Share Based Compensation (Tables)

12 Months Ended

Dec. 31, 2011

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule Of Expense Related To Share-Based Payments

	2011		2010		2009
Stock options	$	9,654	$	3,775	$	2,666
Restricted stock		12,089		22,980		—
Stock-based compensation	$	21,743	$	26,755	$	2,666

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

	Unrecognized Compensation Cost		Weighted Average Period of Expense Recognition (in Years)
Stock options	$	25,765		1.97
Restricted stock		15,102		1.88
Total	$	40,867

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

	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, 2008		7,595		$	6.55		4,375	$	3.82			$	76,629
Granted		1,375			11.46					$	2.96
Exercised		(215	)		1.23								3,608
Forfeited		(693	)		7.42
Outstanding at December 31, 2009		8,062			7.45		5,523		5.15				70,958
Granted		3,724			22.56						9.19
Exercised		(143	)		5.04								3,697
Forfeited		(729	)		11.95
Tendered		(685	)		5.63
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
Vested and expected to vest at December 31, 2011		8,341		$	15.51

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

	Shares			Weighted Average Grant Date Fair Value
Outstanding at December 31, 2008		3,225			2.17
Granted		853			11.35
Cancelled		(63	)		14.00
Outstanding at December 31, 2009		4,015			4.41
Granted		1,475			22.68
Cancelled		(263	)		15.24
Sold/issued		(3,977	)		4.40
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

Stock Options [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule Of Stock Options Exercise Price

Exercise Price	Options Outstanding		Weighted Average Remaining Vesting  Life in Years		Options Exercisable
$0.15		52		—		52
1.20 – 1.56		176		—		176
2.00 – 2.31		810		—		810
5.20		705		—		705
6.55		13		—		13
10.00 – 10.07		1,224		0.69		792
12.00 – 14.00		1,504		0.22		1,225
18.00		108		1.96		52
20.00		414		3.31		81
23.00		2,809		3.31		419
27.37 – 27.83		136		3.82		—
29.00 – 29.90		227		3.13		53
33.49 – 34.72		163		3.65		16
		8,341				4,394

Schedule Of Weighted-Average Assumptions

	2011			2010			2009
Risk-free interest rate		1.47	%		1.93	%		2.61	%
Dividend yield		—			—			—
Expected volatility		37.83	%		44.53	%		31.14	%
Expected life (in years)		4.03			4.19			3.33

Restricted Stock [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule Of Weighted-Average Assumptions

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