Credit Facilities and Commercial Paper (Details 2) (USD $) In Millions, unless otherwise specified				9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014 Access Midstream Partners, L.P. [Member]	Sep. 30, 2014 $1.5 Billion Unsecured Credit Facility [Member]	Sep. 30, 2014 $1.75 Billion Secured Credit Facility [Member] Access Midstream Partners, L.P. [Member]	Sep. 30, 2014 $1.75 Billion Secured Credit Facility [Member] Access Midstream Partners, L.P. [Member] Rate addition to federal funds effective rate [Member]	Sep. 30, 2014 $1.75 Billion Secured Credit Facility [Member] Access Midstream Partners, L.P. [Member] Rate addition to London interbank offered rate (LIBOR) [Member]	Sep. 30, 2014 $1.75 Billion Secured Credit Facility [Member] Access Midstream Partners, L.P. [Member] Rate plus a margin [Member] Maximum [Member]	Sep. 30, 2014 $1.75 Billion Secured Credit Facility [Member] Access Midstream Partners, L.P. [Member] Rate plus a margin [Member] Minimum [Member]	Sep. 30, 2014 $1.75 Billion Secured Credit Facility [Member] Access Midstream Partners, L.P. [Member] Eurodollar rate plus a margin [Member] Maximum [Member]	Sep. 30, 2014 $1.75 Billion Secured Credit Facility [Member] Access Midstream Partners, L.P. [Member] Eurodollar rate plus a margin [Member] Minimum [Member]	Sep. 30, 2014 $1.75 Billion Secured Credit Facility [Member] Access Midstream Partners, L.P. [Member] Leverage-based pricing grid [Member] Maximum [Member]	Sep. 30, 2014 $1.75 Billion Secured Credit Facility [Member] Access Midstream Partners, L.P. [Member] Leverage-based pricing grid [Member] Minimum [Member]	Sep. 30, 2014 $1.75 Billion Secured Credit Facility [Member] Access Midstream Partners, L.P. [Member] Ratings-based pricing grid [Member] Maximum [Member]	Sep. 30, 2014 $1.75 Billion Secured Credit Facility [Member] Access Midstream Partners, L.P. [Member] Ratings-based pricing grid [Member] Minimum [Member]	Sep. 30, 2014 $2.5 Billion Unsecured Credit Facility [Member] Williams Partners L. P. [Member]	Sep. 30, 2014 $2 Billion Unsecured Commercial Paper Notes [Member] Williams Partners L. P. [Member]	Sep. 30, 2014 $2.5 Billion Unsecured Credit Facility Letter of Credit [Member] Williams Partners L. P. [Member]	Sep. 30, 2014 $1.75 Billion Secured Credit Facility Letter of Credit [Member] Access Midstream Partners, L.P. [Member]	Sep. 30, 2014 $1.5 Billion Unsecured Credit Facility Letter of Credit [Member]	Sep. 30, 2014 $1.5 Billion Unsecured Credit Facility Letter of Credit Under Bilateral Bank Agreements [Member]	Sep. 30, 2014 $2.5 Billion Unsecured Credit Facility Letter of Credit Under Bilateral Bank Agreements [Member] Williams Partners L. P. [Member]	Sep. 30, 2014 $1.75 Billion Secured Credit Facility Same-Day Swing Line Advances [Member] Access Midstream Partners, L.P. [Member]	Sep. 30, 2014 $1.75 Billion Secured Credit Facility Accordion Feature [Member] Access Midstream Partners, L.P. [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity				$ 1,500	$ 1,750											$ 2,500	$ 2,000	$ 1,300	$ 200	$ 700			$ 100	$ 2,000
Credit facility, loans outstanding			466	320	466											0
Credit facility, letters of credit outstanding																		0	0	0	14	1
Credit facility, same-day swing line advances																							0
Commercial paper, outstanding	265	225															265
Commercial paper, weighted average interest rate																	0.26%
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
Leverage ratio required					5.5
Leverage ratio required after investment grade status					5.0
Credit facility, basis spread on variable rate						0.50%	1.00%	1.50%	0.50%	2.50%	1.50%
Credit Facility, unused capacity, commitment fee percentage												0.375%	0.25%	0.30%	0.15%
Minimum outstanding principal amount applicable to cross default provisions					$ 50