Stock-based compensation expense recognized in 2013, 2012 and 2011 was approximately $9.1 million, $9.3 million and $9.2 million, respectively. As of December 31, 2013, total compensation cost related to non-vested stock options, restricted stock units and restricted stock not yet recognized was approximately $18.8 million, which is expected to be recognized over an average remaining recognition period of 2.7 years. See Note 3 of Notes to Consolidated Financial Statements for additional information. We review long-lived assets used in operations for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable and the undiscounted cash flows estimated to be generated by the asset are less than the asset’s carrying value. An impairment loss would be recognized in the amount by which the recorded  value of the asset exceeds the fair value of the asset, measured by the quoted market price of an asset or an estimate based on  the best information available in the circumstances. There were no impairment losses recognized during 2013, 2012 or 2011. We evaluate the carrying value of goodwill during the fourth quarter of each year and between annual evaluations if events  occur or circumstances change that would more likely than not reduce the fair value of the reporting unit below its carrying  amount. When evaluating whether goodwill is impaired, we first assess qualitative factors to determine whether it is necessary  to perform the two-step quantitative goodwill impairment test. If we determine that the two-step quantitative test is necessary,  then we compare the fair value of the reporting unit to which the goodwill is assigned to the reporting unit’s carrying amount,  including goodwill. If the carrying amount of the reporting unit exceeds its fair value, then the amount of the impairment loss is measured. There were no impairment losses recognized during 2013, 2012 or 2011. Purchased intangible assets with  finite lives are carried at cost, less accumulated amortization. Amortization is recorded over the estimated useful lives of the  respective assets, which is 2.5 to 14 years. Research and development costs include compensation for engineers and support personnel, outside contracted services,  depreciation and material costs associated with new product development, the enhancement of current products, and product cost reductions. We continually evaluate new product opportunities and engage in intensive research and product  development efforts. Research and development costs totaled $131.1 million, $126.0 million and $100.3 million for the years  ended December 31, 2013, 2012 and 2011, respectively. Other comprehensive income consists of unrealized gains (losses) on available-for-sale securities, reclassification adjustments  for amounts included in net income related to impairments of available-for-sale securities and realized gains (losses) on  available-for-sale securities, defined benefit plan adjustments and foreign currency translation adjustments. The following tables present changes in accumulated other comprehensive income, net of tax, by component for the years  ended December 31, 2011, 2012 and 2013: Other Comprehensive Income Research and Development Costs Impairment of Long-Lived Assets Goodwill and Purchased Intangible Assets Financial Results 43 (In thousands) Unrealized Gains (Losses) on Available-for-Sale Securities Defined Benefit Plan Adjustments Foreign Currency Adjustments Total Balance at December 31, 2010 $23,852 — $3,096 $26,948 Other comprehensive loss before reclassifications (6,784) — (154) (6,938) Amounts reclassified from accumulated other  comprehensive income (6,908) — — (6,908) Balance at December 31, 2011 $10,160 — $2,942 $13,102 Other comprehensive income (loss) before reclassifications 5,426 (1,952) 170 3,644 Amounts reclassified from accumulated other  comprehensive income (5,478) — — (5,478) Balance at December 31, 2012 $10,108 $(1,952) $3,112 $11,268 Other comprehensive income (loss) before reclassifications 5,508 1,061 (2,205) 4,364 Amounts reclassified from accumulated other  comprehensive income (4,879) — — (4,879) Balance at December 31, 2013 $10,737 $(891) $907 $10,753