Stock Incentive Plans - Summary of Weighted Average Assumptions (Details) - Stock Options - USD ($) $ / shares in Units, $ in Thousands |
12 Months Ended | ||
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Dec. 31, 2017 |
Dec. 25, 2016 |
Dec. 27, 2015 |
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| Weighted average assumptions used in estimation of fair value of options | |||
| Risk-free interest rate (as a percent) | 1.80% | 1.20% | 1.40% |
| Expected years until exercise | 4 years 11 months 26 days | 4 years 5 months 26 days | 4 years 9 months 18 days |
| Expected stock volatility (as a percent) | 37.90% | 39.00% | 40.60% |
| Dividend yield (as a percent) | 0.00% | 0.00% | 0.00% |
| Weighted average Black-Scholes fair value per share at date of grant (in dollars per share) | $ 17.11 | $ 20.45 | $ 29.71 |
| Total intrinsic value of options exercised | $ 1,676 | $ 2,624 | $ 4,414 |
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- References No definition available.
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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 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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- Definition Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. 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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- Details
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