|
Stock-Based Employee Compensation (Details 5) (Stock Options [Member])
|
12 Months Ended | ||
|---|---|---|---|
|
Feb. 28, 2013
|
Feb. 29, 2012
|
Feb. 28, 2011
|
|
|
Stock Options [Member]
|
|||
| Weighted average assumptions to estimate fair value of equity instruments using Black-Scholes option-pricing model | |||
| Expected life | 6 years | 5 years 10 months 24 days | 5 years 10 months 24 days |
| Expected volatility | 32.70% | 32.00% | 32.20% |
| Risk-free interest rate | 1.40% | 2.70% | 3.20% |
| Expected dividend yield | 0.00% | 0.00% | 0.00% |
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- 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
|
| X | ||||||||||
|
- Definition
Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- 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
|
| X | ||||||||||
|
- 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
|