The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and the 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. We base our estimates on historical experience, currently available information and various other assumptions that we believe are reasonable under the circumstances. Actual results could differ from these estimates.

Investments in non-consolidated affiliates (20-50 percent owned companies and joint ventures) are accounted for using the equity method. Investments through which we are not able to exercise significant influence over the investee and which we do not have readily determinable fair values are generally accounted for under the cost method.

For the years ended December 31, 2019 and 2018, we recorded impairment charges of $927 and $1,373, respectively, related to certain cost-method investments. The aggregate carrying amount of all investments accounted for under the cost method totaled $8,327 and $8,483 at December 31, 2019 and 2018, respectively, and is included in other assets, net, on our consolidated balance sheets.

Trade accounts receivable are recorded at the invoiced amount and do not bear interest. In evaluating the collectability of accounts receivable, we assess a number of factors, including specific customers’ ability to meet their financial obligations to us, the length of time receivables are past due and historical collection experience. Based on these assessments, we may record a reserve for specific customers, as well as a general reserve and allowance for returns and discounts. If circumstances related to specific customers change, or economic conditions deteriorate such that our past collection experience is no longer relevant, our estimate of the recoverability of accounts receivable could be further reduced from the levels provided for in the consolidated financial statements.

We review long-lived assets, including intangible assets subject to amortization, for impairment whenever events or changes in circumstances indicate that the carrying value of the asset may not be recoverable. Recoverability is assessed for the carrying value of assets held for use based on a review of undiscounted projected cash flows. Impairment losses, where identified, are measured as the excess of the carrying value of the long-lived asset over its estimated fair value as determined by discounted projected cash flows. No impairment charges for intangible assets with finite lives were recorded for the years ended December 31, 2019 and 2018.

Goodwill is the excess of cost of an acquired entity over the amounts assigned to assets acquired and liabilities assumed in a business combination. Goodwill is not amortized. Goodwill is tested for impairment annually in the fourth quarter of each year, and is tested for impairment between annual tests if an event occurs or circumstances change that would indicate the carrying amount may be impaired. Impairment testing for goodwill is done at a reporting unit level, with all goodwill assigned to a reporting unit.

The test for goodwill impairment is a two-step process, first to identify potential goodwill impairment for each reporting unit, and then, if necessary, measure the amount of the impairment loss. Our reporting units are consistent with our geographies in Note 21. We completed the required annual goodwill impairment test during the fourth quarter of 2019. The first step of the goodwill impairment test compared the fair value of each of our reporting units to their carrying value. We estimated the fair value of our reporting units based primarily on the discounted projected cash flows of the underlying operations. The estimated fair value for each of our reporting units was in excess of their respective carrying values as of December 31, 2019.

Owners of noncontrolling interests in a certain subsidiary held the right to require us to acquire either a portion of or all of the remaining ownership interests held by them. The owners’ ability to exercise the “put option” right was subject to the satisfaction of certain conditions, including conditions requiring notice in advance of exercise and timing restrictions of the exercise date. The “put option” right was recorded as mezzanine equity on the consolidated balance sheet at December 31, 2018 at its estimated redemption amount.

On November 19, 2019, we and the noncontrolling interest owners entered into an agreement to amend and restate the subsidiary's operating agreement, specifically amending the terms to the “put option” right and the exercise procedures thereof. On November 25, 2019, the noncontrolling interest owners exercised the “put option” right for all of the remaining ownership

Local currencies generally are considered the functional currencies outside the United States. Assets and liabilities for operations in local-currency environments are translated at month-end exchange rates of the period reported. Income and expense items are translated at average exchange rates of each applicable month. Cumulative translation adjustments are recorded as a component of accumulated other comprehensive income (loss) in shareholders’ equity.

We are exposed to market risk from changes in interest rates, foreign currency exchange rates and commodity prices, which may adversely affect our results of operations and financial condition. We seek to minimize these risks through regular operating and financing activities and, when we consider it to be appropriate, through the use of derivative financial instruments. We do not purchase, hold or sell derivative financial instruments for trading or speculative purposes.

We use derivative financial instruments to manage our exposure to changes in interest rates on outstanding debt instruments. In doing so, we have elected to prepare and maintain the documentation to qualify for hedge accounting treatment under ASC 815, “Derivatives and Hedging,” and therefore, related gains and losses (realized or unrealized) related to derivative instruments are recognized in accumulated other comprehensive income (loss) and are reclassified into earnings when the underlying transaction is recognized in net earnings and, depending on the fair value at the end of the reporting period, derivatives are recorded either in prepaid and other current assets or in accrued liabilities in the consolidated balance sheets.

We and our subsidiaries conduct business in various countries using both their functional currencies and other currencies to effect cross border transactions. As a result, we and our subsidiaries are subject to the risk that fluctuations in foreign exchange rates between the dates that those transactions are entered into and their respective settlement dates will result in a foreign exchange gain or loss. When practicable, we endeavor to match assets and liabilities in the same currency on our U.S. balance sheet and those of our subsidiaries in order to reduce these risks. We, when we consider it to be appropriate, enter into foreign currency contracts to hedge the exposure arising from those transactions. See Note 13. For our hedges of foreign exchange rates and commodity prices, we have elected to not prepare and maintain the documentation to qualify for hedge accounting treatment under ASC 815, “Derivatives and Hedging,” and therefore, changes in fair value are recognized in interest and other expense, net in the consolidated statements of operations and comprehensive loss and, depending on the fair value at the end of the reporting period, derivatives are recorded either in prepaid and other current assets or in accrued liabilities in the consolidated balance sheets.

