We establish provisions for losses on trade receivables if it becomes probable that we will not collect all or part of the outstanding balances. We review collectibility and establish or adjust our allowance as necessary using the specific identification method. As of December 31, 2019 and 2018, we did not have a significant allowance for doubtful accounts.

Commodity inventories, excluding commodity inventories at the Washington refinery, are stated at the lower of cost or net realizable value using the first-in, first-out (“FIFO”) inventory accounting method. Commodity inventories at the Washington refinery are stated at the lower of cost or net realizable value using the last-in, first-out (“LIFO”) inventory accounting method. We value merchandise along with spare parts, materials, and supplies at average cost. As of December 31, 2019, the excess of current replacement cost over LIFO inventory carrying value at the Washington refinery was approximately $6.4 million.

All of the crude oil utilized at the Hawaii refineries is financed by J. Aron & Company LLC (“J. Aron”) under the Supply and Offtake Agreements as described in Note 11—Inventory Financing Agreements. The crude oil remains in the legal title of J. Aron and is stored in our storage tanks governed by a storage agreement. Legal title to the crude oil passes to us at the tank outlet. After processing, J. Aron takes title to the refined products stored in our storage tanks until they are sold to our retail locations or to third parties. We record the inventory owned by J. Aron on our behalf as inventory with a corresponding obligation on our balance sheet because we maintain the risk of loss until the refined products are sold to third parties and we are obligated to repurchase the inventory.

In connection with the consummation of the Washington Acquisition (as defined in Note 4—Acquisitions), we became a party to an intermediation arrangement (the “Washington Refinery Intermediation Agreement”) with Merrill Lynch Commodities, Inc. (“MLC”) as described in Note 11—Inventory Financing Agreements. Under this arrangement, U.S. Oil (as defined in Note 4—Acquisitions) purchases crude oil supplied from third-party suppliers and MLC provides credit support for certain crude oil purchases. MLC’s credit support can consist of either providing a payment guaranty, causing the issuance of a letter of credit from a third party issuing bank, or purchasing crude oil directly from third parties on our behalf. U.S. Oil holds title to all crude oil and refined products inventories at all times and pledges such inventories, together with all receivables arising from the sales of same, exclusively to MLC.

Beginning in 2018, Inventories also include Renewable Identification Numbers (“RINs”), sulfur credits, and other environmental credits. Our RINs assets, which include RINs purchased in the open market and RINs obtained by purchasing biofuels, which are blended into our refined products, are presented as Inventories on our consolidated balance sheets and stated at the lower of cost or net realizable value (“NRV”) as of the end of the reporting period. Our RINs obligations to comply with the Renewable Fuel Standard (“RFS”) (discussed in Note 16—Commitments and Contingencies) are presented as Other accrued liabilities on our consolidated balance sheets and measured at fair value as of the end of the reporting period. Our sulfur credits and other environmental credits generated as part of our refining process are presented as Inventories on our consolidated balance sheets and stated at the lower of cost or NRV as of the end of the reporting period. The net cost of environmental credits is recognized within Cost of revenues (excluding depreciation) in our consolidated statements of operations.

We account for our Investment in Laramie Energy, LLC using the equity method as we have the ability to exert significant influence, but do not control its operating and financial policies. Our proportionate share of net income (loss) of this entity is included in Equity earnings (losses) from Laramie Energy, LLC in the consolidated statements of operations. The investment is reviewed for impairment when events or changes in circumstances indicate that there may have been an other-than-temporary decline in the value of the investment. During the year ended December 31, 2019, we recorded an impairment charge of $81.5 million on our consolidated statement of operations due to the significant decline in natural gas prices during the second and third quarters of 2019. Please read Note 3—Investment in Laramie Energy, LLC for further information.

We capitalize the cost of additions, major improvements, and modifications to property, plant, and equipment. The cost of repairs and normal maintenance of property, plant, and equipment is expensed as incurred. Major improvements and modifications of property, plant, and equipment are those expenditures that either extend the useful life, increase the capacity, or improve the operating efficiency of the asset or the safety of our operations. We compute depreciation of property, plant, and equipment using the straight-line method, based on the estimated useful life of each asset as follows:

We review property, plant, and equipment, operating leases, and other long-lived assets for impairment whenever events or changes in business circumstances indicate the carrying value of the assets may not be recoverable. Impairment is indicated when the undiscounted cash flows estimated to be generated by those assets are less than the assets’ carrying value. If this occurs, an impairment loss is recognized for the difference between the fair value and carrying value. Factors that indicate potential impairment include a significant decrease in the market value of the asset, operating or cash flow losses associated with the use of the asset, and a significant change in the asset’s physical condition or use.

