Segment Disclosures (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Segment revenues:
Total revenues	$ 2,069	$ 1,623	$ 5,496	$ 5,200
Segment profit (loss)	2,934	412	3,741	1,355
Equity earnings (losses)	66	37	55	93
Income (loss) from investments	2,519	(1)	2,523	23
Operating income (loss)	307	336	1,038	1,112
Total assets by reporting segment
Total assets	49,807		49,807		27,142
Service [Member]
Segment revenues:
Total revenues	1,127	736	2,771	2,163
Product [Member]
Segment revenues:
Total revenues	942	887	2,725	3,037
Williams Partners [Member]
Total assets by reporting segment
Total assets	25,814		25,814		23,571
Williams Partners [Member] | Service [Member]
Segment revenues:
Total revenues	765	731	2,291	2,150
Williams Partners [Member] | Product [Member]
Segment revenues:
Total revenues	942	887	2,725	3,037
Access Midstream Partners [Member]
Total assets by reporting segment
Total assets	22,765		22,765		2,161
Access Midstream Partners [Member] | Service [Member]
Segment revenues:
Total revenues	300	0	300	0
Access Midstream Partners [Member] | Product [Member]
Segment revenues:
Total revenues	0	0	0	0
Williams NGL & Petchem Services [Member]
Total assets by reporting segment
Total assets	516		516		486
Williams NGL & Petchem Services [Member] | Service [Member]
Segment revenues:
Total revenues	0	0	0	0
Williams NGL & Petchem Services [Member] | Product [Member]
Segment revenues:
Total revenues	0	0	0	0
Other [Member]
Total assets by reporting segment
Total assets	1,251		1,251		1,359
Other [Member] | Service [Member]
Segment revenues:
Total revenues	62	5	180	13
Other [Member] | Product [Member]
Segment revenues:
Total revenues	0	0	0	0
Operating Segments [Member]
Segment revenues:
Operating income (loss)	349	376	1,163	1,239
Operating Segments [Member] | Williams Partners [Member]
Segment revenues:
Total revenues	1,708	1,618	5,017	5,187
Segment profit (loss)	373	411	1,269	1,332
Equity earnings (losses)	36	31	91	84
Income (loss) from investments	0	(1)	0	(3)
Operating income (loss)	337	381	1,178	1,251
Operating Segments [Member] | Williams Partners [Member] | Service [Member]
Segment revenues:
Total revenues	766	731	2,292	2,150
Operating Segments [Member] | Williams Partners [Member] | Product [Member]
Segment revenues:
Total revenues	942	887	2,725	3,037
Operating Segments [Member] | Access Midstream Partners [Member]
Segment revenues:
Total revenues	300	0	300	0
Segment profit (loss)	2,563	6	2,578	35
Equity earnings (losses)	29	6	42	9
Income (loss) from investments	2,519	0	2,523	26
Operating income (loss)	15	0	13	0
Operating Segments [Member] | Access Midstream Partners [Member] | Service [Member]
Segment revenues:
Total revenues	300	0	300	0
Operating Segments [Member] | Access Midstream Partners [Member] | Product [Member]
Segment revenues:
Total revenues	0	0	0	0
Operating Segments [Member] | Williams NGL & Petchem Services [Member]
Segment revenues:
Total revenues	0	0	0	0
Segment profit (loss)	(3)	(4)	(111)	(7)
Equity earnings (losses)	1	0	(78)	0
Income (loss) from investments	0	0	0	0
Operating income (loss)	(4)	(4)	(33)	(7)
Operating Segments [Member] | Williams NGL & Petchem Services [Member] | Service [Member]
Segment revenues:
Total revenues	0	0	0	0
Operating Segments [Member] | Williams NGL & Petchem Services [Member] | Product [Member]
Segment revenues:
Total revenues	0	0	0	0
Operating Segments [Member] | Other [Member]
Segment revenues:
Total revenues	69	7	194	21
Segment profit (loss)	1	(1)	5	(5)
Equity earnings (losses)	0	0	0	0
Income (loss) from investments	0	0	0	0
Operating income (loss)	1	(1)	5	(5)
Operating Segments [Member] | Other [Member] | Service [Member]
Segment revenues:
Total revenues	69	7	194	21
Operating Segments [Member] | Other [Member] | Product [Member]
Segment revenues:
Total revenues	0	0	0	0
Intersegment Elimination [Member]
Segment revenues:
Total revenues	(8)	(2)	(15)	(8)
Total assets by reporting segment
Total assets	(539)		(539)		(435)
Intersegment Elimination [Member] | Service [Member]
Segment revenues:
Total revenues	(8)	(2)	(15)	(8)
Intersegment Elimination [Member] | Product [Member]
Segment revenues:
Total revenues	0	0	0	0
Intersegment Elimination [Member] | Williams Partners [Member] | Service [Member]
Segment revenues:
Total revenues	(1)	0	(1)	0
Intersegment Elimination [Member] | Williams Partners [Member] | Product [Member]
Segment revenues:
Total revenues	0	0	0	0
Intersegment Elimination [Member] | Access Midstream Partners [Member] | Service [Member]
Segment revenues:
Total revenues	0	0	0	0
Intersegment Elimination [Member] | Access Midstream Partners [Member] | Product [Member]
Segment revenues:
Total revenues	0	0	0	0
Intersegment Elimination [Member] | Williams NGL & Petchem Services [Member] | Service [Member]
Segment revenues:
Total revenues	0	0	0	0
Intersegment Elimination [Member] | Williams NGL & Petchem Services [Member] | Product [Member]
Segment revenues:
Total revenues	0	0	0	0
Intersegment Elimination [Member] | Other [Member] | Service [Member]
Segment revenues:
Total revenues	(7)	(2)	(14)	(8)
Intersegment Elimination [Member] | Other [Member] | Product [Member]
Segment revenues:
Total revenues	0	0	0	0
General Corporate Expenses [Member]
Segment revenues:
Operating income (loss)	$ (42)	$ (40)	$ (125)	$ (127)