Rate Matters and Regulation	12 Months Ended
Dec. 31, 2014
Regulated Operations [Abstract]
Rate Matters and Regulation	Rate Matters and Regulation Regulation and Rates OG&E's retail electric tariffs are regulated by the OCC in Oklahoma and by the APSC in Arkansas. The issuance of certain securities by OG&E is also regulated by the OCC and the APSC. OG&E's wholesale electric tariffs, transmission activities, short-term borrowing authorization and accounting practices are subject to the jurisdiction of the FERC. The Secretary of the U.S. Department of Energy has jurisdiction over some of OG&E's facilities and operations. In 2014, 84 percent of OG&E's electric revenue was subject to the jurisdiction of the OCC, eight percent to the APSC and eight percent to the FERC. The OCC issued an order in 1996 authorizing OG&E to reorganize into a subsidiary of OGE Energy. The order required that, among other things, (i) OGE Energy permit the OCC access to the books and records of OGE Energy and its affiliates relating to transactions with OG&E, (ii) OGE Energy employ accounting and other procedures and controls to protect against subsidization of non-utility activities by OG&E's customers and (iii) OGE Energy refrain from pledging OG&E assets or income for affiliate transactions. In addition, the Energy Policy Act of 2005 enacted the Public Utility Holding Company Act of 2005, which in turn granted to the FERC access to the books and records of OGE Energy and its affiliates as the FERC deems relevant to costs incurred by OG&E or necessary or appropriate for the protection of utility customers with respect to the FERC jurisdictional rates. Completed Regulatory Matters Market-Based Rate Authority On June 29, 2012, OG&E filed its triennial market power update with the FERC to retain its market-based rate authorization in the SPP's energy imbalance service market but to surrender its market-based rate authorization for any market-based rates sales outside of the SPP's energy imbalance service market. On May 2, 2013, the FERC issued an order accepting OG&E's June 2012 triennial market power update. On December 30, 2013, OG&E submitted to the FERC a market-based rate change in status filing and a revised market-based rate tariff that would authorize OG&E to (i) sell electric energy and capacity at market-based rates without geographic restriction, and (ii) sell ancillary services in the SPP and Midcontinent Independent System Operator, Inc. markets. The primary goal of this filing was to implement the market-based rate authority OG&E needs to fully participate in SPP’s Integrated Marketplace. On February 28, 2014, FERC issued a letter order accepting OG&E’s market-based rate filing and tariff effective March 1, 2014. FERC found that OG&E passed the market power screens and satisfied requirements related to horizontal market power and vertical market power. Section 206 Complaint On November 26, 2013, Arkansas Electric Cooperative Corporation filed a complaint at the FERC against OG&E, arguing that the wholesale formula rate contract between OG&E and Arkansas Electric Cooperative Corporation (formerly between OG&E and Arkansas Valley Electric Cooperative) is unjust and unreasonable with respect to several items. OG&E and Arkansas Electric Cooperative Corporation agreed to terms of a settlement and filed the offer of settlement with the FERC on February 24, 2014. On April 17, 2014, the FERC accepted the settlement making it effective March 1, 2014. The reduction in revenue for 2014 was $0.9 million. Fuel Adjustment Clause Review for Calendar Year 2012 The OCC routinely reviews the costs recovered from customers through OG&E's fuel adjustment clause. On July 31, 2013, the OCC Staff filed an application to review OG&E's fuel adjustment clause for calendar year 2012, including the prudence of OG&E's electric generation, purchased power and fuel procurement costs. OG&E filed the necessary information and documents needed to satisfy the OCC's minimum filing requirement rules on October 9, 2013. On April 24, 2014, the OCC administrative law judge at the hearing, on the merits, recommended that the OCC find that OG&E's 2012 electric generation, purchased power and fuel procurement processes and costs were prudent. On June 10, 2014, the OCC issued an order approving OG&E’s practices, policies and judgment regarding its electric generation, purchased power, and fuel procurement processes and costs for the calendar year 2012. The order also found that the costs were prudent, reasonable, and mathematically correct. Integrated Resource Plans In June 2014, OG&E initiated the process to update its Integrated Resource Plans in Oklahoma and Arkansas at OG&E's discretion. The prior Integrated Resource Plan, submitted in 2012, assumed that the Oklahoma SIP would be followed to comply with Regional Haze requirements. Subsequent to holding technical conferences and public stakeholder meetings, OG&E submitted its revised Integrated Resource Plans, which included its environmental compliance plan described below, to the OCC on August 4, 2014 and to the APSC on September 8, 2014. Pending Regulatory Matters FERC Order No. 1000, Final Rule on Transmission Planning and Cost Allocation On July 21, 2011, the FERC issued Order No. 1000, which revised the FERC's existing regulations governing the process for planning enhancements and expansions of the electric transmission grid in a particular region, along with the corresponding process for allocating the costs of such expansions. Order No. 1000 leaves to individual regions to determine whether a previously-approved project is subject to reevaluation and is therefore governed by the new rule. Order No. 1000 requires, among other things, public utility transmission providers, such as the SPP, to participate in a process that produces a regional transmission plan satisfying certain standards, and requires that each such regional process consider transmission needs driven by public policy requirements (such as state or Federal policies favoring increased use of renewable energy resources). Order