Organization and Basis of Presentation (Policies)	9 Months Ended
Organization and Basis of Presentation (Policies)	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Reclassifications	Having classified the Retail Entities as assets held for sale, the condensed consolidated statements of income for the three and nine months ended September 30, 2016 have been reclassified to reflect the results of the Retail Entities as income from discontinued operations, net of taxes.
Basis of Accounting	Our condensed consolidated financial statements include the accounts of Delek and its consolidated subsidiaries. Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with U.S. Generally Accepted Accounting Principles ("GAAP") have been condensed or omitted, although management believes that the disclosures herein are adequate to make the financial information presented not misleading. Our unaudited condensed consolidated financial statements have been prepared in conformity with GAAP applied on a consistent basis with those of the annual audited financial statements included in our Annual Report on Form 10-K filed with the Securities and Exchange Commission ("SEC") on February 28, 2017 (the "Annual Report on Form 10-K") and in accordance with the rules and regulations of the SEC. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto for the year ended December 31, 2016 included in our Annual Report on Form 10-K.
Consolidation of Variable Interest Entity	Our condensed consolidated financial statements include Delek Logistics Partners, LP ("Delek Logistics"), Alon USA Partners, LP (the "Alon Partnership") and AltAir Paramount LLC ("AltAir"), all variable interest entities. As the indirect owner of the general partners of Delek Logistics and the Alon Partnership and the managing member of AltAir, we have the ability to direct the activities of these entities that most significantly impact their economic performance. We are also considered to be the primary beneficiary for accounting purposes for all of these entities and are Delek Logistics' primary customer. As Delek Logistics does not derive an amount of gross margin material to us from third parties, there is limited risk to Delek associated with Delek Logistics' operations. However, in the event that Delek Logistics, the Alon Partnership or AltAir incurs a loss, our operating results will reflect their loss, net of intercompany eliminations, to the extent of our ownership interest in these entities. AltAir's results are included in discontinued operations - see Note 5.
Consolidation	In the opinion of management, all adjustments necessary for a fair presentation of the financial condition and the results of operations for the interim periods have been included. All significant intercompany transactions and account balances have been eliminated in consolidation. All adjustments are of a normal, recurring nature. Operating results for the interim period should not be viewed as representative of results that may be expected for any future interim period or for the full year.
Segment Reporting	Segment Reporting Following the Delek/Alon Merger, Delek's business includes retail operations. Management views aggregated operating results in primarily three reportable segments: refining, logistics and retail. Our corporate activities, results of our asphalt operations and certain other immaterial operating segments, our equity method investments in Alon prior to the Delek/Alon Merger and intercompany eliminations are reported in the corporate, other and eliminations segment. The retail segment markets gasoline, diesel and other refined petroleum products, and convenience merchandise through a network of company-operated retail fuel and convenience stores. Segment reporting is more fully discussed in Note 14. Prior to August 2016, we aggregated our operating units into three reportable segments: refining, logistics and retail. However, in August 2016, Delek entered into a Purchase Agreement to sell the Retail Entities, which consisted of all of the retail segment at that time and a portion of the corporate, other and eliminations segment, to COPEC. As a result of the Purchase Agreement, we met the requirements of ASC 205-20 and ASC 360 to report the results of the Retail Entities as discontinued operations and to classify the Retail Entities as a group of assets held for sale. The Retail Entities were sold in November 2016. The operating results for the Retail Entities, in all periods up until and including the date of the sale, were reclassified to discontinued operations and are no longer reported as part of Delek's retail segment. Effective with the Delek/Alon Merger July 1, 2017 (see Note 2), Delek's retail segment now includes the operations of Alon's approximately 300 owned and leased convenience store sites located primarily in Central and West Texas and New Mexico. These convenience stores typically offer various grades of gasoline and diesel under the Alon brand name and food products, food service, tobacco products, non-alcoholic and alcoholic beverages, general merchandise as well as money orders to the public, primarily under the 7-Eleven and Alon brand names. Substantially all of the motor fuel sold through our retail segment is supplied by our Big Spring refinery (which is owned by the Alon Partnership), which is transferred to the retail segment at prices substantially determined by reference to published commodity pricing information. Our corporate activities, results of certain immaterial operating segments, including Alon's asphalt terminal operations effective with the Delek/Alon Merger, our equity method investment in Alon prior to the Delek/Alon Merger, as well as any discontinued operations, and intercompany eliminations are reported in the corporate, other and eliminations segment. Decisions concerning the allocation of resources and assessment of operating performance are made based on this segmentation. Management measures the operating performance of each of the reportable segments based on the segment contribution margin. Segment contribution margin is defined as net sales less cost of sales and operating expenses, excluding depreciation and amortization. Operations which are not specifically included in the reportable segments are included in the corporate and other category, which primarily consists of operating expenses, depreciation and amortization expense and interest income and expense associated with our discontinued operations and with our corporate headquarters.
