XML 78 R49.htm IDEA: XBRL DOCUMENT

Stock-Based Compensation Plans (Details 1)	12 Months Ended
Stock-Based Compensation Plans (Details 1)	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Schedule of stock option plans
Risk-free interest rates	0.82%	1.45%	1.95%
Expected life	4 years 9 months 18 days	4 years 9 months 18 days	4 years 9 months 18 days
Expected volatility	50.00%	45.00%	41.00%
Dividend yield	0.00%	0.00%	0.00%

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.

+ References+ Details