Mergers and Other Transactions (Narrative) (Details) - USD ($) shares in Millions, $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Notes Receivable, Related Parties					$ 1,370
Note payable to related party	$ 113	$ 0
Goodwill	$ 23	$ 285		$ 923
ETP [Member]
Notes Receivable, Related Parties			$ 541
Number of common units of a subsidiary partnership that are held by a less than wholly-owned subsidiary of the Parent.					17.8
Regency Merger [Member] | ETP [Member]
Number of common units of a subsidiary partnership that are held by a less than wholly-owned subsidiary of the Parent.					15.5