BUSINESS SEGMENT INFORMATION - Net Sales by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 02, 2016	Oct. 03, 2015	Jul. 04, 2015	Apr. 04, 2015	Jan. 03, 2015	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Jan. 02, 2016	Jan. 03, 2015	Dec. 28, 2013
Net sales by geographic region
Net sales	$ 150,499	$ 147,560	$ 147,977	$ 156,655	$ 158,729	$ 146,299	$ 153,232	$ 146,890	$ 602,691	$ 605,150	$ 560,054
United States
Net sales by geographic region
Net sales									231,453	230,807	218,298
Germany
Net sales by geographic region
Net sales									66,246	81,859	75,119
Other European countries
Net sales by geographic region
Net sales									90,853	87,404	81,178
Greater China
Net sales by geographic region
Net sales									64,617	55,158	45,851
Other Pacific Rim countries
Net sales by geographic region
Net sales									105,551	107,854	101,689
Rest of world
Net sales by geographic region
Net sales									$ 43,971	$ 42,068	$ 37,919