Consolidated Balance Sheets - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Assets
Cash and cash equivalents	$ 1,386	$ 1,519
Receivables, less allowance for expected credit loss	736	718
Inventories	192	180
Other current assets	33	29
Total current assets	3,173	3,276
Equity method investments	5,024	4,531
Property, plant and equipment, net	19,191	19,154
Intangibles, net	497	518
Goodwill	7,645	7,645
Right of use assets, net	275	273
Other noncurrent assets	1,015	994
Total assets	37,841	37,511
Liabilities
Accounts payable	149	147
Accrued liabilities	262	295
Accrued property, plant and equipment	253	208
Long-term debt due within one year	1,500	1,693
Accrued interest payable	267	244
Operating lease liabilities	47	45
Total current liabilities	3,069	3,235
Long-term deferred revenue	308	317
Long-term debt	19,725	19,255
Deferred income taxes	18	18
Long-term operating lease liabilities	218	217
Total liabilities	23,792	23,501
Commitments and contingencies (see Note 16)
Series A Preferred Units	0	203
Equity
Accumulated other comprehensive income (loss)	5	(3)
Total MPLX LP partners’ capital	13,820	13,576
Noncontrolling interests	229	231
Total equity	14,049	13,807
Total liabilities, preferred units and equity	37,841	37,511
Related Party [Member]
Assets
Receivables, less allowance for expected credit loss	569	620
Current assets - related parties	826	830
Other current assets	1	1
Right of use assets, net	223	226
Noncurrent assets - related parties	1,021	1,120
Liabilities
Operating lease liabilities	1	2
Other current liabilities	399	396
Long-term deferred revenue	108	110
Long-term liabilities - related parties	330	334
Equity
Limited Partners' Capital Account	4,413	4,257
Nonrelated Party [Member]
Liabilities
Other current liabilities	192	207
Long-term deferred revenue	306	315
Long-term liabilities - related parties	124	125
Equity
Limited Partners' Capital Account	$ 9,402	$ 9,322