Description of the Business and Basis of Presentation	3 Months Ended
Mar. 31, 2017
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 (“MPC 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, 2016. The results of operations for the three months ended March 31, 2017 are not necessarily indicative of the results to be expected for the full year. Certain prior period financial statement amounts have been reclassified to conform to current period presentation. In the first quarter of 2017, we revised our segment reporting in connection with the contribution of certain terminal, pipeline and storage assets to MPLX. See Note 3 for additional information. The operating results for these assets 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 presentation. The results for the pipeline and storage assets were recast effective January 1, 2015 and the results for the terminal assets were recast effective April 1, 2016. Prior to these dates these assets were not considered businesses for accounting purposes and therefore there are no financial results from which to recast segment results. Additionally, the MPLX asset and liability balances as of December 31, 2016 reported in parentheses on our consolidated balance sheets have also been recast to reflect this transaction. See Note 9 and Note 13 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 (“MPC 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, 2016. The results of operations for the three months ended March 31, 2017 are not necessarily indicative of the results to be expected for the full year.

Certain prior period financial statement amounts have been reclassified to conform to current period presentation.

In the first quarter of 2017, we revised our segment reporting in connection with the contribution of certain terminal, pipeline and storage assets to MPLX. See Note 3 for additional information. The operating results for these assets 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 presentation. The results for the pipeline and storage assets were recast effective January 1, 2015 and the results for the terminal assets were recast effective April 1, 2016. Prior to these dates these assets were not considered businesses for accounting purposes and therefore there are no financial results from which to recast segment results. Additionally, the MPLX asset and liability balances as of December 31, 2016 reported in parentheses on our consolidated balance sheets have also been recast to reflect this transaction. See Note 9 and Note 13 for additional information.