Condensed Consolidated Statement of Partners' Capital and Noncontrolling Interest (USD $) In Millions	Total	Common Units [Member]	Class F Units [Member]	General Partner Interest	Noncontrolling Interest
Balance at Dec. 31, 2014	$ 9,585	$ 8,531	$ 153	$ 781	$ 120
Issuance of common units under equity distribution program, net of costs	34	34	0	0	0
Unit-based compensation expenses	3	3	0	0	0
Partner distributions and distributions on unvested unit awards	(218)	(207)	0	(11)	0
Noncontrolling interest contributions, net of distributions	31	0	0	0	31
Net (loss) income	(3)	(9)	2	0	4
Distributions to Series A Preferred Units	(1)	(1)	0	0	0
Balance at Mar. 31, 2015	$ 9,431	$ 8,351	$ 155	$ 770	$ 155