SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Earnings Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 26, 2021	Sep. 27, 2020	Sep. 26, 2021	Sep. 27, 2020
Schedule of Weighted Average Number of Shares, Diluted [Line Items]
Basic (shares)	10,380,900	10,312,939	10,351,319	10,309,457
Effect of dilutive securities:
Weighted-average number of diluted common shares outstanding	10,427,112	10,326,493	10,404,900	10,309,457
Antidilutive securities excluded from computation of earnings per share, amount	408,050	632,419	408,050	445,712
Stock options and restricted stock
Effect of dilutive securities:
Stock options and restricted stock	46,212	13,554	53,581	0
Antidilutive securities excluded from computation of earnings per share, amount	408,050	606,557	408,050	419,850
Warrant
Effect of dilutive securities:
Antidilutive securities excluded from computation of earnings per share, amount	0	25,862	0	25,862