EARNINGS PER SHARE - Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018	Dec. 29, 2018
EARNINGS PER SHARE
Common stock, outstanding	84,820		84,820		84,196
Reconciliation of shares for basic and diluted net income per share
Net income	$ 22,223	$ 18,825	$ 24,390	$ 15,564
Weighted average common shares outstanding—basic	84,577	81,147	84,387	81,283
Effect of dilutive securities	1,650	1,785	1,655	1,673
Weighted average common shares outstanding—diluted	86,227	82,932	86,042	82,956
Basic	$ 0.26	$ 0.23	$ 0.29	$ 0.19
Diluted	$ 0.26	$ 0.23	$ 0.28	$ 0.19