Segment Disclosures Reconciliation of Segment Assets to Consolidated (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Segment assets:
Total assets	$ 47,512	$ 46,835
Williams Partners [Member]
Segment assets:
Total assets	46,938	46,265
Other [Member]
Segment assets:
Total assets	656	685
Intersegment Elimination [Member]
Segment assets:
Total assets	$ (82)	$ (115)