Summary of Significant Accounting Policies Equity Ownership (Details)	8 Months Ended
Dec. 31, 2013	May 01, 2013
CenterPoint [Member]
Percentage Share of Management Rights		50.00%
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%

The number of units or percentage investment held by one or more members or limited partners of the LLC or LP.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 272

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

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