Leases Leases Narrative (Details) - USD ($) $ in Millions	3 Months Ended					6 Months Ended
	Jun. 30, 2020		Mar. 31, 2020	Jun. 30, 2019	[1],[2]	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Lessor, Sales-type Lease, Assumptions and Judgments, Value of Underlying Asset, Amount			$ 171
Sales-type Lease, Lease Receivable			370
Sales-type Lease, Selling Profit (Loss)			209
MPC
Operating Lease, Lease Income	$ 195	[1]		$ 246		$ 381	$ 525
Sales-type Lease, Lease Receivable	423					423
Sales-type Lease, Unguaranteed Residual Asset	20					20		$ 7
Refining Logistics [Member] | MPC
Sales-type Lease, Unguaranteed Residual Asset			$ 10
Third Party [Member]
Operating Lease, Lease Income	66	[1]		$ 68		129	$ 133
Sales-type Lease, Lease Receivable	1					1
Sales-type Lease, Selling Profit (Loss)	$ 0					$ 0

[1] These amounts are presented net of executory costs.

[2] Financial information for the three and six months ended June 30, 2019 has been retrospectively adjusted for the acquisition of ANDX. See Notes 1 and 3.