Investment in Unconsolidated Affiliates (Details) (USD $) In Millions, unless otherwise specified	5 Months Ended
	Sep. 30, 2013		May 01, 2013
Value of Midstream Operations Assets or Equity Acquired			$ 50
Line of Credit Facility, Maximum Borrowing Capacity	1,150.0
Value of Aggregate Midstream Operations Assets or Equity Acquired by Parties Not Offered in Midstream Partnership			100
Enogex LLC [Member]
Percentage of Enogex LLC Contributed			100.00%
Line of Credit Facility, Maximum Borrowing Capacity	400.0	[1]
Southeast Supply Header, LLC [Member]
Percentage of Subsidiary Contributed			24.95%
ArcLight group [Member]
Contributions to Pay Down Short-Term Debt			107.0
OGE Holdings [Member]
Contributions to Pay Down Short-Term Debt			9.1
OGE Energy [Member]
Percentage Share of Management Rights			50.00%
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest	28.50%
Percent of Incentive Distribution Rights			60.00%
Midstream Partnership [Member]
Line of Credit Facility, Maximum Borrowing Capacity			$ 1,400.0
CenterPoint [Member]
Percentage Share of Management Rights			50.00%
Percent of Incentive Distribution Rights			40.00%

[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.