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		9 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014
Schedule of Earnings Per Share [Line Items]
Net income	$ 2,023	$ 537	$ 10,909	$ 4,918
Denominator:
Weighted-average shares outstanding - basic (in shares)	75,129	73,731	74,785	71,215
Weighted-average shares outstanding - diluted (in shares)	76,546	75,023	76,849	72,637
Basic (in usd per share)	$ 0.03	$ 0.01	$ 0.15	$ 0.07
Diluted (in usd per share)	$ 0.03	$ 0.01	$ 0.14	$ 0.07
Stock Options and Restricted Stock Units
Denominator:
Effect of dilutive stock options and restricted stock units (in shares)	1,417	1,292	2,064	1,422