Segment Disclosures Reconciliation of Segment Modified EBITDA to Consolidated (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Reconciliation of Modified EBITDA to net income (loss):
Modified Ebitda	$ 604	$ 1,053	$ 1,559	$ 1,870
Asset Retirement Obligation Accretion Expense For Nonregulated Operations	(9)	(9)	(16)	(16)
Depreciation and amortization expenses	(432)	(419)	(867)	(838)
Equity earnings (losses)	101	93	198	144
Impairment of equity-method investments	0	0	(112)	0
Other investing income (loss) - net	1	0	1	1
Proportional Modified Ebitda of Equity-Method Investments	(191)	(183)	(380)	(319)
Interest Expense	(231)	(203)	(460)	(395)
(Provision) benefit for income taxes	80	0	79	(3)
Net income (loss)	(77)	332	2	444
Operating Segments [Member] | Central [Member]
Reconciliation of Modified EBITDA to net income (loss):
Modified Ebitda	134	160	291	293
Operating Segments [Member] | Northeast G And P [Member]
Reconciliation of Modified EBITDA to net income (loss):
Modified Ebitda	216	183	430	368
Operating Segments [Member] | Atlantic Gulf [Member]
Reconciliation of Modified EBITDA to net income (loss):
Modified Ebitda	357	389	733	724
Operating Segments [Member] | West [Member]
Reconciliation of Modified EBITDA to net income (loss):
Modified Ebitda	158	150	313	311
Operating Segments [Member] | NGL And Petchem Services [Member]
Reconciliation of Modified EBITDA to net income (loss):
Modified Ebitda	(261)	158	(208)	164
Other [Member]
Reconciliation of Modified EBITDA to net income (loss):
Modified Ebitda	$ 0	$ 13	$ 0	$ 10