Reportable Business Segments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended										8 Months Ended	12 Months Ended																													1 Months Ended												12 Months Ended																										8 Months Ended	12 Months Ended		8 Months Ended		12 Months Ended					4 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013		Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012		Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Natural Gas Distribution [Member]	Dec. 31, 2012 Natural Gas Distribution [Member]	Dec. 31, 2011 Natural Gas Distribution [Member]	Dec. 31, 2013 Energy Services [Member]	Dec. 31, 2012 Energy Services [Member]	Dec. 31, 2011 Energy Services [Member]	Dec. 31, 2013 Interstate Pipelines [Member]		Dec. 31, 2012 Interstate Pipelines [Member]		Dec. 31, 2011 Interstate Pipelines [Member]		Dec. 31, 2013 Field Services [Member]		Dec. 31, 2012 Field Services [Member]		Dec. 31, 2011 Field Services [Member]		Dec. 31, 2013 Midstream Investments [Member]		Dec. 31, 2013 Corporate and Other [Member]	Dec. 31, 2012 Corporate and Other [Member]	Dec. 31, 2011 Corporate and Other [Member]	Dec. 31, 2013 Intersegment Eliminations [Member]	Dec. 31, 2012 Intersegment Eliminations [Member]	Dec. 31, 2011 Intersegment Eliminations [Member]	Jul. 31, 2012 Waskom Gas Processing Company [Member]	Jun. 30, 2012 Waskom Gas Processing Company [Member]	Dec. 31, 2013 SESH [Member]		Dec. 31, 2012 SESH [Member]		Dec. 31, 2013 Midstream Partnership [Member]	May 01, 2013 Midstream Partnership [Member]	Dec. 31, 2012 Midstream Partnership [Member]	Dec. 31, 2013 Consolidation, Eliminations [Member]	Dec. 31, 2012 Consolidation, Eliminations [Member]	Dec. 31, 2011 Consolidation, Eliminations [Member]	Dec. 31, 2013 Intersegment Eliminations [Member]	Dec. 31, 2012 Intersegment Eliminations [Member]	Dec. 31, 2011 Intersegment Eliminations [Member]	Dec. 31, 2013 Intersegment Eliminations [Member] Natural Gas Distribution [Member]	Dec. 31, 2012 Intersegment Eliminations [Member] Natural Gas Distribution [Member]	Dec. 31, 2011 Intersegment Eliminations [Member] Natural Gas Distribution [Member]	Dec. 31, 2013 Intersegment Eliminations [Member] Energy Services [Member]	Dec. 31, 2012 Intersegment Eliminations [Member] Energy Services [Member]	Dec. 31, 2011 Intersegment Eliminations [Member] Energy Services [Member]	Dec. 31, 2013 Intersegment Eliminations [Member] Interstate Pipelines [Member]		Dec. 31, 2012 Intersegment Eliminations [Member] Interstate Pipelines [Member]		Dec. 31, 2011 Intersegment Eliminations [Member] Interstate Pipelines [Member]		Dec. 31, 2013 Intersegment Eliminations [Member] Field Services [Member]		Dec. 31, 2012 Intersegment Eliminations [Member] Field Services [Member]		Dec. 31, 2011 Intersegment Eliminations [Member] Field Services [Member]		Dec. 31, 2013 Intersegment Eliminations [Member] Midstream Investments [Member]		Dec. 31, 2013 Intersegment Eliminations [Member] Corporate and Other [Member]	Dec. 31, 2012 Intersegment Eliminations [Member] Corporate and Other [Member]	Dec. 31, 2011 Intersegment Eliminations [Member] Corporate and Other [Member]	Dec. 31, 2013 Midstream Partnership [Member]	Dec. 31, 2012 Midstream Partnership [Member]	Dec. 31, 2011 Midstream Partnership [Member]	Dec. 31, 2013 SESH [Member]		Dec. 31, 2013 SESH [Member]	Dec. 31, 2012 SESH [Member]		Dec. 31, 2011 SESH [Member]		Apr. 30, 2013 Midstream Investments [Member] Waskom [Member]
Segment Reporting Information [Line Items]
Revenue from External Customers	$ 1,543	$ 891	$ 1,235	[1]	$ 1,853	$ 1,551	$ 954	[2]	$ 846	$ 1,550		$ 5,522	$ 4,901	$ 6,102	$ 2,837	$ 2,320	$ 2,823	$ 2,374	$ 1,758	$ 2,488	$ 133	[3],[4]	$ 356	[3]	$ 421	[3]	$ 178	[4],[5]	$ 467	[5]	$ 370	[5]	$ 0	[6]	$ 0	$ 0	$ 0																$ (124)	$ (233)	$ (215)	$ (26)	$ (22)	$ (18)	$ (27)	$ (26)	$ (23)	$ (53)	[3],[4]	$ (146)	[3]	$ (132)	[3]	$ (18)	[4],[5]	$ (39)	[5]	$ (42)	[5]	$ 0	[6]	$ 0	$ 0	$ 0
Depreciation and Amortization												230	285	262	185	173	166	5	6	5	20	[3],[4]	56	[3]	54	[3]	20	[4],[5]	50	[5]	37	[5]	0	[6]	0	0	0
Operating Income (Loss)	91	4	56	[1]	250	211	(152)	[2]	106	229		401	394	662	263	226	226	13	(250)	6	72	[3],[4]	207	[3]	248	[3]	73	[4],[5]	214	[5]	189	[5]	0	[6]	(20)	(3)	(7)
Total Assets	10,542					11,190					10,542	10,542	11,190	10,687	4,976	4,775	4,636	895	839	1,089	0	[3],[4]	4,004	[3]	3,867	[3]	0	[4],[5]	2,453	[5]	1,894	[5]	4,518	[6]	1,149	647	660													(996)	(1,528)	(1,459)
Capital Expenditures for Long-Lived Assets												478	549	599	430	359	295	3	6	5	29	[3],[4]	132	[3]	98	[3]	16	[4],[5]	52	[5]	201	[5]	0	[6]	0	0	0	0	0	0
Equity income											188	188	31	30							7		26		21				5		9																																																173	0	0	15	[7]	8	26	[7]	21	[7]
Interest in jointly-owned asset (in hundredths)																					50.00%						50.00%															50.00%	25.05%
Investment in unconsolidated affiliate																							404		409						63
Percentage of Ownership in Affiliate 2 Acquired																																									50.00%
Equity Interest Contributed, Percentage																																																																																									100.00%
Investment in unconsolidated affiliates	4,518					405					4,518	4,518	405																														199	[7]	404	[7]	4,319	4,300	0
Retail gas sales												4,150	3,328	4,019
Wholesale gas sales												913	613	1,149
Gas transportation and processing												345	847	824
Energy products and services												114	113	110
Total	$ 1,543	$ 891	$ 1,235	[1]	$ 1,853	$ 1,551	$ 954	[2]	$ 846	$ 1,550		$ 5,522	$ 4,901	$ 6,102	$ 2,837	$ 2,320	$ 2,823	$ 2,374	$ 1,758	$ 2,488	$ 133	[3],[4]	$ 356	[3]	$ 421	[3]	$ 178	[4],[5]	$ 467	[5]	$ 370	[5]	$ 0	[6]	$ 0	$ 0	$ 0																$ (124)	$ (233)	$ (215)	$ (26)	$ (22)	$ (18)	$ (27)	$ (26)	$ (23)	$ (53)	[3],[4]	$ (146)	[3]	$ (132)	[3]	$ (18)	[4],[5]	$ (39)	[5]	$ (42)	[5]	$ 0	[6]	$ 0	$ 0	$ 0

