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Stock-Based Compensation And Employee Stock Option Plan (Schedule Of Fair Value Of Options, Weighted Average Assumptions) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2010
Stock-Based Compensation And Employee Stock Option Plan [Abstract]
Stock option exercise price	$ 5.94	$ 5.17
Risk-free interest rate	1.71%	2.74%
Expected option life	7 years 2 months 12 days	7 years 2 months 23 days
Expected volatility	32.15%	33.01%
Weighted average fair value	$ 2.62	$ 1.88

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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