Unconsolidated Affiliates (Details) (USD $)	3 Months Ended						3 Months Ended		3 Months Ended												1 Months Ended			1 Months Ended
	Mar. 31, 2014		Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2014 SESH [Member]	Dec. 31, 2013 SESH [Member]	Mar. 31, 2014 Midstream Partnership [Member]	Dec. 31, 2013 Midstream Partnership [Member]	Mar. 31, 2014 Enable Midstream Partners [Member] CERC Corp [Member]	Mar. 31, 2014 Enable Midstream Partners [Member] OGE [Member]	Mar. 31, 2014 SESH [Member]		Mar. 31, 2013 SESH [Member]		Mar. 31, 2014 Midstream Partnership [Member]	Mar. 31, 2013 Midstream Partnership [Member]	Mar. 31, 2014 Midstream Partnership [Member] CERC Corp [Member]	Mar. 31, 2014 Midstream Partnership [Member] OGE [Member]	Mar. 31, 2014 May 2014 [Member] SESH [Member]	Mar. 31, 2014 may 2015 [Member] SESH [Member]	Apr. 30, 2014 Scenario, Forecast [Member] Midstream Partnership [Member]	Apr. 16, 2014 Scenario, Forecast [Member] Midstream Partnership [Member]	Apr. 16, 2014 Scenario, Forecast [Member] Midstream Partnership [Member] CERC Corp [Member]	Apr. 30, 2014 Scenario, Forecast [Member] Midstream Partnership [Member] ArcLight [Member]	Apr. 16, 2014 Common Stock [Member] Scenario, Forecast [Member] Midstream Partnership [Member]	Apr. 16, 2014 Subordinated Units [Member] Scenario, Forecast [Member] Midstream Partnership [Member]
Term Loan of Affiliate							$ 1,050,000,000
Notes receivable from unconsolidated affiliates	363,000,000			363,000,000			363,000,000
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum							2.10%
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum							2.45%
Interest Receivable							6,000,000
Interest Income (Expense), Net							2,000,000
Transitional Service Costs to be Reimbursed	45,000,000
Transitional Service costs, eliminated	3,000,000
Transitional Service cost receivable	20,000,000
Equity Method Investment, Ownership Percentage					25.05%				58.30%														54.70%
Equity Method Investment, Additional Contribution of Ownership Percentage																			24.95%	0.10%
Limited Partners' Capital Account, Units Issued																			6,322,457	25,341
Cost of natural gas purchases, affiliates	47,000,000
Due to Affiliate, Current	16,000,000
Partners' Capital Account, Units, Sold in Public Offering																					28,750,000			3,750,000
Proceeds from Issuance Initial Public Offering																					466,000,000
Share Price																						$ 20.00
Equity Method Investment, Ownership, Shares																									87,803,909	139,704,916
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%
Investment in unconsolidated affiliates	4,540,000,000			4,518,000,000	200,000,000	199,000,000	4,340,000,000	4,319,000,000
Equity in earnings of unconsolidated affiliates, net	91,000,000		5,000,000								3,000,000	[1]	5,000,000	[1]	88,000,000	0
Operating revenues															1,002,000,000
Cost of sales, excluding depreciation and amortization															633,000,000
Operating income															162,000,000
Net income attributable to Enable															149,000,000
CERC's approximate 58.3% interest	88,000,000														87,000,000
Basis difference accretion gain															1,000,000
Current assets							500,000,000
Non-current assets							10,758,000,000
Current liabilities							1,039,000,000
Non-current liabilities							2,002,000,000
Non-controlling interest							34,000,000
Enable Partner's capital							8,183,000,000
CERC's approximate 58.3% interest, net	4,773,000,000
CERC's basis difference	(433,000,000)
CERC's investment in Enable	4,340,000,000
Basis difference attributable to goodwill as of Closing Date (1)	229,000,000	[2]
Basis difference to be accreted over 30 years as of Closing Date	210,000,000
Total basis difference as of Closing Date	439,000,000
Accumulated accretion of basis difference as of March 31, 2014	(6,000,000)
CERC's basis difference in Enable as of March 31, 2014	433,000,000
Distributions received from Enable											$ 3,000,000		$ 9,000,000		$ 67,000,000	$ 0

[1] On May 1, 2013, CERC contributed a 24.95% interest in SESH to Enable, leaving CERC with a 25.05% interest in SESH

[2] This difference related to CERC’s proportionate share of Enable’s goodwill arising from Enable's acquisition of Enogex, and therefore will not be recognized by CERC.