SEGMENT REPORTING - Geographic data (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2016	Oct. 03, 2015	Oct. 01, 2016	Oct. 03, 2015
GEOGRAPHIC DATA
Net Sales	$ 316,528	$ 277,328	$ 910,641	$ 813,762
% to Total	100.00%	100.00%	100.00%	100.00%
Domestic
GEOGRAPHIC DATA
Net Sales	$ 250,323	$ 223,058	$ 732,688	$ 650,239
% to Total	79.10%	80.40%	80.50%	79.90%
International
GEOGRAPHIC DATA
Net Sales	$ 66,205	$ 54,270	$ 177,953	$ 163,523
% to Total	20.90%	19.60%	19.50%	20.10%