Share-Based Compensation (Schedule Of Assumptions For Stock Options Granted) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Expected volatility, minimum	39.64%	35.56%	31.88%
Expected volatility, maximum	41.09%	39.89%	35.31%
Expected term (in years), minimum	5.66	4.50	5.75
Expected term (in years), maximum	5.89	6.50	6.25
Risk-free rate, minimum	1.24%	1.73%	2.13%
Risk-free rate, maximum	2.76%	3.29%	2.94%
Weighted-average volatility	40.45%	37.76%	33.96%
Weighted-average dividends	1.04%	1.75%	2.22%
Weighted-average term (in years)	5.86	5.43	5.96
Weighted-average risk-free rate	1.97%	2.45%	2.47%
Weighted-average grant date fair value	$ 14.55	$ 7.33	$ 5.31
Minimum [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Expected dividends	0.90%	1.50%	1.91%
Maximum [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Expected dividends	1.19%	1.80%	2.95%