Revision of Prior Period [Axis] Revision of Prior Period [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Business Combination, Recognized Asset Acquired, Property, Plant, and Equipment Business Combination, Recognized Asset Acquired, Property, Plant, and Equipment Commodity Contract [Member] Commodity Contract [Member] Temporary Equity [Abstract] Award Timing Predetermined Award Timing Predetermined [Flag] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Asset Class [Axis] Asset Class [Axis] Entity File Number Entity File Number Income from equity method investments Income from equity method investments Income (Loss) from Equity Method Investments Tabular List, Table Tabular List [Table Text Block] Dividends Declared Dividends Declared [Table Text Block] Schedule of Related Party Transactions Schedule of Related Party Transactions [Table Text Block] Long-term deferred revenue Deferred Revenue, Noncurrent Guarantor Obligations, Maximum Exposure, Undiscounted Guarantor Obligations, Maximum Exposure, Undiscounted Noncurrent assets - related parties Other Receivable, after Allowance for Credit Loss, Noncurrent Position [Axis] Position [Axis] Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Measurement Basis [Axis] Measurement Basis [Axis] Adjustment to Compensation: Adjustment to Compensation [Axis] Related Party Agreements and Transactions Related Party Transactions Disclosure [Text Block] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Current liabilities and other current assets Increase (Decrease) in Accounts Payable and Accrued Liabilities Inventories Inventory, Gross Revenue Revenue from Contract with Customer [Text Block] Distributions to Series A preferred unitholders Payments of Ordinary Dividends, Preferred Stock and Preference Stock Liability, change in timeframe, performance obligation satisfied, revenue recognized Contract with Customer, Liability, Change in Timeframe, Performance Obligation Satisfied, Revenue Recognized Other Comprehensive Income (Loss), Net of Tax Other Comprehensive Income (Loss), Net of Tax Schedule of Segment Reporting Information, by Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Revenue, Remaining Performance Obligation, Amount Revenue, Remaining Performance Obligation, Amount Adjustment to Compensation, Amount Adjustment to Compensation Amount Consolidation, Policy Consolidation, Policy [Policy Text Block] Distribution Made to Limited Partner [Line Items] Distribution Made to Limited Partner [Line Items] Employee Stock Option Share-Based Payment Arrangement, Option [Member] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Investments in unconsolidated affiliates Payments to Acquire Equity Method Investments Measurement Frequency [Axis] Measurement Frequency [Axis] Insider Trading Policies and Procedures [Line Items] Summary of Property, Plant and Equipment Property, Plant and Equipment [Table Text Block] Loss Contingency, Damages Paid, Value Loss Contingency, Damages Paid, Value Total liabilities, preferred units and equity Liabilities and Equity Fair Value, Recurring [Member] Fair Value, Recurring [Member] Derivative [Table] Derivative Instruments, Gain (Loss) [Table] Net income Temporary Equity, Net Income Cover [Abstract] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Maximum [Member] Maximum [Member] Derivative, Average Forward Price Derivative, Average Forward Price Schedule of Equity Method Investments [Table] Equity Method Investment [Table] Less: Net income attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Accounting Policies [Abstract] Accounting Policies [Abstract] Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Debt Instrument [Line Items] Debt Instrument [Line Items] The amount of total loss for the period included in earnings attributable to the change in unrealized loss relating to liabilities still held at end of period Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss) Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Pay vs Performance Disclosure [Line Items] Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Change in fair value of derivatives Increase (Decrease) in Derivative Assets and Liabilities Distributions/adjustments related to equity method investments Distributions/adjustments related to equity method investments Distributions/adjustments related to equity method investments Liabilities Liabilities [Abstract] Schedule of Preferred Units [Table] Partners' Capital, Master Limited Partnership, Preferred Unit [Table] Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] MPLX LP [Member] MPLX LP [Member] MPLX LP [Member] Commitments And Contingencies [Line Items] Commitments And Contingencies [Line Items] Commitments And Contingencies [Line Items] Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Entity Shell Company Entity Shell Company Schedule of Carrying Values and Estimated Fair Values of Debt Instruments Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Long-term liabilities - related parties Other Liabilities, Noncurrent Other Liabilities, Noncurrent Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Deferred revenue Increase (Decrease) in Deferred Revenue Difference between carrying amount and underlying equity Equity Method Investment, Difference Between Carrying Amount and Underlying Equity Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Operating Segments Operating Segments [Member] Schedule of Cash Flow, Supplemental Disclosures Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Company Selected Measure Amount Company Selected Measure Amount Noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Comprehensive income attributable to MPLX LP Comprehensive Income (Loss), Net of Tax, Attributable to Parent Derivative, Forward Price Derivative, Forward Price Disposal Group Name [Domain] Disposal Group Name [Domain] Name Measure Name Net income attributable to MPLX LP Net income attributable to MPLX LP(1): Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent Letter of Credit Letter of Credit [Member] Operating lease liabilities Operating Lease, Liability, Current Senior Note Due April 20236 Senior Note Due April 2036 [Member] Senior Note Due April 2036 Document Fiscal Period Focus Document Fiscal