ACCUMULATED OTHER COMPREHENSIVE LOSS (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2018	Apr. 02, 2017
Accumulated Other Comprehensive Loss, Net of Tax [Roll Forward]
Balance at beginning of period	$ (6,804)	$ (11,433)
Cumulative Effect on Retained Earnings, Net of Tax	(1,525)	0
Total other comprehensive income (loss), net of tax	(1,384)	2,537
Balance at end of period	(9,713)	(8,896)
Foreign currency translation adjustment
Accumulated Other Comprehensive Loss, Net of Tax [Roll Forward]
Balance at beginning of period	(8,329)	(11,684)
Foreign currency translation adjustment, net of tax	(1,384)	1,800
Cumulative Effect on Retained Earnings, Net of Tax	0	0
Balance at end of period	(9,713)	(9,884)
Unrealized gain (loss) on marketable securities
Accumulated Other Comprehensive Loss, Net of Tax [Roll Forward]
Balance at beginning of period	1,525	251
Unrealized gain (loss) on investments, net of tax	0	737
Cumulative Effect on Retained Earnings, Net of Tax	(1,525)	0
Balance at end of period	$ 0	$ 988