Mergers and Other Transactions (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended			12 Months Ended
	Feb. 28, 2014	Dec. 31, 2013	Apr. 30, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Jan. 31, 2015	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Feb. 19, 2014	Jun. 24, 2013
Disposal Group, Including Discontinued Operation, Revenue						$ 415
Proceeds from sale of MGE assets, net of transaction costs				$ 0	$ 0	1,008
Goodwill		$ 1,336		$ 923	$ 1,152	1,336	$ 923	$ 1,152	$ 1,152		$ 1,152	$ 1,152	$ 1,152
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax						65
Regency [Member]
Number of common units of a subsidiary partnership that are held by a less than wholly-owned subsidiary of the Parent.					31,400,000						31,400,000
ETP [Member]
Notes Receivable, Related Parties							$ 1,370
Number of common units of a subsidiary partnership that are held by a less than wholly-owned subsidiary of the Parent.							15,500,000
Number of common units of a subsidiary partnership that are held by a wholly-owned subsidiary of the Parent.					2,200,000
NOTE PAYABLE TO RELATED PARTY														$ 1,090
7.60% Senior Notes, due February 1, 2024 [Member]
Debt Instrument, Interest Rate, Stated Percentage															7.60%
8.25% Senior Notes, due November 14, 2029 [Member]
Debt Instrument, Interest Rate, Stated Percentage															8.25%
Regency 4.50% Senior Notes Due 2023 [Member]
Debt Instrument, Interest Rate, Stated Percentage				4.50%
Guarantor Obligations, Current Carrying Value				$ 600
Class F Units [Member] | Regency [Member]
Number of common units of a subsidiary partnership that are held by a less than wholly-owned subsidiary of the Parent.					6,300,000						6,300,000
Lake Charles LNG Transaction [Member]
Partners' Capital Account, Units, Redeemed	18,700,000
Goodwill														184
Intangible Assets, Net (Excluding Goodwill)														$ 50
SUGS Contribution [Member]
Business Combination, Consideration Transferred			$ 463
Cash Acquired from Acquisition			$ 30
New England Gas Company [Member]
Proceeds from sale of MGE assets, net of transaction costs		40
Noncash or Part Noncash Divestiture, Amount of Consideration Received		$ 20
Missouri Gas Energy
Proceeds from sale of MGE assets, net of transaction costs						$ 975
Regency Merger [Member]
Business Acquisition, Number Of Share Received In Exchange Of Each Share										0.4066
Business Acquisition, Share Price										$ 0.32