[1] Effective May 1, 2013, CERC Corp. contributed CenterPoint Midstream to Enable. See Note 2(b) and Note 10 for further discussion on the formation of Enable and CERC’s investment in Enable, respectively.

[2] See Note 2(b) and Note (4) for further discussion on the acquisition of additional interest in Waskom and the goodwill impairment charge, respectively.

[3] Interstate Pipelines recorded equity income of $7 million, $26 million and $21 million in the years ended December 31, 2013, 2012 and 2011, respectively, from its 50% interest in SESH, a jointly-owned pipeline. These amounts are included in Equity in earnings of unconsolidated affiliates under the Other Income (Expense) caption. Interstate Pipelines’ investment in SESH was $404 million and $409 million as of December 31, 2012 and 2011, respectively, and is included in Investment in unconsolidated affiliates. As discussed above, effective May 1, 2013, CenterPoint Energy reports equity earnings associated with its interest in Enable and equity earnings associated with its retained interest in SESH under a new Midstream Investments segment, and no longer has an Interstate Pipelines reporting segment prospectively.

[4] Results reflected in the year ended December 31, 2013 represent only January 2013 through April 2013.

[5] Field Services recorded equity income of $5 million and $9 million for the years ended December 31, 2012 and 2011, respectively, from its 50% interest in a jointly-owned gas processing plant. These amounts are included in Equity in earnings of unconsolidated affiliates under the Other Income (Expense) caption. Field Services’ investment in the jointly-owned gas processing plant was $63 million as of December 31, 2011, respectively, and is included in Investment in unconsolidated affiliates. Beginning on August 1, 2012, financial results for Waskom are included in operating income due to the July 31, 2012 purchase of the 50% interest in Waskom that CenterPoint Energy did not already own. CERC contributed 100% interest in Waskom to Enable on May 1, 2013. Effective May 1, 2013, CERC equity earnings associated with its interest in Enable under a new Midstream Investments segment, and no longer has a Field Services reporting segment prospectively.

[6] Midstream Investments reported equity earnings of $173 million from Enable and $8 million of equity earnings from CERC’s retained interest in SESH for the eight months ended December 31, 2013. Included in total assets of Midstream Investments as of December 31, 2013 is $4,319 million related to CERC’s investment in Enable and $199 million related to CERC’s retained interest in SESH.

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