LEASES - Additional Information (Details)	3 Months Ended	9 Months Ended
	Sep. 28, 2019 USD ($)	Sep. 28, 2019 USD ($)
LEASES
Operating lease cost	$ 628,000	$ 1,459,000
Short-term lease costs	274,000	484,000
Cash paid, lease liabilities	396,000	1,014,000
Right-of-use assets	60,000	60,000
Lease liabilities	$ 649,000	$ 649,000
Weighted-average remaining lease term	4 years 10 months 24 days	4 years 10 months 24 days
Weighted-average discount rate	6.00%	6.00%