Credit Facilities and Commercial Paper (Details 2) (USD $) In Millions, unless otherwise specified			6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2014 $1.5 Billion Unsecured Credit Facility [Member]	Jun. 30, 2014 $2.5 Billion Unsecured Credit Facility [Member] Williams Partners L. P. [Member]	Jun. 30, 2014 $2.5 Billion Unsecured Credit Facility Letter of Credit [Member] Williams Partners L. P. [Member]	Jun. 30, 2014 $1.5 Billion Unsecured Credit Facility Letter of Credit [Member]	Jun. 30, 2014 $1.5 Billion Unsecured Credit Facility Letter of Credit Under Bilateral Bank Agreements [Member]	Jun. 30, 2014 $2.5 Billion Unsecured Credit Facility Letter of Credit Under Bilateral Bank Agreements [Member] Williams Partners L. P. [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity			$ 1,500	$ 2,500	$ 1,300	$ 700
Credit facility, loans outstanding			300	0
Credit facility, letters of credit outstanding					0	0	15	1
Commercial paper, outstanding	0	225
Maximum ratio of debt to EBITDA			4.75
Minimum aggregate purchase price of acquisitions impacting maximum ratio of debt to EBITDA			$ 50
Maximum ratio of debt to EBITDA after acquisition			5.5