Background and Basis of Presentation (Details)	3 Months Ended		1 Months Ended
Jun. 30, 2013 CERC Corp [Member]	Jun. 30, 2013 OGE [Member]	Jun. 30, 2013 ArcLight [Member]	Jun. 30, 2013 Midstream Partnership [Member]	Apr. 30, 2013 Southeast Supply Header Llc [Member] CERC Corp [Member]	Apr. 30, 2013 Enogex LLC [Member] OGE ARCLIGHT [Member]
Equity Method Investment, Ownership Percentage		28.50%	13.20%	58.30%
Equity Interest Contributed, Percentage					24.95%	100.00%
Nature of Common Ownership or Management Control Relationships	0.5	0.5
Incentive Distribution Right	40.00%	60.00%

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 159

-Paragraph 18

-Subparagraph f

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 18

-Paragraph 20

-Subparagraph a (1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Data Type:	num:percentItemType
Balance Type:	na
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