XML 110 R96.htm IDEA: XBRL DOCUMENT v3.7.0.1

Derivatives - Open Commodity Derivative Contracts - Refined Products (Detail) - Refined Products gal in Thousands	3 Months Ended
	Mar. 31, 2017 gal
Exchange Traded
Derivative [Line Items]
Percentage of derivative contracts expiring in the period	100.00%
Derivative contract expiration date	Jun. 30, 2017
Exchange Traded | Long
Derivative [Line Items]
Notional contracts (in thousands of Total Gallons)	254,058	[1]
Exchange Traded | Short
Derivative [Line Items]
Notional contracts (in thousands of Total Gallons)	133,098	[1]
Over the Counter | Short
Derivative [Line Items]
Notional contracts (in thousands of Total Gallons)	81,257
[1] of the exchange-traded contracts expire in the second quarter of 2017.

X

- Definition

Aggregate notional amount of derivative expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

+ Details

Name:	invest_DerivativeNonmonetaryNotionalAmount
Namespace Prefix:	invest_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Percentage Of Derivative Contracts Expiring in the following quarter.

+ References

No definition available.

+ Details

Name:	mpc_DerivativeInstrumentsPercentageOfDerivativeContractsExpiration1
Namespace Prefix:	mpc_
Data Type:	num:percentItemType
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_DerivativeLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Date the derivative contract matures, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeMaturityDates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_EnergyAxis=mpc_RefinedProductsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_TransactionTypeAxis=us-gaap_ExchangeTradedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PositionAxis=us-gaap_LongMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PositionAxis=us-gaap_ShortMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_TransactionTypeAxis=us-gaap_OverTheCounterMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: