Consolidating Guarantor Financial Information Condensed Balance Sheet (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012
Condensed Balance Sheet Statements, Captions [Line Items]
Cash	$ 50	$ 19	$ 17	$ 53
Intercompany accounts receivable	0	0
All other current assets	542	381
Property, plant, and equipment, net	7,416	4,418
Investment in subsidiaries	0	0
Investment in unconsolidated subsidiaries	2,378	2,097
All other assets	5,073	1,867
TOTAL ASSETS	15,459	8,782
Intercompany accounts payable	0	0
All other current liabilities	730	475
Long-term liabilities	5,610	3,391
Noncontrolling interest	107	102
Total partners’ capital	9,012	4,814
TOTAL LIABILITIES AND PARTNERS’ CAPITAL AND NONCONTROLLING INTEREST	15,459	8,782
Parent Company [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash	0	0	0	0
Intercompany accounts receivable	0	0
All other current assets	0	0
Property, plant, and equipment, net	0	0
Investment in subsidiaries	18,368	10,446
Investment in unconsolidated subsidiaries	0	0
All other assets	0	0
TOTAL ASSETS	18,368	10,446
Intercompany accounts payable	0	0
All other current liabilities	0	0
Long-term liabilities	4,673	2,832
Noncontrolling interest	0	0
Total partners’ capital	13,695	7,614
TOTAL LIABILITIES AND PARTNERS’ CAPITAL AND NONCONTROLLING INTEREST	18,368	10,446
Consolidation, Eliminations [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash	(8)	0	0	0
Intercompany accounts receivable	0	(615)
All other current assets	(1)	0
Property, plant, and equipment, net	(89)	0
Investment in subsidiaries	(18,368)	(10,446)
Investment in unconsolidated subsidiaries	157	102
All other assets	0	0
TOTAL ASSETS	(18,309)	(10,959)
Intercompany accounts payable	0	(615)
All other current liabilities	0	0
Long-term liabilities	(3)	0
Noncontrolling interest	107	102
Total partners’ capital	(18,413)	(10,446)
TOTAL LIABILITIES AND PARTNERS’ CAPITAL AND NONCONTROLLING INTEREST	(18,309)	(10,959)
Non-Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash	43	19	17	53
Intercompany accounts receivable	0	0
All other current assets	5	15
Property, plant, and equipment, net	269	174
Investment in subsidiaries	0	0
Investment in unconsolidated subsidiaries	0	0
All other assets	0	0
TOTAL ASSETS	317	208
Intercompany accounts payable	0	0
All other current liabilities	8	9
Long-term liabilities	3	0
Noncontrolling interest	0	0
Total partners’ capital	306	199
TOTAL LIABILITIES AND PARTNERS’ CAPITAL AND NONCONTROLLING INTEREST	317	208
Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash	15	0	0	0
Intercompany accounts receivable	0	615
All other current assets	538	366
Property, plant, and equipment, net	7,236	4,244
Investment in subsidiaries	0	0
Investment in unconsolidated subsidiaries	2,221	1,995
All other assets	5,073	1,867
TOTAL ASSETS	15,083	9,087
Intercompany accounts payable	0	615
All other current liabilities	722	466
Long-term liabilities	937	559
Noncontrolling interest	0	0
Total partners’ capital	13,424	7,447
TOTAL LIABILITIES AND PARTNERS’ CAPITAL AND NONCONTROLLING INTEREST	$ 15,083	$ 9,087