Price Risk Management Assets And Liabilities (Fair Value Of Derivative Instruments) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Designated as Hedging Instrument [Member]
Total derivatives assets	$ 4	$ 8
Total derivatives liabilities	(14)	(10)
Not Designated as Hedging Instrument [Member]
Total derivatives assets	242	208
Total derivatives liabilities	(407)	(392)
Embedded Derivatives in Regency Preferred Units [Member] | Not Designated as Hedging Instrument [Member]
Total derivatives assets	238	200
Total derivatives liabilities	(393)	(382)
Commodity [Member] | Not Designated as Hedging Instrument [Member]
Total derivatives assets	59	33
Total derivatives liabilities	(53)	(34)
Commodity Derivatives (Margin Deposits) [Member] | Designated as Hedging Instrument [Member]
Total derivatives assets	4	8
Total derivatives liabilities	(14)	(10)
Commodity Derivatives (Margin Deposits) [Member] | Not Designated as Hedging Instrument [Member]
Total derivatives assets	120	110
Total derivatives liabilities	(125)	(116)
Interest Rate Derivatives [Member] | Not Designated as Hedging Instrument [Member]
Total derivatives assets	51	55
Total derivatives liabilities	(213)	(223)
Current Assets Held For Sale [Member] | Commodity [Member] | Not Designated as Hedging Instrument [Member]
Total derivatives assets	8	1
Total derivatives liabilities	0	0
Non-Current Assets Held For Sale [Member] | Commodity [Member] | Not Designated as Hedging Instrument [Member]
Total derivatives assets	0	1
Total derivatives liabilities	0	0
Current Liabilities Held For Sale [Member] | Commodity [Member] | Not Designated as Hedging Instrument [Member]
Total derivatives assets	0	0
Total derivatives liabilities	$ (2)	$ (9)