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Stock-Based Compensation (Schedule of Valuation Assumptions) (Details)	3 Months Ended
	Mar. 31, 2013	Apr. 01, 2012
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	4 years 10 months 28 days	5 years 0 months 4 days
Risk-free interest rate	0.82%	0.89%
Expected volatility	65.22%	62.18%
Expected dividend yield	0.00%	0.00%
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	5 years 11 months 19 days	5 years 11 months 16 days
Risk-free interest rate	0.14%	0.05%
Expected volatility	50.28%	65.67%
Expected dividend yield	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.

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