Benefit Plans (Details 5) | 3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2011
Year | Oct. 01, 2010
Year | Sep. 30, 2011
Year | Oct. 01, 2010
Year | |
Employee Stock Option [Member] | ||||
| Weighted average assumptions: | ||||
| Expected life (years) | 4.75 | 3.52 | 4.75 | 4.00 |
| Volatility | 53.00% | 55.00% | 54.00% | 56.00% |
| Risk-free interest rate | 1.20% | 1.10% | 2.00% | 1.60% |
| Dividend yield | 0.00% | 0.00% | 0.00% | 0.00% |
Employee Stock Purchase Plan Awards [Member] | ||||
| Weighted average assumptions: | ||||
| Expected life (years) | 0.50 | 0.50 | 0.50 | 0.50 |
| Volatility | 46.00% | 43.00% | 45.00% | 46.00% |
| Risk-free interest rate | 0.10% | 0.40% | 0.20% | 0.40% |
| Dividend yield | 0.00% | 0.00% | 0.00% | 0.00% |
| X | ||||||||||
- Details
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| X | ||||||||||
- Definition The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition The risk-free interest rate assumption that is used in valuing an option on its own shares. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The range of expected volatilities used and the weighted-average expected volatility for an entity using a valuation technique with different volatilities during the contractual term. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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