Segment Disclosures Reconciliation of Segment Assets to Consolidated (Details) - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		$ 46,538	$ 47,870
Central [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		13,234	13,914
Northeast G&P [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		13,646	13,827
Atlantic-Gulf [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		13,416	12,171
West [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		4,733	5,035
NGL & Petchem Services [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		2,493	3,306
Other corporate assets [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		141	350
Eliminations [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	[1]	$ (1,125)	$ (733)

[1] Eliminations primarily relate to the intercompany accounts and notes receivable generated by our cash management program.