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Equity And Stock-Based Compensation (Schedule Of Fair Value Of Options, Weighted Average Assumptions) (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Equity And Stock-Based Compensation [Abstract]
Stock option exercise price	$ 5.55	$ 4.44
Risk-free interest rate	1.87%	1.83%
Expected option life in years	5 years	10 years
Expected volatility	31.99%	31.88%
Weighted average fair value	$ 1.74	$ 1.96

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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