Consolidated Statement of Changes in Equity (Unaudited) - 3 months ended Mar. 31, 2018 - USD ($) $ in Millions	Total	Common Units	Class B Units	Total Partners' Equity	AOCI Attributable to Parent [Member]	Noncontrolling Interest [Member]
Beginning balance at Dec. 31, 2017	$ 23,689	$ 21,251	$ 784	$ 22,030	$ (5)	$ 1,659
Adoption of ASC 606 (Note 1)	(148)	(148)	(3)	(151)	0	3
Net income (loss)	384	353	7	360	0	24
Other comprehensive income (loss)	2	0	0	2	2	0
Distributions to partners	(574)	(574)	0	(574)	0	0
Sales of common units (Note 7)	22	22	0	22	0	0
Distributions to noncontrolling interests	(35)	0	0	0	0	(35)
Contributions from noncontrolling interests	3	0	0	0	0	3
Contributions from (distributions to) The Williams Companies, Inc. – net	2	2	0	2	0	0
Net increase (decrease) in equity	(344)	(345)	4	(339)	2	(5)
Ending balance at Mar. 31, 2018	$ 23,345	$ 20,906	$ 788	$ 21,691	$ (3)	$ 1,654