Share-based Compensation (Tables)

Weighted-average grant-date fair values of stock options and the assumptions used in estimating the fair values are as follows:



	Year Ended December 31,
	2014			2013			2012
Weighted-average grant-date fair value per share	$	56.15		$	41.52		$	35.69
Expected term (years)	6.25			6.25			6.25
Risk-free interest rate	1.00		%	1.00		%	1.15		%
Expected volatility	63.73		%	66.80		%	70.71		%

The following table summarizes the Company’s stock option activity:



	December 31, 2014
	Number of Shares		Weighted-average Exercise Price		Aggregate Intrinsic Value		Weighted- average Remaining Contractual Term
Outstanding at beginning of year	510		$	35.54
Granted	74		93.34
Exercised	(23	)	33.84
Forfeited	(9	)	59.53
Outstanding at end of year	552		$	42.92	$	4,040	5.9 years
Vested and expected to vest at end of year	547		$	42.61	$	4,040	5.9 years
Exercisable at end of year	344		$	26.85	$	4,040	4.8 years

The following table summarizes the Company’s unvested restricted stock and RSUs activity:



	December 31, 2014
	Number of Shares		Weighted-Average Grant-Date Fair Value
Unvested at beginning of year	97		$	61.48
Granted	37		92.17
Forfeited	(3	)	76.48
Vested	(43	)	53.17
Unvested at end of year	88		$	77.94

The following table summarizes the Company’s performance units activity:



	December 31, 2014
	Number of Shares		Weighted-Average Grant-Date Fair Value
Unvested at beginning of year	86		$	46.94
Granted	16		93.34
Vested	(51	)	36.45
Unvested at end of year	51		$	72.57

The following table summarizes the Company’s leveraged restricted share unit awards activity:



	December 31, 2014
	Number of Shares	Weighted-average Grant-Date Fair Value
Unvested at beginning of year	40	$	74.36
Granted	19	106.90
Unvested at end of year	59	$	84.85