L's and GMO's request. GMO Missouri Rate Case Proceedings On January 9, 2013, the MPSC issued an order for GMO authorizing an increase in annual revenues of $26.2 million for its Missouri Public Service division and $21.7 million for its St. Joseph Light & Power division effective January 26, 2013. In March 2014, the Missouri Court of Appeals, Western District (Court of Appeals) dismissed appeals of the January 9, 2013, MPSC order that were filed in February 2013 by GMO and the Missouri Energy Consumers Group (MECG) regarding various issues. GMO Missouri Renewable Energy Standard Rate Adjustment Mechanism Proceedings In April 2014, GMO filed an application with the MPSC requesting a Renewable Energy Standard Rate Adjustment Mechanism to recover costs for solar rebates and other compliance costs incurred under the Renewable Energy Standard law in Missouri through a rider mechanism. Annual recovery under the rider would not exceed 1% of GMO's annual revenue requirement as determined by the MPSC in the last rate case. In October 2014, GMO, MPSC staff and other parties entered into a non-unanimous partial stipulation and agreement to settle certain issues in the case. In November 2014, the MPSC approved the partial stipulation and agreement and the rider mechanism is expected to begin in December 2014. A hearing on the remaining issues in this case is scheduled for February 2015.

5. REGULATORY MATTERS

KCP&L Kansas Abbreviated Rate Case Proceedings

In December 2013, KCP&L filed an abbreviated application with KCC to request an increase to its retail revenues of $12.1 million, which was subsequently updated to $11.5 million, including the recovery of costs to reflect the completion of certain components of environmental upgrades at the La Cygne Station, construction work in progress for those components of the upgrades still under construction and updates to certain regulatory asset amortizations. The previously approved return on equity and rate-making equity ratio for KCP&L were not addressed in this case. In July 2014, KCC issued an order authorizing an increase to retail revenues of $11.5 million effective July 25, 2014.

KCP&L Kansas La Cygne Rate Case Treatment Request Proceedings

In July 2014, KCP&L filed a request with KCC to use budget amounts for its Kansas jurisdictional portion of costs for a project to install environmental upgrades at the La Cygne Station in determining its request for new retail rates in its next general rate case. KCP&L also requested to defer to a regulatory asset the Kansas jurisdictional portion of depreciation for the La Cygne project from the time the project is placed into service until the date new retail rates become effective in KCP&L's next general rate case in Kansas. In September 2014, KCC issued an order approving these requests. The La Cygne project is expected to be in-service by June 2015.

KCP&L Missouri La Cygne Construction Accounting Request Proceedings

In June 2014, KCP&L filed a request with the MPSC to use construction accounting for a project to install environmental upgrades at the La Cygne Station. Construction accounting would defer to a regulatory asset KCP&L's Missouri jurisdictional portion of carrying costs (interest) and depreciation expense on the project from the time the project is placed into service until the date new retail rates become effective in KCP&L's next general rate case in Missouri. A hearing in this case is scheduled for mid-December 2014 with an order expected in 2015. The La Cygne project is expected to be in-service by June 2015.

KCP&L Missouri Energy Efficiency Investment Act Proceedings

In June 2014, the MPSC issued an order approving KCP&L's request to recover costs for new and enhanced demand side management programs under the Missouri Energy Efficiency Investment Act (MEEIA). The costs are recovered through a rider mechanism which began in August 2014.

KCP&L Missouri Rate Case Proceedings

In October 2014, KCP&L filed an application with the MPSC to request an increase to its retail revenues of $120.9 million, with a return on equity of 10.3% and a rate-making equity ratio of 50.36%. The request includes recovery of increased transmission and property tax expenses, costs to install environmental upgrades at the La Cygne Station, upgrades at Wolf Creek and other infrastructure and system improvements made to be able to provide reliable electric service. KCP&L also requested authorization to implement a fuel adjustment clause. If approved, new rates are anticipated to be effective on or around September 30, 2015.

KCP&L and GMO Missouri Transmission Cost Accounting Authority Order Proceeding

In September 2013, KCP&L and GMO filed an application with the MPSC requesting an accounting authority order to defer transmission costs above or below the amount included in current base rates, including carrying costs, as a regulatory asset or liability with the recovery from or refund to Missouri retail customers to be determined in the next general rate case for each company. In July 2014, the MPSC issued its order denying KCP&L's and GMO's request.

GMO Missouri Rate Case Proceedings

On January 9, 2013, the MPSC issued an order for GMO authorizing an increase in annual revenues of $26.2 million for its Missouri Public Service division and $21.7 million for its St. Joseph Light & Power division effective January 26, 2013. In March 2014, the Missouri Court of Appeals, Western District (Court of Appeals) dismissed appeals of the January 9, 2013, MPSC order that were filed in February 2013 by GMO and the Missouri Energy Consumers Group (MECG) regarding various issues.

GMO Missouri Renewable Energy Standard Rate Adjustment Mechanism Proceedings

In April 2014, GMO filed an application with the MPSC requesting a Renewable Energy Standard Rate Adjustment Mechanism to recover costs for solar rebates and other compliance costs incurred under the Renewable Energy Standard law in Missouri through a rider mechanism. Annual recovery under the rider would not exceed 1% of GMO's annual revenue requirement as determined by the MPSC in the last rate case. In October 2014, GMO, MPSC staff and other parties entered into a non-unanimous partial stipulation and agreement to settle certain issues in the case. In November 2014, the MPSC approved the partial stipulation and agreement and the rider mechanism is expected to begin in December 2014. A hearing on the remaining issues in this case is scheduled for February 2015.