On January 1, 2019, we adopted Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842), as amended by other ASUs issued through February 2019 (“ASU 2016-02” or “ASC 842”), using the modified retrospective transition method. Under this optional transition method, information presented prior to January 1, 2019 has not been restated and continues to be reported under the accounting standards in effect for the period. There was no adjustment to our opening retained earnings as a result of the adoption of this ASU.

We determine whether a contract is or contains a lease when we have the right to control the use of the identified asset in exchange for consideration. Lease liabilities and right-of-use assets (“ROU assets”) are recognized at the commencement date based on the present value of lease payments over the lease term. We use our incremental borrowing rate in the calculation of present value unless the implicit rate can be readily determined, however, the lease liability associated with leases calculated through the use of implicit rates is not significant. Certain leases include provisions for variable payments based upon percentage of sales and/or other operating metrics; escalation provisions to adjust rental payments to reflect changes in price indices and fair market rents; and provisions for the renewal, termination, and/or purchase of the leased asset. We only consider fixed payments and those options that are reasonably certain to be exercised in the determination of the lease term and the initial measurement of lease liabilities and ROU assets. Expense for finance leases is recognized as amortization expense on a straight-line basis and interest expense on an effective rate basis over the lease term. Expense for operating lease payments is recognized as lease expense on a straight-line basis over the lease term. We do not separate lease and nonlease components of a contract. Leases with an initial term of 12 months or less are not recorded on the balance sheet. Finance lease ROU assets are presented within Property, plant, and equipment and Operating lease ROU assets within Operating lease assets on our consolidated balance sheets. Please read Note 15—Leases for further disclosures and information on leases.

We record asset retirement obligations (“AROs”) in the period in which we have a legal obligation, whether by government action or contractual arrangement, to incur these costs and can make a reasonable estimate of the liability. Our AROs arise from our refining, logistics, and retail operations. AROs are calculated based on the present value of the estimated removal and other closure costs using our credit-adjusted risk-free rate. When the liability is initially recorded, we capitalize the cost by increasing the book value of the related long-lived tangible asset. The liability is accreted to its estimated settlement value with accretion expense recognized in Depreciation, depletion, and amortization (“DD&A”) on our consolidated statements of operations and the related capitalized cost is depreciated over the asset’s useful life. The difference between the settlement amount and the recorded liability is recorded as a gain or loss on asset disposals in our consolidated statements of operations. We estimate settlement dates by considering our past practice, industry practice, contractual terms, management’s intent, and estimated economic lives.

Refinery turnaround costs, which are incurred in connection with planned major maintenance activities at our refineries, are deferred and amortized on a straight-line basis over the period of time estimated until the next planned turnaround (generally three to five years). During 2019, we recognized deferred turnaround costs of approximately $9.8 million. No deferred turnaround costs were recorded during 2018 and 2017. Deferred turnaround costs are presented within Other long-term assets on our consolidated balance sheets.

Goodwill represents the amount the purchase price exceeds the fair value of net assets acquired in a business combination. Goodwill is not amortized, but is tested for impairment annually on October 1. We assess the recoverability of the carrying value of goodwill during the fourth quarter of each year or whenever events or changes in circumstances indicate that the carrying amount of the goodwill of a reporting unit may not be fully recoverable. We first assess qualitative factors to determine whether it is more likely than not that the fair value of the reporting unit is less than its carrying value. If the qualitative assessment indicates that it is more likely than not that the carrying value of a reporting unit exceeds its estimated fair value, a quantitative test is required. Under the quantitative test, we compare the carrying value of the net assets of the reporting unit to the estimated fair value of the reporting unit. If the carrying value exceeds the estimated fair value of the reporting unit, an impairment loss is recorded.

