The preparation of our financial statements in conformity with U.S. generally accepted accounting principles (“GAAP”) and in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. In the opinion of management, all adjustments necessary for a fair presentation of the financial position and the results of operations 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 party in these accompanying consolidated financial statements. All adjustments are of a normal, recurring nature.

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 the segment contribution margin. Segment contribution margin is defined as net revenues less cost of materials and other and operating expenses, excluding depreciation and amortization. Segment reporting is more fully discussed in Note 15.

Accounts receivable primarily consists of trade receivables generated in the ordinary course of business. We perform on-going credit evaluations of our customers and generally do not require collateral on accounts receivable. All accounts receivable amounts are considered to be fully collectible. Accordingly, no allowance for doubtful accounts has been established as of December 31, 2019 and 2018. One third-party customer accounted for approximately 52.5% of the consolidated accounts receivable balance as of December 31, 2019. Two third-party customers accounted for approximately 50.4% of the consolidated accounts receivable balance as of December 31, 2018.

Inventory consists of refined products, which are stated at the lower of cost or net realizable value, with cost determined on a first-in, first-out ("FIFO") basis. Delek Holdings accounted for approximately 78.1% and 64.2% of our inventory purchases in our wholesale marketing and terminalling segment during the year ended December 31, 2019 and December 31, 2018, respectively.

Assets acquired in conjunction with business acquisitions are recorded at estimated fair market value in accordance with the purchase method of accounting as prescribed in Accounting Standards Codification ("ASC") 805, Business Combinations ("ASC 805"). Other acquisitions of property and equipment are carried at cost. Acquisitions of net assets that do not constitute a business are accounted for by allocating the cost of the acquisition to individual assets acquired and liabilities assumed on a relative fair value basis and shall not give rise to goodwill as prescribed in ASC 805.

Property, plant and equipment and intangibles are evaluated for impairment whenever indicators of impairment exist. In accordance with ASC 360, Property, Plant and Equipment and ASC 350, Intangibles - Goodwill and Other, we evaluate the realizability of these long-lived assets as events occur that might indicate potential impairment. In doing so, we assess whether the carrying amount of the asset is unrecoverable by estimating the sum of the future cash flows expected to result from the use of the asset, undiscounted and without interest charges. If the carrying amount is more than the recoverable amount, an impairment charge must be recognized based on the fair value of the asset.

Goodwill in an acquisition represents the excess of the aggregate purchase price over the fair value of the identifiable net assets. Goodwill is reviewed at least annually for impairment, or more frequently if indicators of impairment exist, such as disruptions in our business, unexpected significant declines in operating results, or a sustained market capitalization decline. Goodwill is evaluated for impairment by comparing the carrying amount of the reporting unit to its estimated fair value. The Partnership adopted Accounting Standard Update ("ASU") 2017-04, Goodwill and Other (Topic 350); Simplifying the Test for Goodwill Impairment, during the fourth quarter of 2018. In accordance with this guidance, if a reporting unit's carrying amount exceeds its fair value, the impairment assessment leads to the testing of the implied fair value of the reporting unit's goodwill to its carrying amount if the implied fair value is less than the carrying amount, a goodwill impairment charge is recorded.

In assessing the recoverability of goodwill, assumptions are made with respect to future business conditions and estimated expected future cash flows to determine the fair value of a reporting unit. We may consider inputs such as a market participant weighted average cost of capital, estimated growth rates for revenue, gross profit and capital expenditures based on history and our best estimate of future forecasts, all of which are subject to significant judgment and estimates. We may also estimate the fair values of the reporting units using a multiple of expected future cash flows, such as those used by market participants. If these estimates and assumptions change in the future, due to factors such as a decline in general economic conditions, competitive pressures on sales and margins and other economic and industry factors beyond management's control, an impairment charge may be required. A significant risk to our future results and the potential future impairment of goodwill is the volatility of the crude oil and the refined product markets which is often unpredictable and may negatively impact our results of operations in ways that cannot be anticipated and that are beyond management's control.

We may also elect to perform a qualitative assessment of goodwill balances. The qualitative assessment permits companies to assess whether it is more likely than not (i.e., a likelihood of greater than 50%) that the fair value of a reporting unit is less than its carrying amount. If a company concludes based on the qualitative assessment that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, the company is required to perform the quantitative impairment test. If a company concludes based on the qualitative assessment that it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, it has completed its goodwill impairment test and does not need to perform the quantitative impairment test.

For equity investments that are not required to be consolidated under the variable or voting interest model, we evaluate the level of influence we are able to exercise over an entity’s operations to determine whether to use the equity method of accounting. Our judgment regarding the level of influence over an equity method investment includes considering key factors such as our ownership interest, participation in policy-making and other significant decisions and material intercompany transactions. Equity investments for which we determine we have significant influence are accounted for as equity method investments. Amounts recognized for equity method investments are included in equity method investments in our consolidated balance sheets and adjusted for our share of the net earnings and losses of the investee and cash distributions, which are separately stated in our consolidated statements of income and comprehensive income and our consolidated statements of cash flows. We evaluate our equity method investments presented for impairment whenever events or changes in circumstances indicate that the carrying amounts of such investments may be impaired. A loss is recorded in earnings in the current period if a decline in the value of an equity method investment is determined to be other than temporary. See Note 14 for further information on our equity method investments.

