Intangible assets, including patents, trademarks, and trade names, are carried at cost less accumulated amortization. Intangibles with  determinable lives are amortized using the straight-line method based on the estimated useful life of the intangible. Intangibles with  indeterminable lives, which consist primarily of corporate trade names, are not amortized, but are tested for impairment annually or  whenever events or changes in circumstances indicate that impairment is possible. We review our long-lived assets, including definite-lived intangible assets, for impairment when events or changes in circumstances  indicate that their net book value may not be recovered over their remaining service lives. Indicators of possible impairment may  include significant declines in activity levels in regions where specific assets or groups of assets are located, extended periods of idle  use, declining revenue or cash flow or overall changes in general market conditions. Whenever possible impairment is indicated, we compare the carrying value of the assets to the sum of the estimated undiscounted  future cash flows expected from use, plus salvage value, less the costs of the subsequent disposition of the assets. If impairment is still  indicated, we compare the fair value of the assets to the carrying amount, and recognize an impairment loss for the amount by which  the carrying value exceeds the fair value. We did not record any material impairment charges relating to our long-lived assets held for  use during the years ended December 31, 2013, 2012 and 2011. We record goodwill as the excess of the purchase price over the fair value of the net assets acquired in acquisitions accounted for  under the purchase method of accounting. We test goodwill for impairment annually, or more frequently if circumstances indicate a  possible impairment. We evaluated our goodwill for impairment by comparing the fair value of each of our reporting units, which are our reportable  segments, to their net carrying value as of the balance sheet date. We estimated the fair value of each reporting unit using a  discounted future cash flow analysis. Estimated future cash flows were based on the company’s best estimate of future performance.  Our impairment analysis is quantitative; however, it includes subjective estimates based on assumptions regarding future growth rates,  interest rates and operating expenses. If the carrying value of the reporting unit exceeds the fair value determined, an impairment  loss is recorded to the extent that the implied fair value of the goodwill of the reporting unit is less than its carrying value. We did  not record impairment charges relating to our goodwill or our indefinite-lived intangible assets during the years ended December 31,  2013, 2012 and 2011. We have never identified nor recorded any impairments relating to the goodwill of our current continuing operations. We forecast client demand, considering changes in technology which could result in obsolescence. Our valuation reserve for obsolete  inventory is based on historical regional sales trends, and various other assumptions and judgments including future demand for this  inventory. Our industry is subject to technological change and new product development that could result in obsolete inventory. Our  valuation reserve for obsolete inventory at December 31, 2013 was $2.9 million compared to $3.3 million at December 31, 2012. We maintain a noncontributory defined benefit pension plan for substantially all of our Dutch employees hired before 2007. We utilize  an actuary to assist in determining the value of the projected benefit obligation. This valuation requires various estimates and assump- tions concerning mortality, future pay increases, expected return on plan assets and discount rate used to value our obligations. We  recognize net periodic benefit cost based upon these estimates. As required by current accounting standards, we recognize net periodic  pension costs associated with this plan in income from current operations and recognize the unfunded status of the plan, if any, as a  long-term liability. In addition, we recognize as a component of other comprehensive income, the gains or losses and prior service costs  or credits that arise during the period but are not recognized as components of net periodic pension cost. See Note 10 Pensions and  Other Postretirement Benefit Plans. Furthermore, we sponsor several defined contribution plans for the benefit of our employees. We  expense these contributions in the period the contribution is made. We have two stock-based compensation plans, as described in further detail in Note 13 to our Consolidated Financial Statements.  We evaluate the probability that certain of our stock-based plans will meet targets established within the respective agreements and  result in the vesting of such awards. In addition, we derive an estimated forfeiture rate that is used in calculating the expense for these  awards. For new awards issued and awards modified, repurchased or canceled, the compensation expense is equal to the fair value of  27 Stock-Based Compensation Pensions and Other Postretirement Benefits Obsolete Inventory