Debt - Summary of Outstanding Borrowings (Detail) - USD ($) $ in Millions |
Mar. 31, 2024 |
Dec. 31, 2023 |
|---|---|---|
| Debt Instrument [Line Items] | ||
| MPLX Credit Agreement | $ 0 | $ 0 |
| Finance lease obligations | 6 | 6 |
| Debt and Lease Obligation | 20,706 | 20,706 |
| Unamortized debt issuance costs | (119) | (122) |
| Unamortized discount | (143) | (153) |
| Amounts due within one year | 1,639 | 1,135 |
| Total long-term debt due after one year | 18,805 | 19,296 |
| MPLX LP [Member] | ||
| Debt Instrument [Line Items] | ||
| Senior Notes | 20,657 | 20,657 |
| MarkWest [Member] | ||
| Debt Instrument [Line Items] | ||
| Senior Notes | 12 | 12 |
| ANDX LP [Member] | ||
| Debt Instrument [Line Items] | ||
| Senior Notes | $ 31 | $ 31 |
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- Definition Amount of short-term and long-term debt and lease obligation. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- 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. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount, after accumulated amortization, of debt discount. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Present value of lessee's discounted obligation for lease payments from finance lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of long-term debt and lease obligation, classified as noncurrent. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of long-term debt and lease obligation, classified as current. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset. No definition available.
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