Investment In Unconsolidated Affiliates Changes In Partnership's Investment (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Proceeds from Equity Method Investment, Dividends or Distributions			$ 108	$ 92
Income (Loss) from Equity Method Investments	37	21	103	87
Line of Credit Facility, Maximum Borrowing Capacity	(1,200)		(1,200)		(1,150)
Equity Interest pledged by Regency Energy Partners LP in Regency Intrastate Gas LP	49.99%
Line of Credit Facility, Amount Outstanding	176		176		192
Guarantor Obligations, Maximum Exposure, Undiscounted	222		222
HPC [Member]
Investments in and Advances to Affiliates, at Fair Value, Gross Additions	0	0	0	0
Proceeds from Equity Method Investment, Dividends or Distributions	(196)	(16)	(226)	(46)
Income (Loss) from Equity Method Investments	9	3	28	28
Amortization Of Excess Fair Value Of Unconsoldated Affilaite	(1)	(1)	(4)	(4)
Line of Credit Facility, Maximum Borrowing Capacity	500		500
Borrowing Amount for Return of Capital Distribution	370
Line of Credit Facility, Amount Outstanding	445		445
MEP {Member]
Investments in and Advances to Affiliates, at Fair Value, Gross Additions	0	0	0	0
Proceeds from Equity Method Investment, Dividends or Distributions	(18)	(18)	(56)	(56)
Income (Loss) from Equity Method Investments	11	10	31	31
Amortization Of Excess Fair Value Of Unconsoldated Affilaite	0	0	0	0
Lone Star {Member]
Investments in and Advances to Affiliates, at Fair Value, Gross Additions	51	78	100	253
Proceeds from Equity Method Investment, Dividends or Distributions	(16)	(21)	(56)	(39)
Income (Loss) from Equity Method Investments	18	9	48	32
Amortization Of Excess Fair Value Of Unconsoldated Affilaite	0	0	0	0
Ranch JV {Member]
Investments in and Advances to Affiliates, at Fair Value, Gross Additions	1	10	2	33
Proceeds from Equity Method Investment, Dividends or Distributions	(1)	0	(1)	0
Income (Loss) from Equity Method Investments	0	0	0	0
Amortization Of Excess Fair Value Of Unconsoldated Affilaite	0	0	0	0
Non-recurring Distribution [Member]
Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital			$ 185