Other Income and Expenses (Details) - USD ($) $ in Millions		3 Months Ended			6 Months Ended
		Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Other income (expense) - net [Member] | Atlantic-Gulf [Member]
Segment Reporting Information [Line Items]
Amortization of regulatory assets associated with asset retirement obligations		$ 9		$ 9	$ 17	$ 17
Other income (expense) - net [Member] | NGL & Petchem Services [Member]
Segment Reporting Information [Line Items]
Net foreign currency exchange (gains) losses (1)	[1]	0		1	11	(4)
Selling, general, and administrative expenses [Member] | Central [Member]
Segment Reporting Information [Line Items]
Business combination, merger related costs				5	5	34
Operating and maintenance expenses [Member] | Central [Member]
Segment Reporting Information [Line Items]
Business combination, integration related costs				8		12
Selling, general, and administrative expenses and Operating and maintenance expenses [Member]
Segment Reporting Information [Line Items]
Approximate percentage of workforce reductions			10.00%
Severance and other related costs					25
Selling, general, and administrative expenses and Operating and maintenance expenses [Member] | Central [Member]
Segment Reporting Information [Line Items]
Severance and other related costs					6
Selling, general, and administrative expenses and Operating and maintenance expenses [Member] | Northeast G&P [Member]
Segment Reporting Information [Line Items]
Severance and other related costs					3
Selling, general, and administrative expenses and Operating and maintenance expenses [Member] | Atlantic-Gulf [Member]
Segment Reporting Information [Line Items]
Severance and other related costs					8
Selling, general, and administrative expenses and Operating and maintenance expenses [Member] | West [Member]
Segment Reporting Information [Line Items]
Severance and other related costs					4
Selling, general, and administrative expenses and Operating and maintenance expenses [Member] | NGL & Petchem Services [Member]
Segment Reporting Information [Line Items]
Severance and other related costs					4
Interest incurred [Member]
Segment Reporting Information [Line Items]
Business combination, merger related costs						2
Service revenues [Member] | Atlantic-Gulf [Member]
Segment Reporting Information [Line Items]
Revenue adjustment associated with litigation					15
Net insurance recoveries - Geismar incident [Member] | NGL & Petchem Services [Member] | Geismar Incident [Member]
Segment Reporting Information [Line Items]
Insurance recoveries				126		126
Other income (expense) - net [Member]
Segment Reporting Information [Line Items]
Gain on extinguishment of debt				14		14
Other income (expense) - net [Member] | Atlantic-Gulf [Member]
Segment Reporting Information [Line Items]
Allowance for funds used during construction, capitalized cost of equity		$ 12		$ 19	$ 29	$ 36

[1] Primarily relates to losses incurred on foreign currency transactions and the remeasurement of U.S. dollar denominated current assets and liabilities within our Canadian operations.