NET INCOME (LOSS) PER SHARE - Summary of Computation of Net Income Per Share of Common Stock (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015	Jun. 29, 2014
Schedule of Earnings Per Share [Line Items]
Net income	$ 2,581	$ 1,916	$ 8,886	$ 4,381
Denominator:
Weighted-average shares outstanding - basic (in shares)	74,920	73,532	74,611	69,943
Weighted-average shares outstanding - diluted (in shares)	77,019	74,679	76,973	71,405
Basic (in usd per share)	$ 0.03	$ 0.03	$ 0.12	$ 0.06
Diluted (in usd per share)	$ 0.03	$ 0.03	$ 0.12	$ 0.06
Stock Options and Restricted Stock Units
Denominator:
Effect of dilutive stock options and restricted stock units (in shares)	2,099	1,147	2,362	1,462