Segment Disclosures Reconciliation of Segment Revenues to Consolidated (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment revenues
Service revenues	$ 1,351	$ 1,261
Sales revenue services commodity consideration	101	0
Product sales	636	727
Total revenues	2,088	1,988
Williams Partners [Member]
Segment revenues
Service revenues	1,346	1,256
Product sales	636	727
Other [Member]
Segment revenues
Service revenues	5	5
Product sales	0	0
Intersegment Elimination [Member]
Segment revenues
Service revenues	(3)	(3)
Sales revenue services commodity consideration	0
Product sales	0	0
Total revenues	(3)	(3)
Intersegment Elimination [Member] | Williams Partners [Member]
Segment revenues
Service revenues	0	0
Product sales	0	0
Intersegment Elimination [Member] | Other [Member]
Segment revenues
Service revenues	(3)	(3)
Product sales	0	0
Operating Segments [Member] | Williams Partners [Member]
Segment revenues
Service revenues	1,346	1,256
Sales revenue services commodity consideration	101
Product sales	636	727
Total revenues	2,083	1,983
Operating Segments [Member] | Other [Member]
Segment revenues
Service revenues	8	8
Sales revenue services commodity consideration	0
Product sales	0	0
Total revenues	$ 8	$ 8