Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2013

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

Schedule of Shares Available for Future Grants

The following table summarizes the number of shares available for future grants under our 2011 Plan:

	As of December 31
(000)	2013
Shares available for future grants	4,501

Schedule of Stock-Based Compensation Expense

The following table summarizes our stock-based compensation expense and the related income tax benefit we recorded in the past three years:

($000)	2013		2012		2011
Restricted stock units	$	14,163	$	13,451	$	12,765
Restricted stock	388		5,013		2,196
Stock options	492		441		342
Total stock-based compensation expense	$	15,043	$	18,905	$	15,303
Income tax benefit related to the stock-based compensation expense	$	4,027	$	3,686	$	3,535

Schedule of Uncategorized Stock-Based Compensation Expense

The following table summarizes the amount of unrecognized stock-based compensation expense as of December 31, 2013 and the expected number of months over which the expense will be recognized:

	Unrecognized stock-based compensation expense ($000)		Expected amortization period (months)
Restricted stock units	$	31,306	33
Restricted stock	517		16
Stock options	585		16
Total unrecognized stock-based compensation expense	$	32,408	32

Schedule of Restricted Stock Units Award Activity

The following table summarizes restricted stock unit activity during the past three years:

Restricted Stock Units (RSUs)	Unvested		Vested but Deferred		Total		Weighted Average Grant Date Value per RSU
RSUs Outstanding - January 1, 2011	777,666		45,189		822,855		$	47.14
Granted	292,398		—		292,398		57.36
Dividend equivalents	2,673		—		2,673		48.57
Vested	(256,623	)	—		(256,623	)	48.28
Vested but deferred	(1,753	)	1,753		—		—
Issued	—		(26,866	)	(26,866	)	46.69
Forfeited	(73,318	)	—		(73,318	)	47.59
RSUs Outstanding - December 31, 2011	741,043		20,076		761,119		50.66
Granted	341,282		—		341,282		56.26
Dividend equivalents	6,405		130		6,535		52.02
Vested	(270,695	)	—		(270,695	)	50.12
Vested but deferred	(892	)	892		—		—
Issued	—		(2,316	)	(2,316	)	73.28
Forfeited	(89,998	)	—		(89,998	)	50.84
RSUs Outstanding - December 31, 2012	727,145		18,782		745,927		53.37
Granted	287,848		—		287,848		72.04
Dividend equivalents	2,773		157		2,930		57.39
Vested	(278,549	)	—		(278,549	)	50.41
Issued	—		(2,257	)	(2,257	)	49.40
Forfeited	(59,215	)	—		(59,215	)	57.58
RSUs Outstanding - December 31, 2013	680,002		16,682		696,684		62.02

Schedule of Stock Options, Valuation Assumptions

In May 2011, we granted 86,106 stock options under the 2004 Stock Incentive Plan. In November 2011, we granted 6,095 stock options under the 2011 Plan. We estimated the fair value of the options on the grant date using a Black-Scholes option-pricing model. The weighted average fair value of options granted during 2011 was $23.81 per share, based on the following assumptions:

Assumptions for Black-Scholes Option Pricing Model
Expected life (years):	7.4
Volatility factor:	35.1	%
Dividend yield:	0.35	%
Interest rate:	2.87	%

Schedule of Options Granted at Exercise Price Below Fair Value per Share on Grant Date

The first table includes activity for options granted at an exercise price below the fair value per share of our common stock on the grant date; the second table includes activity for all other option grants.

	2013				2012				2011
Options Granted At an Exercise Price Below the Fair Value Per Share on the Grant Date	Underlying Shares		Weighted Average Exercise Price		Underlying Shares		Weighted Average Exercise Price		Underlying Shares		Weighted Average Exercise Price
Options outstanding—beginning of year	282,695		$	20.55	398,859		$	19.72	648,885		$	18.91
Granted	—		—		—		—		—		—
Canceled	(250	)	21.48		(650	)	14.70		—		—
Exercised	(102,886	)	21.09		(115,514	)	20.19		(250,026	)	19.25
Options outstanding—end of year	179,559		21.47		282,695		20.55		398,859		19.72
Options exercisable—end of year	179,559		$	21.47	282,695		$	20.55	398,859		$	19.72

Schedule of All Other Option Granted

	2013				2012				2011
All Other Option Grants, Excluding Activity Shown Above	Underlying Shares		Weighted Average Exercise Price		Underlying Shares		Weighted Average Exercise Price		Underlying Shares		Weighted Average Exercise Price
Options outstanding—beginning of year	391,784		$	28.98	818,552		$	22.76	1,207,540		$	17.09
Granted	—		—		—		—		92,201		57.42
Canceled	(1,352	)	16.19		(22,330	)	39.75		(1,960	)	16.04
Exercised	(136,460	)	16.84		(404,438	)	16.60		(479,229	)	16.17
Options outstanding—end of year	253,972		36.48		391,784		28.98		818,552		22.76
Options exercisable—end of year	219,449		$	33.18	337,684		$	24.42	726,351		$	18.36

Schedule of Intrinsic Value of Stock Options Exercised During Period

The following table summarizes the total intrinsic value (difference between the market value of our stock on the date of exercise and the exercise price of the option) of options exercised:

($000)	2013		2012		2011
Intrinsic value of options exercised	$	12,801	$	22,526	$	29,899

Schedule of Options, Vested and Expected to Vest, Outstanding and Exercisable

The table below shows additional information for options outstanding and exercisable as of December 31, 2013:

	Options Outstanding						Options Exercisable
Range of Exercise Prices	Number of  Options	Weighted Average Remaining Contractual Life (years)	Weighted Average Exercise Price		Aggregate Intrinsic Value ($000)		Exercisable Shares	Weighted Average Remaining Contractual Life (years)	Weighted Average Exercise Price		Aggregate Intrinsic Value ($000)
$14.70	285	0.93	$	14.70	$	18	285	0.93	$	14.70	$	18
$21.40 - $48.90	361,571	1.17	24.88		19,238		361,571	1.17	24.88		19,238
$57.28 - $59.35	71,675	7.52	57.46		1,479		37,152	7.52	57.45		710
$14.70 - $59.35	433,531	2.22	30.26		$	20,735	399,008	1.76	27.91		$	19,966
Vested or Expected to Vest
$14.70 - $59.35	433,531	2.22	$	30.26	$	20,735

Schedule of Tax Benefits Related To Share Based Compensation

The following table summarizes our excess tax benefits for the past three years:

($000)	2013		2012		2011
Excess tax benefits related to stock-based compensation	$	5,898	$	7,210	$	9,525