Reportable Segments Segment Assets (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019	[1]	Dec. 31, 2018
Segment Reporting Information [Line Items]
Assets	$ 98,484	$ 102,296		$ 88,609
Intrastate transportation and storage
Segment Reporting Information [Line Items]
Assets	6,972	6,648
Interstate transportation and storage
Segment Reporting Information [Line Items]
Assets	17,413	18,111
Midstream
Segment Reporting Information [Line Items]
Assets	19,132	20,332
NGL and refined products transportation and services
Segment Reporting Information [Line Items]
Assets	21,803	19,145
Crude oil transportation and services
Segment Reporting Information [Line Items]
Assets	21,481	22,933
Investment In Sunoco LP [Member]
Segment Reporting Information [Line Items]
Assets	4,985	5,438
Investment In USAC [Member]
Segment Reporting Information [Line Items]
Assets	3,058	3,730
All other
Segment Reporting Information [Line Items]
Assets	$ 3,640	$ 5,959

[1] *As adjusted. See Note 1.