Accounts Receivable	Accounts Receivable Accounts receivable primarily consists of trade receivables generated in the ordinary course of business. Delek recorded an allowance for doubtful accounts related to trade receivables of $4.8 million as of September 30, 2017. Delek had no allowance for doubtful accounts as of December 31, 2016. Credit is extended based on evaluation of the customer’s financial condition. We perform ongoing credit evaluations of our customers and require letters of credit, prepayments or other collateral or guarantees as management deems appropriate. Allowance for doubtful accounts is based on a combination of current sales and specific identification methods. Credit risk is minimized as a result of the ongoing credit assessment of our customers and a lack of concentration in our customer base. Credit losses are charged to allowance for doubtful accounts when deemed uncollectible. Our allowance for doubtful accounts is reflected as a reduction of accounts receivable in the consolidated balance sheets.
Inventory	Inventory Crude oil, work-in-process, refined products, blendstocks and asphalt inventory for all of our operations, excluding the refinery located in Tyler, Texas (the "Tyler refinery") and merchandise inventory in our Retail segment, are stated at the lower of cost determined using the first-in, first-out (“FIFO”) basis or net realizable value. Cost of all inventory at the Tyler refinery is determined using the last-in, first-out (“LIFO”) inventory valuation method and inventory is stated at the lower of cost or market. Retail merchandise inventory consists of cigarettes, beer, convenience merchandise and food service merchandise and is stated at estimated cost as determined by the retail inventory method. Crude oil, work-in-process, refined products, blendstocks and asphalt inventory for all of our operations, excluding the Tyler refinery and merchandise inventory in our Retail segment, are stated at the lower of cost determined using the FIFO basis or net realizable value. Cost of all inventory at the Tyler refinery is determined using the LIFO inventory valuation method and inventory is stated at the lower of cost or market. Retail merchandise inventory consists of cigarettes, beer, convenience merchandise and food service merchandise and is stated at estimated cost as determined by the retail inventory method.
Property, Plant and Equipment	Property, Plant and Equipment Depreciation for retail store equipment and site improvements is computed using the straight-line method over management's estimated useful lives of the related assets, which is 7-40 years. In accordance with ASC 360, Delek evaluates the realizability of property, plant and equipment as events occur that might indicate potential impairment.
Asset Retirement Obligations	Asset Retirement Obligations In the retail segment, we have asset retirement obligations related to the removal of underground storage tanks and the removal of brand signage at owned and leased retail sites which are legally required under the applicable leases. The asset retirement obligation for storage tank removal on leased retail sites is accreted over the expected life of the owned retail site or the average retail site lease term. We have asset retirement obligations with respect to our refineries due to various legal obligations to clean and/or dispose of these assets at the time they are retired. However, the majority of these assets can be used for extended and indeterminate periods of time provided that they are properly maintained and/or upgraded. It is our practice and intent to continue to maintain these assets and make improvements based on technological advances.
Revenue Recognition	Revenue Recognition In the retail segment, we derive service revenues from the sale of lottery tickets, money orders, car washes and other ancillary product and service offerings. Retail segment service revenue and related costs are recorded at gross amounts and net amounts, as appropriate, in accordance with the provisions of ASC 605-45, Revenue Recognition - Principal Agent Considerations ("ASC 605-45").
Cost of Goods Sold and Operating Expenses	Cost of Goods Sold and Operating Expenses For the retail segment, cost of goods sold comprises the costs of specific products sold. Retail cost of sales includes motor fuels and merchandise. Retail fuel cost of sales represents the cost of purchased fuel, including transportation costs. Merchandise cost of sales includes the delivered cost of merchandise purchases, net of merchandise rebates and commissions. Operating expenses include costs such as wages of employees, lease expense, utility expense and other costs of operating the stores. Asphalt cost of sales includes costs of purchased asphalt, blending materials and transportation costs.
