Organization and Basis of Presentation (Policies)	3 Months Ended
Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting	Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with U.S. generally accepted accounting principles ("U.S. 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 U.S. GAAP applied on a consistent basis with those of the annual audited financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2018 (our "Annual Report on Form 10-K"), filed with the Securities and Exchange Commission (the "SEC") on March 1, 2019. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2018 included in our Annual Report on Form 10-K.
Consolidation	All adjustments necessary for a fair presentation of the financial position and the results of operations for the interim periods presented have been included. All intercompany accounts and transactions have been eliminated. Such intercompany transactions do not include those with Delek Holdings' or our general partner, which are presented as related parties in these accompanying condensed consolidated financial statements. 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.
New Accounting Pronouncements	New Accounting Pronouncements Adopted During Q1 2019 Accounting Standard Update ("ASU") 2017-12, Derivatives and Hedging - Targeted Improvements to Accounting for Hedging Activities 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 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 the effective date and the adoption did not have a material impact on our business, financial condition and results of operations. ASU 2016-02, Leases In February 2016, 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. The 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 expedients, 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 $20.2 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 16 for further information. Accounting Pronouncements Not Yet Adopted 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.
Inventory	Inventory is stated at the lower of cost or net realizable value, with cost determined on a first-in, first-out basis.
Net Income Per Unit	We use the two-class method when calculating the net income per unit applicable to limited partners because we have more than one participating class of securities. Our participating securities consist of common units, general partner units and IDRs. The two-class method is based on the weighted-average number of common units outstanding during the period. Basic net income per unit applicable to limited partners is computed by dividing limited partners’ interest in net income, after deducting our general partner’s 2% interest and IDRs, by the weighted-average number of outstanding common units. Our net income is allocated to our general partner and limited partners in accordance with their respective partnership percentages after giving effect to priority income allocations for IDRs, which are held by our general partner pursuant to our Partnership Agreement. The IDRs are paid following the close of each quarter.
Segment Data	Our operating segments adhere to the accounting policies used for our consolidated financial statements. Our operating segments are managed separately because each segment requires different industry knowledge, technology and marketing strategies. 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 its reportable segments based on segment contribution margin. Segment contribution margin is defined as net revenues less cost of materials and other and operating expenses, excluding depreciation and amortization.
Property, Plant and Equipment, Impairment	In accordance with ASC 360, Property, Plant & Equipment, we evaluate the realizability of property, plant and equipment as events occur that might indicate potential impairment.
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 our assets and liabilities that fall under the scope of ASC 825, Financial Instruments. We apply 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 commodity 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. Commodity swaps, exchange-traded futures, physical commodity forward purchase and sale contracts are generally valued using industry-standard models that consider various assumptions, including quoted forward prices, spot prices, interest rates, time value, volatility factors and contractual prices for the underlying instruments, as well as other relevant economic measures. The degree to which these inputs are observable in the forward markets determines the classification as Level 2 or 3. Our contracts are valued based on exchange pricing and/or price index developers such as Platts or Argus and are, therefore, classified as Level 2.

Organization and Basis of Presentation (Policies)

3 Months Ended

Mar. 31, 2019

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with U.S. generally accepted accounting principles ("U.S. 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 U.S. GAAP applied on a consistent basis with those of the annual audited financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2018 (our "Annual Report on Form 10-K"), filed with the Securities and Exchange Commission (the "SEC") on March 1, 2019. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2018 included in our Annual Report on Form 10-K.

Consolidation

All adjustments necessary for a fair presentation of the financial position and the results of operations for the interim periods presented have been included. All intercompany accounts and transactions have been eliminated. Such intercompany transactions do not include those with Delek Holdings' or our general partner, which are presented as related parties in these accompanying condensed consolidated financial statements. 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.

New Accounting Pronouncements

New Accounting Pronouncements Adopted During Q1 2019

Accounting Standard Update ("ASU") 2017-12, Derivatives and Hedging - Targeted Improvements to Accounting for Hedging Activities

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 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 the effective date and the adoption did not have a material impact on our business, financial condition and results of operations.

ASU 2016-02, Leases

In February 2016, 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. The 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 expedients, 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 $20.2 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 16 for further information.

Accounting Pronouncements Not Yet Adopted

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.

Inventory

Inventory is stated at the lower of cost or net realizable value, with cost determined on a first-in, first-out basis.

Net Income Per Unit

We use the two-class method when calculating the net income per unit applicable to limited partners because we have more than one participating class of securities. Our participating securities consist of common units, general partner units and IDRs. The two-class method is based on the weighted-average number of common units outstanding during the period. Basic net income per unit applicable to limited partners is computed by dividing limited partners’ interest in net income, after deducting our general partner’s 2% interest and IDRs, by the weighted-average number of outstanding common units. Our net income is allocated to our general partner and limited partners in accordance with their respective partnership percentages after giving effect to priority income allocations for IDRs, which are held by our general partner pursuant to our Partnership Agreement. The IDRs are paid following the close of each quarter.

Segment Data

Our operating segments adhere to the accounting policies used for our consolidated financial statements. Our operating segments are managed separately because each segment requires different industry knowledge, technology and marketing strategies. 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 its reportable segments based on segment contribution margin. Segment contribution margin is defined as net revenues less cost of materials and other and operating expenses, excluding depreciation and amortization.

Property, Plant and Equipment, Impairment

In accordance with ASC 360, Property, Plant & Equipment, we evaluate the realizability of property, plant and equipment as events occur that might indicate potential impairment.

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 our assets and liabilities that fall under the scope of ASC 825, Financial Instruments.

We apply 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 commodity 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.

Commodity swaps, exchange-traded futures, physical commodity forward purchase and sale contracts are generally valued using industry-standard models that consider various assumptions, including quoted forward prices, spot prices, interest rates, time value, volatility factors and contractual prices for the underlying instruments, as well as other relevant economic measures. The degree to which these inputs are observable in the forward markets determines the classification as Level 2 or 3. Our contracts are valued based on exchange pricing and/or price index developers such as Platts or Argus and are, therefore, classified as Level 2.