Share Based Compensation (Tables)

12 Months Ended

Dec. 31, 2013

Summary of Expense Related to Share-Based Payments

The table below summarizes the expense related to share-based payments for the years ended December 31 (in thousands):

	2013		2012		2011
Stock options	$	11,677	$	10,341	$	9,654
Restricted stock		14,999		8,934		12,089
Stock-based compensation	$	26,676	$	19,275	$	21,743

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 December 31, 2013:

	Unrecognized Compensation Cost		Weighted Average Period of Expense Recognition (in Years)
Stock options	$	22,492		1.71
Restricted stock		22,312		1.04
Total	$	44,804

Summary of Changes in 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 following periods (shares and aggregate intrinsic value in thousands):

	Shares			Weighted Average Exercise Price		Options Exercisable at End of Year		Weighted Average Exercise Price of Exercisable Options		Weighted Average Fair Value of Options Granted During the Year		Aggregate Intrinsic Value
Outstanding at December 31, 2010		10,229		$	12.79		5,168	$	6.06			$	128,472
Granted		526			30.56					$	9.72
Exercised		(2,008	)		4.51								50,921
Forfeited		(406	)		20.96
Outstanding at December 31, 2011		8,341			15.51		4,394		10.13				119,802
Granted		1,223			36.94						10.82
Exercised		(2,925	)		9.38								129,488
Forfeited		(74	)		20.43
Outstanding at December 31, 2012		6,565			22.17		2,666		14.71				206,636
Granted		307			80.77						23.00
Exercised		(1,425	)		21.13								136,807
Forfeited		(116	)		28.68
Outstanding at December 31, 2013		5,331			25.68		2,589		16.57				487,673
Vested and expected to vest at December 31, 2013		5,331		$	25.68

Schedule of Weighted-Average Assumptions

The fair value of restricted stock shares based on market conditions was estimated using the Monte Carlo option pricing model with the following assumptions during 2013 and 2011. There were no restricted stock shares granted based on market conditions in 2012.

	2013			2011
Risk-free interest rate		0.42	%		1.25	%
Dividend yield		—			—
Expected volatility		30.00	%		37.00	%
Expected life (in years)		1.75			0.63

Summary of Changes in 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 following periods (shares in thousands):

	Shares			Weighted Average Grant Date Fair Value
Outstanding at December 31, 2010		1,250		$	21.93
Granted		261			31.08
Cancelled		(50	)		21.00
Sold/issued		(621	)		23.12
Outstanding at December 31, 2011		840			23.15
Granted		131			41.69
Cancelled		(25	)		33.49
Issued		(474	)		22.05
Outstanding at December 31, 2012		472			28.98
Granted		358			92.16
Cancelled		(31	)		35.42
Issued		(165	)		30.93
Outstanding at December 31, 2013		634		$	67.83

Stock Options [Member]

Schedule of Stock Options Exercise Price

The following table summarizes information about stock options outstanding at December 31, 2013 (shares in thousands):

Exercise Price	Options Outstanding		Weighted Average Remaining Vesting  Life in Years		Options Exercisable
$1.20 – 6.548		517		—		517
10.00 – 14.00		832		—		832
18.00 – 20.00		287		1.00		142
23.00		1,980		1.38		754
27.83 – 34.72		290		1.44		108
35.04 – 40.65		1,070		2.48		236
47.63 – 58.02		108		2.96		—
74.99 – 87.61		212		3.46		—
111.09		35		3.81		—
		5,331				2,589

Schedule of Weighted-Average Assumptions

The fair value of stock option awards granted was estimated using the Black-Scholes option pricing model with the following weighted-average assumptions for the years ended December 31 as follows:

	2013			2012			2011
Risk-free interest rate		0.76	%		0.59	%		1.47	%
Dividend yield		—			—			—
Expected volatility		34.95	%		36.49	%		37.83	%
Expected life (in years)		4.00			4.00			4.03