Investment In Unconsolidated Affiliates Selected I/S Data for each of the Unconsolidated Affiliates (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
HPC [Member]
Equity method investments, total revenues	$ 38	$ 42	$ 116	$ 130
Equity method investments, operating income	19	21	58	71
Equity method investments, net income	18	6	56	55
MEP {Member]
Equity method investments, total revenues	66	65	194	196
Equity method investments, operating income	34	33	101	101
Equity method investments, net income	21	21	63	63
Lone Star {Member]
Equity method investments, total revenues	537	165	1,320	490
Equity method investments, operating income	61	31	162	110
Equity method investments, net income	61	31	160	110
Ranch JV {Member]
Equity method investments, total revenues	4	0	10	0
Equity method investments, operating income	1	(1)	2	(1)
Equity method investments, net income	$ 1	$ (1)	$ 2	$ (1)