We have no employees. Rather, we are managed by the directors and officers of our general partner. However, Delek Holdings employees providing services to the Partnership are covered under Delek Holdings’ insurance programs. Delek Holdings has workers' compensation and liability insurance with varying retentions and deductibles with limits that management considers adequate.

It is our policy to accrue environmental and clean-up related costs of a non-capital nature when it is both probable that a liability has been incurred and the amount can be reasonably estimated. Environmental liabilities represent the current estimated costs to investigate and remediate contamination at our properties. This estimate is based on internal and third-party assessments of the extent of the contamination, the selected remediation technology and review of applicable environmental regulations, typically considering estimated activities and costs for the next 15 years, unless a specific longer range estimate is practicable. Accruals for estimated costs from environmental remediation

obligations generally are recognized no later than completion of the remedial feasibility study and include, but are not limited to, costs to perform remedial actions and costs of machinery and equipment that are dedicated to the remedial actions and that does not have an alternative use. Such accruals are adjusted as further information develops or circumstances change. We discount environmental liabilities to their present value if payments are fixed and determinable. Expenditures for equipment necessary for environmental issues relating to ongoing operations are capitalized. Estimated recoveries of costs from other parties are recorded on an undiscounted basis as assets when their realization is deemed probable. See Note 17 for further information on crude oil releases impacting our properties and related accruals.

We recognize liabilities which represent the fair value of a legal obligation to perform asset retirement activities, including those that are conditional on a future event, when the amount can be reasonably estimated. These obligations are related to the required cleanout of our pipelines and terminal tanks and removal of certain above-grade portions of our pipelines situated on right-of-way property.

Revenue is measured based on consideration specified in a contract with a customer. The Partnership recognizes revenue when it satisfies a performance obligation by transferring control over a product or by providing services to a customer. The adoption of ASC 606, Revenue from Contracts with Customers ("ASC 606") beginning January 1, 2018, did not materially change our revenue recognition patterns, which are described below. The principles for recognizing revenue as codified in ASC 605, Revenue Recognition ("ASC 605"), were applied during the years ended December 31, 2017. No restatements to revenues or expenses were required to be made to our consolidated statements of income, as we applied the modified retrospective transition method in adopting ASC 606.

Service, Product and Lease Revenues. Revenues for products sold are generally recognized upon delivery of product, which is when title and control of the product is transferred. Transaction prices for these products are typically at market rates for the product at the time of delivery. Service revenues are recognized as crude oil, intermediate and refined products are shipped through, delivered by or stored in our pipelines, trucks, terminals and storage facility assets, as applicable. We do not recognize product revenues for these services, as the product does not represent a promised good in the context of ASC 606. All service revenues are based on regulated tariff rates or contractual rates. Payment terms require customers to pay shortly after delivery and do not contain significant financing components.

Certain agreements for gathering, transportation, storage, terminalling, and offloading with Delek Holdings are considered operating leases under ASC 840, Leases ("ASC 840"). As part of the adoption, we applied the permitted practical expedient to not separate lease and non-lease components under the predominance principle to designated asset classes associated with the provision of logistics services. We have determined that the predominant component of the related agreements currently in effect is the lease component. Therefore, the combined component is accounted for under the applicable lease accounting guidance. Refer to Note 5 for further information.

Up-Front payments to Customers. We record up-front payments to customers in accordance with ASC 606. We evaluate the nature of each payment, the rights and obligations under the related contract, and whether the payment meets the definition of an asset. When an asset is recognized for an up-front payment to a customer, the asset is amortized, as a reduction of revenue, in a manner that reflects the pattern and period over which the asset is expected to provide benefit.

Revenues Related to Reimbursements. In addition to the agreements noted above, we have cost reimbursement provisions in certain of our agreements with Delek Holdings that provide for reimbursement by the Company for certain costs, including certain capital expenditures. Such reimbursements are recorded in other long-term liabilities and are amortized to revenue over the life of the underlying revenue agreement corresponding to the asset.

Cost of materials and other includes (i) all costs of purchased refined products, additives and related transportation of such products, (ii) costs associated with the operation of our trucking assets, which primarily include allocated employee costs and other costs related to fuel, truck leases and repairs and maintenance, (iii) the cost of pipeline capacity leased from a third-party, and (iv) gains and losses related to our commodity hedging activities.

Operating expenses include the costs associated with the operation of owned terminals and pipelines and terminalling expense at third-party locations, excluding depreciation and amortization. These costs primarily include outside services, allocated employee costs, repairs and maintenance costs and energy and utility costs. Operating expenses related to the wholesale business are excluded from cost of sales because they primarily relate to costs associated with selling the products through our wholesale business.