Our intangible assets include relationships with customers, trade names, and trademarks. These intangible assets are amortized over their estimated useful lives on a straight-line basis. We evaluate the carrying value of our intangible assets when impairment indicators are present. When we believe impairment indicators may exist, projections of the undiscounted future cash flows associated with the use of and eventual disposition of the intangible assets are prepared. If the projections indicate that their carrying values are not recoverable, we reduce the carrying values to their estimated fair values.

We capitalize environmental expenditures that extend the life or increase the capacity of facilities as well as expenditures that prevent environmental contamination. We expense costs that relate to an existing condition caused by past operations and that do not contribute to current or future revenue generation. We record liabilities when environmental assessments and/or remedial efforts are probable and can be reasonably estimated. Cost estimates are based on the expected timing and extent of remedial actions required by governing agencies, experience gained from similar sites for which environmental assessments or remediation have been completed, and the amount of our anticipated liability considering the proportional liability and financial abilities of other responsible parties. Usually, the timing of these accruals coincides with the completion of a feasibility study or our commitment to a formal plan of action. Estimated liabilities are not discounted to present value and are presented within Other liabilities on our consolidated balance sheets. Environmental expenses are recorded in Operating expense (excluding depreciation) on our consolidated statements of operations.

For our forward contracts that are derivatives, we have elected the normal purchase normal sale exclusion, as it is our policy to fulfill or accept the physical delivery of the product and we will not net settle. Therefore, we did not recognize the unrealized gains or losses related to these contracts in our consolidated financial statements. We apply the accrual method of accounting to our forward contracts.

All derivative instruments not designated as normal purchases or sales are recorded in the balance sheet as either assets or liabilities measured at their fair values. Changes in the fair value of these derivative instruments are recognized currently in earnings. We have not designated any derivative instruments as cash flow or fair value hedges and, therefore, do not apply hedge accounting treatment.

In addition, we may have other financial instruments, such as warrants or embedded debt features, that may be classified as liabilities when either (a) the holders possess rights to net cash settlement, (b) physical or net equity settlement is not in our control, or (c) the instruments contain other provisions that cause us to conclude that they are not indexed to our equity. Our

embedded derivatives include: our obligations to repurchase crude oil and refined products from J. Aron at the termination of the Supply and Offtake Agreements and to repay MLC for monthly crude oil and refined product financing under the Washington Refinery Intermediation Agreement and the redemption option and the related make-whole premium on our 5.00% Convertible Senior Notes. These liabilities were initially recorded at fair value and subsequently adjusted to fair value at the end of each reporting period through earnings.

We use the asset and liability method of accounting for income taxes. Under the asset and liability method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and net operating loss (“NOL”) and tax credit carry forwards. Deferred tax assets and liabilities are measured using enacted income tax rates expected to apply to taxable income in the years in which those differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in income tax rates is recognized in the results of operations in the period that includes the enactment date. The realizability of deferred tax assets is evaluated quarterly based on a “more likely than not” standard and, to the extent this threshold is not met, a valuation allowance is recorded.

We have determined that any uncertain tax positions outstanding at December 31, 2019 and 2018 would not have a material impact on our financial condition, results of operations, or cash flows as any uncertain tax positions taken would have been fully covered by the Company’s deferred tax assets related to its historical net operating losses and corresponding valuation allowance.

As a general rule, our open years for Internal Revenue Service (“IRS”) examination purposes are 2016, 2017, and 2018. However, since we have NOL carryforwards, the IRS has the ability to make adjustments to items that originate in a year otherwise barred by the statute of limitations in order to re-determine tax for an open year to which those items are carried. Therefore, in a year in which a NOL deduction is claimed, the IRS may examine the year in which the NOL was generated and adjust it accordingly for purposes of assessing additional tax in the year the net operating loss deduction was claimed. Any penalties or interest as a result of an examination will be recorded in the period assessed.

We recognize the cost of share-based payments on a straight-line basis over the period the employee provides service, generally the vesting period, and include such costs in General and administrative expense (excluding depreciation) and Operating expense (excluding depreciation) in the consolidated statements of operations. We account for forfeitures as they occur. The grant date fair value of restricted stock awards is equal to the market price of our common stock on the date of grant. The fair value of stock options is estimated using the Black-Scholes option-pricing model as of the date of grant. The fair value of the discount offered on the employee stock purchase plan is equal to 15% of the market price of our common stock on the purchase date.

