(3) Stockholders' Equity

Dividends

On October 10, 2017, our board of directors declared a dividend of $0.32 per share of common stock. This dividend is to be paid in cash on November 22, 2017 to shareholders of record at the close of business on October 25, 2017. 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:



	2017		2016
First quarter	$	0.32	0.30
Second quarter	0.32		0.30
Third quarter	0.32		0.30
Fourth quarter	0.32		0.30
Total	$	1.28	1.20

Stock Options

The following tables summarize the details of options granted under our stock option plan that were still outstanding as of September 30, 2017, and the assumptions used to value these grants. All such grants 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		September 30, 2017
Date of Grant	Options Granted	Option Exercise (Strike) Price		Closing Stock Price on Date of Grant		Options Outstanding	Options Exercisable
January 3, 2017	764,789	$	47.00	$	46.95	725,542	—
April 19, 2016	845,440	$	46.00	$	45.74	757,522	—
April 21, 2015	893,220	$	42.00	$	41.26	700,746	—
April 22, 2014	955,000	$	56.00	$	50.53	572,500	116,250
April 16, 2013	205,000	$	54.00	$	49.25	104,250	57,250
April 17, 2012	1,235,000	$	54.00	$	49.01	957,938	776,103
April 19, 2011	410,000	$	35.00	$	31.78	72,550	47,550
April 20, 2010	530,000	$	30.00	$	27.13	107,800	82,800
April 21, 2009	790,000	$	27.00	$	17.61	221,650	221,650
Total	6,628,449					4,220,498	1,301,603



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
January 3, 2017	1.9	%	5.00	2.6	%	24.49	%	$	8.40
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

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 nine-month periods ended September 30, 2017 and 2016 was $4.0 and $2.9, respectively. Unrecognized stock-based compensation expense related to outstanding unvested stock options as of September 30, 2017 was $15.9 and is expected to be recognized over a weighted average period of 4.37 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 per share calculation because they were anti-dilutive:



	Nine-month Period		Three-month Period
Reconciliation	2017	2016	2017	2016
Basic weighted average shares outstanding	288,451,470	288,907,934	287,456,943	288,995,492
Weighted shares assumed upon exercise of stock options	140,104	227,908	121,100	154,114
Diluted weighted average shares outstanding	288,591,574	289,135,842	287,578,043	289,149,606



	Nine-month Period			Three-month Period
Summary of Anti-dilutive Options Excluded	2017		2016	2017		2016
Options to purchase shares of common stock	3,881,605		3,061,217	3,848,126		3,335,439
Weighted average exercise price of options	$	49.21	50.17	$	49.18	49.67

Any dilutive impact summarized above related to periods when the average market price of our stock exceeded the exercise price of the potentially dilutive stock options then outstanding.