We sponsor a retirement benefit for one of our non-U.S. subsidiaries in the form of a defined benefit pension plan. Accounting standards require the cost of providing this pension benefit be measured on an actuarial basis. Actuarial gains and losses resulting from both normal year-to-year changes in valuation assumptions and differences from actual experience are deferred and amortized. The application of these accounting standards require us to make assumptions and judgements that can significantly affect these measurements. Our critical assumptions in performing these actuarial valuations include the selection of the discount rate to determine the present value of the pension obligations that affects the amount of pension expense recorded in any given period. Changes in the discount rate could have a material effect on our reported pension obligations and related pension expense. See Note 16.

We recognize compensation expense for our stock-based compensation programs, which include stock options, restricted stock, restricted stock units (“RSU”) and performance shares. For service-based awards, stock-based compensation is estimated at the grant date based on the fair value of the awards expected to vest and recognized as expense ratably over the requisite service period of the award. For stock options and awards with market conditions, compensation cost is determined at the individual tranche level. We recognize forfeitures when they occur.

Income taxes are accounted for under the asset and liability method. Deferred income 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 tax benefit carryforwards. Deferred income tax liabilities and assets at the end of each period are determined using enacted tax rates.

We establish a valuation allowance for those jurisdictions in which the expiration date of tax benefit carryforwards or projected taxable earnings leads us to conclude that it is “more likely than not” that a deferred tax asset will not be realized. The evaluation process includes the consideration of all available evidence regarding historical results and future projections including the estimated timing of reversals of existing taxable temporary differences and potential tax planning strategies. Once a valuation allowance is established, it is maintained until a change in factual circumstances gives rise to sufficient income of the appropriate character and timing that will allow a partial or full utilization of the deferred tax asset.

On January 1, 2019, we adopted the FASB ASU No. 2016-02, “Leases (Topic 842),” which requires the recognition of right-of-use (“ROU”) assets and related operating and finance lease liabilities on the balance sheet. We adopted ASU 2016-02 effective January 1, 2019 using the cumulative-effect adjustment transition method, which applies the provisions of the standard at the effective date without adjusting the comparative periods presented. As permitted under ASU 2016-02, we applied the practical expedients that allowed us to not (1) reassess historical lease classifications, (2) recognize short-term leases on the balance sheet, nor (3) separate lease and non-lease components for its real estate leases. As a result of the adoption of ASU 2016-02 on January 1, 2019, we recorded operating lease liabilities and ROU assets of $38,415. The adoption of ASU 2016-02 had an immaterial impact on our consolidated statement of operations and consolidated statement of cash flows for the year ended December 31, 2019. For additional information about leases, see Note 5.

In August 2017, the FASB issued ASU No. 2017-12, “Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities” (“ASU 2017-12”), in order to create more transparency around how economic results are presented within both the financial statements and in the footnotes and to better align the results of cash flow and fair value hedge accounting with risk management activities. ASU 2017-12 is effective for fiscal years beginning after December 15, 2018, with early adoption permitted. We adopted ASU 2017-12 in the third quarter of 2019 and the implementation of this guidance did not have a material effect on our consolidated financial statements.

In August 2018, the FASB issued ASU 2018-15, “Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40),” which aligns the requirements for capitalizing implementation costs incurred in a service contract hosting arrangement with those of developing or obtaining internal-use software. This standard is effective for interim and annual reporting periods beginning after December 15, 2019, and early adoption is permitted. We have elected not to adopt the provisions of this ASU early and are evaluating the impact the new standard will have on our consolidated financial statements.

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 the performance of Step 2 from the goodwill impairment test. In performing its annual or interim impairment testing, an entity will instead compare the fair value of the reporting unit with its carrying amount and recognize any impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value. Additionally, an entity should consider income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit when measuring the goodwill impairment loss. The standard is effective for fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual impairment tests performed on testing dates after January 1, 2017. We have elected not to adopt the provisions of this standard early.

In June 2016, the FASB issued ASU 2016-13, “Measurement of Credit Losses on Financial Instruments” (“ASU 2016-13”), which provides guidance regarding the measurement of credit losses for financial assets and certain other instruments that are not accounted for at fair value through net income, including trade and other receivables, debt securities, net investment in leases, and off-balance sheet credit exposures. The new guidance requires companies to replace the current incurred loss impairment methodology with a methodology that measures all expected credit losses for financial assets based on historical experience, current conditions, and reasonable and supportable forecasts. The guidance expands the disclosure requirements regarding credit losses, including the credit loss methodology and credit quality indicators. In May 2019, the FASB issued ASU 2019-05, “Financial Instruments—Credit Losses (Topic 326),” which provides transition relief to entities adopting ASU 2016-13 by allowing entities to elect the fair value option on certain financial instruments. ASU 2016-13 will be effective for annual reporting periods, including interim reporting within those periods, beginning after December 15, 2019. Early adoption is permitted for annual reporting periods, including interim periods after December 15, 2018 and will be applied using a modified retrospective approach. We elected not to early adopt the provisions of this ASU and we do not expect there to be a material impact to the consolidated financial statements upon adoption of this standard in 2020.

In December 2019, the FASB issued ASU 2019-12, “Income Taxes (Topic 740) - Simplifying the Accounting for Income Taxes,” which simplifies the accounting for income taxes by eliminating some exceptions to the general approach in Accounting Standards Codification 740, Income Taxes. It also clarifies certain aspects of the existing guidance to promote more consistent application. This standard is effective for calendar-year public business entities in 2021 and interim periods within that year, and early adoption is permitted. We are currently not early adopting and are in the process of evaluating the impact the new standard will have on our consolidated financial statements.