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Subsequent Events (Details) - Senior Notes - USD ($) $ in Millions | Mar. 01, 2026 | Feb. 12, 2026 | May 20, 2024 | Dec. 31, 2025 | Aug. 11, 2025 | Dec. 31, 2024
--- | --- | --- | --- | --- | --- | ---
Subsequent Event [Line Items] |  |  |  |  |  |
Debt Instrument, Face Amount |  |  |  |  | $ 4,500 |
Senior Note Due June 2034 |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |
Debt Instrument, Issuance Date |  |  | May 20, 2024 |  |  |
Debt Instrument, Face Amount |  |  | $ 1,650 |  |  |
Interest rate, stated percentage |  |  | 5.50% |  |  |
Percent of par |  |  | 98.778% |  |  |
Senior Note Due June 2034 | MPLX LP [Member] |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |
Interest rate, stated percentage |  |  |  | 5.50% |  |
Long-term debt, gross |  |  |  | $ 1,650 |  | $ 1,650
Senior Notes Due March 2026 [Member] | MPLX LP [Member] |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |
Interest rate, stated percentage |  |  |  | 1.75% |  |
Long-term debt, gross |  |  |  | $ 1,500 |  | $ 1,500
Subsequent Event | Senior Notes Due April 2036 |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |
Debt Instrument, Issuance Date |  | Feb. 12, 2026 |  |  |  |
Debt Instrument, Face Amount |  | $ 1,000 |  |  |  |
Interest rate, stated percentage |  | 5.30% |  |  |  |
Percent of par |  | 99.678% |  |  |  |
Subsequent Event | Senior Notes Due April 2056 |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |
Debt Instrument, Issuance Date |  | Feb. 12, 2026 |  |  |  |
Debt Instrument, Face Amount |  | $ 500 |  |  |  |
Interest rate, stated percentage |  | 6.10% |  |  |  |
Percent of par |  | 98.453% |  |  |  |
Subsequent Event | Senior Notes Due March 2026 [Member] | MPLX LP [Member] |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |
Interest rate, stated percentage | 1.75% |  |  |  |  |
Repayments of Debt | $ 1,500 |  |  |  |  |

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