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Stock Compensation (Schedule Of Weighted-Average Assumptions Used To Determine The Fair Value Of Options) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of options			4 years 3 months	4 years
Expected stock price volatility			60.00%	65.00%
Risk-free interest rate			0.71%	1.25%
ESPP Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of options	6 months	6 months	6 months	6 months
Expected stock price volatility	44.00%	36.00%	54.00%	41.00%
Risk-free interest rate	0.16%	0.10%	0.06%	0.16%

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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