No. 1000 also directs public utility transmission providers to coordinate with neighboring transmission planning regions. In addition, Order No. 1000 establishes specific regional cost allocation principles and directs public utility transmission providers to participate in regional and interregional transmission planning processes that satisfy these principles. On the issue of determining how entities are to be selected to develop and construct the specific transmission projects, Order No. 1000 directs public utility transmission providers to remove from the FERC-jurisdictional tariffs and agreements provisions that establish any Federal "right of first refusal" for the incumbent transmission owner (such as OG&E) regarding transmission facilities selected in a regional transmission planning process, subject to certain limitations. However, Order No. 1000 is not intended to affect the right of an incumbent transmission owner (such as OG&E) to build, own and recover costs for upgrades to its own transmission facilities, and Order No. 1000 does not alter an incumbent transmission owner's use and control of existing rights of way. Order No. 1000 also clarifies that incumbent transmission owners may rely on regional transmission facilities to meet their reliability needs or service obligations. The SPP's pre-Order No. 1000 tariff included a "right of first refusal" for incumbent transmission owners and this provision has played a role in OG&E being selected by the SPP to build previous transmission projects in Oklahoma. These changes to the "right of first refusal" apply only to "new transmission facilities," which are facilities subject to evaluation or reevaluation (under the applicable local or regional transmission planning process) after November 13, 2012. On May 29, 2013, the Governor signed House Bill 1932 into law which establishes a right of first refusal for Oklahoma incumbent transmission owners, including OG&E, to build new transmission projects with voltages under 300 kilovolts that interconnect to those incumbent owners' existing facilities. OG&E believes this law is consistent with the language of Order No. 1000. On August 15, 2014, the U.S. Court of Appeals for the D.C. Circuit issued an order denying all appeals of Order No. 1000. The FERC has issued two orders on the SPP's Order No. 1000 compliance filings. In its most recent order, issued October 16, 2014, the FERC confirmed that “right of first refusal” language should be removed from the SPP tariff and Membership Agreement as applied to most transmission facilities, but that several types of facilities would remain subject to a right of first refusal. Projects that retained the right of first refusal included facilities that would operate below 100 kilovolts, facilities selected as part of the SPP’s Aggregate Study process, and short-term reliability projects. The FERC also approved SPP’s new competitive solicitation process for projects that are not subject to a right of first refusal. FERC found that SPP may consider state and local laws and regulations when deciding whether SPP will hold a competitive solicitation for a proposed project. On December 15, 2014, OG&E filed an appeal in the District of Columbia Circuit Court of Appeals of a portion of the October 2014 FERC order requiring removal of the right of first refusal language from the Membership Agreement. The court has not yet acted on OG&E's appeal. OGE Energy cannot, at this time, determine the precise impact of Order No. 1000 on OG&E. OGE Energy has no reason to believe that the implementation of Order No. 1000 will impact OG&E's transmission projects currently under development and construction for which OG&E has received a notice to proceed from the SPP. Energy Efficiency Program Filing On February 14, 2014, OG&E filed an application with the APSC requesting approval of interim modifications to approved Energy Efficiency Programs, new tariff revisions and the waiver of certain provisions of the Commission’s Rules for Conservation and Energy Efficiency Programs. Environmental Compliance Plan On August 6, 2014, OG&E filed an application with the OCC for approval of its plan to comply with EPA’s MATS and Regional Haze FIP while serving the best long-term interests of customers in light of future environmental uncertainties. The application seeks approval of the environmental compliance plan and for a recovery mechanism for the associated costs. The environmental compliance plan includes installing dry scrubbers at Sooner Units 1 and 2 and the conversion of Muskogee Units 4 and 5 to natural gas. The application also asks the Commission to predetermine the prudence of replacing OG&E's soon-to-be retired Mustang steam turbines in late 2017 (approximately 460 MW) with 400 MW of new, efficient combustion turbines at the Mustang site in 2018 and 2019 and approval for a recovery mechanism for the associated costs. OG&E estimates the total capital cost associated with its environmental compliance plan included in this application to be approximately $1.1 billion. The OCC hearing on OG&E's application is scheduled to commence on March 3, 2015. Multiple parties advocating a variety of positions have intervened in the proceeding. OG&E expects a ruling from the OCC in the second quarter of 2015. At this time, OG&E cannot predict the outcome of the proceeding. OG&E plans to file applications in the first quarter of 2015 seeking related approvals from the APSC. Fuel Adjustment Clause Review for Calendar Year 2013 The OCC routinely reviews the costs recovered from customers through OG&E's fuel adjustment clause. On July 31, 2014, the OCC Staff filed an application to review OG&E's fuel adjustment clause for calendar year 2013, including the prudence of OG&E's electric generation, purchased power and fuel procurement costs. OG&E filed the necessary information and documents needed to satisfy the OCC's minimum filing requirement rules on September 29, 2014. A procedural schedule has not been established as of this date. OG&E expects an order in the second quarter of 2015.

