LEASES - Supplemental cash flow information (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 03, 2020	Mar. 29, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flow from operating leases	$ 1,705	$ 1,109
Operating cash flow from finance leases	9	31
Financing cash flow from finance leases	96	88
Right-of-use assets obtained in exchange for lease liabilities for operating leases	$ 984	$ 851