Period Focus Award Timing Method Award Timing Method [Text Block] Schedule of Distributions Made to Limited Partner [Table] Distributions Made to Limited Partner [Table] Award Type Award Type [Axis] Revision of Prior Period, Adjustment Revision of Prior Period, Adjustment [Member] Legal Entity [Axis] Legal Entity [Axis] Total assets Assets Investment, Name [Domain] Investment, Name [Domain] Trading Symbol Trading Symbol Stockholders Equity [Line Items] Stockholders Equity [Line Items] Stockholders Equity [Line Items] Purchased product costs Purchased product costs [Member] Purchased product costs [Member] Alternative Investment, Valuation Technique [Extensible Enumeration] Alternative Investment, Valuation Technique [Extensible Enumeration] Total MPLX LP partners’ capital Partners' Capital Entity Address, City or Town Entity Address, City or Town Operating activities: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Deferred Revenue [Domain] Deferred Revenue [Domain] Segment Reporting, Other Segment Item, Amount Segment Reporting, Other Segment Item, Amount Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Income Statement Location [Domain] Statement of Income Location, Balance [Domain] Distributions Partners' Capital Account, Distributions Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Property, Plant and Equipment, Additions Property, Plant and Equipment, Additions Business Combination, Voting Equity Interest Acquired, Percentage Business Combination, Consideration Transferred Entity Emerging Growth Company Entity Emerging Growth Company Entity Partnership, Units Outstanding Entity Common Stock, Shares Outstanding ROU assets obtained in exchange for new operating lease obligations Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Equity Method Investments, Including Held for Sale Equity Method Investments, Including Held for Sale Equity Method Investments, Including Held for Sale Business Combination, Recognized Asset Acquired, Asset Business Combination, Recognized Asset Acquired, Asset Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Derivative, Gain (Loss) on Derivative, Net Derivative, Gain (Loss) on Derivative, Net Equity method investments Equity Method Investments Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Business Combination [Domain] Business Combination [Domain] Related Party [Member] Related Party [Member] PEO PEO [Member] Disaggregation of Revenue Table Disaggregation of Revenue [Table Text Block] Interest income Investment Income, Interest Other Derivatives Not Designated as Hedging Instruments Liabilities at Fair Value Price Risk Derivative Instruments Not Designated as Hedging Instruments, at Fair Value, Net Changes in: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Restatement Determination Date Restatement Determination Date Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Beginning Balance Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Ending Balance Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Income Statement [Abstract] Income Statement [Abstract] Provision for income taxes Income Tax Expense (Benefit) Performance Guarantee Performance Guarantee [Member] Conversion of Series A preferred units Partners' Capital Account, Exchanges and Conversions Intangibles, net Intangible Assets, Net (Excluding Goodwill) Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Product and Service [Domain] Product and Service [Domain] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Gross PP&E Property, Plant and Equipment, Gross Adjusted EBITDA Adjusted EBITDA Adjusted EBITDA Property, Plant and Equipment Property, Plant and Equipment [Member] Net income Net income Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Guarantor Obligations, Origin and Purpose Guarantor Obligations, Origin and Purpose Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Business Combination [Table] Business Combination [Table] Distributions Temporary Equity Account, Distributions Temporary Equity Account, Distributions Other Income and Expenses [Abstract] Purchased product costs Cost, Direct Material Business Combination, Recognized Asset Acquired and Liability Assumed Business Combination, Recognized Asset Acquired and Liability Assumed [Table Text Block] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Net Working Capital Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Net Working Capital Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Net Working Capital City Area Code City Area Code Acquisitions and Other Transactions Mergers, Acquisitions and Dispositions Disclosures [Text Block] Acquisitions, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] All Trading Arrangements All Trading Arrangements [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Accrued liabilities Accrued Liabilities, Current Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Schedule of Contract with Customer, Contract Asset, Contract Liability, and Receivable Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] General and administrative expenses General and Administrative Expense Capital Expenditures Total capital expenditures Capital Expenditures Capital Expenditures Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Net cash provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Related Party Transactions [Abstract] Related Party Transactions [Abstract] Equity Method Investments and Joint Ventures [Abstract] Equity Method Investments and Joint Ventures [Abstract] Subsequent Event Subsequent Event [Member] Other current assets Business Combination, Recognized Asset Acquired, Other Asset, Current Schedule of Equity Method Investments Schedule of Equity Method Investments [Line Items] Goodwill Goodwill Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] LOOP LLC Loop LLC [Member] LOOP LLC [Member] PEO Total Compensation Amount PEO Total Compensation Amount Depreciation Depreciation Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Commitments And Contingencies [Table] Commitments And Contingencies [Table] Commitments And Contingencies [Table] Derivative Liability, Subject to Master Netting Arrangement, before Offset Derivative Liability, Subject to Master Netting Arrangement, before Offset Business