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Stock Options - Range of Expected Volatilities for Options (Detail)
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6 Months Ended | 3 Months Ended | 6 Months Ended | |
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May 31, 2013
Service-Based Vesting Condition Options [Member]
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May 31, 2012
Service-Based Vesting Condition Options [Member]
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May 31, 2012
Performance and Market-Based Vesting Condition Options [Member]
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May 31, 2012
Performance and Market-Based Vesting Condition Options [Member]
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| Range of expected volatilities for options | ||||
| Minimum expected volatility | 111.60% | 111.30% | 113.50% | 111.30% |
| Maximum expected volatility | 114.90% | 114.60% | 113.50% | 113.50% |
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- Details
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- Definition
The estimated measure of the maximum 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. No definition available.
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- Definition
The estimated measure of the minimum 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. No definition available.
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