Investment in Unconsolidated Affiliates (Details) (USD $) In Millions, unless otherwise specified									8 Months Ended
	Jun. 30, 2013	May 01, 2013	Jun. 30, 2013 Enogex LLC [Member]		May 01, 2013 Enogex LLC [Member]	May 01, 2013 Southeast Supply Header, LLC [Member]	May 01, 2013 ArcLight group [Member]	May 01, 2013 OGE Holdings [Member]	Dec. 31, 2013 OGE Energy [Member]	May 01, 2013 OGE Energy [Member]	May 01, 2013 Midstream Partnership [Member]	May 01, 2013 CenterPoint [Member]
Value of Midstream Operations Assets or Equity Acquired		$ 50
Percentage of Enogex LLC Contributed					100.00%
Percentage of Subsidiary Contributed						24.95%
Percentage Share of Management Rights										50.00%		50.00%
Contributions to Pay Down Short-Term Debt							107.0	9.1
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest									28.50%
Percent of Incentive Distribution Rights										60.00%		40.00%
Line of Credit Facility, Maximum Borrowing Capacity	1,150.0		400.0	[1]							1,400.0
Value of Aggregate Midstream Operations Assets or Equity Acquired by Parties Not Offered in Midstream Partnership		$ 100

[1] This bank facility is available to back up OG&E's commercial paper borrowings and to provide revolving credit borrowings. This bank facility can also be used as a letter of credit facility. At June 30, 2013, there was $2.1 million supporting letters of credit.