Consolidated Statement of Changes in Equity (USD $) In Millions	Total	Common Stock	Additional Paid-in Capital [Member]	Retained Earnings (Deficit)	Accumulated Other Comprehensive Loss	Treasury Stock	Total Stockholders' Equity	Noncontrolling Interests
Beginning balance at Dec. 31, 2009	$ 8,562	$ 618	$ 7,678	$ 903	$ (168)	$ (1,041)	$ 7,990	$ 572
Net income (loss)	(922)	0	0	(1,097)	0	0	(1,097)	175
Other comprehensive income (loss)	86	0	0	0	86	0	86	0
Cash dividends - common stock (Note 13)	(284)	0	0	(284)	0	0	(284)	0
Dividends and distributions to noncontrolling interests	(145)	0	0	0	0	0	0	(145)
Issuance of common stock from debentures conversion (Note 13)	2	0	2	0	0	0	2	0
Stock-based compensation and related common stock issuances, net of tax	57	2	55	0	0	0	57	0
Sales of limited partner units of Williams Partners L.P.	806	0	0	0	0	0	0	806
Changes in William Partners L.P. ownership interest, net	(28)	0	49	0	0	0	49	(77)
Ending balance at Dec. 31, 2010	8,134	620	7,784	(478)	(82)	(1,041)	6,803	1,331
Net income (loss)	661	0	0	376	0	0	376	285
Other comprehensive income (loss)	(88)	0	0	0	(88)	0	(88)	0
Cash dividends - common stock (Note 13)	(457)	0	0	(457)	0	0	(457)	0
Dividends and distributions to noncontrolling interests	(214)	0	0	0	0	0	0	(214)
Issuance of common stock from debentures conversion (Note 13)	14	1	13	0	0	0	14	0
Stock-based compensation and related common stock issuances, net of tax	108	4	104	0	0	0	108	0
Changes in William Partners L.P. ownership interest, net	(12)	0	18	0	0	0	18	(30)
Distribution of WPX Energy, Inc to shareholders (Note 3)	(5,561)	0	0	(5,261)	(219)	0	(5,480)	(81)
Other	1	1	1	0	0	0	2	(1)
Ending balance at Dec. 31, 2011	2,586	626	7,920	(5,820)	(389)	(1,041)	1,296	1,290
Net income (loss)	1,065	0	0	859	0	0	859	206
Other comprehensive income (loss)	27	0	0	0	27	0	27	0
Cash dividends - common stock (Note 13)	(742)	0	0	(742)	0	0	(742)	0
Dividends and distributions to noncontrolling interests	(387)	0	0	0	0	0	0	(387)
Issuance of common stock from debentures conversion (Note 13)	6	1	5	0	0	0	6	0
Stock-based compensation and related common stock issuances, net of tax	104	6	98	0	0	0	104	0
Sales of limited partner units of Williams Partners L.P.	1,559	0	0	0	0	0	0	1,559
Issuances of limited partner units of Williams Partners L.P. related to acquisitions	1,044	0	0	0	0	0	0	1,044
Changes in William Partners L.P. ownership interest, net	(416)	0	699	0	0	0	699	(1,115)
Sales of common stock (Note 13)	2,495	83	2,412	0	0	0	2,495	0
Reconsolidation Of Noncontrolling Interest In Wilpro Entities (Note 3)	65	0	0	0	0	0	0	65
Contributions to Constitution Pipeline Company, LLC (Note 1)	14	0	0	0	0	0	0	14
Other	7	0	0	8	0	0	8	(1)
Ending balance at Dec. 31, 2012	$ 7,427	$ 716	$ 11,134	$ (5,695)	$ (362)	$ (1,041)	$ 4,752	$ 2,675