v3.24.3
Investments and Noncontrolling Interests (Schedule of Equity Method Investments) (Details) - USD ($)
$ in Millions
 9 Months Ended
Jul. 31, 2024
Sep. 30, 2024
Sep. 30, 2023
Mar. 22, 2024
Dec. 31, 2023
Schedule of Equity Method Investments          
Equity method investments   $ 4,558     $ 3,743
Payments to Acquire Interest in Joint Venture   414 $ 90    
BANGL, LLC          
Schedule of Equity Method Investments          
Equity method investment, ownership percentage 45.00%        
Payments to Acquire Interest in Joint Venture $ 210        
Difference between carrying amount and underlying equity $ 156        
L&S          
Schedule of Equity Method Investments          
Equity method investments   $ 2,148     1,832
L&S | BANGL, LLC          
Schedule of Equity Method Investments          
Equity method investment, ownership percentage   45.00%      
Equity method investments [1]   $ 275     63
L&S | Illinois Extension Pipeline Company, L.L.C.          
Schedule of Equity Method Investments          
Equity method investment, ownership percentage   35.00%      
Equity method investments   $ 231     228
L&S | LOOP LLC          
Schedule of Equity Method Investments          
Equity method investment, ownership percentage   41.00%      
Equity method investments   $ 313     314
L&S | MarEn Bakken Company LLC(2)          
Schedule of Equity Method Investments          
Equity method investment, ownership percentage   25.00%      
Equity method investments [2]   $ 530     449
L&S | WPC Parent, LLC(3)          
Schedule of Equity Method Investments          
Equity method investment, ownership percentage   30.00%      
Equity method investments [3]   $ 206      
L&S | Whistler Pipeline LLC [Member]          
Schedule of Equity Method Investments          
Equity method investments [3]         214
L&S | Other VIEs and Non-VIEs          
Schedule of Equity Method Investments          
Equity method investments [4]   $ 593     564
L&S | Indirect Ownership Interest [Member] | Bakken Pipeline System [Member]          
Schedule of Equity Method Investments          
Equity method investment, ownership percentage   9.19%      
G&P          
Schedule of Equity Method Investments          
Equity method investments   $ 2,410     1,911
G&P | 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   $ 335     336
G&P | MarkWest Utica EMG, L.L.C.          
Schedule of Equity Method Investments          
Equity method investment, ownership percentage   59.00%      
Equity method investments   $ 717     676
G&P | Ohio Gathering Company L.L.C.          
Schedule of Equity Method Investments          
Equity method investment, ownership percentage   35.00%   36.00%  
Equity method investments [5]   $ 488     0
G&P | Sherwood Midstream LLC          
Schedule of Equity Method Investments          
Equity method investment, ownership percentage   50.00%      
Equity method investments   $ 492     500
G&P | Other VIEs and Non-VIEs          
Schedule of Equity Method Investments          
Equity method investments   $ 378     $ 399
G&P | Indirect Ownership Interest [Member] | Ohio Gathering Company L.L.C.          
Schedule of Equity Method Investments          
Equity method investment, ownership percentage   38.00%      
[1] In July 2024, we purchased an additional 20 percent ownership interest in BANGL, LLC, increasing our ownership interest to 45 percent, as discussed in Note 3.
[2] 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”).
[3] Reflects the dilution of MPLX’s ownership interest in Whistler Pipeline, LLC and the formation of a new entity, WPC Parent, LLC, as discussed in Note 3. The carrying value at September 30, 2024 represents our ownership in WPC Parent, LLC, and the carrying value at December 31, 2023 represents our ownership interest in Whistler Pipeline, LLC.
[4] Some investments included within Other have also been deemed to be VIEs.
[5] We acquired a 36 percent direct interest in OGC in the Utica Midstream Acquisition discussed in Note 3. We also hold a 38 percent indirect interest in OGC through our ownership interest in MarkWest Utica EMG, L.L.C.