REVOLVING BANK LOAN AND LONG-TERM DEBT (Details)	3 Months Ended
	Mar. 31, 2018 USD ($) agreement	Mar. 31, 2018 USD ($)	Apr. 01, 2017 USD ($)	Dec. 30, 2017 USD ($)
Debt Instrument [Line Items]
Number of separate amendments to the Credit agreement | agreement	8
Maximum revolving credit facility line	$ 20,000,000	$ 20,000,000
Minimum tangible net worth threshold, percentage of the consolidated net income	50.00%	50.00%
Tangible net worth	$ 33,752,000	$ 33,752,000
Maximum balance sheet leverage ratio		1.00
Period over which existing cash balance, anticipated cash flow from operations and borrowings available under the credit agreement will be sufficient to cover expected cash needs		12 months
Period Ending July 01, 2017
Debt Instrument [Line Items]
Minimum tangible net worth threshold, base amount	$ 31,000,000	$ 31,000,000
Minimum | Period Ending July 1, 2017
Debt Instrument [Line Items]
Fixed charge coverage ratio		1.15
Revolving Credit Facility
Debt Instrument [Line Items]
Borrowings as a percentage of capital expenditures	80.00%	80.00%
Annual capital expenditures for fiscal year 2016, maximum		$ 5,500,000
Outstanding amount	$ 5,700,000	5,700,000		$ 3,500,000
Highest balance outstanding during the period		6,200,000	$ 3,650,000
Average outstanding		3,792,000	$ 1,895,000
Outstanding amount of letters of credit total	$ 4,955,000	$ 4,955,000
Revolving Credit Facility | Minimum
Debt Instrument [Line Items]
Borrowings as a percentage of eligible accounts receivable	80.00%	80.00%
Borrowings as a percentage of eligible inventories	50.00%	50.00%
Maximum inventory borrowings	$ 8,500,000	$ 8,500,000
Revolving Credit Facility | LIBOR
Debt Instrument [Line Items]
Variable interest rate base		LIBOR
Percentage points added to the reference rate		2.25%
Revolving Credit Facility | Prime Rate
Debt Instrument [Line Items]
Variable interest rate base		prime rate