Share-Based Compensation (Details) (USD $)	3 Months Ended	6 Months Ended
Jul. 03, 2011	Jul. 04, 2010	Jul. 03, 2011	Jul. 04, 2010
Option Plan Shares [Member]
Fair value of stock options granted to employees, officers and non-employee board members and ESPP shares granted to employees
Dividend yield	0.00%	0.00%	0.00%	0.00%
Expected volatility	43.00%	49.00%	43.00%	50.00%
Risk-free interest rate	1.33%	1.84%	1.68%	1.59%
Expected lives (in Years)	4.3	4.3	4.3	3.8
Estimated annual forfeiture rate	8.57%	7.32%	8.57%	7.32%
Weighted average fair value at purchase date	$ 16.11	$ 17.01	$ 17.75	$ 11.90
Employee Stock Purchase Plan Shares [Member]
Fair value of stock options granted to employees, officers and non-employee board members and ESPP shares granted to employees
Dividend yield	0.00%	0.00%	0.00%	0.00%
Expected volatility	43.00%	59.00%	43.00%	59.00%
Risk-free interest rate	0.17%	0.18%	0.17%	0.18%
Expected lives (in Years)	0.5	0.5	0.5	0.5
Weighted average fair value at purchase date	$ 13.79	$ 8.58	$ 13.79	$ 8.58

The period of time an equity-based award is expected to be outstanding. An equity-based award's expected term is generally determined based on, among other factors, the instrument's contractual term and the effects of employees' expected exercise and post-vesting employment termination behavior.

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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.

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