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STOCK- BASED COMPENSATION - Performance-based Restricted Stock Units (Details) - Performance-based Restricted Stock Unit $ / shares in Units, $ in Thousands | 12 Months Ended
--- | ---
Dec. 26, 2020 USD ($) tradeName $ / shares shares | Dec. 28, 2019 $ / shares shares
Stock Based Compensation |  |
Vesting period of performance-based stock units | 3 years |
Shares granted | shares | 35,181 | 31,344
Grants (in dollars per share) | $ / shares | $ 125.41 | $ 136.14
Compensation expense | $ | $ 3,165 |
Number of plans | tradeName | 2 |
Minimum |  |
Stock Based Compensation |  |
Performance target (percent) | 0.00% |
Maximum |  |
Stock Based Compensation |  |
Performance target (percent) | 200.00% |

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