Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2012

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Share Based Compensation and Related Benefits

In 2012, 2011 and 2010, we recorded share-based compensation and related benefits as follows:

	Year ended December 31,
(Dollars in thousands)	2012			2011			2010
Share-based compensation expense	$	21,861		$	18,221		$	13,761
Income tax benefit related to share-based compensation expense	(6,011		)	(4,833		)	(3,400		)
Capitalized compensation costs	2,647			1,466			996

Unrecognized Share Based Compensation Expense

As of December 31, 2012, unrecognized share-based compensation expense was as follows:

(Dollars in thousands)	Unrecognized   Expense		Average Expected Recognition   Period - in Years
Stock options	$	15,464	2.61
Restricted stock units	24,187		2.69
Total unrecognized share-based compensation expense	$	39,651

Weighted Average Assumptions and Fair Values Used for Employee Stock Options and Restricted Stock Units

The following weighted average assumptions and fair values were used for our employee stock options and restricted stock units:

Equity incentive plan awards	2012			2011			2010
Weighted average expected term of options in years	4.6			4.6			4.5
Weighted average expected volatility of the Company's underlying common stock	50.4		%	48.7		%	45.1		%
Risk-free interest rate	0.83			2.00			2.23
Expected dividend yield	—		%	—		%	—		%
Weighted average grant date fair value-stock options	$	27.00		$	25.12		$	19.15
Weighted average grant date fair value-restricted stock units	63.07			59.69			46.96

Weighted Average Assumptions and Fair Values Used for ESPP

The following weighted average assumptions and fair values were used for our ESPP:

ESPP	2012			2011			2010
Expected term in years	0.5			0.5			0.5
Weighted average expected volatility of the Company's underlying common stock	43.5		%	27.3		%	36.7		%
Risk-free interest rate	0.11			0.15			0.22
Expected dividend yield	—			—			—
Weighted average fair value	$	14.43		$	13.02		$	10.22

Stock Option Information Related to Equity Incentive Plan

The table below provides stock option information related to the 1997 Equity Incentive Plan and the 2006 Equity Incentive Plan for the year ended December 31, 2012:

	Options		Weighted Average  Exercise Price		Weighted Average Remaining Contractual   Life in Years	Aggregate   Intrinsic Value   of In-The- Money Options
Outstanding at December 31, 2011	2,439,360		$	42.64
Granted	399,462		63.82
Exercised	(704,631	)	34.99
Forfeited	(67,710	)	49.81
Expired	(6,068	)	36.21
Outstanding at December 31, 2012	2,060,413		49.15		3.92	$	18,509,590
Vested and expected to vest at December 31, 2012	1,986,049		48.78		3.86	18,329,727
Exercisable at December 31, 2012	1,091,812		44.50		2.70	12,891,111

Stock Options Outstanding

The following table summarizes information regarding stock options outstanding as of December 31, 2011:

	Outstanding Options				Exercisable Options
Range of Exercise Prices	Shares	Weighted Average  Remaining Contractual Life in Years	Weighted Average Exercise  Price		Shares	Weighted Average Exercise  Price
$15.35-27.83	227,557	3.32	$	19.61	148,303	$	19.59
27.84-45.23	266,237	3.97	37.62		163,882	36.47
45.24-48.63	140,522	1.70	47.85		128,278	47.93
48.64-48.80	241,392	2.32	48.76		241,392	48.76
48.81-49.69	234,837	4.28	49.18		107,823	49.19
49.70-55.87	237,117	1.33	52.28		212,176	52.21
55.88-60.46	350,813	5.31	60.05		89,419	60.02
60.47-63.62	11,920	6.20	62.46		539	60.62
$63.63-64.43	350,018	6.33	64.37		—	—
	2,060,413	3.92	49.15		1,091,812	44.50

Information for Restricted Stock Units under Equity Incentive Plan

The table below provides information for restricted stock units under the 2006 Equity Incentive Plan for the year ended December 31, 2012:

	Shares		Weighted Average     Grant Date Fair     Value
Nonvested at December 31, 2011	499,119		$	52.72
Granted	343,997		63.07
Vested	(205,933	)	49.42
Forfeited	(51,640	)	58.93
Nonvested at December 31, 2012	585,543		59.42

Summary of Information Regarding Stock Option and Restricted Stock Activity

The following table summarizes information regarding stock option and restricted stock activity during 2012, 2011 and 2010:

	Year ended December 31,
(Dollars in thousands)	2012		2011		2010
Total intrinsic value of stock options exercised	$	17,419	$	20,772	$	11,871
Total grant date fair value of stock options vested	17,169		14,771		12,086
Total intrinsic value of restricted stock vested	12,747		9,142		6,313
Total grant date fair value of restricted stock vested	10,176		7,240		5,522