Combination, Recognized Asset Acquired, Asset [Abstract] Business Combination, Recognized Asset Acquired, Asset [Abstract] Equity Components [Axis] Equity Components [Axis] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Nature of Operations Nature of Operations [Text Block] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Product [Member] Product [Member] Number of reportable segments Number of Reportable Segments Beginning balance Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs Business Combination, Recognized Asset Acquired, Receivable, Current Business Combination, Recognized Asset Acquired, Receivable, Current Other Performance Measure, Amount Other Performance Measure, Amount Debt issuance costs Payments of Debt Issuance Costs Entity Address, State or Province Entity Address, State or Province Principal payments under finance lease obligations Finance Lease, Principal Payments Other VIEs and Non-VIEs Other VIEs and Non-VIEs [Member] Other VIEs and Non-VIEs [Member] Related Party [Domain] Related and Nonrelated Parties [Domain] Total current liabilities Liabilities, Current Common - diluted Weighted Average Limited Partnership Units Outstanding, Diluted Other Current Liabilities [Member] Other Current Liabilities [Member] Net change in cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Excluding Exchange Rate Effect, Including Discontinued Operation Capitalized interest Interest Costs Capitalized Adjustment Business Combination, Consideration Transferred and Preacquisition Equity Interest in Acquiree Business Combination, Consideration Transferred and Preacquisition Equity Interest in Acquiree Derivative Instrument [Axis] Derivative Instrument [Axis] Individual: Individual [Axis] ROU assets obtained in exchange for new finance lease obligations Right-of-Use Asset Obtained in Exchange for Finance Lease Liability Other current assets Other Assets, Current Increase in capital accruals Increase (Decrease) In Accruals for Capital Expenditures Increase (Decrease) In Accruals for Capital Expenditures Entity [Domain] Entity [Domain] Net cash used in investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Per Unit Data (See Note 7) Earnings Per Unit [Abstract] Remaining performance obligation, expected timing of satisfaction, years Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Unrealized Gain (Loss) on Derivatives and Commodity Contracts Unrealized Gain (Loss) on Derivatives and Commodity Contracts Interest paid (net of amounts capitalized) Interest Paid, Excluding Capitalized Interest, Operating Activity Document Fiscal Year Focus Document Fiscal Year Focus Basis of Accounting, Policy Basis of Accounting, Policy [Policy Text Block] Product Sales Product Sales [Member] Product Sales [Member] Right of use assets, net Right of use assets Operating Lease, Right-of-Use Asset Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Deferred Revenue from Contracts with Customers, Noncurrent Deferred Revenue from Contracts with Customers, Noncurrent Deferred Revenue from Contracts with Customers, Noncurrent Long-term debt - repayments Repayments of Long-Term Debt Entity Interactive Data Current Entity Interactive Data Current Contributions Partners' Capital Account, Contributions Carrying Value Reported Value Measurement [Member] Crude Oil and Products Logistics Crude Oil and Products Logistics [Member] Crude Oil and Products Logistics [Member] Other taxes Taxes, Miscellaneous Equity [Abstract] Equity [Abstract] Senior Notes Senior Notes Interest and Other Financial Costs Interest and Other Income [Table Text Block] Segment Reporting Disclosure Segment Reporting Disclosure [Text Block] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Long-term debt due within one year Amounts due within one year Long-Term Debt and Lease Obligation, Current Contributions from MPC Proceeds from Contributions from Parent Debt and Lease Obligation Debt and Lease Obligation Long-Lived Tangible Asset [Axis] Long-Lived Tangible Asset [Axis] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Conversion of Series A preferred units Temporary Equity, Other Changes Sherwood Midstream LLC Sherwood Midstream LLC [Member] Sherwood Midstream LLC Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Business Combination, Contingent Consideration, Liability Business Combination, Contingent Consideration, Liability Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Excluding Portion Attributable to Temporary Equity The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest and excluding the portion attributable to temporary equity. Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Long-term deferred revenue, additions/(deletions) Deferred Revenue, Noncurrent, Period Increase (Decrease) Deferred Revenue, Noncurrent, Period Increase (Decrease) Other noncurrent assets Other Assets, Noncurrent Accrued interest payable Interest Payable, Current Entity Central Index Key Entity Central Index Key PEO Name PEO Name Total revenues and other income Revenues Revenues Preferred Units [Line Items] Preferred Units [Line Items] Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Supplemental Cash Flow Elements [Abstract] Supplemental Cash Flow Elements [Abstract] Purchases - related parties Costs and Expenses, Related Party Assets and liabilities - related parties Increase (Decrease) in Due from Related Parties, Current Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Schedule of Stockholders Equity Schedule of Stockholders Equity [Table Text Block] Revolving Credit Facility Revolving Credit Facility [Member] Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value Ending balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value Finance lease obligations Finance Lease, Liability Arrangement Duration Trading Arrangement Duration Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Deferred revenue, revenue recognized Deferred Revenue, Revenue Recognized Segments [Axis] Segments [Axis] Schedule of Derivative Instruments in Statement of Financial Position, Fair Value Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Beginning Balance Ending Balance Temporary Equity, Carrying Amount, Attributable to Parent Partners' Capital Account, Units, Converted