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Stock-Based Compensation (Schedule Of Weighted Average Value And Assumptions For Fair Value Of Options) (Details) (USD $)	3 Months Ended
	Mar. 31, 2012 Y	Mar. 31, 2011 Y
Stock-Based Compensation [Abstract]
Weighted average fair value	$ 23.39	$ 19.22
Risk-free interest rate	1.00%	2.80%
Expected life in years	5	6
Expected volatility	45.70%	41.90%
Expected dividend yield	0.50%	0.50%

The period of time an equity-based award is expected to be outstanding. An equity-based award's expected term is generally determined based on, among other factors, the instrument's contractual term and the effects of employees' expected exercise and post-vesting employment termination behavior.

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