XML 88 R65.htm IDEA: XBRL DOCUMENT v3.25.1
Credit Agreement (Detail) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2025
Dec. 31, 2024
Debt Instrument [Line Items]    
Long-term Line of Credit $ 0 $ 0
MPLX Revolving Credit Facility due June 2027    
Debt Instrument [Line Items]    
Line of Credit Facility, Maximum Borrowing Capacity $ 2,000  
Debt Instrument, Description of Variable Rate Basis Adjusted Term SOFR or the Alternate Base Rate, both as defined in the MPLX Credit Agreement, plus an applicable margin.  
MPLX Revolving Credit Facility due June 2027 | Letter of Credit    
Debt Instrument [Line Items]    
Line of Credit Facility, Maximum Borrowing Capacity $ 150