XML 63 R51.htm IDEA: XBRL DOCUMENT
v3.7.0.1

Investments & NCI Sherwood Midstream Holdings (Details) - USD ($) $ in Millions |  | 3 Months Ended | 6 Months Ended |
--- | --- | --- | --- | ---
Jan. 01, 2017 | Jun. 30, 2017 | Jun. 30, 2017 | Jun. 30, 2016 | Dec. 31, 2016
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Contribution of fixed assets to joint venture | [1] |  |  | $ 337 | $ 0 |
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity |  |  | $ 1,100 | 1,100 |  | $ 1,100
Distributions from unconsolidated affiliates - return of capital |  |  |  | 24 | $ 0 |
Equity method investments |  |  | 3,368 | $ 3,368 |  | $ 2,471
Sherwood Midstream Holdings [Member] |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Fair Value Of Assets Contributed |  | $ 209 | $ 10 |  |  |
Equity Method Investment, Ownership Percentage |  |  | 86.00% | 86.00% |  |
Contribution of fixed assets to joint venture |  | 203 |  |  |  |
Gain (Loss) on Disposition of Assets |  | 2 |  |  |  |
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity |  |  | $ 14 | $ 14 |  |
Distributions from unconsolidated affiliates - return of capital |  | $ 45 |  |  |  |
Equity method investments |  |  | $ 165 | $ 165 |  |
Direct Ownership Interest [Member] | Sherwood Midstream Holdings [Member] |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Equity Method Investment, Ownership Percentage |  | 79.00% |  |  |  |
Indirect Ownership Interest [Member] | Sherwood Midstream Holdings [Member] |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Equity Method Investment, Ownership Percentage |  |  | 13.90% | 13.90% |  |
Sherwood Midstream LLC [Member] | Sherwood Midstream Holdings [Member] |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Equity Method Investment, Ownership Percentage |  | 21.00% |  |  |  |
Payments to Acquire Interest in Joint Venture |  | $ 44 | $ 4 |  |  |
[1] | Contribution of assets to Sherwood Midstream and Sherwood Midstream Holdings. See Note 4.

X
- Definition The fair value of assets contributed to the Partnership in noncash investing or financing activities. + References No definition available. + Details
Name: | mpc_FairValueOfAssetsContributed
Namespace Prefix: | mpc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Value of property contributed in noncash investing and financing activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4313-108586 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586 + Details
Name: | us-gaap_ContributionOfProperty
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Difference between amount at which an investment accounted for under the equity method of accounting is carried (reported) on the balance sheet and amount of underlying equity in net assets the reporting Entity has in the investee. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=66022249&loc=d3e33749-111570 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_EquityMethodInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2443-110228 + Details
Name: | us-gaap_GainLossOnDispositionOfAssets1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash outflow associated with the investment in or advances to an entity in which the reporting entity shares control of the entity with another party or group. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585 + Details
Name: | us-gaap_PaymentsToAcquireInterestInJointVenture
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of distribution received from equity method investee for return of investment, classified as investing activities. Excludes distribution for return on investment, classified as operating activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 21D -URI http://asc.fasb.org/extlink&oid=98514028&loc=SL94080555-108585 + Details
Name: | us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ScheduleOfEquityMethodInvestmentsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=mpc_SherwoodMidstreamHoldingsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | mpc_OwnershipTypeAxis=mpc_DirectOwnershipInterestMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | mpc_OwnershipTypeAxis=mpc_IndirectOwnershipInterestMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=mpc_SherwoodMidstreamLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |