Segment Disclosures Recon from Segment to Consolidated - Assets and Investments (Details) - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		$ 46,040	$ 45,302
Equity-method investments		6,235	7,821
Atlantic Gulf [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		16,575	16,346
Northeast G And P [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		15,399	14,526
West [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		13,487	13,948
Other [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		1,151	849
Operating Segments [Member] | Atlantic Gulf [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Equity-method investments		741	776
Operating Segments [Member] | Northeast G And P [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Equity-method investments		3,973	5,319
Operating Segments [Member] | West [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Equity-method investments		1,521	1,726
Operating Segments [Member] | Other [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Equity-method investments		0	0
Intersegment Eliminations [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	[1]	(572)	(367)
Equity-method investments		$ 0	$ 0

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