Share-based Compensation (Tables)

12 Months Ended

Dec. 31, 2014

The following table summarizes the Company’s stock option activity (in thousands, except per share data and years) for the periods indicated:


	Stock Options Outstanding
	Shares			Weighted Average Exercise Price Per Share		Aggregate Intrinsic Value		Weighted Average Remaining Contractual Term (Years)


Balance as of January 1, 2012		517		$	20.31
Granted		0			0
Exercised		(501	)		20.30	$	51,564
Forfeited/Expired		0			0

Balance as of December 31, 2012		16		$	20.81
Granted		600			92.84
Exercised		(16	)		20.81	$	1,262
Forfeited/Expired		0			0

Balance as of December 31, 2013		600		$	92.84
Granted		745			125.46
Exercised		(9	)		92.84	$	653
Forfeited/Expired		(135	)		104.48

Balance as of December 31, 2014		1,201		$	111.77


Exercisable as of December 31, 2014		141		$	92.84	$	9,794		7.7
Expected to vest as of December 31, 2014		1,060		$	114.29		51,001		9.1

Total		1,201		$	111.77	$	60,795		9.0

Range Of Exercise Prices

Stock options outstanding as of December 31, 2014 are comprised of the following range of exercise prices per share (in thousands, except per share data and years):


	Stock Options Outstanding at December 31, 2014
Range of Exercise Prices per Share	Shares		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Term (Years)


$92.84 - $120.00		596	$	96.34		8.5
$120.01 - $150.00		520	$	121.43		9.3
$150.01 - $160.88		85	$	160.88		9.8

Total		1,201	$	111.77		9.0

Assumptions Used in Black-Scholes Option-Pricing Model

The weighted average grant date fair value of stock option awards using the Black-Scholes option pricing model was $55.84 and $42.03 for each share subject to a stock option granted during the years ended December 31, 2014 and December 31, 2013, respectively, based on the following assumptions:


	Years Ended December 31,
	2014			2013
Expected term of options in years		6.3			6.3
Expected volatility		41.5 - 42.5	%		42.8	%
Risk-free interest rate		2.1 - 2.3	%		2.5	%
Expected dividend yield		0.0	%		0.0	%