Transactions with Affiliates (Details) (USD $)	3 Months Ended			3 Months Ended					1 Months Ended	3 Months Ended
	Mar. 31, 2014 employee	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2014 Affiliated Entity [Member]	Mar. 31, 2013 Affiliated Entity [Member]	Mar. 31, 2014 Williams Partners L.P. [Member]	Dec. 31, 2013 Williams Partners L.P. [Member]	Mar. 31, 2014 Williams Field Services Group, LLC [Member]	Apr. 30, 2014 Williams Partners Operating LLC [Member]	Mar. 31, 2014 Williams Partners Operating LLC [Member]	Mar. 31, 2013 Williams Partners Operating LLC [Member]
Related Party Transaction [Line Items]
Advances to affiliate	$ 603,014,000		$ 526,380,000			$ 603,000,000	$ 526,400,000
Related party transaction, rate	0.01%
Operating revenues, related party	1,300,000	5,900,000
Cost of natural gas sales, related party	3,400,000	2,400,000
Entity number of employees	0
Expenses, related party	75,200,000	74,600,000		(1,300,000)	(1,500,000)
Pre-payments for capital projects								4,200,000
Equity distributions	112,000,000	65,000,000							123,000,000	112,000,000	65,000,000
Contributions	$ 54,000,000	$ 55,000,000							$ 40,000,000	$ 54,000,000	$ 55,000,000