On January 1, 2018, we adopted ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU 2014-09” or “ASC 606”), as amended by other ASUs, using the modified retrospective method applied to all contracts that were not completed as of January 1, 2018. As such, the comparative financial information for prior periods has not been adjusted and continues to be reported under Financial Accounting Standards Board (“FASB”) ASC Topic 605, Revenue Recognition (“ASC 605”). We did not identify any significant differences in our existing revenue recognition policies that require modification under the new standard; therefore, we did not recognize a cumulative adjustment on opening equity as of January 1, 2018.

Our refining and retail segment revenues are primarily associated with the sale of refined products. We recognize revenues upon physical delivery of refined products to a customer, which is the point in time at which control of the refined products is transferred to the customer. The refining segment’s contracts with its customers state the terms of the sale, including the description, quantity, delivery terms, and price of each product sold. Payments from customers are generally due in full within 2 to 30 days of product delivery or invoice date.

We account for certain transactions on a net basis under FASB ASC Topic 845, “Nonmonetary Transactions.” These transactions include nonmonetary crude oil and refined product exchange transactions, certain crude oil buy/sell arrangements, and sale and purchase transactions entered into with the same counterparty that are deemed to be in contemplation with one another.

Upon adoption of ASC 606, we made an accounting policy election to apply the sales tax practical expedient, whereby all taxes assessed by a governmental authority that are both imposed on and concurrent with a revenue-producing transaction and collected from our customers will be recognized on a net basis within Cost of revenues (excluding depreciation). This change in our accounting policy did not have a material impact on our consolidated financial information for the years ended December 31, 2019 and 2018.

Cost of revenues (excluding depreciation) includes the hydrocarbon-related costs of inventory sold, transportation costs of delivering product to customers, crude oil consumed in the refining process, costs to satisfy our RINs obligations, and certain hydrocarbon fees and taxes. Cost of revenues (excluding depreciation) also includes the unrealized gains (losses) on derivatives and inventory valuation adjustments. Certain direct operating expenses related to our logistics segment are also included in Cost of revenues (excluding depreciation).

Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). Fair value measurements are categorized with the highest priority given to unadjusted quoted prices in active markets for identical assets or liabilities and the lowest priority given to unobservable inputs. The three levels of the fair value hierarchy are as follows:

The level in the fair value hierarchy within which the fair value measurement is categorized is based on the lowest level input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of the fair value of assets and liabilities and their placement within the fair value hierarchy levels. Our policy is to recognize transfers in and/or out of fair value hierarchy levels as of the end of the reporting period for which the event or change in circumstances caused the transfer. We have consistently applied these valuation techniques for the periods presented. The fair value of the J. Aron repurchase obligation derivative is measured using estimates of the prices and differentials assuming settlement at the end of the reporting period.

Basic income (loss) per share (“EPS”) is computed by dividing net income (loss) attributable to common stockholders by the sum of the weighted-average number of common shares outstanding and the weighted-average number of shares issuable under the warrants. The common stock warrants are included in the calculation of basic EPS because they are issuable for minimal consideration. Basic and diluted EPS are computed taking into account the effect of participating securities. Participating securities include restricted stock that has been issued but has not yet vested. Please read Note 19—Income (Loss) Per Share for further information.

We may, on occasion, enter into transactions denominated in currencies other than the U.S. dollar, which is our functional currency. Gains and losses resulting from changes in currency exchange rates between the functional currency and the currency in which a transaction is denominated are included in Other income (expense), net, in the accompanying consolidated statement of operations in the period in which the currency exchange rates change.

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). This ASU requires expected credit losses on financial instruments to be recorded over the estimated life of the financial instrument. Prior to this ASU, the guidance required recording of credit losses when those losses were incurred. ASU 2016-13 is applicable to credit losses and allowances on loans, debt securities, trade receivables, net investments in leases, off-balance-sheet credit exposures, reinsurance receivables, and certain other financial assets, but excludes derivative assets under FASB ASC Topic 815 “Derivatives and Hedging.” The guidance in this ASU is effective for fiscal years and interim periods beginning after December 15, 2019, with early adoption permitted, and primarily requires adoption on the modified retrospective transition method. On January 1, 2020, we adopted this ASU and our adoption did not have a material impact on our financial condition, results of operations, cash flows, or related disclosures.

