XML 66 R49.htm IDEA: XBRL DOCUMENT

Stock-Based Compensation Expense - Weighted-Average Assumptions Used In Estimating Fair Values of Stock Options Granted (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Oct. 02, 2011	Sep. 30, 2012	Oct. 02, 2011
Schedule Of Stock Options [Line Items]
Risk-free rate	2.00%	3.60%	2.00%	3.60%
Expected dividend yield	1.20%	1.00%	1.20%	1.00%
Expected volatility	44.00%	42.00%	44.00%	42.00%
Expected term (in years)	5 years 7 months 6 days	5 years 2 months 12 days	5 years 7 months 6 days	5 years 4 months 24 days

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