SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Earnings Per Share (Details) - shares	3 Months Ended	6 Months Ended
Jul. 01, 2018	Jun. 25, 2017	Jul. 01, 2018	Jun. 25, 2017
Schedule of Weighted Average Number of Shares, Diluted [Line Items]
Basic (shares)	9,235,353	8,746,100	8,998,364	8,707,528
Effect of dilutive securities:
Weighted-average number of diluted common shares outstanding	9,538,545	9,050,596	9,301,370	8,986,136
Antidilutive securities excluded from computation of earnings per share, amount	0	82,250	163,600	82,250
Employee Stock Option
Effect of dilutive securities:
Stock options	256,414	267,905	261,960	245,828
Antidilutive securities excluded from computation of earnings per share, amount	0	50,000	163,600	50,000
Warrant
Effect of dilutive securities:
Warrants	46,778	36,591	41,046	32,780
Antidilutive securities excluded from computation of earnings per share, amount	0	32,250	0	32,250

Schedule of Weighted Average Number of Shares, Diluted [Line Items]

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of call options and warrants using the treasury stock method.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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