Organization and Basis of Presentation (Policies)	3 Months Ended
Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting	Our condensed consolidated financial statements include the accounts of Delek and its 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 consolidated financial statements included in our Annual Report on Form 10-K filed with the Securities and Exchange Commission ("SEC") on March 1, 2019 (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, 2018 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"), which is a variable interest entity. As the indirect owner of the general partner of Delek Logistics, we have the ability to direct the activities of this entity that most significantly impact its economic performance. We are also considered to be the primary beneficiary for accounting purposes for this entity 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 incurs a loss, our operating results will reflect such loss, net of intercompany eliminations, to the extent of our ownership interest in this entity.
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.
Reclassifications	Certain prior period amounts have been reclassified in order to conform to the current period presentation.
New Accounting Pronouncements	New Accounting Pronouncements Adopted During 2019 Accounting Standards Update ("ASU") 2016-02, Leases In February 2016, the Financial Accounting Standards Board (the "FASB") issued guidance that requires the recognition of a lease liability and a right-of-use asset, initially measured at the present value of the lease payments, in the statement of financial condition for all leases with terms longer than one year. The guidance was subsequently amended to consider the impact of practical expedients and provide additional clarifications. This guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. We adopted the new lease standard on January 1, 2019. We elected the package of practical expedients which, among other things, allows us to carry forward the historical lease classification. For certain lease classes, we have elected the practical expedient not to separate lease and non-lease components, which allows us to combine the components if certain criteria are met. Further, we elected the optional transition method, which allows us to recognize a cumulative-effect adjustment to the opening balance sheet of retained earnings at the date of adoption and to not recast our comparative periods. We have not elected the hindsight practical expedient, which would have allowed us to use hindsight in determining the reasonably certain lease term. The adoption of the lease accounting guidance had no impact on January 1, 2019 retained earnings and resulted in the recognition of a $211.0 million lease liability and a corresponding right-of-use asset on our consolidated balance sheet. The adoption did not have a material impact on our consolidated income statement. See Note 20 for further information. ASU 2017-12, Derivatives and Hedging - Targeted Improvements to Accounting for Hedging Activities In August 2017, 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 guidance is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Companies are required to apply the guidance on a modified retrospective transition method in which the cumulative effect of the change is recognized within equity in the consolidated balance sheet as of the date of adoption. We adopted this guidance on January 1, 2019 and the adoption did not have a material impact on our business, financial condition or results of operations. See Note 11. Accounting Pronouncements Not Yet Adopted ASU 2018-15, Intangible - Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract In August 2018, the FASB issued guidance related to customers’ accounting for implementation costs incurred in a cloud computing arrangement that is considered a service contract. This pronouncement aligns the requirements for capitalizing implementation costs in such arrangements with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. This pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted, including adoption in any interim period for which financial statements have not been issued. Entities can choose to adopt the new guidance prospectively or retrospectively. 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. ASU 2018-14, Compensation - Changes to the Disclosure Requirements for Defined Benefit Plans In August 2018, the FASB issued guidance related to disclosure requirements for defined benefit plans. The pronouncement eliminates, modifies and adds disclosure requirements for defined benefit plans. The pronouncement is effective for fiscal years ending after December 15, 2020, and early adoption is permitted. We expect to adopt this guidance on or before the effective date and do not expect adopting this new guidance will have a material impact on our business, financial condition or results of operations. ASU 2018-13, Fair Value Measurement - Changes to the Disclosure Requirements for Fair Value Measurement In August 2018, the FASB issued guidance related to disclosure requirements for fair value measurements. The pronouncement eliminates, modifies and adds disclosure requirements for fair value measurements. The pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2019, with early adoption permitted. We expect to adopt this guidance on or before the effective date and do not expect adopting this new guidance will have a material impact on our business, financial condition or results of operations. ASU 2016-13, Financial Instruments - Measurement of Credit Losses on Financial Instruments 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.