Interest Expense	Interest Expense Interest expense includes interest expense on debt, letters of credit, financing fees, the amortization, net of accretion, of debt discounts or premium and amortization of deferred debt issuance costs, but excludes capitalized interest. Original issuance discount and debt issuance costs are amortized ratably over the term of the related debt.
Postretirement Benefits	Postretirement Benefits In connection with the Delek/Alon Merger, we now have defined benefit pension and postretirement medical plans for certain former Alon employees. We recognize the underfunded status of our defined benefit pension and postretirement medical plans as a liability. Changes in the funded status of our defined benefit pension and postretirement medical plans are recognized in other comprehensive income in the period when the changes occur. The funded status represents the difference between the projected benefit obligation and the fair value of the plan assets. The projected benefit obligation is the present value of benefits earned to date by plan participants, including the effect of assumed future salary increases. Plan assets are measured at fair value. We use December 31, of each year, as the measurement date for plan assets and obligations for all of our defined benefit pension and postretirement medical plans. See Note 18 for more information regarding our postretirement benefits.
New Accounting Pronouncements	New Accounting Pronouncements In August 2017, the Financial Accounting Standards Board (the "FASB") issued guidance to better align financial reporting for hedging activities with the economic objectives of those activities for both financial (e.g., interest rate) and commodity risks. The guidance was intended to create more transparency in the presentation of financial results, both on the face of the financial statements and in the footnotes, and simplify the application of hedge accounting guidance. This amendment is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Companies are required to apply the amendment on a modified retrospective transition method in which the cumulative effect of the change will be recognized within equity in the consolidated balance sheet as of the date of adoption. Early adoption is permitted, including in an interim period. If a company early adopts in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes the interim period. We expect to adopt this guidance on or before the effective date and are currently evaluating the impact that adopting this new guidance will have on our business, financial condition and results of operations. In May 2017, the FASB issued guidance that clarifies when changes to the terms or conditions of a share-based payment award must be accounted for as modifications. The modification accounting guidance applies if the value, vesting conditions or classification of the award changes. This guidance is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years, and can be early adopted for any interim or annual financial statements that have not yet been issued. We expect to adopt this guidance on or before the effective date and are currently evaluating the impact that adopting this new guidance will have on our business, financial condition and results of operations. In March 2017, the FASB issued guidance that will require that an employer disaggregate the service cost component from the other components of net benefit cost with respect to defined benefit postretirement employee benefit plans. Service cost is required to be reported in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net periodic benefit cost are required to be reported outside the subtotal for operating income. Additionally, only the service cost component of net benefit costs are eligible for capitalization. The guidance is effective January 1, 2018, with early adoption permitted. We expect to adopt this guidance on or before the effective date and are currently evaluating the impact that adopting this new guidance will have on our business, financial condition and results of operations. In January 2017, the FASB issued guidance concerning the goodwill impairment test that eliminates Step 2, which required a comparison of the implied fair value of goodwill of the reporting unit with the carrying amount of that goodwill for that reporting unit. It also eliminates the requirements for any reporting unit with a zero or negative carrying amount to perform a qualitative assessment and, if it fails that qualitative assessment, to perform Step 2 of the goodwill impairment test. An entity still has the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. This guidance is effective for annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We expect to adopt this guidance on or before the effective date and we do not anticipate that the adoption will have a material impact on our business, financial condition or results of operations. In January 2017, the FASB issued guidance clarifying the definition of a business in order to assist entities with evaluating when a set of transferred assets and activities is considered a business. In general, we expect that the revised definition will result in fewer acquisitions being accounted for as business combinations than under the current guidance. This guidance is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted under certain circumstances. We early adopted this guidance during the three months ended September 30, 2017, and as a result accounted for two immaterial acquisitions occurring during the three months ended September 30, 2017 as asset acquisitions rather than business combinations. The adoption did not have a material impact on our business, financial condition and results of operations. In June 2016, the FASB issued guidance requiring the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. Financial institutions and other organizations will now use forward-looking information to better inform their credit loss estimates. This guidance is effective for interim and annual periods beginning after December 15, 2019. We expect to adopt this guidance on or before the effective date and are currently evaluating the impact that adopting this new guidance will have