Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2013

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

Share Based Compensation and Related Benefits

In 2013, 2012 and 2011, we recorded share-based compensation and related benefits as follows:

	Year ended December 31,
(Dollars in thousands)	2013			2012			2011
Share-based compensation expense	$	25,413		$	21,861		$	18,221
Income tax benefit related to share-based compensation expense	(7,989		)	(6,011		)	(4,833		)
Capitalized compensation costs	2,809			2,647			1,466

Unrecognized Share Based Compensation Expense

As of December 31, 2013, unrecognized share-based compensation expense was as follows:

(Dollars in thousands)	Unrecognized   Expense		Average Expected Recognition   Period - in Years
Stock options	$	14,978	2.51
Restricted stock units	30,374		2.54
Total unrecognized share-based compensation expense	$	45,352

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	2013			2012			2011
Weighted average expected term of options in years	4.7			4.6			4.6
Weighted average expected volatility of the Company's underlying common stock	44.6		%	50.4		%	48.7		%
Risk-free interest rate	0.70			0.83			2.00
Expected dividend yield	—			—			—
Weighted average grant date fair value-stock options	$	27.28		$	27.00		$	25.12
Weighted average grant date fair value-restricted stock units	71.57			63.07			59.69

Weighted Average Assumptions and Fair Values Used for ESPP

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

ESPP	2013			2012			2011
Expected term in years	0.5			0.5			0.5
Weighted average expected volatility of the Company's underlying common stock	22.3		%	43.5		%	27.3		%
Risk-free interest rate	0.11			0.11			0.15
Expected dividend yield	—			—			—
Weighted average fair value	$	15.35		$	14.43		$	13.02

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, 2013:

	Options		Weighted Average  Exercise Price		Weighted Average Remaining Contractual   Life in Years	Aggregate   Intrinsic Value   of In-The- Money Options
Outstanding at December 31, 2012	2,060,413		$	49.15
Granted	313,472		71.68
Exercised	(796,101	)	45.74
Forfeited	(62,672	)	57.18
Expired	(953	)	51.86
Outstanding at December 31, 2013	1,514,159		55.27		4.27	$	75,092,637
Vested and expected to vest at December 31, 2013	1,468,430		54.91		4.23	73,347,808
Exercisable at December 31, 2013	680,684		44.50		3.01	41,087,846

Stock Options Outstanding

The following table summarizes information regarding stock options outstanding as of December 31, 2013:

	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
$19.48-31.13	172,546	2.33	$	21.14	172,546	$	21.14
31.14-48.46	155,853	2.98	44.87		116,455	45.08
48.47-49.01	106,426	1.36	48.76		105,713	48.76
49.02-54.19	179,865	3.34	49.47		113,889	49.44
54.20-60.51	274,356	4.40	59.94		108,683	60.08
60.52-63.62	10,044	5.26	62.63		2,484	62.66
63.63-64.40	298,493	5.33	64.37		60,120	64.37
64.41-73.76	305,279	6.32	71.03		794	64.43
$73.77-95.64	11,297	6.60	86.90		—	—
	1,514,159	4.27	55.27		680,684	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, 2013:

	Shares		Weighted Average     Grant Date Fair     Value
Nonvested at December 31, 2012	585,543		$	59.42
Granted	328,905		71.57
Vested	(190,438	)	57.44
Forfeited	(41,663	)	62.34
Nonvested at December 31, 2013	682,347		65.93

Summary of Information Regarding Stock Option and Restricted Stock Activity

The following table summarizes information regarding stock option and restricted stock activity during 2013, 2012 and 2011:

	Year ended December 31,
(Dollars in thousands)	2013		2012		2011
Total intrinsic value of stock options exercised	$	25,520	$	17,419	$	20,772
Total grant date fair value of stock options vested	18,168		17,169		14,771
Total intrinsic value of restricted stock vested	14,176		12,747		9,142
Total grant date fair value of restricted stock vested	10,940		10,176		7,240