Rate Matters and Regulation

Regulation and Rates

OG&E's retail electric tariffs are regulated by the OCC in Oklahoma and by the APSC in Arkansas. The issuance of certain securities by OG&E is also regulated by the OCC and the APSC. OG&E's wholesale electric tariffs, transmission activities, short-term borrowing authorization and accounting practices are subject to the jurisdiction of the FERC. The Secretary of the U.S. Department of Energy has jurisdiction over some of OG&E's facilities and operations. In 2014, 84 percent of OG&E's electric revenue was subject to the jurisdiction of the OCC, eight percent to the APSC and eight percent to the FERC.

The OCC issued an order in 1996 authorizing OG&E to reorganize into a subsidiary of OGE Energy. The order required that, among other things, (i) OGE Energy permit the OCC access to the books and records of OGE Energy and its affiliates relating to transactions with OG&E, (ii) OGE Energy employ accounting and other procedures and controls to protect against subsidization of non-utility activities by OG&E's customers and (iii) OGE Energy refrain from pledging OG&E assets or income for affiliate transactions. In addition, the Energy Policy Act of 2005 enacted the Public Utility Holding Company Act of 2005, which in turn granted to the FERC access to the books and records of OGE Energy and its affiliates as the FERC deems relevant to costs incurred by OG&E or necessary or appropriate for the protection of utility customers with respect to the FERC jurisdictional rates.

Completed Regulatory Matters

Market-Based Rate Authority

On June 29, 2012, OG&E filed its triennial market power update with the FERC to retain its market-based rate authorization in the SPP's energy imbalance service market but to surrender its market-based rate authorization for any market-based rates sales outside of the SPP's energy imbalance service market. On May 2, 2013, the FERC issued an order accepting OG&E's June 2012 triennial market power update.

