Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2012

Stockholders' Equity Note [Abstract]

Summary of Authorized, Issued and Outstanding Shares

Our authorized, issued, and, outstanding shares (stated in whole numbers) at year end consist of the following:



	Par Value	2012	2011
Preferred Stock	.01/share
Authorized		5,000,000	5,000,000
Shares issued and outstanding		—	—
Common Stock	.01/share
Authorized		400,000,000	400,000,000
Shares issued and outstanding		296,564,382	295,258,674

Summary of Stock Option Plan Activity and Summary of Stock Options Granted

A summary of the activity under our stock option plan is as follows:



	Options outstanding		Exercise Price¹		Remaining Life²
Outstanding as of January 1, 2012	5,132,750		$	24.92	4.72
Granted	1,235,000		$	54.00	8.41
Exercised/earned	(1,305,708	)	$	22.70
Cancelled/forfeited	(226,250	)	$	34.12
Outstanding as of December 31, 2012	4,835,792		$	32.51	5.40
Exercisable as of December 31, 2012	1,168,792		$	22.95	3.45



	Options outstanding		Exercise Price¹		Remaining Life²
Outstanding as of January 1, 2011	5,320,000		$	24.03	5.50
Granted	410,000		$	35.00	7.93
Exercised/earned	(397,250	)	22.50
Cancelled/forfeited	(200,000	)	$	26.78
Outstanding as of December 31, 2011	5,132,750		$	24.92	4.72
Exercisable as of December 31, 2011	1,852,750		$	22.50	3.16


¹	Weighted-average exercise price


²	Weighted-average remaining contractual life in years

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		December 31, 2012
Date of grant	Options granted	Option exercise (strike) price		Closing stock price on date of grant		Options outstanding	Options vested
April 17, 2012	1,235,000	$	54.00	$	49.01	1,177,500	—
April 19, 2011	410,000	$	35.00	$	31.78	380,000	—
April 20, 2010	530,000	$	30.00	$	27.13	380,000	—
April 21, 2009	790,000	$	27.00	$	17.61	540,000	—
April 15, 2008	550,000	$	27.00	$	24.35	286,167	116,167
April 17, 2007	4,380,000	$	22.50	$	20.15	2,072,125	1,052,625
Total	7,895,000					4,835,792	1,168,792

Summary of Fair Value Assumptions for Options Granted



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 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
April 17, 2007	4.6	%	4.85	1.0	%	31.59	%	$	5.63

Reconciliation of Denominators used in Computation of Basic and Diluted Earnings per Share



Reconciliation	2012	2011	2010
Basic-weighted average shares outstanding	296,089,348	295,053,790	294,861,424
Weighted shares assumed upon exercise of stock options	1,061,602	814,936	—
Diluted-weighted average shares outstanding	297,150,950	295,868,726	294,861,424

Summary of Anti-Dilutive Options Excluded



Summary of anti-dilutive options excluded	2012		2011	2010
Options to purchase shares of common stock	847,254		704,384	5,328,246
Weighted-average exercise prices of options	$	54.00	32.05	23.94