Equity Compensation (Tables)

3 Months Ended

Mar. 31, 2012

Equity Compensation [Abstract]

Schedule Of Stock-Based Compensation Expense And Related Income Tax Benefit Recognized In Condensed Consolidated Statements Of Income

	Three Months Ended March 31,
	2012			2011
Stock-based compensation expense	$	4,483		$	3,914
Income tax (benefit)	($	1,726	)	($	1,507	)

Schedule Of Stock Options Granted, Forfeited, Exercised And Expired

	Three Months Ended March 31, 2012
				Weighted					Weighted
				Average		Aggregate			Average		Aggregate
	# of			Exercise		Exercise			Remaining		Intrinsic
	Shares			Price		Price			Contractual Term		Value (1)
Outstanding at beginning of period		1,765,881		$	79.24	$	139,922
Granted		156,500		$	75.16		11,763
Forfeited		0		$	0		0
Exercised		(104,054	)	$	44.86		(4,668	)
Expired		(1,734	)	$	17.25		(30	)
Outstanding at end of period		1,816,593		$	80.91	$	146,987			3.7	$	11,047
Exercisable at end of period		1,452,086		$	80.10	$	116,310			3.1	$	11,047

(1) The aggregate intrinsic value of the stock options was calculated by identifying those stock options that had a lower exercise price than the closing market price of our common stock on March 30, 2012 and multiplying the difference between the closing market price of our common stock and the exercise price of each of those stock options by the number of shares subject to those stock options that were outstanding or exercisable, as applicable.

Schedule Of Stock Options Granted And Exercised

	Three Months Ended March 31,
	2012		2011
Shares subject to stock options granted		156,500		159,500
Weighted average grant date fair value per share	$	31.36	$	28.90
Shares subject to stock options exercised		104,054		60,530
Intrinsic value of stock options exercised	$	2,489	$	911
Proceeds received from stock options exercised	$	4,668	$	3,028
Tax benefits realized from stock options exercised	$	864	$	351

Fair Value Of Stock Option Grant

	Three Months Ended  March 31,
	2012			2011
Risk-free interest rates		0.7	%		1.8	%
Expected lives (in years)		4.5			4.7
Volatility		51	%		48	%
Dividend yield		None			None

Number Of Restricted Stock Units Granted, Forfeited And Vested

	Three Months Ended March 31, 2012
	# of RSUs			Weighted Average  Grant Date Fair Value
Unvested at beginning of period		314,006		$	79.44
Granted		257,694		$	75.12
Forfeited		(5,191	)	$	76.56
Vested		(90,149	)	$	81.12
Unvested at end of period		476,360		$	76.81