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Investments and Noncontrolling Interest (Equity Method Investments) (Details) - USD ($) $ in Millions |  | 12 Months Ended |
--- | --- | --- | ---
May 29, 2024 | Dec. 31, 2025 | Dec. 31, 2024 | Dec. 31, 2023 | Jul. 31, 2024
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Equity method investments |  |  | $ 4,798 |  | $ 4,531 |  |
Investments - redemptions, repayments, return of capital and sales proceeds |  |  | 293 |  | 146 | $ 3 |
BANGL, LLC |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Ownership percentage |  |  |  |  |  |  | 45.00%
Equity Method Investment, Additional Ownership Acquired |  |  |  |  |  |  | 20.00%
MarkWest EMG Jefferson Dry Gas Gathering Company, L.L.C.(4) |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Contribution of Property |  |  | 125 |  |  |  |
Investments - redemptions, repayments, return of capital and sales proceeds |  |  | 42 |  |  |  |
WPC Parent, LLC |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Investments - redemptions, repayments, return of capital and sales proceeds |  | $ 134 |  |  |  |  |
Crude Oil and Products Logistics [Member] |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Equity method investments |  |  | $ 1,581 |  | 1,595 |  |
Crude Oil and Products Logistics [Member] | Illinois Extension Pipeline Company, L.L.C. |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Ownership percentage |  |  | 35.00% |  |  |  |
Equity method investments |  |  | $ 208 |  | 218 |  |
Crude Oil and Products Logistics [Member] | LOOP LLC |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Ownership percentage |  |  | 41.00% |  |  |  |
Equity method investments |  |  | $ 313 |  | 310 |  |
Crude Oil and Products Logistics [Member] | MarEn Bakken Company LLC(1) |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Ownership percentage |  |  | 25.00% |  |  |  |
Equity method investments | [1] |  | $ 502 |  | 526 |  |
Crude Oil and Products Logistics [Member] | Other VIEs and Non-VIEs [Member] |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Equity method investments | [2] |  | $ 558 |  | 541 |  |
Crude Oil and Products Logistics [Member] | Bakken Pipeline System | Indirect Ownership Interest |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Ownership percentage |  |  | 9.19% |  |  |  |
Natural Gas & NGL Services [Member] |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Equity method investments |  |  | $ 3,217 |  | 2,936 |  |
Natural Gas & NGL Services [Member] | Rockies Operations |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Equity method investments |  |  |  |  | 129 |  |
Natural Gas & NGL Services [Member] | Other VIEs and Non-VIEs [Member] |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Equity method investments | [2] |  | 565 |  | $ 418 |  |
Natural Gas & NGL Services [Member] | BANGL, LLC |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Ownership percentage | [3] |  |  |  | 45.00% |  |
Equity method investments | [3] |  | $ 0 |  | $ 281 |  |
Natural Gas & NGL Services [Member] | MarkWest EMG Jefferson Dry Gas Gathering Company, L.L.C.(4) |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Ownership percentage |  |  | 67.00% |  |  |  |
Equity method investments |  |  | $ 407 | [4] | 329 |  |
Natural Gas & NGL Services [Member] | MarkWest Utica EMG, L.L.C. |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Ownership percentage |  |  | 61.00% |  |  |  |
Equity method investments |  |  | $ 890 |  | 742 |  |
Natural Gas & NGL Services [Member] | Ohio Gathering Company L.L.C. |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Ownership percentage |  |  | 32.00% |  |  |  |
Equity method investments | [5] |  | $ 444 |  | 470 |  |
Natural Gas & NGL Services [Member] | Ohio Gathering Company L.L.C. | Indirect Ownership Interest |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Ownership percentage |  |  | 41.00% |  |  |  |
Natural Gas & NGL Services [Member] | Sherwood Midstream LLC |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Ownership percentage |  |  | 50.00% |  |  |  |
Equity method investments |  |  | $ 475 |  | 488 |  |
Natural Gas & NGL Services [Member] | WPC Parent, LLC |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Ownership percentage |  |  | 30.00% |  |  |  |
Equity method investments |  |  | $ 273 |  | 208 |  |
Natural Gas & NGL Services [Member] | Texas City Logistics LLC |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Ownership percentage |  |  | 50.00% |  |  |  |
Equity method investments |  |  | $ 163 |  | $ 0 |  |
[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. The December 31, 2024 Natural Gas and NGL Services value includes $129 million in investments associated with the Rockies, which were divested in the fourth quarter 2025.
[3] | At December 31, 2024, we owned a 45 percent interest in BANGL. On July 1, 2025, we acquired the remaining 55 percent interest in BANGL. As a result of acquiring the remaining interest, we obtained control and now consolidate BANGL.
[4] | On March 31, 2025, MPLX contributed a wholly-owned subsidiary with a fair value of $125 million to MarkWest EMG Jefferson Dry Gas Gathering Company, L.L.C. As a result of the transaction, MPLX received special distributions of $42 million in 2025, which are reflected as a return of capital on the Consolidated Statement of Cash Flows.
[5] | MPLX also holds a 41 percent indirect interest in OGC through our ownership interest in MarkWest Utica EMG, L.L.C.

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