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Investments and Noncontrolling Interests (Schedule of Equity Method Investments) (Details) - USD ($) $ in Millions | 3 Months Ended |  |
--- | --- | --- | ---
Mar. 31, 2026 | Mar. 31, 2025 | Dec. 31, 2025 | Jun. 16, 2025
Schedule of Equity Method Investments |  |  |  |  |
Equity method investments |  | $ 4,981 |  | $ 4,798 |
Equity Method Investments, Including Held for Sale |  | 4,981 |  | 4,798 |
Investments - redemptions, repayments, return of capital and sales proceeds |  | $ 0 | $ 21 |  |
MXP Parent, LLC |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investment, ownership percentage |  |  |  |  | 10.00%
Indirect Ownership Interest [Member] | Bakken Pipeline System [Member] |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investment, ownership percentage |  | 9.19% |  |  |
Crude Oil and Products Logistics |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investments |  | $ 1,582 |  | 1,581 |
Crude Oil and Products Logistics | Illinois Extension Pipeline Company, L.L.C. |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investment, ownership percentage |  | 35.00% |  |  |
Equity method investments |  | $ 219 |  | 208 |
Crude Oil and Products Logistics | LOOP LLC |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investment, ownership percentage |  | 41.00% |  |  |
Equity method investments |  | $ 314 |  | 313 |
Crude Oil and Products Logistics | MarEn Bakken Company LLC(1) |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investment, ownership percentage |  | 25.00% |  |  |
Equity method investments | [1] | $ 495 |  | 502 |
Crude Oil and Products Logistics | Other VIEs and Non-VIEs |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investments | [2] | $ 554 |  | 558 |
Crude Oil and Products Logistics | Other VIEs and Non-VIEs | Minimum [Member] |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investment, ownership percentage |  | 17.00% |  |  |
Crude Oil and Products Logistics | Other VIEs and Non-VIEs | Maximum [Member] |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investment, ownership percentage |  | 67.00% |  |  |
Natural Gas and NGL Services |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investments |  | $ 3,399 |  | 3,217 |
Natural Gas and NGL Services | MarkWest EMG Jefferson Dry Gas Gathering Company, L.L.C. |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investment, ownership percentage |  | 67.00% |  |  |
Equity method investments |  | $ 398 |  | 407 |
Natural Gas and NGL Services | MarkWest Utica EMG, L.L.C. |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investment, ownership percentage |  | 62.00% |  |  |
Equity method investments |  | $ 933 |  | 890 |
Natural Gas and NGL Services | Ohio Gathering Company L.L.C. |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investment, ownership percentage |  | 32.00% |  |  |
Equity method investments | [3] | $ 432 |  | 444 |
Natural Gas and NGL Services | Sherwood Midstream LLC |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investment, ownership percentage |  | 50.00% |  |  |
Equity method investments |  | $ 472 |  | 475 |
Natural Gas and NGL Services | WPC Parent, LLC |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investment, ownership percentage |  | 30.00% |  |  |
Equity method investments |  | $ 269 |  | 273 |
Natural Gas and NGL Services | Other VIEs and Non-VIEs |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investments | [2] | $ 444 |  | 367 |
Natural Gas and NGL Services | Other VIEs and Non-VIEs | Minimum [Member] |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investment, ownership percentage |  | 10.00% |  |  |
Natural Gas and NGL Services | Other VIEs and Non-VIEs | Maximum [Member] |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investment, ownership percentage |  | 51.00% |  |  |
Natural Gas and NGL Services | Texas City Logistics LLC |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investment, ownership percentage |  | 50.00% |  |  |
Equity method investments |  | $ 228 |  | 163 |
Natural Gas and NGL Services | MXP Parent, LLC |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investment, ownership percentage |  | 10.00% |  |  |
Equity method investments |  | $ 223 |  | $ 198 |
Natural Gas and NGL Services | Indirect Ownership Interest [Member] | Ohio Gathering Company L.L.C. |  |  |  |  |
Schedule of Equity Method Investments |  |  |  |  |
Equity method investment, ownership percentage |  | 42.00% |  |  |
[1] | The investment in MarEn Bakken Company LLC includes our 9.19 percent indirect interest in a joint venture (“Dakota Access”) that owns and operates the Dakota Access Pipeline and Energy Transfer Crude Oil Pipeline projects (collectively, the “Bakken Pipeline system”).
[2] | Included within Other are certain equity method investments that have been deemed to be VIEs.
[3] | MPLX also holds a 42 percent indirect interest in Ohio Gathering Company L.L.C. through our ownership interest in MarkWest Utica EMG, L.L.C.

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