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Stock Award Plans (Details 3) (Employee Stock Purchase Plan, USD $)
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3 Months Ended | |
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Mar. 31, 2013
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Mar. 31, 2012
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Employee Stock Purchase Plan
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| Weighted-average assumptions relating to options granted | ||
| Risk-free interest rate (as a percent) | 0.20% | 0.10% |
| Expected term (in years) | 1 year 4 months 24 days | 6 months |
| Dividend yield (as a percent) | 0.00% | 0.00% |
| Expected volatility (as a percent) | 58.00% | 49.70% |
| Additional disclosures | ||
| Shares reserved for future issuance | 467,747 | |
| Award offering period | 24 months | |
| Number of purchase periods per award offering period | 4 | |
| Award purchase period | 6 months | |
| Purchase price expressed as a percentage of fair market value of common stock on the first day of the offering period (as a percent) | 85.00% | |
| Purchase price expressed as a percentage of fair market value of common stock on the purchase date (as a percent) | 85.00% | |
| Total incremental fair value for the Purchase Plan reset | $ 874,000 | |
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- Definition
Represents the incremental fair value for awards under the Purchase Plan reset feature. No definition available.
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- Definition
Represents the offering period for awards under the equity-based compensation plan. No definition available.
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- Definition
Represents the purchase period for awards under the equity-based compensation plan. No definition available.
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- Definition
Represents the number of purchase periods per award offering period under the equity-based compensation plan. No definition available.
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- Definition
Represents the purchase price expressed as a percentage of the fair market value of common stock on the first day of the offering period. No definition available.
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- Definition
Represents the purchase price expressed as a percentage of the fair market value of common stock on the purchase date. No definition available.
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- Definition
Aggregate number of common shares reserved for future issuance. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- 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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- Definition
Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- 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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- Details
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