Price Risk Management Assets And Liabilities Partnership's Derivative Assets And Liabilities, Amount Of Gain/(Loss) Reclassified From AOCI Into Income (Effective Portion) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Amount of Gain/(Loss) Reclassified from AOCI into Income (Effective Portion)	$ 0	$ (4)
Amount of Gain/(Loss) Recognized in Income representing hedge ineffectiveness and amount excluded from the assessment of effectiveness	(3)	(6)
Amount of Gain (Loss) Recognized In Income On Derivatives	(98)	12
Losses on interest rate derivatives	(77)	(2)
Commodity Derivatives - Trading [Member]
Amount of Gain (Loss) Recognized In Income On Derivatives	(2)	7
Commodity derivatives
Amount of Gain/(Loss) Reclassified from AOCI into Income (Effective Portion)	0	(4)
Amount of Gain/(Loss) Recognized in Income representing hedge ineffectiveness and amount excluded from the assessment of effectiveness	(3)	(6)
Amount of Gain (Loss) Recognized In Income On Derivatives	$ (19)	$ 7