Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Revenues and other income:
Sales-type lease revenue		$ 37	$ 34	$ 110	$ 102
Sales-type lease revenue - related parties		113	118	344	359
Income from equity method investments		186	149	542	631
Gain on equity method investments		484	0	484	20
Total revenues and other income		3,619	2,972	9,746	8,870
Costs and expenses:
Cost of revenues (excludes items below)		395	404	1,153	1,159
Purchased product costs		493	403	1,384	1,148
Purchases - related parties		396	402	1,234	1,162
Depreciation and amortization	[1]	346	322	996	959
General and administrative expenses		126	107	345	323
Other taxes		36	32	101	99
Total costs and expenses		1,818	1,697	5,286	4,925
Income from operations		1,801	1,275	4,460	3,945
Net interest and other financial costs		243	226	706	692
Income before income taxes		1,558	1,049	3,754	3,253
Provision for income taxes		3	2	5	5
Net income		1,555	1,047	3,749	3,248
Less: Net income attributable to noncontrolling interests		10	10	30	30
Net income attributable to MPLX LP	[2]	1,545	1,037	3,719	3,218
Dividends, Preferred Stock		0	6	0	21
Limited partners' interest in net income attributable to MPLX LP		$ 1,545	$ 1,031	$ 3,719	$ 3,197
Net income attributable to MPLX LP per limited partner unit:
Common - basic		$ 1.52	$ 1.01	$ 3.65	$ 3.14
Common - diluted		$ 1.52	$ 1.01	$ 3.65	$ 3.14
Weighted average limited partner units outstanding:
Common - basic		1,019	1,020	1,020	1,016
Common - diluted		1,019	1,020	1,020	1,016
Nonrelated Party [Member]
Revenues and other income:
Rental income		$ 68	$ 63	$ 196	$ 187
Other Income		4	7	19	38
Costs and expenses:
Rental cost of sales		22	22	61	61
Related Party [Member]
Revenues and other income:
Rental income		228	216	655	644
Other Income		40	40	121	117
Costs and expenses:
Rental cost of sales		4	5	12	14
Service [Member]
Revenues and other income:
Revenue from Contract with Customer, Excluding Assessed Tax - Third parties		750	709	2,153	2,050
Revenue from Contract with Customer, Excluding Assessed Tax, Related Parties		1,094	1,066	3,253	3,102
Service, Other [Member]
Revenues and other income:
Revenue from Contract with Customer, Excluding Assessed Tax - Third parties		64	86	233	265
Product [Member]
Revenues and other income:
Revenue from Contract with Customer, Excluding Assessed Tax - Third parties		525	433	1,510	1,191
Revenue from Contract with Customer, Excluding Assessed Tax, Related Parties		$ 26	$ 51	$ 126	$ 164

[1] Depreciation and amortization attributable to Crude Oil and Products Logistics was $139 million and $407 million for the three and nine months ended September 30, 2025, respectively, and $132 million and $393 million for the three and nine months ended September 30, 2024, respectively. Depreciation and amortization attributable to Natural Gas and NGL Services was $207 million and $589 million for the three and nine months ended September 30, 2025, respectively, and $190 million and $566 million for the three and nine months ended September 30, 2024, respectively.

[2] Allocation of net income attributable to MPLX LP assumes all earnings for the period have been distributed based on the distribution priorities applicable to the period.