XML 53 R41.htm IDEA: XBRL DOCUMENT
v3.7.0.1

Equity-Based Compensation Plan (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2017
Phantom Units [Member] |
Equity Transactions And Share Based Compensation [Line Items] |
Summary of Share-based Compensation, Restricted Stock Units Award Activity | The following is a summary of phantom unit award activity of MPLX LP common units for the six months ended June 30, 2017:
| Number of Units |  | Weighted Average Fair Value
Outstanding at December 31, 2016 | 1,173,411 |  |  | $ | 33.09 |
Granted | 529,434 |  |  | 36.86 |
Settled | (268,154 | ) |  | 33.47 |
Forfeited | (62,852 | ) |  | 34.66 |
Outstanding at June 30, 2017 | 1,371,839 |  |  | 34.40 |
Performance Shares [Member] |
Equity Transactions And Share Based Compensation [Line Items] |
Summary of Share-based Compensation, Restricted Stock Units Award Activity | The following is a summary of the equity-classified performance unit award activity for the six months ended June 30, 2017:
| Number of Units
Outstanding at December 31, 2016 | 1,799,249 |
Granted | 1,407,062 |
Settled | (464,500 | )
Forfeited | (15,312 | )
Outstanding at June 30, 2017 | 2,726,499 |

X
- Definition Equity Transactions And Share Based Compensation [Line Items] + References No definition available. + Details
Name: | mpc_EquityTransactionsAndShareBasedCompensationLineItems
Namespace Prefix: | mpc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the number and weighted-average grant date fair value for restricted stock units that were outstanding at the beginning and end of the year, and the number of restricted stock units that were granted, vested, or forfeited during the year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_PhantomShareUnitsPSUsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |