Share Based Compensation (Tables)

6 Months Ended

Jun. 30, 2012

Summary Of Expense Related To Share-Based Payments

The table below summarizes the expense recognized related to share-based payments recognized for the three and six month periods ended June 30 (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2012		2011		2012		2011
Stock options	$	2,349	$	2,594	$	4,626	$	5,054
Restricted stock		1,611		5,248		3,167		6,929
Stock-based compensation	$	3,960	$	7,842	$	7,793	$	11,983

Summary Of Total Unrecognized Compensation Cost Related To Stock-Based Compensation

The following table summarizes the Company’s total unrecognized compensation cost related to stock-based compensation as of June 30, 2012 (in thousands):

	Unrecognized Compensation Cost		Weighted Average Period of Expense Recognition (in Years)
Stock options	$	23,674		2.26
Restricted stock		10,095		1.51
Total	$	33,769

Summary Of Changes In The Number Of Shares Of Common Stock Under Option

The following summarizes the changes in the number of shares of common stock under option for the six month period ended June 30, 2012 (shares and aggregate intrinsic value in thousands):

	Shares			Weighted Average Exercise Price		Options Exercisable at End of Period		Weighted Average Exercise Price of Exercisable Options		Weighted Average Fair Value of Options Granted During the Period	Aggregate Intrinsic Value
Outstanding at December 31, 2011		8,341		$	15.51		4,394	$	10.13		$	119,802
Granted		235			40.65
Exercised		(1,584	)		7.50							43,596
Forfeited		(30	)		10.00
Outstanding at June 30, 2012		6,962		$	18.20		3,339	$	11.83		$	117,228
Expected to vest as of June 30, 2012		6,962		$	18.20

Schedule Of Weighted-Average Assumptions

The fair value of stock option awards granted was estimated using the Black-Scholes option pricing model during the six months ended June 30, 2012 and 2011, with the following weighted-average assumptions for grants during the period.

	Six Months Ended June 30,
	2012	2011
Risk-free interest rate	0.64%	1.78%
Dividend yield	—	—
Expected volatility	34.31%	39.27%
Expected life (in years)	4.0	4.0

Schedule Of Weighted-Average Assumptions

The fair value of restricted stock shares granted which included market conditions during the six months ended June 30, 2011 was estimated using the Monte Carlo option pricing model at the grant date, with the following assumptions.

	Six Months Ended June 30, 2011
Risk-free interest rate	1.25%
Dividend yield	—
Expected volatility	37.00%
Expected life (in years)	0.63

Summary Of Changes In The Number Of Shares Of Restricted Stock And Restricted Stock Units

The following table summarizes the changes in the number of shares of restricted stock and restricted stock units for the six months ended June 30, 2012 (shares in thousands):

	Shares			Weighted Average Grant  Date Fair Value
Unvested at December 31, 2011		840		$	23.15
Granted		66			36.76
Vested		(47	)		29.80
Unvested at June 30, 2012		859		$	23.91