Stockholders' Equity - Summary of stock option activity (Details) - USD ($) $ / shares in Units, $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 27, 2019 |
Dec. 28, 2018 |
Dec. 29, 2017 |
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| Shares | |||
| Outstanding (in shares) | 191,808 | 191,808 | |
| Granted (in shares) | 0 | 0 | |
| Exercised (in shares) | (76,169) | 0 | |
| Forfeited (in shares) | 0 | 0 | |
| Outstanding (in shares) | 115,639 | 191,808 | 191,808 |
| Exercisable (in shares) | 115,639 | ||
| Weighted Average Exercise Price | |||
| Outstanding (in usd per share) | $ 20.23 | $ 20.23 | |
| Granted (in usd per share) | 0 | 0 | |
| Exercised (in usd per share) | 20.23 | 0 | |
| Forfeited (in usd per share) | 0 | 0 | |
| Outstanding (in usd per share) | 20.23 | $ 20.23 | $ 20.23 |
| Exercisable (in usd per share) | $ 20.23 | ||
| Aggregate Intrinsic Value | |||
| Outstanding | $ 2,051 | $ 2,129 | $ 33 |
| Exercisable | $ 2,051 | ||
| Weighted Average Remaining Contractual Term (in years) | |||
| Outstanding | 6 years 2 months 12 days | 7 years 2 months 12 days | 8 years 2 months 12 days |
| Exercisable | 6 years 2 months 12 days | ||
| X | ||||||||||
- References No definition available.
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- Definition The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Weighted average price of options that were either forfeited or expired. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Gross number of share options (or share units) granted during the period. No definition available.
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| X | ||||||||||
- Definition Number of options outstanding, including both vested and non-vested options. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- References No definition available.
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| X | ||||||||||
- References No definition available.
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- Definition Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Weighted average price at which option holders acquired shares when converting their stock options into shares. No definition available.
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| X | ||||||||||
- Definition Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options. No definition available.
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- Definition Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
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| X | ||||||||||
- Definition Weighted average remaining contractual term for fully vested and expected to vest exercisable or convertible options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Weighted average remaining contractual term for fully vested and expected to vest options outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Number of share options (or share units) exercised during the current period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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