LEASES - Supplemental cash flow information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jul. 03, 2020	Jun. 28, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flow from operating leases	$ 3,377	$ 2,345
Operating cash flow from finance leases	17	64
Financing cash flow from finance leases	296	300
Right-of-use assets obtained in exchange for lease liabilities for operating leases	$ 2,552	$ 1,223