XML 104 R87.htm IDEA: XBRL DOCUMENT v3.8.0.1

Fair Value Measurments - Recurring - Significant Unobservable Inputs in Level 3 Valuation (Details) - Fair Value, Inputs, Level 3 [Member]	3 Months Ended
	Mar. 31, 2018
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Embedded Derivative Renewal Term	5 years
Embedded derivatives in commodity contracts
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value Inputs Probability of Renewal	62.50%
Fair Value Inputs Probability of Renewal Second Term	82.00%

X

- Definition

Represents the term for which the counterparty has the option to renew a purchase agreement related to an embedded derivative.

+ References

No definition available.

+ Details

Name:	mpc_EmbeddedDerivativeRenewalTerm
Namespace Prefix:	mpc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

[Line Items] for Schedule of the inputs used in the fair value measurement of assets and liabilities. This disclosure may include, but is not limited to, the fair value of the asset and liabilities, valuation technique used to measure fair value, the inputs used to measure fair value, the ranges of the inputs, and the weighted averages of the inputs. [Table]

+ References

No definition available.

+ Details

Name:	mpc_FairValueInputsAssetsandLiabilitiesQuantitativeInformationLineItems
Namespace Prefix:	mpc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Represents the percentage of likelihood of renewal of the commodity contract with embedded derivative.

+ References

No definition available.

+ Details

Name:	mpc_FairValueInputsProbabilityOfRenewal
Namespace Prefix:	mpc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Represents the percentage of likelihood of renewal of the commodity contract with embedded derivative for the second term of the contract.

+ References

No definition available.

+ Details

Name:	mpc_FairValueInputsProbabilityofRenewalSecondTerm
Namespace Prefix:	mpc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_EmbeddedDerivativeFinancialInstrumentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: