XML 59 R47.htm IDEA: XBRL DOCUMENT
v3.7.0.1

Acquisition of Hardin Street Marine LLC (Details) $ in Millions |  |  | 6 Months Ended
--- | --- | --- | ---
Mar. 01, 2017 USD ($) | Mar. 31, 2016 USD ($) shares | Jun. 30, 2017 USD ($)
Business Acquisition [Line Items] |  |  |
Contribution from MPC |  |  | $ 12
Number of tow boats |  | 18 |
Number of barges |  | 219 |
Hardin Street Marine [Member] |  |  |
Business Acquisition [Line Items] |  |  |
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned |  | $ 600 |
Business Acquisition, Effective Date of Acquisition |  | Mar. 31, 2016 |
Limited Partner [Member] | Hardin Street Marine [Member] |  |  |
Business Acquisition [Line Items] |  |  |
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares | shares |  | 22,534,002 |
Business Acquisition, Equity Interest Issued or Issuable, Fair Value Assigned |  | $ 669 |
General Partner | Hardin Street Marine [Member] |  |  |
Business Acquisition [Line Items] |  |  |
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares | shares |  | 459,878 |
Business Acquisition, Equity Interest Issued or Issuable, Fair Value Assigned |  | $ 14 |
MPC |  |  |
Business Acquisition [Line Items] |  |  |
Contribution from MPC | $ 6 | $ 15 |
Percentage of MPC volumes shipped |  | 60.00% |

X
- Definition Fair value of equity interests (such as common shares, preferred shares, or partnership interest) issued or issuable to acquire the entity. + References No definition available. + Details
Name: | mpc_BusinessAcquisitionEquityInterestIssuedorIssuableFairValueAssigned
Namespace Prefix: | mpc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Capital Contribution By Related Party + References No definition available. + Details
Name: | mpc_CapitalContributionByRelatedParty
Namespace Prefix: | mpc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Number of Tow Boats + References No definition available. + Details
Name: | mpc_NumberofTowBoats
Namespace Prefix: | mpc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of barges + References No definition available. + Details
Name: | mpc_Numberofbarges
Namespace Prefix: | mpc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percent of Volumes Shipped + References No definition available. + Details
Name: | mpc_PercentofVolumesShipped
Namespace Prefix: | mpc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date when the acquirer obtains control of the acquiree, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 25 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=84229725&loc=d3e845-128460 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 25 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=84229725&loc=d3e848-128460 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463 + Details
Name: | us-gaap_BusinessAcquisitionEffectiveDateOfAcquisition1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Value of equity interests (such as common shares, preferred shares, or partnership interest) issued or issuable to acquire the entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b)(4) -URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479 + Details
Name: | us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Number of shares of equity interests issued or issuable to acquire entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b)(4) -URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479 + Details
Name: | us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
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_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=mpc_HardinStreetMarineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PartnerTypeOfPartnersCapitalAccountAxis=us-gaap_LimitedPartnerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PartnerTypeOfPartnersCapitalAccountAxis=us-gaap_GeneralPartnerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=mpc_MarathonPetroleumCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |