Reportable Segments Table - Revenues (External and Intersegment) by Investments (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019		Sep. 30, 2020	Sep. 30, 2019
Revenues	$ 9,955	$ 13,495	[1]	$ 28,920	$ 40,493	[1]
Intrastate Transportation And Storage [Member]
Revenues	654	764		1,763	2,385
Investment In Sunoco LP [Member]
Revenues	2,805	4,331		8,157	12,498
Investment In USAC [Member]
Revenues	161	175		509	520
Interstate Transportation and Storage [Member]
Revenues	471	479		1,380	1,470
Midstream [Member]
Revenues	1,377	1,580		3,565	4,496
NGL and refined products transportation and services [Member]
Revenues	2,623	2,878		7,457	8,521
Crude oil transportation and services [Member]
Revenues	2,850	4,453		8,877	13,685
Other Segments [Member]
Revenues	367	441		1,372	1,276
Intersegment Eliminations [Member]
Revenues	(1,353)	(1,606)		(4,160)	(4,358)
Intersegment [Member] | Intrastate Transportation And Storage [Member]
Revenues	40	89		148	270
Intersegment [Member] | Investment In Sunoco LP [Member]
Revenues	4	3		53	4
Intersegment [Member] | Investment In USAC [Member]
Revenues	3	6		9	15
Intersegment [Member] | Interstate Transportation and Storage [Member]
Revenues	5	4		15	16
Intersegment [Member] | Midstream [Member]
Revenues	792	876		2,088	2,792
Intersegment [Member] | NGL and refined products transportation and services [Member]
Revenues	416	607		1,466	1,181
Intersegment [Member] | Crude oil transportation and services [Member]
Revenues	1	0		4	0
Intersegment [Member] | Other Segments [Member]
Revenues	92	21		377	80
External Customers [Member] | Intrastate Transportation And Storage [Member]
Revenues	614	675		1,615	2,115
External Customers [Member] | Investment In Sunoco LP [Member]
Revenues	2,801	4,328		8,104	12,494
External Customers [Member] | Investment In USAC [Member]
Revenues	158	169		500	505
External Customers [Member] | Interstate Transportation and Storage [Member]
Revenues	466	475		1,365	1,454
External Customers [Member] | Midstream [Member]
Revenues	585	704		1,477	1,704
External Customers [Member] | NGL and refined products transportation and services [Member]
Revenues	2,207	2,271		5,991	7,340
External Customers [Member] | Crude oil transportation and services [Member]
Revenues	2,849	4,453		8,873	13,685
External Customers [Member] | Other Segments [Member]
Revenues	$ 275	$ 420		$ 995	$ 1,196

[1] *As adjusted. See Note 1.