on our business, financial condition and results of operations. In March 2016, the FASB issued guidance that simplifies several aspects of the accounting for share-based payment award transactions, including the accounting for excess tax benefits and deficiencies, classification of awards as either equity or liabilities and classification of excess tax benefits on the statement of cash flows. This guidance is effective for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years and can be early adopted for any interim or annual financial statements that have not yet been issued. We prospectively adopted this guidance on January 1, 2017 and the adoption did not have a material impact on our business, financial condition or results of operations. In January 2016, the FASB issued guidance that affects the accounting for equity investments, financial liabilities accounted for under the fair value option and the presentation and disclosure requirements for financial instruments. Under the new guidance, all equity investments in unconsolidated entities (other than those accounted for using the equity method of accounting) will generally be measured at fair value through earnings. There will no longer be an available-for-sale classification for equity securities with readily determinable fair values. For financial liabilities when the fair value option has been elected, changes in fair value due to instrument-specific credit risk will be recognized separately in other comprehensive income. It will require public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes and separate presentation of financial assets and financial liabilities by measurement category and form of financial asset, and will eliminate the requirement for public business entities to disclose the method and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost.The new guidance is effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. We expect to adopt this guidance on or before the effective date and currently do not expect this new guidance to have a material impact on our business, financial condition or results of operations. In July 2015, the FASB issued guidance requiring entities to measure FIFO or average cost inventory at the lower of cost and net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. This guidance does not change the measurement of inventory measured using LIFO or the retail inventory method. This guidance is effective for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. We adopted this guidance on January 1, 2017 and the adoption did not have a material impact on our business, financial condition or results of operations. In May 2014, the FASB issued guidance regarding “Revenue from Contracts with Customers,” to clarify the principles for recognizing revenue. The core principle of the new guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance also requires improved interim and annual disclosures that enable the users of financial statements to better understand the nature, amount, timing, and uncertainty of revenues and cash flows arising from contracts with customers. The new guidance is effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period, and can be adopted retrospectively. We expect to adopt this guidance on January 1, 2018. As part of our efforts to prepare for adoption, beginning in 2016, we formed a project implementation team as well as a project timeline to evaluate this new standard for the subsidiaries of Delek prior to the acquisition of Alon. We also reviewed and gained an understanding of the new revenue recognition accounting guidance, performed scoping to identify and evaluate revenue streams under the new standard, and continue to review industry specific implementation guidance. During the third quarter of 2017, we developed our control framework over revenue recognition, including implementation, and we performed testing to confirm our understanding of identified revenue streams of Old Delek. In connection with the Delek/Alon Merger which was effective July 1, 2017, we performed a similar analysis of the revenue streams/contracts of Alon and its subsidiaries in connection with our integration efforts. We are continuing to evaluate the impact of the standard on our business processes, accounting systems, controls and financial statement disclosures, including the integration of Alon, and expect to implement any changes to accommodate the new accounting and disclosure requirements prior to adoption on January 1, 2018. We preliminarily expect to use the modified retrospective adoption method to apply this standard, under which the cumulative effect of initially applying the new guidance will be recognized as an adjustment to the opening balance of retained earnings in the first quarter of 2018.
Fair Value Measurements	The fair values of financial instruments are estimated based upon current market conditions and quoted market prices for the same or similar instruments. Management estimates that the carrying value approximates fair value for all of Delek’s assets and liabilities that fall under the scope of ASC 825, Financial Instruments ("ASC 825"). Delek applies the provisions of ASC 820, Fair Value Measurements ("ASC 820"), which defines fair value, establishes a framework for its measurement and expands disclosures about fair value measurements. ASC 820 applies to our commodity and interest rate derivatives that are measured at fair value on a recurring basis. The standard also requires that we assess the impact of nonperformance risk on our derivatives. Nonperformance risk is not considered material to our financial statements at this time. ASC 820 requires disclosures that categorize assets and liabilities measured at fair value into one of three different levels depending on the observability of the inputs employed in the measurement. Level 1 inputs are quoted prices in active markets for identical assets or liabilities. Level 2 inputs are observable inputs other than quoted prices included within Level 1 for the asset or liability, either directly or indirectly through market-corroborated inputs. Level 3 inputs are unobservable inputs for the asset or liability reflecting our assumptions about pricing by market participants.