Stockholders' Equity | (2) Stockholders’ Equity Dividends On July 11, 2016 , our board of directors declared a dividend of $0.30 per share of common stock. This dividend is to be paid in cash on August 23, 2016 to shareholders of record at the close of business on July 26, 2016 . Since 2011, we have paid quarterly dividends. Our board of directors expects to continue paying quarterly dividends, provided the future determination as to payment of dividends will depend on the financial needs of the Company and such other factors as deemed relevant by the board of directors. The following table presents the dividends either paid previously or declared by our board of directors for future payment on a per share basis: 2016 2015 First quarter $ 0.30 0.28 Second quarter 0.30 0.28 Third quarter 0.30 0.28 Fourth quarter 0.28 Total $ 0.90 1.12 Stock Options The following tables summarize the details of grants made under our stock option plan that are still outstanding, and the assumptions used to value these grants. All options granted were effective at the close of business on the date of grant. Options Granted Option Exercise (Strike) Price Closing Stock Price on Date of Grant June 30, 2016 Date of Grant Options Outstanding Options Exercisable April 19, 2016 845,440 $ 46.00 $ 45.74 819,466 — April 21, 2015 893,220 $ 42.00 $ 41.26 775,020 — April 22, 2014 955,000 $ 56.00 $ 50.53 642,500 10,000 April 16, 2013 205,000 $ 54.00 $ 49.25 115,000 2,500 April 17, 2012 1,235,000 $ 54.00 $ 49.01 1,015,250 617,500 April 19, 2011 410,000 $ 35.00 $ 31.78 200,800 163,300 April 20, 2010 530,000 $ 30.00 $ 27.13 181,725 121,725 April 21, 2009 790,000 $ 27.00 $ 17.61 252,650 208,900 April 15, 2008 550,000 $ 27.00 $ 24.35 114,100 114,100 Total 6,413,660 4,116,511 1,238,025 Date of Grant Risk-free Interest Rate Expected Life of Option in Years Expected Dividend Yield Expected Stock Volatility Estimated Fair Value of Stock Option April 19, 2016 1.3 % 5.00 2.6 % 26.34 % $ 8.18 April 21, 2015 1.3 % 5.00 2.7 % 26.84 % $ 7.35 April 22, 2014 1.8 % 5.00 2.0 % 28.55 % $ 9.57 April 16, 2013 0.7 % 5.00 1.6 % 37.42 % $ 12.66 April 17, 2012 0.9 % 5.00 1.4 % 39.25 % $ 13.69 April 19, 2011 2.1 % 5.00 1.6 % 39.33 % $ 11.20 April 20, 2010 2.6 % 5.00 1.5 % 39.10 % $ 8.14 April 21, 2009 1.9 % 5.00 1.0 % 38.80 % $ 3.64 April 15, 2008 2.7 % 5.00 1.0 % 30.93 % $ 7.75 All of the options in the tables above vest and become exercisable over a period of up to eight years . Generally, each option will terminate approximately nine years after the grant date. The fair value of each share-based option is estimated on the date of grant using a Black-Scholes valuation method that uses the assumptions listed above. The risk-free interest rate is based on the U.S. Treasury rate over the expected life of the option at the time of grant. The expected life is the average length of time over which we expect the employee groups will exercise their options, which is based on historical experience with similar grants. The dividend yield is estimated over the expected life of the option based on our current dividend payout, historical dividends paid, and expected future cash dividends. Expected stock volatilities are based on the movement of our stock price over the most recent historical period equivalent to the expected life of the option. Compensation expense equal to the grant date fair value is recognized for all of these awards over the vesting period. The stock-based compensation expense for the six -month periods ended June 30, 2016 and 2015 was $1,700 and $3,441 , respectively. Unrecognized stock-based compensation expense related to outstanding unvested stock options as of June 30, 2016 was $16,993 and is expected to be recognized over a weighted average period of 4.90 years . Any future changes in estimated forfeitures will impact this amount. Earnings Per Share The following tables present a reconciliation of the denominators used in the computation of basic and diluted earnings per share and a summary of the options to purchase shares of common stock which were excluded from the diluted earnings calculation because they were anti-dilutive: Six-month Period Three-month Period Reconciliation 2016 2015 2016 2015 Basic weighted average shares outstanding 288,863,482 293,191,566 288,918,945 291,176,985 Weighted shares assumed upon exercise of stock options 268,820 678,586 200,525 653,152 Diluted weighted average shares outstanding 289,132,302 293,870,152 289,119,470 291,830,137 Six-month Period Three-month Period Summary of Anti-dilutive Options Excluded 2016 2015 2016 2015 Options to purchase shares of common stock 2,941,864 2,395,247 3,253,343 2,724,639 Weighted average exercise price of options $ 50.39 $ 52.97 $ 49.91 $ 51.56 Any dilutive impact summarized above relates to periods when the average market price of our stock exceeded the exercise price of the potentially dilutive option securities then outstanding. |