Consolidated Statement of Changes in Equity (Unaudited) - USD ($) $ in Millions	Total	Total Stockholders’ Equity	Preferred Stock [Member]	Common Stock	Capital in Excess of Par Value	Retained Deficit	AOCI	Treasury Stock	Noncontrolling Interests
Period Start at Dec. 31, 2017	$ 16,175	$ 9,656	$ 0	$ 861	$ 18,508	$ (8,434)	$ (238)	$ (1,041)	$ 6,519
Adoption of new accounting standards	(121)	(84)	0	0	0	(23)	(61)	0	(37)
Net income (loss)	270	152	0	0	0	152	0	0	118
Other comprehensive income (loss)	6	5	0	0	0	0	5	0	1
Cash dividends – common stock	(281)	(281)	0	0	0	(281)	0	0	0
Dividends and distributions to noncontrolling interests	(187)	0	0	0	0	0	0	0	(187)
Stock-based compensation and related common stock issuances, net of tax	19	19	0	1	18	0	0	0	0
Sales of limited partner units of Williams Partners L.P.	22	0	0	0	0	0	0	0	22
Changes in ownership of consolidated subsidiaries, net	(2)	7	0	0	7	0	0	0	(9)
Contributions from noncontrolling interests	3	0	0	0	0	0	0	0	3
Other	(1)	(1)	0	0	0	(1)	0	0	0
Net increase (decrease) in equity	(272)	(183)	0	1	25	(153)	(56)	0	(89)
Period End at Mar. 31, 2018	15,903	9,473	0	862	18,533	(8,587)	(294)	(1,041)	6,430
Period Start at Dec. 31, 2018	15,997	14,660	35	1,245	24,693	(10,002)	(270)	(1,041)	1,337
Net income (loss)	214	195	0	0	0	195	0	0	19
Other comprehensive income (loss)	3	3	0	0	0	0	3	0	0
Cash dividends – common stock	(460)	(460)	0	0	0	(460)	0	0	0
Dividends and distributions to noncontrolling interests	(41)	0	0	0	0	0	0	0	(41)
Stock-based compensation and related common stock issuances, net of tax	11	11	0	1	10	0	0	0	0
Contributions from noncontrolling interests	4	0	0	0	0	0	0	0	4
Other	(3)	(3)	0	0	0	(3)	0	0	0
Net increase (decrease) in equity	(272)	(254)	0	1	10	(268)	3	0	(18)
Period End at Mar. 31, 2019	$ 15,725	$ 14,406	$ 35	$ 1,246	$ 24,703	$ (10,270)	$ (267)	$ (1,041)	$ 1,319