Common Stock (Tables)

12 Months Ended

Dec. 31, 2014

The following schedule provides information related to our stock repurchase program for each of the three years ended December 31, 2014. All of the shares repurchased during 2013 and 2012 related to income tax withholding obligations resulting from the exercise of stock options and the vesting of restricted stock grants. No shares were repurchased during 2013 or 2012 pursuant to our publicly announced stock repurchase program. During 2014, 548,192 shares ($58.0 million in the aggregate) were repurchased pursuant to the terms of our recently authorized stock repurchase program and 480,972 shares ($42.7 million in the aggregate) were repurchased in connection with income tax withholding obligations resulting from the exercise of stock options and the vesting of restricted stock grants.


	Additional dollars authorized for repurchase (in thousands)		Total number of shares purchased		Total number of shares cancelled		Average price paid per share for forfeited restricted shares	Total number of shares purchased as part of publicly announced programs		Average price pad per share for shares purchased as part of publicly announced program		Aggregate purchase price paid (in thousands)		Aggregate purchase price paid for shares purchased as part of publicly announced program		Maximum number of shares that may yet be purchased under the program		Maximum number of dollars that may yet be purchased under the program (in thousands)
Balance as of January 1, 2012																	767,704		N/A
2012		—		433,312		—	N/A		—		N/A	$	19,154		N/A		767,704		N/A
2013		—		427,170		—	N/A		—		N/A	$	27,201		N/A		767,704		N/A
2014	$	400,000		1,029,164		767,704	N/A		548,192	$	105.71	$	100,749	$	57,950		N/A	$	342,050

Total for three year period ended December 31, 2014	$	400,000		1,889,646		767,704	N/A		548,192	$	105.71	$	147,104	$	57,950

Weighted-Average Assumptions Fair Value of Option Grants

The weighted-average assumptions reflected below were based upon twenty-one options grants for the five-year period ending December 31, 2014 and eighteen option grants for each of the five-year periods ended December 31, 2013 and 2012.


Year Ended December 31,	2014			2013			2012
Volatility		35	%		36	%		33	%
Interest rate		1	%		1	%		1	%
Expected life (years)		3.4			3.6			3.5
Forfeiture rate		10	%		11	%		10	%
Dividend yield		0.4	%		0.5	%		0.6	%

Stock Option Activity

The table below summarizes our stock option activity during each of the last three years:


Outstanding Options	Number of Shares			Average Option Price		Range (High-Low)
Balance, January 1, 2012		7,558,945		$	31.63	$	54.79-$16.22
Granted		2,966,850		$	37.01	$	44.83-$36.95
Exercised		(2,608,007	)	$	23.22	$	46.97-$16.22
Cancelled		(481,550	)	$	38.00	$	46.97-$16.22

Balance, January 1, 2013		7,436,238		$	36.31	$	54.79-$16.22
Granted		2,889,750		$	53.51	$	79.79-$53.38
Exercised		(2,288,666	)	$	32.27	$	54.79-$16.22
Cancelled		(416,364	)	$	43.93	$	53.38-$16.22

Balance, January 1, 2014		7,620,958		$	43.63	$	79.79-$30.32
Granted		2,845,500		$	78.65	$	102.21-$78.17
Exercised		(2,277,469	)	$	38.50	$	73.65-$30.32
Cancelled		(291,538	)	$	55.63	$	78.17-$36.95

Balance, December 31, 2014		7,897,451		$	57.29	$	102.21-$36.95

Outstanding options vested and exercisable as of December 31, 2014		1,412,422		$	43.59	$	79.79-$36.97

Information about Unvested Options

The following table provides information about unvested options for the year December 31, 2014:


	Shares			Weighted Average Grant Date Fair Value
Unvested options as of January 1, 2014		5,864,830		$	12.12
Granted		2,845,500		$	17.23
Vested		(1,937,013	)	$	11.90
Cancelled		(288,288	)	$	13.64

Unvested options as of December 31, 2014		6,485,029		$	14.36

Information about all Outstanding Options

The following table provides information regarding all options outstanding at December 31, 2014:


	Options Outstanding		Options Exercisable
Number of options outstanding		7,897,451		1,412,422
Weighted average exercise price	$	57.29	$	43.59
Aggregate intrinsic value as of December 31, 2014	$	426,248,728	$	95,577,868
Weighted average remaining contractual life		2.9		1.8

Weighted Average Remaining Contractual Life for Options Outstanding and Weighted Average Exercise Price Per Share for Exercisable Options

The weighted average remaining contractual life for options outstanding and weighted average exercise price per share for exercisable options at December 31, 2014 were as follows:


Exercise Price	Options Outstanding		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Life (in Years)		Exercisable Options		Weighted Average Exercise Price Per Share		Expected to Vest Options (a)		Weighted Average Exercise Price Per Share
Exercise Price	Shares		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Life (in Years)		Shares		Weighted Average Exercise Price Per Share		Shares		Weighted Average Exercise Price Per Share
$36.95 – $43.46		1,690,463	$	37.00		2.0		465,688	$	37.02		1,100,460	$	36.99
$43.67 – $46.97		1,201,213		43.68		1.0		647,025		43.67		497,938		43.68
$53.38 – $73.65		2,241,625		53.52		3.0		299,209		53.58		1,745,261		53.51
$78.17 – $102.21		2,764,150		78.66		4.2		500		79.79		2,483,140		78.66

Total		7,897,451	$	57.29		2.9		1,412,422	$	43.59		5,826,799	$	60.27

(a)	Assumes a weighted average forfeiture rate of 10.2%.