Deferred financing costs are included in other non-current assets in the accompanying consolidated balance sheets and represent expenses related to issuing and amending our revolving credit facility. Deferred financing costs associated with our 6.750% Senior Notes are included as a reduction to the associated debt balance in the accompanying consolidated balance sheets. These costs represent expenses related to issuing the senior notes. These amounts are amortized ratably over the remaining term of the respective financing and are included in interest expense in the accompanying consolidated statements of income and comprehensive income.

In accordance with ASC 842-20, Leases - Lessee ("ASC 842-20"), we classify leases with contractual terms longer than twelve months as either operating or finance. Finance leases are generally those leases that are highly specialized or allow us to substantially utilize or pay for the entire asset over its useful life. All other leases are classified as operating leases.

We lease primarily transportation equipment. Our leases do not have any outstanding renewal options. Certain leases also include options to purchase the leased equipment. Certain of our lease agreements include rates based on equipment usage. Our lease agreements do not contain any material residual value guarantees or material restrictive covenants.

We calculate the total lease expense for the entire noncancelable lease period, considering renewals for all periods for which it is reasonably certain to be exercised, and record lease expense on a straight-line basis in the accompanying consolidated statements of income. Accordingly, a lease liability is recognized for these leases and is calculated to be the present value of the fixed lease payments, as defined by ASC 842-20, using a discount rate based on our incremental borrowing rate. A corresponding right-of-use asset is recognized based on the lease liability and adjusted for certain costs and prepayments.

We are not a taxable entity for federal income tax purposes or the income taxes of those states that follow the federal income tax treatment of partnerships. Instead, for purposes of these income taxes, each partner of the Partnership is required to take into account its share of items of income, gain, loss and deduction in computing its federal and state income tax liabilities, regardless of whether cash distributions are made to such partner by the Partnership. The taxable income reportable to each partner takes into account differences between the tax basis and fair market value of our assets and financial reporting bases of assets and liabilities, the acquisition price of such partner's units and the taxable income allocation requirements under the Partnership's First Amended and Restated Agreement of Limited Partnership, as amended (the "Partnership Agreement").

We are subject to income taxes in certain states that do not follow the federal tax treatment of Partnerships. These taxes are accounted for under the provisions of ASC 740, Income Taxes ("ASC 740"). This statement generally requires the Partnership to record deferred income taxes for the differences between the book and tax bases of its assets and liabilities, which are measured using enacted tax rates and laws that will be in effect when the differences are expected to reverse. Deferred income tax expense or benefit represents the net change during the year in our deferred income tax assets and liabilities, exclusive of the amounts held in other comprehensive income.

U.S. GAAP requires management to evaluate uncertain tax positions taken by the Partnership. The financial statement effects of a tax position are recognized when the position is more likely than not, based on the technical merits, to be sustained upon examination by the Internal Revenue Service. Management has analyzed the tax positions taken by the Partnership, and has concluded that there are no uncertain positions taken or expected to be taken. The Partnership is subject to routine audits by taxing jurisdictions.

Our general partner provides equity-based compensation to officers, directors and employees of our general partner or its affiliates, and certain consultants, affiliates of our general partner or other individuals who perform services for us, which includes unit options, restricted units, phantom units, unit appreciation rights, distribution equivalent rights, other unit-based awards and unit awards. The fair value of our phantom units is determined based on the closing market price of our common units on the grant date. The estimated fair value of our phantom units is amortized over the vesting period using the straight line method. Awards vest over one- to five-year service periods, unless such awards are amended in accordance with the LTIP (as defined in Note 13). It is our practice to issue new units when phantom units vest.

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 incentive distribution rights ("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 to our general partner, which is the holder of the IDRs pursuant to our Partnership Agreement. See Notes 6 and 12 for further discussion.

Prior to the adoption of ASC 606, the Partnership's policy was to exclude sales, use and excise taxes from revenue when we are an agent of the taxing authority, in accordance with the applicable guidance in ASC 605. Upon the adoption of ASC 606, we made the accounting policy election to exclude from revenue all taxes assessed by a governmental authority, including sales, use and excise taxes, that are both imposed on and concurrent with a specific revenue-producing transaction and collected on behalf of a customer.

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. 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 partners' equity and resulted in the recognition of a $2.7 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 statement of income. See Note 18 for further information.

In December 2019, the FASB issued guidance intended to simplify various aspects related to accounting for income taxes, eliminate certain exceptions within ASC 740 and clarify certain aspects of the current guidance to promote consistency among reporting entities. The pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2020, with early adoption permitted. We expect to adopt this guidance on 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.

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 prospectively on 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 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 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.

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. Organizations will now use forward-looking information to better inform their credit loss estimates. We are currently evaluating the impact that adopting this new guidance will have on our business, financial condition and results of operations, which includes scoping, accounting, and disclosure considerations and historical analysis of applicable assets. The new guidance will be effective beginning with the first quarter of 2020 and will not have a material impact on our business, financial condition or results of operations.