Description of Business and Basis of Presentation	9 Months Ended
Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Basis of Presentation	Description of Business and Basis of Presentation Description of business — Murphy USA Inc. (“Murphy USA” or the “Company”) markets refined products through a network of retail gasoline stations and to unbranded wholesale customers. Murphy USA’s owned retail stations are almost all located in close proximity to Walmart stores in 25 states and use the brand name Murphy USA®. Murphy USA also markets gasoline and other products at standalone stations under the Murphy Express brand. At September 30, 2016, Murphy USA had a total of 1,364 Company stations. Basis of Presentation — Murphy USA was incorporated in March 2013 and, in connection with its incorporation, Murphy USA issued 100 shares of common stock, par value $0.01 per share, to Murphy Oil Corporation (“Murphy Oil”) for $1.00. On August 30, 2013, Murphy USA was separated from Murphy Oil through the distribution of 100% of the common stock of Murphy USA to holders of Murphy Oil stock. In preparing the financial statements of Murphy USA in conformity with accounting principles generally accepted in the United States, management has made a number of estimates and assumptions related to the reporting of assets, liabilities, revenues, expenses and the disclosure of contingent assets and liabilities. Actual results may differ from these estimates. Interim Financial Information — The interim period financial information presented in these consolidated financial statements is unaudited and includes all known accruals and adjustments, in the opinion of management, necessary for a fair presentation of the consolidated financial position of Murphy USA and its results of operations and cash flows for the periods presented. All such adjustments are of a normal and recurring nature. These interim consolidated financial statements should be read together with our audited financial statements for the years ended December 31, 2015, 2014 and 2013, included in our Annual Report on Form 10-K (File No. 001-35914), as filed with the Securities and Exchange Commission under the Securities Exchange Act of 1934 on February 26, 2016. Recently Issued Accounting Standards— In November 2015, the FASB issued ASU No. 2015-17, "Balance Sheet Classification of Deferred Taxes," which amended existing accounting guidance related to the presentation of deferred tax liabilities and assets. The amended guidance requires that all deferred tax liabilities and assets be classified as noncurrent on the balance sheet. This guidance is effective for reporting periods beginning after December 15, 2016; however, early adoption is permitted at the beginning of a fiscal year. The Company adopted ASU No. 2015-17 during the quarter ended March 31, 2016 and has applied this guidance prospectively to its deferred tax liabilities and assets. For the period ended December 31, 2015, current deferred tax liabilities of $1.7 million remain classified as current in the accompanying balance sheet. In February 2016, the FASB issued ASU No. 2016-02, "Leases (Topic 842)" (“ASU 2016-02”). ASU 2016-02 amends the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets. Lessor accounting will remain similar to lessor accounting under previous GAAP, while aligning with the FASB’s new revenue recognition guidance. ASU 2016-02 is effective for the Company beginning January 1, 2019. Early adoption of ASU 2016-02 is permitted. The standard requires a modified retrospective transition approach for all leases existing at, or entered into after, the date of initial application, with an option to use certain transition relief. While this ASU will have impact on our internal processes and controls and result in a change to our accounting, we are still in the evaluation and information gathering stage of implementing the guidance and can not yet estimate the potential impact. On March 30, 2016, the FASB issued ASU No. 2016-09, "Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting", which amends the current stock compensation guidance. The amendments simplify the accounting for the taxes related to stock based compensation, including adjustments to how excess tax benefits and a company’s payments for tax withholdings should be classified. The standard is effective for fiscal periods beginning after December 15, 2016, with early adoption permitted. While we do not anticipate this ASU having a significant financial impact, we are currently evaluating the adoption of this standard on our consolidated financial statements and expect to adopt the standard effective January 1, 2017.

Description of Business and Basis of Presentation

Description of business — Murphy USA Inc. (“Murphy USA” or the “Company”) markets refined products through a network of retail gasoline stations and to unbranded wholesale customers. Murphy USA’s owned retail stations are almost all located in close proximity to Walmart stores in 25 states and use the brand name Murphy USA®. Murphy USA also markets gasoline and other products at standalone stations under the Murphy Express brand. At September 30, 2016, Murphy USA had a total of 1,364 Company stations.

Basis of Presentation — Murphy USA was incorporated in March 2013 and, in connection with its incorporation, Murphy USA issued 100 shares of common stock, par value $0.01 per share, to Murphy Oil Corporation (“Murphy Oil”) for $1.00. On August 30, 2013, Murphy USA was separated from Murphy Oil through the distribution of 100% of the common stock of Murphy USA to holders of Murphy Oil stock.

In preparing the financial statements of Murphy USA in conformity with accounting principles generally accepted in the United States, management has made a number of estimates and assumptions related to the reporting of assets, liabilities, revenues, expenses and the disclosure of contingent assets and liabilities. Actual results may differ from these estimates.

Interim Financial Information — The interim period financial information presented in these consolidated financial statements is unaudited and includes all known accruals and adjustments, in the opinion of management, necessary for a fair presentation of the consolidated financial position of Murphy USA and its results of operations and cash flows for the periods presented. All such adjustments are of a normal and recurring nature.

These interim consolidated financial statements should be read together with our audited financial statements for the years ended December 31, 2015, 2014 and 2013, included in our Annual Report on Form 10-K (File No. 001-35914), as filed with the Securities and Exchange Commission under the Securities Exchange Act of 1934 on February 26, 2016.

Recently Issued Accounting Standards— In November 2015, the FASB issued ASU No. 2015-17, "Balance Sheet Classification of Deferred Taxes," which amended existing accounting guidance related to the presentation of deferred tax liabilities and assets. The amended guidance requires that all deferred tax liabilities and assets be classified as noncurrent on the balance sheet. This guidance is effective for reporting periods beginning after December 15, 2016; however, early adoption is permitted at the beginning of a fiscal year. The Company adopted ASU No. 2015-17 during the quarter ended March 31, 2016 and has applied this guidance prospectively to its deferred tax liabilities and assets. For the period ended December 31, 2015, current deferred tax liabilities of $1.7 million remain classified as current in the accompanying balance sheet.

In February 2016, the FASB issued ASU No. 2016-02, "Leases (Topic 842)" (“ASU 2016-02”). ASU 2016-02 amends the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets. Lessor accounting will remain similar to lessor accounting under previous GAAP, while aligning with the FASB’s new revenue recognition guidance. ASU 2016-02 is effective for the Company beginning January 1, 2019. Early adoption of ASU 2016-02 is permitted. The standard requires a modified retrospective transition approach for all leases existing at, or entered into after, the date of initial application, with an option to use certain transition relief. While this ASU will have impact on our internal processes and controls and result in a change to our accounting, we are still in the evaluation and information gathering stage of implementing the guidance and can not yet estimate the potential impact.

On March 30, 2016, the FASB issued ASU No. 2016-09, "Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting", which amends the current stock compensation guidance. The amendments simplify the accounting for the taxes related to stock based compensation, including adjustments to how excess tax benefits and a company’s payments for tax withholdings should be classified. The standard is effective for fiscal periods beginning after December 15, 2016, with early adoption permitted. While we do not anticipate this ASU having a significant financial impact, we are currently evaluating the adoption of this standard on our consolidated financial statements and expect to adopt the standard effective January 1, 2017.