In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment (“ASU 2017-04”), which eliminates Step 2 from the current goodwill impairment test. Under ASU 2017-04, an entity is no longer required to determine goodwill impairment by calculating the implied fair value of goodwill by assigning the fair value of a reporting unit to all of its assets and liabilities as if that reporting unit had been acquired in a business combination. Under ASU 2017-04, an entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value. The guidance in this ASU is effective for fiscal years and interim periods beginning after December 15, 2019, with early adoption permitted. This ASU should be applied prospectively from the date of adoption. This ASU will change the policy under which we perform our annual goodwill impairment assessment by eliminating Step 2 of the test.

In August 2018, the FASB issued ASU No. 2018-13, Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement (“ASU 2018-13”). This ASU amends, adds, and removes certain disclosure requirements under FASB ASC Topic 820 “Fair Value Measurement.” The guidance in ASU 2018-13 is effective for fiscal years and interim periods beginning after December 15, 2019, with early adoption permitted. This ASU will result in expanded disclosures within our interim and annual footnote disclosures, however, we do not expect the adoption of ASU 2018-13 to have a material impact on our financial condition, results of operations, or cash flows.

In August 2018, the FASB issued ASU No. 2018-14, Disclosure Framework—Changes to the Disclosure Requirements for Defined Benefit Plans (“ASU 2018-14”). This ASU amends, adds, and removes certain disclosure requirements under FASB ASC Topic 715 “Compensation—Retirement Benefits.” The guidance in ASU 2018-14 is effective for fiscal years beginning after December 15, 2020, with early adoption permitted. This ASU will result in expanded disclosures within our interim and annual footnote disclosures, however, we do not expect the adoption of ASU 2018-14 to have a material impact on our financial condition, results of operations, or cash flows.

In August 2018, the FASB issued ASU No. 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract (“ASU 2018-15”). This ASU requires entities to account for implementation costs incurred in a cloud computing agreement that is a service contract under the guidance in FASB ASC Topic 350, “Goodwill and Intangible Assets,” which results in a capitalized and amortizable intangible asset. The guidance in ASU 2018-15 is effective for fiscal years and interim periods beginning after December 15, 2019, with early adoption permitted. On January 1, 2020, we adopted ASU 2018-15 under the prospective method and information that was presented prior to January 1, 2020 has not been restated and continues to be reported under the accounting standards in effect for that period. The adoption of ASU 2018-15 did not have a material impact on our financial condition, results of operations, or cash flows.

In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”). The objective of ASU 2019-12 is to simplify the accounting for income taxes by removing certain exceptions to general principles and to clarify and amend guidance to improve consistency under FASB ASC 740 “Income Taxes.” The guidance in ASU 2019-12 is effective for fiscal years beginning after December 15, 2020, with early adoption permitted. We are in the process of determining the method(s) of adoption and the impact this guidance will have on our financial condition, results of operations, and cash flows.

On January 1, 2019, we adopted ASU No. 2016-02, Leases (Topic 842), as amended by other ASUs issued through February 2019 (“ASU 2016-02” or “ASC 842”), using the modified retrospective transition method. Under this optional transition method, information presented prior to January 1, 2019 has not been restated and continues to be reported under the accounting standards in effect for the period. There was no adjustment to our opening retained earnings as a result of the adoption of this ASU.

ASC 842 had a material impact on our consolidated balance sheet; however, it did not materially impact our consolidated statement of operations or statement of cash flows. As a result of the adoption of ASC 842, we recorded ROU assets and lease liabilities related to operating leases of $347 million and $349 million, respectively. Our accounting for finance leases remained substantially unchanged. Additionally, we acquired operating lease assets and lease liabilities of $62 million in connection with the Washington Acquisition (as defined in Note 4—Acquisitions). Please read Note 15—Leases for further disclosures and information.

On January 1, 2019, we adopted ASU No. 2018-02, Income Statement—Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income (“ASU 2018-02”) and elected not to reclassify to retained earnings the stranded effects in Accumulated Other Comprehensive Income related to the changes in the statutory tax rate that were charged to income from continuing operations under the requirements of FASB ASC Topic 740, “Income Taxes.” The adoption of ASU 2018-02 did not have a material impact on our financial condition, results of operations, and cash flows.