v3.19.2
Document and Entity Information
Sep. 06, 2019
Cover [Abstract]  
Amendment Flag false
Entity Central Index Key 0001552000
Document Type 8-K
Document Period End Date Sep. 06, 2019
Entity Registrant Name MPLX LP
Entity Incorporation State Country Code DE
Entity File Number 001-35714
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
City Area Code (419)
Local Phone Number 421-2414
Written Communications false
Soliciting Material false
Pre Commencement Tender Offer false
Pre Commencement Issuer Tender Offer false
Security 12b Title Common Units Representing Limited Partnership Interests
Trading Symbol MPLX
Security Exchange Name NYSE
Entity Emerging Growth Company false