SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 5) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended			32 Months Ended
	May 31, 2014	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014	Dec. 31, 2016	Feb. 28, 2015
Research and Development
Research and development expenses		$ 8,300	$ 11,600	$ 13,900
Stock Repurchase Program
Authorized amount	$ 500,000					$ 250,000
Length of authorization period	12 months
Shares acquired under share repurchase program		441,949	1,435,488	2,711,149	4,588,131
Amount paid for share repurchase		$ 53,800	$ 168,983	$ 395,045	$ 617,800