Partners' Capital Account, Units, Converted Partners' Capital Account, Units, Converted Less comprehensive income attributable to: Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest [Abstract] Exercise Price Award Exercise Price Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Entity Filer Category Entity Filer Category Service revenue - product related Service revenue - product related [Member] Service revenue - product related Class of Stock [Domain] Class of Stock [Domain] Local Phone Number Local Phone Number Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Payment for (Proceeds from) Other Investing Activity Payment for (Proceeds from) Other Investing Activity All other, net Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Other Item Subsequent Event Type [Axis] Subsequent Event Type [Axis] Lease receivables Net Investment in Lease, before Allowance for Credit Loss, Current Series A Preferred Unit-holders Temporary Equity [Member] Temporary Equity Limited Partners' Capital Account Limited Partners' Capital Account Stock Repurchased and Retired During Period, Shares Number of common units repurchased Stock Repurchased and Retired During Period, Shares Business Combination, Recognized Liability Assumed, Accrued Liabilities, Current Business Combination, Recognized Liability Assumed, Accrued Liabilities, Current Business Combination, Recognized Liability Assumed, Accrued Liabilities, Current Percent of Par Percent of Par Percent of Par Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Excluding Goodwill Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Excluding Goodwill Business Combination, Recognized Asset Acquired, Cash and Cash Equivalent Business Combination, Recognized Asset Acquired, Cash and Cash Equivalent Disposal Group, Including Discontinued Operation, Consideration Disposal Group, Including Discontinued Operation, Consideration Assets Assets [Abstract] Guarantee of Indebtedness of Others [Member] Guarantee of Indebtedness of Others [Member] Credit Facility [Axis] Credit Facility [Axis] Nonrelated Party [Member] Nonrelated Party [Member] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Balance Sheet Location [Axis] Statement of Financial Position Location, Balance [Axis] Deferred Revenue from Contracts with Customers, Current Deferred Revenue from Contracts with Customers, Current Deferred Revenue from Contracts with Customers, Current Realized gain (loss) Derivative Instruments Not Designated as Hedging Instruments, Realized Gain (Loss), Net Amount of realized gain (loss) of derivative instruments not designated or qualifying as hedging instruments. Debt Instrument [Axis] Debt Instrument [Axis] Fair Value Disclosures Fair Value Disclosures [Text Block] Business Combination [Line Items] Business Combination [Line Items] Credit Facility [Domain] Credit Facility [Domain] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Entity Address, Address Line One Entity Address, Address Line One Other noncurrent assets Business Combination, Recognized Asset Acquired, Asset, Noncurrent Accumulated Other Comprehensive Income AOCI Attributable to Parent [Member] Debt Instrument, Interest Rate, Stated Percentage Debt Instrument, Interest Rate, Stated Percentage Investment, Name [Axis] Investment, Name [Axis] Long-term operating lease liabilities Operating Lease, Liability, Noncurrent Distribution Made to Limited Partner, Cash Distributions Declared Distribution Made to Limited Partner, Cash Distributions Declared Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract] MPLX Revolving Credit Facility due April 2031 MPLX Revolving Credit Facility due April 2031 [Member] MPLX Revolving Credit Facility due April 2031 Derivative Disclosure Derivative Instruments and Hedging Activities Disclosure [Text Block] Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] [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] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Fair Value as of Grant Date Award Grant Date Fair Value Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Abstract] Entity Registrant Name Entity Registrant Name Schedule of Business Combination, Consideration Schedule of Business Combination, Consideration [Table Text Block] Schedule of Business Combination, Consideration Net income attributable to MPLX LP per limited partner unit: Net Income (Loss), Per Outstanding Limited Partnership Unit, Basic, Net of Tax [Abstract] Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Alternative Investment, Measurement Input Alternative Investment, Measurement Input Rockies Operations Rockies Operations [Member] Rockies Operations Common - basic Weighted Average Limited Partnership Units Outstanding, Basic Total costs and expenses Costs and Expenses Debt Instrument, Issuance Date Debt Instrument, Issuance Date Related Party Transaction [Line Items] Related Party Transaction [Line Items] Deferred income taxes Deferred Income Taxes and Other Tax Liabilities, Noncurrent Document Quarterly Report Document Quarterly Report Business Combination, Recognized Liability Assumed, Accrued Property, Plant and Equipment, Current Business Combination, Recognized Liability Assumed, Accrued Property, Plant and Equipment, Current Business Combination, Recognized Liability Assumed, Accrued Property, Plant and Equipment, Current Long-term contract assets Contract with Customer, Asset, before Allowance for Credit Loss, Noncurrent Reconciliation of Other Significant Reconciling Items from Segments to Consolidated Segment, Reconciliation of Other Items from Segments to Consolidated [Table Text Block] Long-Term Debt, Fair Value Long-Term Debt, Fair Value Revision of Prior Period [Domain] Revision of Prior Period [Domain] Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] BANGL, LLC BANGL, LLC [Member] BANGL, LLC Energy [Axis] Energy [Axis] Cash distributions declared per limited partner common unit Distribution Made to Limited Partner, Distributions Declared, Per Unit Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Accounting Standards Update and Change in Accounting Principle [Abstract] Schedule of Debt Schedule of Debt [Table Text Block] Segment Reconciling Items [Member] Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment [Member] Related Party [Axis] Related and Nonrelated Parties [Axis] Title Trading Arrangement, Individual Title Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Service [Member] Service [Member] Net interest and other financial costs Interest and Debt Expense, Total Interest and Debt Expense Other Noncurrent Liabilities [Member] Other Noncurrent Liabilities [Member] Restatement Determination Date: Restatement Determination Date [Axis] Payments to Acquire Businesses, Gross Payments to Acquire Businesses, Gross Non-PEO NEO Non-PEO NEO [Member] Letters of Credit Outstanding, Amount Letters of Credit Outstanding, Amount Contract assets, additions/(deletions) Contract with Customer, Asset Increase (Decrease) Contract with Customer, Asset Increase (Decrease) Position [Domain] Position [Domain] Interest and Other Financial Costs Interest and Other Financial Costs Interest and Other Financial Costs Date of record Distribution Made to Limited Partner, Date of Record All other, net Proceeds from (Payment for) Other Financing Activity Interest expense Interest Expense, Debt Unguaranteed residual assets Sales-type Lease, Unguaranteed Residual Asset Contract Balances [Table] Contract Balances [Table] Contract Balances Business Combination, Recognized Liability Assumed, Liability [Abstract] Business Combination, Recognized Liability Assumed, Liability [Abstract] Segment Reporting, Revenue Reconciling Item [Line Items] Segment Reporting, Revenue Reconciling Item [Line Items] ANDX LP [Member] ANDX LP [Member] ANDX LP [Member] Name Trading Arrangement, Individual Name All Award Types Award Type [Domain] Embedded Derivative, Fair Value of Embedded Derivative Liability Embedded Derivative, Fair Value of Embedded Derivative Liability Sales Revenue, Goods, Related Party, Net Zero Sales Revenue, Goods, Related Party, Net Zero Revenue from related parties from the sale of goods in the normal course of business that net zero on the financial statements due to the terms of the contract. Previously Reported Previously Reported [Member] Equity Awards Adjustments Equity Awards Adjustments [Member] Other Noncash Income (Expense) Other Noncash Income (Expense) Reconciliation of Revenue from Segments to Consolidated [Table] Reconciliation of Revenue from Segments to Consolidated [Table] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Other Income Other Income Other Income Compensation Amount Outstanding Recovery Compensation Amount Debt Instrument, Face Amount Debt Instrument, Face Amount Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Fair Value Estimate of Fair Value Measurement [Member] Share Repurchase Program [Axis] Share Repurchase Program [Axis] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Name Awards Close in Time to MNPI Disclosures, Individual Name Energy [Domain] Energy [Domain] Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Common Unit-holder MPC CommonStock_RelatedPartyInterest [Member] CommonStock_RelatedPartyInterest Revenues and other income: Revenues [Abstract] Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Long-term debt Total long-term debt due after one year Long-Term Debt and Lease Obligation Contract With Customer Non Current Asset Reclassified To Receivable Contract With Customer Non Current Asset Reclassified To Receivable Contract With Customer Non Current Asset Reclassified To Receivable Long-term operating lease liabilities Operating Lease, Liability, Noncurrent, Related Party Operating Lease, Liability, Noncurrent, Related Party Liability Class [Axis] Liability Class [Axis] Bakken Pipeline System [Member] Bakken Pipeline System [Member] Bakken Pipeline System [Member] Segments [Domain] Segments [Domain] Loss Contingency, Damages Sought, Value Loss Contingency, Damages Sought, Value Income Statement Location [Axis] Statement of Income Location, Balance [Axis] Line of Credit Facility, Remaining Borrowing Capacity Line of Credit Facility, Remaining Borrowing Capacity Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration] Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Balance Sheet Location [Domain] Statement of Financial Position Location, Balance [Domain] Line of Credit, Current Line of Credit, Current Inventories Increase (Decrease) in Inventories Amortization of deferred financing costs and debt discount Amortization of Debt Issuance Costs and Discounts Minimum [Member] Minimum [Member] Accumulated Depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Earnings Per Unit, Policy Earnings Per Share, Policy [Policy Text Block] Company Selected Measure Name Company Selected Measure Name Net transfers of property, plant and equipment to lease receivable Property, Plant and Equipment, Transfers and Changes Accrued liabilities for environmental remediation Accrual for Environmental Loss Contingencies Description of Embedded Derivative Description of Embedded Derivative Fair Value Measurement [Domain] Fair Value Measurement [Domain] Disposal of assets Proceeds from Sales of Assets, Investing Activities Senior Notes [Member] Senior Notes [Member] MarEn Bakken Company LLC(1) MarEn Bakken Company LLC [Member] MarEn Bakken Company LLC [Member] Debt Debt Disclosure [Text Block] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Accounts payable Accounts Payable, Current Payments on operating leases Operating Lease, Payments Revenue from Contract with Customer, Excluding Assessed Tax - Third parties Revenue from Contract with Customer, Excluding Assessed Tax, Third parties Revenue from Contract with Customer, Excluding Assessed Tax, Third parties Revenue from Contract with Customer, Excluding Assessed Tax - from third parties. Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Equity Method Investment, Remaining Ownership Interest Purchased Equity Method Investment, Remaining Ownership Interest Purchased Equity Method Investment, Remaining Ownership Interest Purchased Business Combination, Recognized Liability Assumed, Liability Business Combination, Recognized Liability Assumed, Liability Net Income (Loss) Available to Common Stockholders, Diluted Net Income (Loss) Available to Common Stockholders, Diluted All Executive Categories All Executive Categories [Member] Senior Note Due April 2056 Senior Note Due April 2056 [Member] Senior Note Due April 2056 Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Commitments and contingencies (see Note 16) Commitments and Contingencies Financial Support to Nonconsolidated Legal Entity [Axis] Financial Support to Nonconsolidated Legal Entity [Axis] Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Derivative [Table] Derivative [Table] Business Combination [Axis] Business Combination [Axis] Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Revenue Not from Contract with Customer, Other Revenue Not from Contract with Customer, Other Long-Term Debt, Maturity, Year One Business Combination, Recognized Liability Assumed, Long-Term Debt, Current Entity Small Business Entity Small Business Business Combination, Voting Equity Interest Acquired, Percentage Business Combination, Voting Equity Interest Acquired, Percentage Units Outstanding Balance at December 31, 2025 Balance at March 31, 2026 Limited Partners' Capital Account, Units Outstanding Non-controlling Interests Noncontrolling Interest [Member] Document Transition Report Document Transition Report Business Combination, Recognized Asset Acquired, Other Asset, Noncurrent Business Combination, Recognized Asset Acquired, Other Asset, Noncurrent Equity method investment, ownership percentage Equity Method Investment, Ownership Percentage Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Accounting Standards Accounting Standards Update and Change in Accounting Principle [Text Block] Underlying Securities Award Underlying Securities Amount Weighted average units outstanding: Net Income (Loss), Per Outstanding Limited Partnership Unit, Basic, Other Disclosure [Abstract] Equity Component [Domain] Equity Component [Domain] Document Period End Date Document Period End Date PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Illinois Extension Pipeline Company, L.L.C. Illinois Extension Pipeline Company LLC [Member] Illinois Extension Pipeline Company LLC [Member] Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Unit-based compensation awards Partners' Capital Account, Unit-Based Payment Arrangement, Number of Units Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Average cost per unit(1) Shares Acquired, Average Cost Per Share Document Type Document Type Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Texas City Logistics LLC Texas City Logistics LLC [Member] Texas City Logistics LLC Net Income Per Limited Partner Unit Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Product and Service [Axis] Product and Service [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Accrued property, plant and equipment Accrued Property Plant and Equipment Current Carrying value as of the balance sheet date of obligations incurred through that date and payable for property, plant and equipment. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Revenue from Contract with Customer, Excluding Assessed Tax Revenue from Contract with Customer, Excluding Assessed Tax Ohio Gathering Company L.L.C. Ohio Gathering Company L.L.C. [Member] Ohio Gathering Company L.L.C. All Individuals All Individuals [Member] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Additions to property, plant and equipment Additions to property, plant and equipment Payments to Acquire Property, Plant, and Equipment Name Forgone Recovery, Individual Name Distribution Made to Limited Partner, Declaration Date Distribution Made to Limited Partner, Declaration Date Total current assets Assets, Current Statistical Measurement [Axis] Statistical Measurement [Axis] Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Disposal Group Classification [Axis] Disposal Group Classification [Axis] Disposal Group, Not Discontinued Operations Disposal Group, Not Discontinued Operations [Member] Current assets - related parties Other Receivables, Net, Current Common - basic Common - basic Net Income (Loss), Per Outstanding Limited Partnership Unit, Basic, Net of Tax Senior Notes Due March 2026 Senior Notes Due March 2026 [Member] Senior Notes Due March 2026 Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Disposal Group Name [Axis] Disposal Group Name [Axis] Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Derivative, Term of Contract Derivative, Term of Contract Net Income (Loss) Available to Common Stockholders, Basic Net Income (Loss) Available to Common Stockholders, Basic Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Share Repurchase Program [Domain] Share Repurchase Program [Domain] Contingent consideration(3) Business Combination, Contingent Consideration, Liability Business Combination, Fair Value of Contingent Consideration at Acquisition Date Business Combination, Fair Value of Contingent Consideration at Acquisition Date Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Customer-Related Intangible Assets Customer-Related Intangible Assets [Member] Schedule of Derivative Instruments, Gain (Loss) Derivative Instruments, Gain (Loss) [Table Text Block] Operating Expenses Operating Expenses Right of use assets and operating lease liabilities Increase (Decrease) in Other Operating Assets and Liabilities, Net Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Line of Credit Facility, Remaining Borrowing Capacity, Percentage Line of Credit Facility, Remaining Borrowing Capacity, Percentage Line of Credit Facility, Remaining Borrowing Capacity, Percentage WPC Parent, LLC WPC Parent, LLC [Member] WPC Parent, LLC MPLX Credit Agreement Long-term Line of Credit Long-Term Line of Credit Loss on disposal of assets Gain (Loss) on Disposition of Assets Gain (Loss) on Disposition of Assets Partner Type of Partners' Capital Account, Name [Domain] Partner Type of Partners' Capital Account, Name [Domain] Business Combination, Recognized Liability Assumed, Accounts Payable, Current Business Combination, Recognized Liability Assumed, Accounts Payable, Current Deferred revenue Deferred Revenue, Current Schedule of Related Party Transactions, by Related Party [Table] Related Party Transaction [Table] Depreciation and amortization Depreciation and Amortization Cost, Depreciation and Amortization Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Ownership Type [Domain] Ownership Type [Domain] [Domain] for Direct or Indirect Ownership Interest Receivables, less allowance for expected credit loss Receivables Accounts Receivable, after Allowance for Credit Loss, Current Title of 12(b) Security Title of 12(b) Security Total equity Beginning Balance Ending Balance Partners' Capital, Including Portion Attributable to Noncontrolling Interest Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Service, Other [Member] Service, Other [Member] MXP Parent, LLC MXP Parent, LLC [Member] MXP Parent, LLC Number of Renewals Number of Renewals Number of Times for Automatic Renewal Earnings Per Share [Abstract] Earnings Per Share [Abstract] Consolidation Items [Domain] Consolidation Items [Domain] Business Description and Basis of Presentation Business Description and Basis of Presentation [Text Block] Investments - redemptions, repayments, return of capital and sales proceeds Proceeds from Equity Method Investment, Distribution, Return of Capital Long-term deferred revenue, revenue recognized Deferred Revenue, Noncurrent, Revenue Recognized Deferred Revenue, Noncurrent, Revenue Recognized Investments and Noncontrolling Interests Equity Method Investments and Joint Ventures Disclosure [Text Block] Unit repurchases Stock Repurchased and Retired During Period, Value Embedded Derivative [Member] Embedded Derivative Financial Instruments [Member] Asset under Construction [Member] Asset under Construction [Member] Other Stockholders' Equity, Other Unrealized and realized loss included in Net Income(1) Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings MarkWest Utica EMG, L.L.C. MarkWest Utica EMG [Member] MarkWest Utica EMG [Member] Distributions to LP unitholders Distribution Made to Limited Partner, Cash Distributions Paid Revenue from Contract with Customer, Excluding Assessed Tax, Related Parties Revenue from Contract with Customer, Excluding Assessed Tax, Related Parties Revenue from Contract with Customer, Excluding Assessed Tax, Related Parties Award Timing Disclosures [Line Items] Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted Measurement Frequency [Domain] Measurement Frequency [Domain] Property, Plant and Equipment Property, Plant and Equipment Disclosure [Text Block] Property, plant and equipment, net Net PP&E Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization Equity Equity [Text Block] Partner Type [Axis] Partner Type [Axis] Cost of revenues (excludes items below) Direct Operating Costs Fair Value, Net Derivative Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Fair Value, Net Derivative Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Line of Credit Facility, Current Borrowing Capacity Line of Credit Facility, Current Borrowing Capacity Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Deferred Revenue, Additions Deferred Revenue, Additions Contribution of assets(1) Contribution of Net Assets Contribution of Net Assets Expiration Date Trading Arrangement Expiration Date Long-term lease receivables Net Investment in Lease, before Allowance for Credit Loss, Noncurrent Equity Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Equity Method Investments Equity Method Investments [Table Text Block] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Other financial costs Other Financial Costs Other Financial Costs Unit repurchases Cash paid for common units repurchased(1) Payments for Repurchase of Common Stock Adoption Date Trading Arrangement Adoption Date Business Combination, Contingent Consideration, Range of Outcomes, Maximum, Amount Business Combination, Contingent Consideration, Range of Outcomes, Maximum, Amount Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Current receivables Increase (Decrease) in Accounts Receivable Series A Preferred Stock [Member] Series A Preferred Stock [Member] Entity Current Reporting Status Entity Current Reporting Status Derivative [Line Items] Derivative [Line Items] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Contract with Customer, Asset Increase (Decrease), Noncurrent Contract with Customer, Asset Increase (Decrease), Noncurrent Contract with Customer, Asset Increase (Decrease), Noncurrent Income from operations Operating Income (Loss) Class of Treasury Stock Class of Treasury Stock [Table Text Block] Accounts payable Accounts Payable, Current, Related Party Accounts Payable, Current, Related Party Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Executive Category: Executive Category [Axis] Repayments of Debt Repayments of Debt Sales-type lease revenue Sales-type Lease, Revenue Noncontrolling interests Partners' Capital Attributable to Noncontrolling Interest Long-term debt borrowings Proceeds from Issuance of Long-Term Debt Class of Stock [Axis] Class of Stock [Axis] Current Fiscal Year End Date Current Fiscal Year End Date Interest and Other Financial Costs Interest and Other Income [Text Block] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Other current liabilities Business Combination, Recognized Liability Assumed, Other Liability, Current Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Statement [Table] Statement [Table] Derivative Liability Derivative Liability Long-term receivables Accounts Receivable, after Allowance for Credit Loss, Noncurrent Adjustments to reconcile net income to net cash provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Sales-type lease revenue - related parties Sales-type lease revenue, related parties Sales-type lease revenue, related parties Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Natural Gas and NGL Services Natural Gas and NGL Services [Member] Natural Gas and NGL Services Stockholders Equity [Table] Stockholders Equity [Table] Stockholders Equity [Table] Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less), and Goodwill Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less), and Goodwill Contract with customer, liability Contract with Customer, Liability Variable Rate [Domain] Variable Rate [Domain] Summary of Reconciliation of Additions to Property, Plant and Equipment to Total Capital Expenditures Schedule Of Reconciliation Of Additions To Property Plant And Equipment To Total Capital Expenditures [Table Text Block] Schedule of Reconciliation