Name:	mpc_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsWeightedAverageGrantDateFairValueForfeited
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Data Type:	num:perShareItemType
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Share Based Compensation Arrangement By Share Based Payment Award Non Option Equity Instruments Weighted Average Grant Date Fair Value Issued

No definition available.

Name:	mpc_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsWeightedAverageGrantDateFairValueIssued
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Data Type:	num:perShareItemType
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Share Based Compensation Arrangement By Share Based Payment Award Non Option Equity Instruments Weighted Average Grant Date Fair Value Outstanding

No definition available.

Name:	mpc_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsWeightedAverageGrantDateFairValueOutstanding
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Data Type:	num:perShareItemType
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Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments. Weighted Average Grant Fair Value [Roll Forward]

No definition available.

Name:	mpc_SharebasedCompensationArrangementbySharebasedPaymentAwardNonOptionEquityInstruments.WeightedAverageGrantFairValueRollForward
Namespace Prefix:	mpc_
Data Type:	xbrli:stringItemType
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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

Number of non-option equity instruments exercised by participants.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised
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Data Type:	xbrli:sharesItemType
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Period Type:	duration

Number of shares under non-option equity instrument agreements that were cancelled as a result of occurrence of a terminating event.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
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Period Type:	duration

Net number of non-option equity instruments granted to participants.

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Data Type:	xbrli:sharesItemType
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Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber
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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.