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Employee Stock Plans (Weighted-Average Assumptions Used To Estimate Fair Value Of Each Employee Stock Option And SARs) (Details)
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9 Months Ended | |
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Jan. 31, 2012
years
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Jan. 31, 2011
years
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| Employee Stock Plans [Abstract] | ||
| Expected volatility | 47.07% | 47.67% |
| Risk-free interest rate | 1.47% | 1.83% |
| Expected option life (in years) | 5.00 | 5.00 |
| Expected dividend yield | 0.00% | 0.00% |
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- Details
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- Definition
The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The risk-free interest rate assumption that is used in valuing an option on its own shares. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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