On December 30, 2013, OG&E submitted to the FERC a market-based rate change in status filing and a revised market-based rate tariff that would authorize OG&E to (i) sell electric energy and capacity at market-based rates without geographic restriction, and (ii) sell ancillary services in the SPP and Midcontinent Independent System Operator, Inc. markets. The primary goal of this filing was to implement the market-based rate authority OG&E needs to fully participate in SPP’s Integrated Marketplace. On February 28, 2014, FERC issued a letter order accepting OG&E’s market-based rate filing and tariff effective March 1, 2014. FERC found that OG&E passed the market power screens and satisfied requirements related to horizontal market power and vertical market power.

Section 206 Complaint

On November 26, 2013, Arkansas Electric Cooperative Corporation filed a complaint at the FERC against OG&E, arguing that the wholesale formula rate contract between OG&E and Arkansas Electric Cooperative Corporation (formerly between OG&E and Arkansas Valley Electric Cooperative) is unjust and unreasonable with respect to several items. OG&E and Arkansas Electric Cooperative Corporation agreed to terms of a settlement and filed the offer of settlement with the FERC on February 24, 2014. On April 17, 2014, the FERC accepted the settlement making it effective March 1, 2014. The reduction in revenue for 2014 was $0.9 million.

Fuel Adjustment Clause Review for Calendar Year 2012

The OCC routinely reviews the costs recovered from customers through OG&E's fuel adjustment clause. On July 31, 2013, the OCC Staff filed an application to review OG&E's fuel adjustment clause for calendar year 2012, including the prudence of OG&E's electric generation, purchased power and fuel procurement costs. OG&E filed the necessary information and documents needed to satisfy the OCC's minimum filing requirement rules on October 9, 2013. On April 24, 2014, the OCC administrative law judge at the hearing, on the merits, recommended that the OCC find that OG&E's 2012 electric generation, purchased power and fuel procurement processes and costs were prudent. On June 10, 2014, the OCC issued an order approving OG&E’s practices, policies and judgment regarding its electric generation, purchased power, and fuel procurement processes and costs for the calendar year 2012. The order also found that the costs were prudent, reasonable, and mathematically correct.

Integrated Resource Plans

In June 2014, OG&E initiated the process to update its Integrated Resource Plans in Oklahoma and Arkansas at OG&E's discretion. The prior Integrated Resource Plan, submitted in 2012, assumed that the Oklahoma SIP would be followed to comply with Regional Haze requirements. Subsequent to holding technical conferences and public stakeholder meetings, OG&E submitted its revised Integrated Resource Plans, which included its environmental compliance plan described below, to the OCC on August 4, 2014 and to the APSC on September 8, 2014.

Pending Regulatory Matters

FERC Order No. 1000, Final Rule on Transmission Planning and Cost Allocation

On July 21, 2011, the FERC issued Order No. 1000, which revised the FERC's existing regulations governing the process for planning enhancements and expansions of the electric transmission grid in a particular region, along with the corresponding process for allocating the costs of such expansions. Order No. 1000 leaves to individual regions to determine whether a previously-approved project is subject to reevaluation and is therefore governed by the new rule.

Order No. 1000 requires, among other things, public utility transmission providers, such as the SPP, to participate in a process that produces a regional transmission plan satisfying certain standards, and requires that each such regional process consider transmission needs driven by public policy requirements (such as state or Federal policies favoring increased use of renewable energy resources). Order No. 1000 also directs public utility transmission providers to coordinate with neighboring transmission planning regions. In addition, Order No. 1000 establishes specific regional cost allocation principles and directs public utility transmission providers to participate in regional and interregional transmission planning processes that satisfy these principles.