of Additions to Property, Plant And Equipment to Total Capital Expenditures [Table Text Block] Distributions from unconsolidated affiliates Proceeds from Equity Method Investment, Distribution Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Financial Support to Nonconsolidated Legal Entity [Domain] Financial Support to Nonconsolidated Legal Entity [Domain] Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less) Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value Inputs Probability of Renewal Fair Value Inputs Probability of Renewal Represents the percentage of likelihood of renewal of the commodity contract with embedded derivative. All Adjustments to Compensation All Adjustments to Compensation [Member] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Amendment Flag Amendment Flag Financial Guarantee [Member] Financial Guarantee [Member] Whiptail Midstream Acquisition Whiptail Midstream Acquisition [Member] Whiptail Midstream Acquisition Termination Date Trading Arrangement Termination Date Net cash (used in) provided by financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Measure: Measure [Axis] Contract assets Contract with Customer, Asset, before Allowance for Credit Loss Rental cost of sales Direct Costs of Leased and Rented Property or Equipment Long-Lived Tangible Asset [Domain] Long-Lived Tangible Asset [Domain] Stock Repurchase Program, Remaining Authorized Repurchase Amount Share Repurchase Program, Remaining Authorized, Amount Supplemental Cash Flow Information Cash Flow, Supplemental Disclosures [Text Block] Debt Instrument, Description of Variable Rate Basis Debt Instrument, Description of Variable Rate Basis Liabilities, Other than Long-Term Debt, Noncurrent Business Combination, Recognized Liability Assumed, Liability, Noncurrent Disposal Group Classification [Domain] Disposal Group Classification [Domain] Schedule of Net Income Per Unit, Basic and Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Contract with Customer, Asset, Reclassified to Receivable Contract with Customer, Asset, Reclassified to Receivable Segment Reporting [Abstract] Segment Reporting [Abstract] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Entity Tax Identification Number Entity Tax Identification Number Costs and expenses: Costs and Expenses [Abstract] Unamortized discount Debt Instrument, Unamortized Discount Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Trading Arrangement: Trading Arrangement [Axis] Total Shareholder Return Amount Total Shareholder Return Amount Common - diluted Net Income (Loss), Net of Tax, Per Outstanding Limited Partnership Unit, Diluted Rental income Operating Lease, Lease Income Fair Value Inputs, Assets and Liabilities, Quantitative Information [Table] Fair Value Inputs, Assets and Liabilities, Quantitative Information [Table] 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] Northwind Midstream Northwind Midstream [Member] Northwind Midstream Insider Trading Arrangements [Line Items] Distribution date Distribution Made to Limited Partner, Distribution Date Security Exchange Name Security Exchange Name MPLX Revolving Credit Facility due June 2027 MPLX Revolving Credit Facility due July 2027 [Member] MPLX Revolving Credit Facility due July 2027 Total liabilities Liabilities Business Combination Purchase Price Allocation Goodwill Expected Tax Deductible Percent Business Combination Purchase Price Allocation Goodwill Expected Tax Deductible Percent Business Combination Purchase Price Allocation Goodwill Expected Tax Deductible Percent Distributions to noncontrolling interests Payments of Ordinary Dividends, Noncontrolling Interest Limited Liability Company or Limited Partnership, Business, Formation Date Limited Liability Company or Limited Partnership, Business, Formation Date Settlements Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Settlements Line of Credit Facility, Maximum Borrowing Capacity Line of Credit Facility, Maximum Borrowing Capacity Adjusted EBITDA attributable to noncontrolling interests Adjusted EBITDA attributable to noncontrolling interests Adjusted EBITDA attributable to noncontrolling interests Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Prepaid Prepaid Expense, Current Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Other current liabilities Other Liabilities, Current Investments - acquisitions and contributions Payments to Acquire Interest in Joint Venture Swing-line Loan Swing-line Loan [Member] Swing-line Loan Asset Class [Domain] Asset Class [Domain] Repayments of Debt Business Combination, Achieved in Stages, Preacquisition Equity Interest in Acquiree, Fair Value Long-Term Debt Business Combination, Recognized Liability Assumed, Long-Term Debt, Noncurrent Equity Method Investment, Addition Ownership Acquired Equity Method Investment, Additional Ownership Acquired Equity Method Investment, Additional Ownership Acquired Weighted average limited partner units outstanding: Limited Partners' Capital Account [Abstract] Statement [Line Items] Statement [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Unamortized debt issuance costs Unamortized Debt Issuance Expense Variable Rate [Axis] Variable Rate [Axis] Consolidation Items [Axis] Consolidation Items [Axis] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Cash and cash equivalents Cash and Cash Equivalent Indirect Ownership Interest [Member] Indirect Ownership Interest [Member] Indirect Ownership Interest Common Unit-holders Public Common Stock [Member] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Ownership Type [Axis] Ownership Type [Axis] Direct or Indirect Ownership Interest Non-NEOs Non-NEOs [Member] Marathon Petroleum Corporation [Member] Marathon Petroleum Corporation [Member] Marathon petroleum corporation. MarkWest EMG Jefferson Dry Gas Gathering Company, L.L.C. MarkWest EMG Jefferson Dry Gas Gathering Company, L.L.C. [Member] MarkWest EMG Jefferson Dry Gas Gathering Company, L.L.C. [Member] Long-term operating lease liabilities Business Combination, Recognized Liability Assumed, Operating Lease Liability, Long-term Business Combination, Recognized Liability Assumed, Operating Lease Liability, Long-term Valuation Technique, Discounted Cash Flow [Member]