Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Sales-type lease revenue		$ 34	$ 28	$ 101	$ 28
Sales-type lease revenue - related parties		129	118	379	343
Income from equity method investments		159	125	438	335
Total revenues and other income		2,912	3,401	8,315	8,951
Costs and Expenses, Related Party		442	364	1,160	1,034
Depreciation and amortization	[1]	301	302	907	925
General and administrative expenses		102	88	280	248
Other taxes		44	30	102	97
Total costs and expenses		1,758	1,727	4,790	5,100
Operating Income (Loss)		1,154	1,674	3,525	3,851
Interest expense, net of amounts capitalized		223	217	673	627
Other financial costs, net		2	19	28	59
Income before income taxes		929	1,438	2,824	3,160
Provision for income taxes		1	1	2	6
Net income		928	1,437	2,822	3,154
Less: Net income attributable to noncontrolling interests		10	9	28	26
Net income attributable to MPLX LP	[2]	918	1,428	2,794	3,128
Limited partners' interest in net income attributable to MPLX LP		$ 893	$ 1,395	$ 2,718	$ 3,032
Net income attributable to MPLX LP per limited partner unit:
Common - basic		$ 0.89	$ 1.36	$ 2.70	$ 2.97
Common - diluted		$ 0.89	$ 1.36	$ 2.70	$ 2.97
Weighted average limited partner units outstanding:
Common - basic		1,001	1,010	1,001	1,012
Common - diluted		1,001	1,011	1,001	1,013
Nonrelated Party [Member]
Rental income		$ 61	$ 75	$ 181	$ 268
Other Income		7	505	28	494
Rental cost of sales		20	22	60	101
Related Party [Member]
Rental income		207	201	612	564
Other Income		32	28	90	82
Rental cost of sales		8	10	24	44
General and administrative expenses		72	60	197	173
Affiliated Entity
Related-party interest and other financial costs		0	0	0	5
Service [Member]
Revenue from Contract with Customer, Excluding Assessed Tax - third and related parties		641	627	1,881	1,758
Revenue from Contract with Customer, Excluding Assessed Tax, Related Parties		1,038	948	2,962	2,801
Service, Other [Member]
Revenue from Contract with Customer, Excluding Assessed Tax - third and related parties		75	83	214	324
Product [Member]
Revenue from Contract with Customer, Excluding Assessed Tax - third and related parties		478	617	1,274	1,812
Revenue from Contract with Customer, Excluding Assessed Tax, Related Parties		51	46	155	142
Oil and Gas, Refining and Marketing [Member]
Cost of Goods and Services Sold		367	371	1,023	981
Natural Gas, Midstream [Member]
Cost of Goods and Services Sold		474	540	1,234	1,670
Series A Preferred Stock [Member]
Net income attributable to MPLX LP	[2]	26	41	80	89
Dividends, Preferred Stock		25	23	71	65
Series B Preferred Stock [Member]
Net income attributable to MPLX LP	[2]		10	5	31
Dividends, Preferred Stock		0	10	5	31
Common Unit-holders Public
Net income attributable to MPLX LP	[2]	$ 892	$ 1,377	$ 2,709	$ 3,008

[1] Depreciation and amortization attributable to L&S was $130 million and $399 million for the three and nine months ended September 30, 2023, respectively, and $128 million and $387 million for the three and nine months ended September 30, 2022, respectively. Depreciation and amortization attributable to G&P was $171 million and $508 million for the three and nine months ended September 30, 2023, respectively, and $174 million and $538 million for the three and nine months ended September 30, 2022, respectively.

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