Description of the Business and Basis of Presentation	3 Months Ended
Mar. 31, 2016
Accounting Policies [Abstract]
Description of the Business and Basis of Presentation	Description of the Business and Basis of Presentation Description of the Business—Our business consists of refining and marketing, retail and midstream services conducted primarily in the Midwest, Gulf Coast, East Coast, Northeast and Southeast regions of the United States, through subsidiaries, including Marathon Petroleum Company LP, Speedway LLC and its subsidiaries (“Speedway”) and MPLX LP and its subsidiaries (“MPLX”). See Note 9 for additional information about our operations. Basis of Presentation—All significant intercompany transactions and accounts have been eliminated. These interim consolidated financial statements are unaudited; however, in the opinion of our management, these statements reflect all adjustments necessary for a fair statement of the results for the periods reported. All such adjustments are of a normal, recurring nature unless otherwise disclosed. These interim consolidated financial statements, including the notes, have been prepared in accordance with the rules of the SEC applicable to interim period financial statements and do not include all of the information and disclosures required by U.S. GAAP for complete financial statements. These interim consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2015. The results of operations for the three months ended March 31, 2016 are not necessarily indicative of the results to be expected for the full year. We completed a two-for-one stock split in June 2015. All historical share and per share data included in these consolidated financial statements has been retroactively restated on a post-split basis. In the first quarter of 2016, we revised our segment reporting of the operating results for our inland marine business and our investment in an ocean vessel joint venture, Crowley Ocean Partners LLC (“Crowley Ocean Partners”) in connection with the contribution of our inland marine business to MPLX. See Note 3 for additional information. These operating results are now reported in our Midstream segment. Previously they were reported as part of our Refining & Marketing segment. Comparable prior period information has been recast to reflect our revised segment presentation. See Note 9 for additional information.

Description of the Business and Basis of Presentation

Description of the Business—Our business consists of refining and marketing, retail and midstream services conducted primarily in the Midwest, Gulf Coast, East Coast, Northeast and Southeast regions of the United States, through subsidiaries, including Marathon Petroleum Company LP, Speedway LLC and its subsidiaries (“Speedway”) and MPLX LP and its subsidiaries (“MPLX”).

See Note 9 for additional information about our operations.

Basis of Presentation—All significant intercompany transactions and accounts have been eliminated.

These interim consolidated financial statements are unaudited; however, in the opinion of our management, these statements reflect all adjustments necessary for a fair statement of the results for the periods reported. All such adjustments are of a normal, recurring nature unless otherwise disclosed. These interim consolidated financial statements, including the notes, have been prepared in accordance with the rules of the SEC applicable to interim period financial statements and do not include all of the information and disclosures required by U.S. GAAP for complete financial statements.

These interim consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2015. The results of operations for the three months ended March 31, 2016 are not necessarily indicative of the results to be expected for the full year.

We completed a two-for-one stock split in June 2015. All historical share and per share data included in these consolidated financial statements has been retroactively restated on a post-split basis.

In the first quarter of 2016, we revised our segment reporting of the operating results for our inland marine business and our investment in an ocean vessel joint venture, Crowley Ocean Partners LLC (“Crowley Ocean Partners”) in connection with the contribution of our inland marine business to MPLX. See Note 3 for additional information. These operating results are now reported in our Midstream segment. Previously they were reported as part of our Refining & Marketing segment. Comparable prior period information has been recast to reflect our revised segment presentation. See Note 9 for additional information.