Organization and Basis of Presentation (Policies)

3 Months Ended

Mar. 31, 2019

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Our condensed consolidated financial statements include the accounts of Delek and its 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 consolidated financial statements included in our Annual Report on Form 10-K filed with the Securities and Exchange Commission ("SEC") on March 1, 2019 (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, 2018 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"), which is a variable interest entity. As the indirect owner of the general partner of Delek Logistics, we have the ability to direct the activities of this entity that most significantly impact its economic performance. We are also considered to be the primary beneficiary for accounting purposes for this entity 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 incurs a loss, our operating results will reflect such loss, net of intercompany eliminations, to the extent of our ownership interest in this entity.

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.

Reclassifications

Certain prior period amounts have been reclassified in order to conform to the current period presentation.

New Accounting Pronouncements

New Accounting Pronouncements Adopted During 2019

Accounting Standards Update ("ASU") 2016-02, Leases

In February 2016, the Financial Accounting Standards Board (the "FASB") issued guidance that requires the recognition of a lease liability and a right-of-use asset, initially measured at the present value of the lease payments, in the statement of financial condition for all leases with terms longer than one year. The guidance was subsequently amended to consider the impact of practical expedients and provide additional clarifications. This guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. We adopted the new lease standard on January 1, 2019. We elected the package of practical expedients which, among other things, allows us to carry forward the historical lease classification. For certain lease classes, we have elected the practical expedient not to separate lease and non-lease components, which allows us to combine the components if certain criteria are met. Further, we elected the optional transition method, which allows us to recognize a cumulative-effect adjustment to the opening balance sheet of retained earnings at the date of adoption and to not recast our comparative periods. We have not elected the hindsight practical expedient, which would have allowed us to use hindsight

in determining the reasonably certain lease term. The adoption of the lease accounting guidance had no impact on January 1, 2019 retained earnings and resulted in the recognition of a $211.0 million lease liability and a corresponding right-of-use asset on our consolidated balance sheet. The adoption did not have a material impact on our consolidated income statement. See Note 20 for further information.

ASU 2017-12, Derivatives and Hedging - Targeted Improvements to Accounting for Hedging Activities

In August 2017, 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 guidance is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Companies are required to apply the guidance on a modified retrospective transition method in which the cumulative effect of the change is recognized within equity in the consolidated balance sheet as of the date of adoption. We adopted this guidance on January 1, 2019 and the adoption did not have a material impact on our business, financial condition or results of operations. See Note 11.

Accounting Pronouncements Not Yet Adopted

ASU 2018-15, Intangible - Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract

In August 2018, the FASB issued guidance related to customers’ accounting for implementation costs incurred in a cloud computing arrangement that is considered a service contract. This pronouncement aligns the requirements for capitalizing implementation costs in such arrangements with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. This pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted, including adoption in any interim period for which financial statements have not been issued. Entities can choose to adopt the new guidance prospectively or retrospectively. 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.

ASU 2018-14, Compensation - Changes to the Disclosure Requirements for Defined Benefit Plans

In August 2018, the FASB issued guidance related to disclosure requirements for defined benefit plans. The pronouncement eliminates, modifies and adds disclosure requirements for defined benefit plans. The pronouncement is effective for fiscal years ending after December 15, 2020, and early adoption is permitted. We expect to adopt this guidance on or before the effective date and do not expect adopting this new guidance will have a material impact on our business, financial condition or results of operations.

ASU 2018-13, Fair Value Measurement - Changes to the Disclosure Requirements for Fair Value Measurement

In August 2018, the FASB issued guidance related to disclosure requirements for fair value measurements. The pronouncement eliminates, modifies and adds disclosure requirements for fair value measurements. The pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2019, with early adoption permitted. We expect to adopt this guidance on or before the effective date and do not expect adopting this new guidance will have a material impact on our business, financial condition or results of operations.

ASU 2016-13, Financial Instruments - Measurement of Credit Losses on Financial Instruments

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.