XML 42 R1.htm IDEA: XBRL DOCUMENT v3.25.4
Document and Entity Information - USD ($)
$ in Billions
 12 Months Ended
Dec. 31, 2025
Feb. 20, 2026
Jun. 30, 2025
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Transition Report false    
Entity File Number 001-35714    
Entity Registrant Name MPLX LP    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 27-0005456    
Entity Address, Address Line One 200 E. Hardin Street    
Entity Address, City or Town Findlay    
Entity Address, State or Province OH    
Entity Address, Postal Zip Code 45840-3229    
City Area Code 419    
Local Phone Number 422-2121    
Title of 12(b) Security Common Units Representing Limited Partnership Interests    
Trading Symbol MPLX    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Public Float     $ 19.1
Entity Common Stock, Shares Outstanding   1,015,204,337  
Amendment Flag false    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Entity Central Index Key 0001552000    
Current Fiscal Year End Date --12-31    
Document Period End Date Dec. 31, 2025