TD Ameritrade 2018 Annual Report

32 Critical Accounting Policies and Estimates The preparation of our consolidated financial statements requires us to make judgments and estimates that may have a significant impact upon our financial results. Note 1, under Item 8, Financial Statements and Supplementary Data —Notes to Consolidated Financial Statements, of this Form 10-K contains a summary of our significant accounting policies, many of which require the use of estimates and assumptions. We believe that the following areas are particularly subject to management's judgments and estimates and could materially affect our results of operations and financial position. Valuation of goodwill and acquired intangible assets We test goodwill and our indefinite-lived acquired intangible asset for impairment on at least an annual basis, or whenever events occur or changes in circumstances indicate that the carrying values may not be recoverable. In performing the goodwill impairment tests, we utilize quoted market prices of our common stock to estimate the fair value of the Company as a whole. The estimated fair value is then allocated to our reporting unit and is compared with the carrying value of the reporting unit. No impairment charges have resulted from our annual goodwill impairment tests. To determine if the indefinite-lived intangible asset is impaired, we first assess certain qualitative factors. Based on this assessment, if it is determined that more likely than not the fair value of the indefinite-lived intangible asset is less than its carrying amount, we perform a quantitative impairment test. No impairment charges have resulted from the annual indefinite-lived intangible asset impairment tests. We review our finite-lived acquired intangible assets for impairment whenever events occur or changes in circumstances indicate that the carrying amount of such asset may not be recoverable. We evaluate recoverability by comparing the undiscounted cash flows associated with the asset to the asset's carrying amount. We also evaluate the remaining useful lives of intangible assets each reporting period to determine if events or trends warrant a revision to the remaining period of amortization. We have had no events or trends that have warranted a material revision to the originally estimated useful lives. Estimates of effective income tax rates, uncertain tax positions, deferred income taxes and related valuation allowances We estimate our income tax expense based on the various jurisdictions where we conduct business. This requires us to estimate our current income tax obligations and to assess temporary differences between the financial statement carrying amounts and tax bases of assets and liabilities. Temporary differences result in deferred income tax assets and liabilities. We must evaluate the likelihood that deferred income tax assets will be realized. To the extent we determine that realization is not "more likely than not,"we establish a valuation allowance. Establishing or increasing a valuation allowance results in a corresponding increase to income tax expense in our consolidated financial statements. Conversely, to the extent circumstances indicate that a valuation allowance can be reduced or is no longer necessary, that portion of the valuation allowance is reversed, reducing income tax expense. We must make significant judgments to calculate our provision for income taxes, our deferred income tax assets and liabilities and any valuation allowance against our deferred income tax assets. We must also exercise judgment in determining the need for, and amount of, any accruals for uncertain tax positions. Because the application of tax laws and regulations to many types of transactions is subject to varying interpretations, amounts reported in our consolidated financial statements could be significantly changed at a later date upon final determinations by taxing authorities. Accruals for contingent liabilities Accruals for contingent liabilities, such as legal and regulatory claims and proceedings, reflect an estimate of probable losses for each matter. In making such estimates, we consider many factors, including the progress of the matter, prior experience and the experience of others in similar matters, available defenses, insurance coverage, indemnification provisions and the advice of legal counsel and other experts. In many matters, such as those in which substantial or indeterminate damages or fines are sought, or where cases or proceedings are in the early stages, it is not possible to determine whether a loss will be incurred, or to estimate the range of that loss, until the matter is close to resolution, in which case no accrual is made until that time. Because matters may be resolved over long