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Stock Incentive Plan - Fair Value Assumptions (Details) (Stock Options, USD $)
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12 Months Ended | ||
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Dec. 31, 2012
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Dec. 31, 2011
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Dec. 31, 2010
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| Fair value significant assumptions: | |||
| Future dividends | $ 0 | $ 0 | $ 0 |
| Risk-free interest rate, minimum | 0.82% | 1.35% | 2.59% |
| Risk-free interest rate, maximum | 1.25% | 2.58% | 3.11% |
| Expected volatility, minimum | 32.00% | 32.00% | 57.00% |
| Expected volatility, maximum | 33.00% | 59.00% | |
| Expected life | 6 years 6 months | 6 years 6 months | |
| Cliff vesting period | 1 year | ||
| Ratable vesting period | 5 years | ||
| Options ratable vesting frequency | 1 year | ||
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Minimum
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| Fair value significant assumptions: | |||
| Expected life | 6 years | ||
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Maximum
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| Fair value significant assumptions: | |||
| Expected life | 6 years 6 months | ||
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- Definition
Share-based Compensation Arrangement by Share-based Payment Award, Award Cliff Vesting Period No definition available.
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- Definition
Share-based Compensation Arrangement by Share-based Payment Award, Award Ratable Vesting Frequency No definition available.
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- Definition
Share-based Compensation Arrangement by Share-based Payment Award, Award Ratable Vesting Period No definition available.
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- Details
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- Definition
The estimated amount of dividends to be paid to holders of the underlying shares (expected dividends) over the option's term. Dividends are taken into account because payment of dividends to shareholders reduces the fair value of the underlying shares, and option holders generally do not receive dividends. 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 maximum 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. No definition available.
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- Definition
The estimated measure of the minimum 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. No definition available.
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- Definition
The maximum risk-free interest rate assumption that is used in valuing an option on its own shares. No definition available.
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- Definition
The minimum risk-free interest rate assumption that is used in valuing an option on its own shares. No definition available.
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