Impairments - Schedule of Goodwill (Details) $ in Millions	3 Months Ended
Mar. 31, 2020 USD ($)
Goodwill [Line Items]
Goodwill, beginning balance	$ 20,040
Impairments	(7,330)
Transfers	0
Goodwill, ending balance	12,710
Refining & Marketing
Goodwill [Line Items]
Goodwill, beginning balance	5,572
Impairments	(5,516)
Transfers	(56)
Goodwill, ending balance	0
Retail
Goodwill [Line Items]
Goodwill, beginning balance	4,951
Impairments	0
Transfers	0
Goodwill, ending balance	4,951
Midstream
Goodwill [Line Items]
Goodwill, beginning balance	9,517
Impairments	(1,814)
Transfers	56
Goodwill, ending balance	$ 7,759

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of transfers into (out of) an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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