General, Description of Business, and Basis of Presentation (Details) (USD $) In Millions, except Share data, unless otherwise specified	9 Months Ended	6 Months Ended	3 Months Ended	9 Months Ended	1 Months Ended		9 Months Ended	6 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended			9 Months Ended			9 Months Ended
	Sep. 30, 2014	Jul. 02, 2014 Access Midstream Partners Acquisition [Member]	Jun. 30, 2014 Canada Acquisition [Member]	Sep. 30, 2014 Canada Acquisition [Member]	Oct. 31, 2014 Canada Acquisition [Member] Subsequent Event [Member]	Feb. 28, 2014 Class D Units [Member] Canada Acquisition [Member]	Sep. 30, 2014 Class D Units [Member] Canada Acquisition [Member] Future Facility Expansion [Member]	Jul. 02, 2014 Access Midstream Partners, L.P. [Member] Access Midstream Partners Acquisition [Member]	Sep. 30, 2014 Appalachia Midstream Services, LLC [Member]	Sep. 30, 2014 Williams Partners L.P.	Sep. 30, 2014 Constitution Pipeline Company LLC [Member]	Sep. 30, 2014 General Partner [Member]	Jul. 01, 2014 General Partner [Member] Access Midstream Partners Acquisition [Member]	Sep. 30, 2014 General and Limited Partner [Member] Access Midstream Partners, L.P. [Member]	Sep. 30, 2014 General and Limited Partner [Member] Williams Partners L.P.	Jul. 01, 2014 Limited Partner [Member] Access Midstream Partners, L.P. [Member] Access Midstream Partners Acquisition [Member]	Sep. 30, 2014 Noncontrolling Interest [Member]	Sep. 30, 2014 Capital in excess of par value [Member]	Sep. 30, 2014 Accumulated Other Comprehensive Income (Loss) [Member]	Sep. 30, 2014 Deferred Income Taxes [Member]	Sep. 30, 2014 Gulfstream Natural Gas System, L.L.C.[Member]	Sep. 30, 2014 Bluegrass Pipeline Company Llc [Member]	Sep. 30, 2014 Utica East Ohio Midstream, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage																					50.00%	50.00%	49.00%
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Number of Gathering Systems									10
Variable Interest Entity Ownership Percentage											41.00%
Business Acquisition, Percentage of Voting Interests Acquired													50.00%
Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest									47.00%
Master limited partnership, ownership percentage														51.00%	66.00%
Equity Interest in Acquiree, Including Subsequent Acquisition, Percentage													100.00%			50.00%
Proceeds from Divestiture of Businesses			$ 31	$ 56
Reduction in incentive distribution rights payment					2
Number Of Limited Partner Units Received						25,577,521	0	55,100,000
Payments to Acquire Businesses, Gross		5,995
General partner ownership percentage												2.00%
Other Commitment							200
Sale of Stock, Number of Shares Issued in Transaction										1,080,448
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net	36																118	(62)	(20)
Income Tax Effects Allocated Directly to Equity, Other																				$ 36