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Stock-Based Compensation Stock-Based Compensation (Schedule Of Fair Value Of The Restricted Stock Awards Granted To Non-Employee Directors During Previous Period) (Details) (Restricted Stock [Member], USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options or shares granted	24,606	4,167	392,542	196,748
Estimated fair value (in millions)	$ 1.0	$ 0.2	$ 16.6	$ 10.3
Non-employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options or shares granted	24,606		24,606	31,500
Estimated fair value (in millions)	$ 1.0		$ 1.0	$ 0.7
Estimate of stock volatility				48.00%
Risk free interest rate				2.00%
Expected annual life based on prior experience (in years)				5

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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- Definition

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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