GEOGRAPHIC AND CUSTOMER CONCENTRATION INFORMATION - Net Sales by Geographic Area (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 29, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jul. 01, 2012	Apr. 01, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	$ 40,783	$ 33,840	$ 24,574	$ 20,237	$ 20,740	$ 20,398	$ 34,884	$ 50,504	$ 119,434	$ 126,526	$ 184,947
Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk percentage									100.00%	100.00%	100.00%
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount									12,350	17,476	10,311
United States | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk percentage									10.00%	14.00%	6.00%
Korea
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount									22,173	47,611	84,623
Korea | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk percentage									19.00%	38.00%	46.00%
Taiwan
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount									50,782	28,577	37,507
Taiwan | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk percentage									43.00%	23.00%	20.00%
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount									20,250	8,562	12,110
China | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk percentage									17.00%	7.00%	7.00%
Other Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount									8,740	13,615	21,002
Other Asia | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk percentage									7.00%	10.00%	11.00%
Europe and others
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount									$ 5,139	$ 10,685	$ 19,394
Europe and others | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk percentage									4.00%	8.00%	10.00%