Transactions with Affiliates (Details) (USD $)	3 Months Ended		6 Months Ended			3 Months Ended		6 Months Ended					6 Months Ended		1 Months Ended
	Jun. 30, 2014 employee	Jun. 30, 2013	Jun. 30, 2014 employee	Jun. 30, 2013	Dec. 31, 2013	Jun. 30, 2014 Affiliated Entity [Member]	Jun. 30, 2013 Affiliated Entity [Member]	Jun. 30, 2014 Affiliated Entity [Member]	Jun. 30, 2013 Affiliated Entity [Member]	Jun. 30, 2014 Williams Partners L.P. [Member]	Dec. 31, 2013 Williams Partners L.P. [Member]	Mar. 31, 2014 Williams Field Services Group, LLC [Member]	Jun. 30, 2014 Williams Partners Operating LLC [Member]	Jun. 30, 2013 Williams Partners Operating LLC [Member]	Jul. 31, 2014 Subsequent Event [Member] Williams Partners Operating LLC [Member]
Related Party Transaction [Line Items]
Advances to affiliate	$ 466,802,000		$ 466,802,000		$ 526,380,000					$ 466,800,000	$ 526,400,000
Related party transaction, rate			0.01%
Operating revenues, related party	1,500,000	6,600,000	2,800,000	12,500,000
Cost of natural gas sales, related party	3,400,000	1,600,000	6,800,000	4,000,000
Entity number of employees	0		0
Expenses, related party	74,500,000	78,900,000	149,700,000	153,500,000		(1,900,000)	(1,900,000)	(3,200,000)	(3,400,000)
Pre-payments for capital projects												4,200,000
Equity distributions			235,000,000	123,000,000									235,000,000	123,000,000	83,000,000
Contributions			$ 94,000,000	$ 107,000,000									$ 94,000,000	$ 107,000,000	$ 70,000,000