On the issue of determining how entities are to be selected to develop and construct the specific transmission projects, Order No. 1000 directs public utility transmission providers to remove from the FERC-jurisdictional tariffs and agreements provisions that establish any Federal "right of first refusal" for the incumbent transmission owner (such as OG&E) regarding transmission facilities selected in a regional transmission planning process, subject to certain limitations. However, Order No. 1000 is not intended to affect the right of an incumbent transmission owner (such as OG&E) to build, own and recover costs for upgrades to its own transmission facilities, and Order No. 1000 does not alter an incumbent transmission owner's use and control of existing rights of way. Order No. 1000 also clarifies that incumbent transmission owners may rely on regional transmission facilities to meet their reliability needs or service obligations. The SPP's pre-Order No. 1000 tariff included a "right of first refusal" for incumbent transmission owners and this provision has played a role in OG&E being selected by the SPP to build previous transmission projects in Oklahoma. These changes to the "right of first refusal" apply only to "new transmission facilities," which are facilities subject to evaluation or reevaluation (under the applicable local or regional transmission planning process) after November 13, 2012. On May 29, 2013, the Governor signed House Bill 1932 into law which establishes a right of first refusal for Oklahoma incumbent transmission owners, including OG&E, to build new transmission projects with voltages under 300 kilovolts that interconnect to those incumbent owners' existing facilities. OG&E believes this law is consistent with the language of Order No. 1000. On August 15, 2014, the U.S. Court of Appeals for the D.C. Circuit issued an order denying all appeals of Order No. 1000.

The FERC has issued two orders on the SPP's Order No. 1000 compliance filings. In its most recent order, issued October 16, 2014, the FERC confirmed that “right of first refusal” language should be removed from the SPP tariff and Membership Agreement as applied to most transmission facilities, but that several types of facilities would remain subject to a right of first refusal. Projects that retained the right of first refusal included facilities that would operate below 100 kilovolts, facilities selected as part of the SPP’s Aggregate Study process, and short-term reliability projects. The FERC also approved SPP’s new competitive solicitation process for projects that are not subject to a right of first refusal. FERC found that SPP may consider state and local laws and regulations when deciding whether SPP will hold a competitive solicitation for a proposed project. On December 15, 2014, OG&E filed an appeal in the District of Columbia Circuit Court of Appeals of a portion of the October 2014 FERC order requiring removal of the right of first refusal language from the Membership Agreement. The court has not yet acted on OG&E's appeal.

OGE Energy cannot, at this time, determine the precise impact of Order No. 1000 on OG&E. OGE Energy has no reason to believe that the implementation of Order No. 1000 will impact OG&E's transmission projects currently under development and construction for which OG&E has received a notice to proceed from the SPP.

Energy Efficiency Program Filing

On February 14, 2014, OG&E filed an application with the APSC requesting approval of interim modifications to approved Energy Efficiency Programs, new tariff revisions and the waiver of certain provisions of the Commission’s Rules for Conservation and Energy Efficiency Programs.

Environmental Compliance Plan

On August 6, 2014, OG&E filed an application with the OCC for approval of its plan to comply with EPA’s MATS and Regional Haze FIP while serving the best long-term interests of customers in light of future environmental uncertainties. The application seeks approval of the environmental compliance plan and for a recovery mechanism for the associated costs. The environmental compliance plan includes installing dry scrubbers at Sooner Units 1 and 2 and the conversion of Muskogee Units 4 and 5 to natural gas. The application also asks the Commission to predetermine the prudence of replacing OG&E's soon-to-be retired Mustang steam turbines in late 2017 (approximately 460 MW) with 400 MW of new, efficient combustion turbines at the Mustang site in 2018 and 2019 and approval for a recovery mechanism for the associated costs. OG&E estimates the total capital cost associated with its environmental compliance plan included in this application to be approximately $1.1 billion. The OCC hearing on OG&E's application is scheduled to commence on March 3, 2015. Multiple parties advocating a variety of positions have intervened in the proceeding. OG&E expects a ruling from the OCC in the second quarter of 2015. At this time, OG&E cannot predict the outcome of the proceeding. OG&E plans to file applications in the first quarter of 2015 seeking related approvals from the APSC.

Fuel Adjustment Clause Review for Calendar Year 2013

The OCC routinely reviews the costs recovered from customers through OG&E's fuel adjustment clause. On July 31, 2014, the OCC Staff filed an application to review OG&E's fuel adjustment clause for calendar year 2013, including the prudence of OG&E's electric generation, purchased power and fuel procurement costs. OG&E filed the necessary information and documents needed to satisfy the OCC's minimum filing requirement rules on September 29, 2014. A procedural schedule has not been established as of this date. OG&E expects an order in the second quarter of 2015.