STOCK-BASED COMPENSATION (Details 2) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 04, 2015	Jun. 28, 2014	Jul. 04, 2015	Jun. 28, 2014
Total stock-based compensation expense included in the Company's consolidated statements of operations
Stock-based compensation expense	$ 2,743	$ 3,110	$ 6,827	$ 5,447
Cost of sales
Total stock-based compensation expense included in the Company's consolidated statements of operations
Stock-based compensation expense	285	279	681	491
Selling, general and administrative expenses
Total stock-based compensation expense included in the Company's consolidated statements of operations
Stock-based compensation expense	2,126	2,465	5,322	4,301
Research and development expense.
Total stock-based compensation expense included in the Company's consolidated statements of operations
Stock-based compensation expense	$ 332	$ 366	$ 824	$ 655