Stockholders' Equity

6 Months Ended

Jun. 30, 2020

Stockholders' Equity Note [Abstract]

Stockholders' Equity

(4) Stockholders' Equity

Dividends

On July 13, 2020, our board of directors declared a dividend of $0.25 per share of common stock to be paid in cash on August 25, 2020 to shareholders of record at the close of business on July 28, 2020. Since 2011, we have paid quarterly dividends. Our board of directors currently intends to continue paying quarterly dividends, provided that any future determination as to payment of dividends will depend on the financial condition and results of operations of the company and such other factors as are 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:

	2020		2019
First quarter	$	0.250	0.215
Second quarter	0.250		0.215
Third quarter	0.250		0.220
Fourth quarter			0.220
Total	$	0.750	0.870

Stock Options

The following tables summarize the details of options granted under our stock option plans that were outstanding as of June 30, 2020, 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		June 30, 2020
Date of Grant						Options Outstanding	Options Exercisable
January 2, 2020	902,263	$	38.00	$	37.230	891,871	24,964
January 2, 2019	1,316,924	$	26.00	$	25.705	1,242,736	29,010
January 2, 2018	1,087,936	$	27.50	$	27.270	923,634	297,568
January 3, 2017	1,529,578	$	23.50	$	23.475	1,086,892	472,572
April 19, 2016	1,690,880	$	23.00	$	22.870	1,036,809	537,431
April 21, 2015	1,786,440	$	21.00	$	20.630	689,259	439,859
April 22, 2014	1,910,000	$	28.00	$	25.265	452,323	291,073
April 16, 2013	410,000	$	27.00	$	24.625	63,844	45,106
April 17, 2012	2,470,000	$	27.00	$	24.505	181,440	181,440
Total	13,104,021					6,568,808	2,319,023

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 2, 2020	1.7	%	5.00	2.4	%	25.70	%	$	6.81
January 2, 2019	2.5	%	5.00	2.9	%	23.96	%	$	4.40
January 2, 2018	2.2	%	5.00	2.3	%	23.45	%	$	5.02
January 3, 2017	1.9	%	5.00	2.6	%	24.49	%	$	4.20
April 19, 2016	1.3	%	5.00	2.6	%	26.34	%	$	4.09
April 21, 2015	1.3	%	5.00	2.7	%	26.84	%	$	3.68
April 22, 2014	1.8	%	5.00	2.0	%	28.55	%	$	4.79
April 16, 2013	0.7	%	5.00	1.6	%	37.42	%	$	6.33
April 17, 2012	0.9	%	5.00	1.4	%	39.25	%	$	6.85

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 ten 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, 2020 and 2019 was $2.9 and $2.9, respectively. Unrecognized stock-based compensation expense related to outstanding unvested stock options as of June 30, 2020 was $15.1 and is expected to be recognized over a weighted average period of 4.17 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:

	Six-month Period		Three-month Period
Reconciliation	2020	2019	2020	2019
Basic weighted average shares outstanding	573,550,730	572,669,693	573,197,303	573,159,138
Weighted shares assumed upon exercise of stock options	1,577,540	1,105,366	1,754,697	1,392,211
Diluted weighted average shares outstanding	575,128,270	573,775,059	574,952,000	574,551,349

	Six-month Period			Three-month Period
Summary of Anti-dilutive Options Excluded	2020		2019	2020		2019
Options to purchase shares of common stock	893,428		450,960	895,566		—
Weighted average exercise prices of options	$	38.00	27.53	$	38.00	—

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.