Short-Term Debt and Credit Facility	9 Months Ended
Sep. 30, 2018
Short-term Debt [Abstract]
Short-Term Debt and Credit Facility [Text Block]	Short-Term Debt and Credit Facility At September 30, 2018, there was $299.7 million in advances to OGE Energy compared to $112.5 million at December 31, 2017. OG&E has an intercompany borrowing agreement with OGE Energy whereby OG&E has access to up to $350.0 million of OGE Energy's revolving credit amount. At September 30, 2018, there were no intercompany borrowings under this agreement. At September 30, 2018, there were $0.3 million supporting letters of credit at a weighted-average interest rate of 1.05 percent. There were no outstanding commercial paper borrowings at September 30, 2018. In March 2017, OG&E entered into an unsecured five-year $450.0 million revolving credit agreement. The facility contained an option, which could be exercised up to two times, to extend the term of the facility for an additional year. Effective March 9, 2018, OG&E utilized one of those extensions to extend the maturity of its credit facility from March 8, 2022 to March 8, 2023. OGE Energy's and OG&E's ability to access the commercial paper market could be adversely impacted by a credit ratings downgrade or major market disruptions. Pricing grids associated with OGE Energy's and OG&E's credit facilities could cause annual fees and borrowing rates to increase if an adverse rating impact occurs. The impact of any future downgrade could include an increase in the costs of OGE Energy's and OG&E's short-term borrowings, but a reduction in OGE Energy's and OG&E's credit ratings would not result in any defaults or accelerations. Any future downgrade of OG&E could also lead to higher long-term borrowing costs and, if below investment grade, would require OG&E to post collateral or letters of credit. OG&E must obtain regulatory approval from the FERC in order to borrow on a short-term basis. OG&E has the necessary regulatory approvals to incur up to $800.0 million in short-term borrowings at any one time for a two-year period beginning January 1, 2017 and ending December 31, 2018. OG&E has requested renewal of this authority for an additional two-year period and expects to receive approval prior to the expiration of its current authority.

Short-Term Debt and Credit Facility

At September 30, 2018, there was $299.7 million in advances to OGE Energy compared to $112.5 million at December 31, 2017. OG&E has an intercompany borrowing agreement with OGE Energy whereby OG&E has access to up to $350.0 million of OGE Energy's revolving credit amount. At September 30, 2018, there were no intercompany borrowings under this agreement. At September 30, 2018, there were $0.3 million supporting letters of credit at a weighted-average interest rate of 1.05 percent. There were no outstanding commercial paper borrowings at September 30, 2018.

In March 2017, OG&E entered into an unsecured five-year $450.0 million revolving credit agreement. The facility contained an option, which could be exercised up to two times, to extend the term of the facility for an additional year. Effective March 9, 2018, OG&E utilized one of those extensions to extend the maturity of its credit facility from March 8, 2022 to March 8, 2023.

OGE Energy's and OG&E's ability to access the commercial paper market could be adversely impacted by a credit ratings downgrade or major market disruptions. Pricing grids associated with OGE Energy's and OG&E's credit facilities could cause annual fees and borrowing rates to increase if an adverse rating impact occurs. The impact of any future downgrade could include an increase in the costs of OGE Energy's and OG&E's short-term borrowings, but a reduction in OGE Energy's and OG&E's credit ratings would not result in any defaults or accelerations. Any future downgrade of OG&E could also lead to higher long-term borrowing costs and, if below investment grade, would require OG&E to post collateral or letters of credit.

OG&E must obtain regulatory approval from the FERC in order to borrow on a short-term basis. OG&E has the necessary regulatory approvals to incur up to $800.0 million in short-term borrowings at any one time for a two-year period beginning January 1, 2017 and ending December 31, 2018. OG&E has requested renewal of this authority for an additional two-year period and expects to receive approval prior to the expiration of its current authority.