LEASES - Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 28, 2020	Dec. 28, 2019
ASSETS
Operating lease assets	$ 36,272	$ 37,768
Finance lease assets	1,068
Total lease assets	37,340
Current liabilities
Operating lease liabilities	7,867	7,768
Finance lease liabilities	188
Liabilities, Noncurrent [Abstract]
Operating lease liabilities, non-current	40,372	$ 42,200
Finance lease liabilities	902
Total lease liabilities	$ 49,329