XML 89 R68.htm IDEA: XBRL DOCUMENT
v3.26.1

Fair Values - Recurring - Significant Unobservable Inputs in Level 3 Valuation (Details) | 3 Months Ended
--- | ---
Mar. 31, 2026 $ / gal
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] |
Derivative, Term of Contract | 5 years
Embedded Derivative [Member] |
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] |
Derivative, Term of Contract | 5 years
Level 3 [Member] |
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] |
Derivative, Average Forward Price | 0.85
Fair Value Inputs Probability of Renewal | 100.00%
Minimum [Member] | Level 3 [Member] |
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] |
Derivative, Forward Price | 0.69
Maximum [Member] | Level 3 [Member] |
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] |
Derivative, Forward Price | 2.21

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: | mplx_FairValueInputsAssetsandLiabilitiesQuantitativeInformationLineItems
Namespace Prefix: | mplx_
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: | mplx_FairValueInputsProbabilityOfRenewal
Namespace Prefix: | mplx_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The average forward price on the group of price risk forward or futures contracts, such as gas futures contracts. + References No definition available. + Details
Name: | us-gaap_DerivativeAverageForwardPrice
Namespace Prefix: | us-gaap_
Data Type: | srt-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition The forward price on the price risk forward or futures contract, such as a gas futures contract. + References No definition available. + Details
Name: | us-gaap_DerivativeForwardPrice
Namespace Prefix: | us-gaap_
Data Type: | srt-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_DerivativeTermOfContract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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

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

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |