Summary of Significant Accounting Policies Equity Ownership (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Jun. 30, 2014	Mar. 31, 2014
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest		6.90%
OGE Energy [Member]
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest	26.70%	28.50%
Percent of Subordinated Limited Partner Units		61.40%
Percent of Incentive Distribution Rights		60.00%
Percentage Share of Management Rights		50.00%
OGE Holdings [Member]
Units Held by Limited Partners of the LLC or LP.		42,832,291
Subordinated Units Held by Limited Partners of the LLC or LP.		68,150,514
CenterPoint [Member]
Percent of Subordinated Limited Partner Units		61.40%
Percent of Incentive Distribution Rights		40.00%
Percentage Share of Management Rights		50.00%
Enable Midstream Partners [Member]
Partners' Capital Account, Units, Sold in Public Offering		28,750,000
Proceeds from Issuance Initial Public Offering		$ 466.0