Property, Plant and Equipment (Summary of Property, Plant and Equipment) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2020	Sep. 30, 2020		Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Impairment of Long-Lived Assets Held-for-use	$ 174
Property, plant and equipment, gross		$ 26,919		$ 26,867
Less accumulated depreciation(1)		5,304	[1]	4,722
Property, plant and equipment, net		21,615		22,145
L&S
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		12,671		12,934
L&S | Terminals
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		6,001		5,572
L&S | Marine
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		961		906
L&S | Terminals and related assets
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		1,534		1,109
L&S | Refineries and related assets
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		2,196		2,870
L&S | Land, building and other
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		1,576		1,817
L&S | Construction-in-progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		403		660
G&P
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		14,248		13,933
G&P | Pipelines
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		7,413		7,159
G&P | Processing, fractionation and storage facilities
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		5,944		5,545
G&P | Land, building and other
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		509		484
G&P | Construction-in-progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		$ 382		$ 745
Maximum [Member] | L&S | Terminals
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		51 years
Maximum [Member] | L&S | Marine
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		20 years
Maximum [Member] | L&S | Terminals and related assets
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		40 years
Maximum [Member] | L&S | Refineries and related assets
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		40 years
Maximum [Member] | L&S | Land, building and other
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		61 years
Maximum [Member] | G&P | Pipelines
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		40 years
Maximum [Member] | G&P | Processing, fractionation and storage facilities
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		40 years
Maximum [Member] | G&P | Land, building and other
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		40 years
Minimum [Member] | L&S | Terminals
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		2 years
Minimum [Member] | L&S | Marine
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		15 years
Minimum [Member] | L&S | Terminals and related assets
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		4 years
Minimum [Member] | L&S | Refineries and related assets
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		13 years
Minimum [Member] | L&S | Land, building and other
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		1 year
Minimum [Member] | G&P | Pipelines
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		5 years
Minimum [Member] | G&P | Processing, fractionation and storage facilities
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		10 years
Minimum [Member] | G&P | Land, building and other
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		3 years

[1] The September 30, 2020 balance includes property, plant and equipment impairment charges recorded during the first quarter of 2020 as discussed below.