can be given with respect to the final outcome of these matters. We adjust reserves for our uncertain tax positions due to changing facts and circumstances, such as the closing of a tax audit, judicial rulings, refinement of estimates or realization of earnings or deductions that differ from our estimates. To the extent that the final outcome of these matters is different than the amounts recorded, such differences generally will impact our provision for income taxes in the period in which such a determination is made. Our provisions for income taxes include the impact of reserve provisions and changes to reserves that are considered appropriate and also include the related interest and penalties.

In addition, as a part of our accounting for business combinations, intangible assets are recognized at fair values and goodwill is measured as the excess of consideration transferred over the net estimated fair values of assets acquired. Impairment charges associated with goodwill are generally not tax deductible and will result in an increased effective income tax rate in the period that any impairment is recorded. Amortization expenses associated with acquired intangible assets are generally not tax deductible pursuant to our existing tax structure; however, deferred taxes have been recorded for non-deductible amortization expenses as a part of the accounting for business combinations. We have taken into account the allocation of these identified intangibles among different taxing jurisdictions, including those with nominal or zero percent tax rates, in establishing the related deferred tax liabilities.

Legal and Other Contingencies

We are currently involved in various claims and legal proceedings. Quarterly, we review the status of each significant matter and assess our potential financial exposure. A description of our accounting policies associated with contingencies assumed as a part of a business combination is provided under “Business Combinations” above. For legal and other contingencies that are not a part of a business combination, we accrue a liability for an estimated loss if the potential loss from any claim or legal proceeding is considered probable and the amount can be reasonably estimated. Significant judgment is required in both the determination of probability and the determination as to whether the amount of an exposure is reasonably estimable. Because of uncertainties related to these matters, accruals are based only on the best information available at the time the accruals are made. As additional information becomes available, we reassess the potential liability related to our pending claims and litigation and may revise our estimates. Such revisions in the estimates of the potential liabilities could have a material impact on our results of operations and financial position.

Stock-Based Compensation

We account for share-based payments to employees, including grants of employee stock options, restricted stock-based awards and purchases under employee stock purchase plans, in accordance with ASC 718, Compensation—Stock Compensation, which requires that share-based payments (to the extent they are compensatory) be