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SHAREHOLDERS’ EQUITY - Stock Purchase Plan (Details) - Employee Stock Purchase Plan - shares | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 27, 2019 | Dec. 29, 2017 | Jun. 08, 2017 | Dec. 28, 2007
Employee Stock Purchase Plan |  |  |  |
Number of shares of common stock reserved for issuance |  |  | 1,125,000 | 300,000
Number of additional shares authorized |  | 825,000 |  |
Purchase price per share as a percentage of fair market value | 85.00% |  |  |
Number of shares available for issuance | 679,000 |  |  |
Minimum |  |  |  |
Employee Stock Purchase Plan |  |  |  |
Percentage of participant's earnings to be contributed under a share based compensation plan | 1.00% |  |  |
Maximum |  |  |  |
Employee Stock Purchase Plan |  |  |  |
Percentage of participant's earnings to be contributed under a share based compensation plan | 10.00% |  |  |

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- Definition Aggregate number of common shares reserved for future issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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