Summary of Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	12 Months Ended			1 Months Ended		1 Months Ended				3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended
	Jul. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jul. 31, 2012 Waskom Gas Processing Company [Member]	Jun. 30, 2012 Waskom Gas Processing Company [Member]	Jul. 31, 2012 Waskom Gas Processing Company [Member]	Jul. 31, 2012 Gathering and Related Assets [Member]	May 31, 2013 Enogex LLC [Member] OGE ARCLIGHT [Member]	May 31, 2013 Southeast Supply Header Llc [Member]	Dec. 31, 2013 Enable Midstream Partners [Member]	Dec. 31, 2013 Enable Midstream Partners [Member]	Dec. 31, 2013 Enable Midstream Partners [Member] OGE [Member]	Dec. 31, 2013 Enable Midstream Partners [Member] OGE [Member]	Dec. 31, 2013 Enable Midstream Partners [Member] ArcLight [Member]
Summary of Accounting Policies [Line Items]
Allowance for Funds Used During Construction, Capitalized Interest		$ 1	$ 2	$ 1
Minimum Ownership Interest Percentage For Investments Recorded Using Entity Method		20.00%
Maximum Ownership Interest Percentage For Investments Recorded Using Entity Method		50.00%
Equity Interest Contributed, Percentage									100.00%	24.95%
Equity Method Investment, Ownership Percentage						50.00%					58.30%	58.30%	28.50%	28.50%	13.20%
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest												50.00%		50.00%
Incentive Distribution Right											40.00%		60.00%
Percentage of Ownership in Affiliate 2 Acquired					50.00%
Business Acquisition, Cost of Acquired Entity, Cash Paid	273
Business Acquisition, Purchase Price Allocation, Remaining Interest					201
Business Acquisition, Purchase Price Allocation, Property, Plant and Equipment	253
Business Acquisition, Purchase Price Allocation, Goodwill Amount	16
Step acquisition gain	136	0	136	0
Business Combination, Step Acquisition, Equity Interest in Acquiree, Percentage						50.00%
Acquisition	24		24				17	7
Amount of removal costs recognized as a component of depreciation expense recorded as a regulatory liability		593	573
Allowance for doubtful accounts		25	23
Provision for doubtful accounts		20	15	25
Write-downs of natural gas inventory to lower of cost or market		4	4	11
Materials and supplies		34	83
Natural gas		145	145
Total inventory		179	228
Margin deposits		4	12
Under Recovered Gas Costs		22	86
Over Recovered Gas Costs		$ 42	$ 6