OGE Energy Midstream Partnership with CenterPoint Energy, Inc. (Details) (USD $) In Millions, unless otherwise specified	8 Months Ended
	Dec. 31, 2013	May 01, 2013	Mar. 31, 2013
Percentage of Subsidiary Owned by Another Company		50.00%
Line of Credit Facility, Maximum Borrowing Capacity			$ 1,550.0
Value of Midstream Operations Assets or Equity Acquired		50.0
Value of Aggregate Midstream Operations Assets or Equity Acquired by Parties Not Offered in Midstream Partnership		100.0
Enogex Llc [Member]
Percentage of Enogex LLC Contributed		100.00%
Line of Credit Facility, Maximum Borrowing Capacity			400.0	[1]
Long-term debt			700.0
OGE Holdings [Member]
Contributions to Pay Down Short-Term Debt		9.1
OGE Energy [Member]
Percentage of Limited Partner Interests Held in Midstream Partnership	28.50%
Percent of Limited Partner Interests Held if Approvals Are Obtained	28.00%
Percentage Share of Management Rights		50.00%
General Partner's Share of Undistributed Earnings, Incentive Distribution Right Embedded in General Partner Interest		60.00%
CenterPoint [Member]
Percentage of Limited Partner Interests Held in Midstream Partnership	58.30%
Percent of Limited Partner Interests Held if Approvals Are Obtained	59.00%
Percentage Share of Management Rights		50.00%
General Partner's Share of Undistributed Earnings, Incentive Distribution Right Embedded in General Partner Interest		40.00%
Long-term debt			363.0
ArcLight group [Member]
Contributions to Pay Down Short-Term Debt		107.0
Percentage of Limited Partner Interests Held in Midstream Partnership	13.20%
Percent of Limited Partner Interests Held if Approvals Are Obtained	13.00%
Southeast Supply Header, LLC [Member]
Percentage of Subsidiary Contributed		49.00%
Midstream Partnership [Member]
Term Loan Facility		1,050.0
Outstanding Intercompany Borrowings		1,050.0
Line of Credit Facility, Maximum Borrowing Capacity		1,400.0

[1] This bank facility was available to provide revolving credit borrowings for Enogex LLC. Effective May 1, 2013, the Midstream Partnership entered into a $1.4 billion, five-year senior unsecured revolving credit facility in accordance with the terms of the Master Formation Agreement and Enogex LLC's $400 million revolving credit facility was terminated.