98 years of continued employment. A summary of stock option activity for the year ended December 31, 2012 is as follows (options in thousands and aggregate intrinsic value in millions): W eighted A verage W eighted A verage Remaining Aggregate Options Outstanding Exercise Price Contractual T erm Intrinsic V alue Outstanding at December 31, 2011 1,553.4 $ 32.92 6.8 years $ 4.7 Granted 353.0 32.50     Exercised (14.0 ) 7.53     Forfeited or Expired (77.6 ) 34.06     Outstanding as of December 31, 2012 1,814.8 $ 32.99 5.9 years $ 9.5 Exercisable at December 31, 2012 1,260.1 $ 32.80 4.7 years $ 8.9 Options expected to vest in the next twelve months 286.6 $ 31.96 8.1 years $ 0.6 During the years ended December 31, 2012 , 201 1 and 2010 , the weighted average grant date fair value of options granted was $ 32.50 , $ 24.1 1 and $ 13.91 , respectively , the total intrinsic value of options exercised was $ 0.3 million , $ 2.8 million , and $ 0.6 million , respectively , and the total fair value of options vested during the periods was $ 18.7 million , $ 14.3 million , and $ 1 1.4 million , respectively . At December 31, 2012 and 201 1 , the total compensation cost related to nonvested options not yet recognized was $ 3.4 million and $ 3.3 million with a weighted average expense recognition period of 1.8 years and 1.8  years, respectively . The fair value of each option award is estimated on the date of grant using the Black-Scholes valuation model using the following weighted-average assumptions:   Year Ended   Dec 31, 2012 Dec 31, 2011 Dec 31, 2010 Risk-free interest rate (1) 1.0 % 2.4 % 2.3 % Expected dividend yield (2) 0 N/A N/A Expected option life (3) 5.0 years 5.0 years 5.1 years Expected stock price volatility (4) 68.0 % 65.6 % 65.2 % Weighted average fair value of options granted $ 18.20 $ 24.11 $ 13.91 (1) Risk-fr ee inter est rate — This is the U.S. T reasury rate at the grant date having a term approximately equal to the expected life of the option. An increase in the risk-free interest rate will increase compensation expense. (2) Expected dividend yield — The Company has not made any dividend payments on common stock since 2002 and it does not have plans to pay dividends on common stock in the foreseeable future. Any dividends paid in the future will decrease compensation expense. (3) Expected option life — This is the period of time over which the options granted are expected to remain outstanding and is based on historical experience. Options granted have a maximum term of ten years. An increase in expected life will increase compensation expense. (4) Expected stock price volatility — This is a measure of the amount by which a price has fluctuated or is expected to fluctuate. The Company uses actual historical changes in the market value of the Company’ s stock to calculate the volatility assumption as it is management’ s belief that this is the best indicator of future volatility . An increase in the expected volatility will increase compensation expense. Additional information regarding options outstanding as of December 31, 2012 is as follows (options in thousands): Range of Option Prices Options Outstanding Weighted Average Exercise Price Weighted Average Remaining Contractual Life Options Exercisable Weighted Average Exercise Price $0 -$14 114.7 $ 11.34 1.9 114.7 $ 11.34 $14 - $28 840.2 $ 21.72 5.6 719.5 $ 21.05 $28 -$42 306.7 $ 32.50 9.1 0.7 $ 31.98 $42 - $56 284.0 $ 45.20 6.7 156.0 $ 47.11 $56 - $70 269.2 $ 65.05 3.9 269.2 $ 65.05 Nonvested Stock The majority of the nonvested stock and stock unit awards issued under the 2005 Plan are restricted as to transferability and salability with these restrictions being removed in equal annual installments over the five-year period following the grant date. T able of Contents