Unaudited Quarterly Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended										12 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, 2012	Dec. 31, 2011
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
Operating Income (Loss)	91	4	56	[1]	250	211	(152)	[2]	106	229	401	394	662
Net Income (Loss)	$ 66	$ 32	$ (162)	[1]	$ 128	$ 104	$ (127)	[2]	$ 42	$ 118	$ 64	$ 137	$ 316

[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.