XML 92 R70.htm IDEA: XBRL DOCUMENT

Stock-Based Compensation - Weighted Average Assumptions Used to Estimated Fair Value of Units Granted (Detail)	12 Months Ended
	Jan. 28, 2012
Time-based unit [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	56.00%
Expected life (years)	9 months 18 days
Risk-free interest rate	0.19%
Dividend yield
Performance-based units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	56.00%
Expected life (years)	9 months 18 days
Risk-free interest rate	0.21%
Dividend yield

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