Share-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2012

Share-Based Compensation [Abstract]

Schedule Of Weighted Averages Of The Assumptions Used In Estimating The Fair Value Of Stock Option Awards

	For the Three Months Ended March 31,
	2012			2011
Expected stock price volatility		34	%		33	%
Expected term, in years		4.6			4.8
Risk-free interest rate		0.8	%		2.4	%
Weighted average fair value of options granted	$	26.36		$	24.99