XML 68 R49.htm IDEA: XBRL DOCUMENT

Stock-Based Compensation (Details)	3 Months Ended		9 Months Ended
Stock-Based Compensation (Details)	Sep. 29, 2012	Oct. 01, 2011	Sep. 29, 2012	Oct. 01, 2011
Stock Options [Member]
Assumption of stock option's fair value
Expected life	4 years 7 months 12 days	4 years 7 months 12 days	4 years 6 months	4 years 6 months
Volatility	75.44%	77.47%	77.96%	77.02%
Risk free interest rate	0.74%	1.01%	0.84%	1.89%
Dividends	0.00%	0.00%	0.00%	0.00%
Employee Stock Purchase Plan [Member]
Assumption of stock option's fair value
Expected life	6 months	6 months	6 months	6 months
Volatility	38.58%	65.91%	45.47%	73.41%
Risk free interest rate	0.16%	0.17%	0.12%	0.19%
Dividends	0.00%	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